Equipment Catalog No. 20 - Davis-Lynch Casing Equipment

EQUIPMENT CATALOG NO. 20

New from DavisType 512-CAF Convertible Down/Up-Jet

Auto-Fill Float Shoe . . . . . . . . . . . . . . . . . . . . 1

Davis Manual-Fill Float ShoesFloat Shoe Type 500-PVTS . . . . . . . . . . . . . . . . . . 2-3Down-Jet Float Shoe Type 501-PVTS . . . . . . . . . . 2-3Double-Valve Down-Jet Float Shoe

Type 501 DV-PVTS . . . . . . . . . . . . . . . . . . . . . . 2-3Guide Shoes Types 600 and 601 . . . . . . . . . . . . . 2-3Down-Jet Set Shoe

with Lug Nose Type “S” . . . . . . . . . . . . . . . . . 2-3Ribbed Down-Jet Float Shoe . . . . . . . . . . . . . . . . 2-3Needle Nose Float Shoe . . . . . . . . . . . . . . . . . . . 2-3Mule Shoe Type 610 . . . . . . . . . . . . . . . . . . . . . . 3Texas Pattern Casing Shoes

Types 800 and 800ST . . . . . . . . . . . . . . . . . . . . 3

Davis Manual-Fill Float CollarsFloat Collar Type 700-PVTS . . . . . . . . . . . . . . . . . 4Lock-Down Anti-Rotation Plug System Type LAP 4Lock-Down Anti-Rotation Plug System Type LAP/N 5Combination Brush/Plug . . . . . . . . . . . . . . . . . . . 5

Davis Self-Filling Float Shoes and Float CollarsPump Convert PVTS Automatic Fill-Up

Shoes and Collars . . . . . . . . . . . . . . . . . . . . . . 5Drop Ball Convert Automatic

Fill-Up Shoes and Collars . . . . . . . . . . . . . . . . . 6Drop Ball Convert Differential

Fill-Up Shoes and Collars . . . . . . . . . . . . . . . . . 6Standard Stock Float Equipment Data . . . . . . . . 7

Davis Insert Float Valves Insert Float Valve Type 900 F . . . . . . . . . . . . . . . . 7Insert Float Fill-Up Valve Type 904 F . . . . . . . . . . 7

Davis Thread CompoundsThread Locking Compound . . . . . . . . . . . . . . . . . 7Thread Sealing and Lubricating Compounds . . . 7Non-Metallic Thread Compound . . . . . . . . . . . . . 7Super-Seal Thread Compound . . . . . . . . . . . . . . 7

Davis Inner-String Cementing EquipmentTag-In Equipment . . . . . . . . . . . . . . . . . . . . . . . . 8-9Pack-Off Head Assemblies . . . . . . . . . . . . . . . . . . 8-9Inner-String Adapters . . . . . . . . . . . . . . . . . . . . . 9Latch-Down Wiper Plug . . . . . . . . . . . . . . . . . . . 9

Screw-In Equipment . . . . . . . . . . . . . . . . . . . . . . 10-11Latch-In Equipment . . . . . . . . . . . . . . . . . . . . . . . 10-11Special Inner-String Cementing Equipment . . . . 11

Davis Extended Reach EquipmentFlotation Collar . . . . . . . . . . . . . . . . . . . . . . . . . . 12-13

Davis Cementing Enhancement DevicesNon-Welded Centralizer . . . . . . . . . . . . . . . . . . . 14Close-Tolerance Bow Spring Centralizer . . . . . . . 14Non-Welded Semi-Rigid Centralizer . . . . . . . . . . 14-15“NW” Type Centralizer Dimension and

Performance Data . . . . . . . . . . . . . . . . . . . . . . 14Non-Welded Turbolizer . . . . . . . . . . . . . . . . . . . . 15Cement Basket . . . . . . . . . . . . . . . . . . . . . . . . . . 15“SR” Type Semi-Rigid Centralizer Dimension

and Performance Data . . . . . . . . . . . . . . . . . . 15Non-Welded Rigid Centralizer . . . . . . . . . . . . . . 16Stop Collars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Spherical Stand-Off Device . . . . . . . . . . . . . . . . . 16“R” Type Rigid Centralizer Dimension Data . . . . 16Solid Body Flow Diverter . . . . . . . . . . . . . . . . . . . 17Centralizer Application Analysis . . . . . . . . . . . . . 17

Davis Stage Cementing Collars and EquipmentType 778 MC Mechanical

Stage Cementing Collar . . . . . . . . . . . . . . . . . 18Type 777 HY Hydraulic-Opening

Stage Cementing Collar . . . . . . . . . . . . . . . . . 19Plug Systems for Two- and Three-Stage

Cementing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-21Specification Tables for

Type 778 MC and Type 777 HY . . . . . . . . . . . . 22Packer Stage Cementing Collar

Type 778-100 . . . . . . . . . . . . . . . . . . . . . . . . . . 23-25

Davis Inflatable PackersInflatagrip Longseal Packers . . . . . . . . . . . . . . . . 26Packers with Continuous Reinforcing . . . . . . . . . 27Inflatagrip® Feature . . . . . . . . . . . . . . . . . . . . . . 27Integral Casing Packer . . . . . . . . . . . . . . . . . . . . . 28Packer Selection Data . . . . . . . . . . . . . . . . . . . . . 28

Fill and Circulate Tool . . . . . . . . . . . . . . . . . . . . . 29

Visit our website at www.davis-lynch.com

Table of Contents (Page numbers indicated refer to actual catalog pages, not pages of CD presentation.)

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Text Box

Davis-Lynch, LLC Equipment Catalog No. 20 For direct access to any of the pages below, click on the title

1

NEWfrom Davis

Davis Type 512-CAFConvertible Down/Up-Jet Auto-Fill Float Shoe*Consistent with the Davis tradition ofoffering new technology to meetoperators’ requirements, we haverecently introduced this shoe to theindustry. The unique Type 512-CAFshoe offers several design features/benefits to assist the operator inmeeting objectives to successfully runcasing to bottom, and carry outcementing operations. The field appli-cations for this shoe range from closetolerance liners to full casing stringsrun to surface, or landed in a sub-seawellhead.

The list of features/benefits thatthis shoe provides for operatorsincludes:• The ability for casing/liner to self-fillas it is being run into the hole. This

self-filling action can significantlyreduce surge pressures on the forma-tion, and also reduce running timefor casing/liner. The result of this canbe substantial savings in rig time, anda reduction in the amount of drillingfluid lost during the casing/liner run.The Type 512-CAF shoe is availablewith several options for flow througharea for the self-filling feature. (SeeFig. 1).• The ability to circulate throughdown jets/center of shoe while run-ning in the hole. This provides ameans of washing casing/liner to seatif required. (See Fig. 2).• Once converted, the ability forcement to be pumped through up-jets for optimum cement placement.(See Fig. 3).• Double valve assembly in shoeallowing for redundancy to preventcement u-tube after completion ofcementing operations.• Ball seat for conversion of shoe canserve a multi-purpose function.Conversion pressure can be adjustedto allow for setting hydraulic typeliner hangers, prior to convertingshoe at higher-pressure value. Thisallows for single ball to be utilized

rather than multiple balls as in previ-ous systems.• Single ball conversion on liner appli-cations also allows for greater flowthrough area for self-filling ofcasing/liner. This allows for maximumsurge reduction, and minimizespotential of self-filling feature beingcompromised by solids encounteredin the well bore.• Large flow through area for self-fill-ing action makes the Type 512-CAFshoe optimum for close toleranceapplications with casings being land-ed at the sub-sea wellhead, in deepwater drilling environments.• Shoe has been drilled out with PDCbits successfully on several applica-tions.• Components of Type 512-CAF shoecan also be installed into a collar ifdesired, and run together with aguide shoe.

The Type 512-CAF shoe has been suc-cessfully used on numerous wells todate. Available in a full range of cas-ing sizes, contact your Davis represen-tative for full information.

*Patent Pending

Fig. 1Casing self-filling as it is

run in the hole

Fig. 2Circulating through down-jets/

center of shoe

Fig. 3Shoe converted, valves actuated.

Cementing through up-jets.

2

Type 500-PVTS

Ribbed Down-JetFloat Shoe

Needle NoseFloat ShoeType “S” Set Shoe

Type 501-PVTS Type 501 DV-PVTS

Type 600

Davis manual-fill float shoes and floatcollars are simple in design and oper-ation. They have been engineeredand manufactured to withstand thehigh temperatures encountered andthe high pressures created by differ-ences in fluid columns when floating,landing, and cementing strings of cas-ing.

Davis’ standard design manual-fillfloat shoes and float collars are man-ufactured with the Davis PVTS valve.This valve is a spring-actuated,plunger-type, one-way check valve. Itis designed to withstand high temper-atures and large volumes of fluidspumped at high flow rates. It alsoprovides an effective seal under bothhigh- and low-pressure conditionswhen casing is run and cemented ineither the vertical or horizontal posi-tion.

The valve housing and closure ele-ment are made with a phenolic mate-rial. High strength concrete is thecompound that molds the valve inthe machined housing to form astrong singular unit. Despite the highcompressive strength of the concrete,and the shear strength of the valve,Davis float shoes and collars are easilydrilled with conventional or PDC bits.

Because of its proven performancequalities, the PVTS valve is used in allmanual-fill Davis float equipmentincluding double-valve shoes and col-lars, and all inner-string cementingequipment including the tag-in,screw-in, and latch-in designs.

Since Davis float shoes and floatcollars are usually manufactured fromsteel that has a greater wall thicknessthan the pipe body of the casingstring they are run in, they normallyhave burst and collapse resistancegreater than the casing string.Float Shoe Type 500-PVTS

This shoe features a strong, round-ed concrete nose that aids in guidingthe casing string to bottom and incor-porates the PVTS back-pressure valveassembly. These features make thisDavis shoe highly preferred for con-ventional cementing jobs.Down-Jet Float Shoe Type 501-PVTS

Along with all the features incor-porated into the Type 500-PVTS floatshoe, the popular Type 501-PVTSmodel features properly drilled andangled down-jet ports. The even dis-tribution of fluid through theseraised ports delivers to the user sever-al advantages, including the added

assurance that circulation can beestablished when casing becomesplugged during running or is landedon bottom. The angle of the portsassists if casing has to be washed tobottom, and the spacing of the portsassists in breaking up or preventingcement channeling.Double-Valve Down-Jet Float ShoeType 501 DV-PVTS

For additional protection, choosethis shoe which combines the maxi-mum security of a unitized doublecheck valve along with all the bene-fits inherent in the Type 501-PVTS.Guide Shoes Types 600 and 601

The rounded design of the con-crete noses of these Davis shoesassists in guiding the casing stringinto the hole and safely to the bot-tom. Both have flat-finished concretetops to provide strong surfaces forlanding cement plugs. The Type 600(shown) has a single fluid outletthrough the nose while the Type 601(not shown) has down-jets whichdeliver the efficient washing action,cement slurry distribution and otherbenefits of the Type 501-PVTS.Down-Jet Set Shoe withLug Nose Type “S”

This Davis shoe comes with a spe-cial drillable lug nose for use whencasing is run as a liner, lowered ondrill pipe and set on bottom. Whenbottom is contacted, the nose piecewill prevent the casing from rotatingwhen the drill pipe is released fromthe liner. This lug nose design canalso be incorporated into self-fillingshoes.Ribbed Down-Jet Float Shoe

The externally raised ribs of thisshoe aid in centering the casing at

bottom and promote more even dis-tribution of cement to reduce the riskof channeling. Ribbed float collars arealso available.Needle Nose Float Shoe

Field-proved for over 20 years, theDavis Needle Nose Float Shoe hasprovided operators with an aid to runcasing in adverse conditions. With itstapered aluminum nose, it has beenextremely effective for running casingthrough tight spots, different geo-metric sections in the wellbore, andprevious casing strings that have beendamaged.

It incorporates down-jet ports thatcreate turbulent flow at the shoe forwashing, conditioning, or cementing.The Needle Nose Shoe can beequipped with the Davis Type PVTSvalve, which has been proven to meetor exceed API RP 10 F category III C.,or with a self-filling type valve.Mule Shoe Type 610

The Davis Mule Shoe is used whenthe running of casing is hindered byhole conditions. When the shoeencounters a ledge in the wellbore,for example, it is rotated so that thefluid under pump pressure washesthe ledge off. The shoe can also beused to facilitate getting over or byobstacles in the hole.Texas Pattern Casing ShoesTypes 800 and 800ST

These types of casing shoes arepopular for use in reinforcing the endof the casing on shallow strings. Theyhelp the casing to run past bridges,and they provide maximum circula-tion through the casing. They areavailable with smooth-surface or saw-tooth bottoms.

Davis Manual-Fill Float Shoes

3

Mule ShoeType 610

Casing ShoeType 800

Casing ShoeType 800 ST

4

Davis Manual-Fill Float CollarsFloat Collar Type 700-PVTS (Fig. 1, below)

This Davis collar comes equippedwith a flat concrete surface and loaddistributor plate for landing and seal-ing cement plugs. It normally isoffered with pin and box thread con-nections, but it is also available withdouble-box connections. Both ofthese designs embody the positive-seal, PDC drillable Davis PVTS spring-operated plunger-type valve moldedin place with high strength concrete.

When a back-pressure valve is notdesired or required in a float collar,Davis has available the Type 701Baffle Collar (not shown). This collarallows fluid flow in either directionand provides a strong concrete sur-face to land and seal cement plugs. Itis often run in tandem with the DavisType 501 DV-PVTS double-valve,down-jet float shoe.Lock-Down Anti-Rotation PlugSystem Type LAP (Surface launch andsub sea launch)*

Available for both surface launchand sub sea launch applications,Davis offers the Type LAP plug sys-tem. The Type LAP system incorpo-rates our first generation of mecha-nism to prevent plug rotation whiledrilling out. This system is still usedon some surface launch applications

*US Patent No. 5,842,517

involving specialty floatequipment (such asauto-fill types), and isavailable through a jointventure with BJ ServicesCo. for sub sea applica-tions. BJ Services Co. hasincorporated the DavisType LAP mechanisminto their respective subsea launch plugs, so theBJ plugs can be run withDavis Type LAP float col-lars (Fig. 2, below), andprovide an effective means to preventrotation while drilling out.

The system features a float collarthat incorporates a threaded typereceiver to receive a collet type insert.A bottom plug with collet insert onbottom, and threaded type receiveron top of plug. The top plug featuresa collet type insert on the bottomend. The collet feature allows for thebottom plug to latch into the floatcollar, as well as for the top plug tolatch-in to the bottom plug. Oncelatched in, right hand rotation duringdrill out tightens up the engagementof the plugs and collar, with thethreaded profiles on the collet andreceiver. Some notable features/bene-fits are: • Once engaged the latch-in design

Lock-Down/Anti-Rotation Top and Bottom Cementing Plugs

Fig. 1Type 700-PVTS

Fig. 2Type 700 LAP Float Collar with

Lock-Down/Anti Rotation Receiver

Fig. 3Type 700 LAP/N Float Collar with

Lock-Down/Anti Rotation Receiver

prevents plugs from becoming disen-gaged by pressure acting on theplugs from below, or being mechani-cally disengaged during the drill-outprocess. A significant improvementover other designs that only meshagainst rotation, this lock-down fea-ture is unique to Davis.• Five-wiper premium quality plugsprovide for most efficient casing wip-ing.• Type LAP collars and plugs are fieldproven for easy drill out with PDCbits.• System allows for use of multiplebottom plugs or no bottom plugs ifdesired. • Davis float shoes are also availablewith the Type LAP insert uponrequest.

*US Patent No. 5,234,052

Davis offers three types of self-fillingequipment: the pump converted,PVTS valve equipped automatic-fill,the drop ball converted automatic-fill,and the drop ball converted differen-tial-fill. All three types are simple indesign to give top-quality perfor-mance.Pump Convert PVTS AutomaticFill-Up Shoes and Collars

The Davis Type 505 AD-PVTS auto-matic fill-up shoe and the Davis Type705 A-PVTS automatic fill-up collarutilize the proven Davis PVTS valve inself-filling equipment. The shoe andcollar offer a fixed radial area thatallows fluid to enter the casing andseek its own height. This action low-ers surge pressures on formations to aminimum, reduces casing runningtime and, the chances of it stickingare lessened. Casing can be circulatedat any time, with low rates, withoutconverting the valve from the fill-upto the back-pressure mode.

Conversion from the fill-up to theback-pressure mode can be accom-plished at any time while casing isbeing run by introducing a pre-deter-mined flow rate to the equipment.Furthermore, if at casing runningtime it is determined that self-fillingequipment is not desirable, the valvecan be converted by manually forcingthe plunger to its fully open positionand removing the three retainingballs. Doing this requires filling thecasing from the top as it is run.

Once conversion is carried out, all

the benefits of the proven Davis PVTSvalve are realized, including PDC bitdrillability and high pressure andtemperature ratings.

Davis Self-Filling Float Shoes and Float CollarsDavis CombinationBrush/Plug**

5

Lock-Down Anti-Rotation PlugSystem Type LAP/N (Surface launch)*

Available for surface launch appli-cations, Davis offers the Type LAP/Nplug system. This system incorporatesour latest generation of mechanismto prevent plug rotation whiledrilling out. The system features afloat collar (Fig. 3, opposite page)with a heavy duty “tooth like” insertincorporated, a bottom cementingplug with heavy duty inserts incorpo-rated on top and bottom, as well as atop plug with a heavy duty insertincorporated on bottom. The uniqueangled tooth design of the systemallows for easy engagement betweenplug and collar, as well as betweenplugs. Notable features/benefits are: • Once engaged the angled tooth

design prevents plugsfrom becoming disen-gaged by pressure act-ing on the plugs frombelow, or being disen-gaged during the drill-out process. A signifi-cant improvement over other designs that onlymesh against rotation,this lock-down feature isunique to Davis.• Five-wiper premiumquality plugs provide for most efficient casing wiping.• Type LAP/N collars and plugs are fieldproven for easy drill out with PDC bits.• System allows for use of multiple bottom plugs or no bottom plugs ifdesired.

• Davis float shoes are also availablewith the Type LAP/N insert uponrequest.

Lock-Down/Anti-Rotation Plugs Type LAP/N (Surface Launch)

An alternative to more typical wellbore clean-outs, the DavisCombination Brush/Plug can saveoperators time and associated costs,by eliminating the requirement torun a work string/casing scraper onsome applications. Available for sev-eral sizes of production casings, con-tact your Davis representative formore information.

* US Patent 5,842,517

** Patent Pending

Running InType 705 A-PVTS

Valve ActuatedType 505 AD-PVTS

6

Davis Self-FillingFloat Shoes andFloat Collars–cont.Drop Ball Convert Automatic Fill-UpShoes and Collars

The Davis Type 505 AF automaticfill-up shoe and the Davis Type 705 AFautomatic fill-up collar allow maxi-mum filling of the casing while it isbeing run in the hole, with the fluidentering the casing free to seek itsown level. The filling action reducescasing running time and lowers surgepressures on formations to a mini-mum. Provided the conversion ballhas not been dropped, casing can becirculated at any time without affect-ing the fill-up operation.Drop Ball Convert Differential Fill-UpShoes and Collars

The Davis Type 506 differential fill-up shoe and the Davis Type 706 dif-ferential fill-up collar allow optimum,metered filling of the casing, while itis being run in the hole. This fillingaction reduces casing running time,lowers surge pressures on formations,and minimizes the possibility of stick-ing. Providing the conversion ball hasnot been dropped, casing can be cir-culated at any time without affectingthe fill-up operation.

Both the differential and the auto-matic fill-up equipment can be con-verted from the fill-up to the back-pressure mode at anytime during thecasing run by dropping the weightedball furnished with each piece. Afterallowing sufficient time for the ball toreach the equipment, conversion canbe achieved by applying approxi-mately 500 psi of pump pressure. Ifboth a shoe and collar are present inthe casing string, the same ball willconvert both pieces in two “like-but-separate” actions.

Running InType 705 AF

Valve ActuatedType 505 AF

Running InType 706

Valve ActuatedType 506

NominalCasing Size Weight Range O.D. I.D. Burst Collapse

(Inches) (Lbs/Ft) (Inches) (Inches) (PSI) (PSI)

4-1/2 9.5–13.5 5.000 4.031 9,300 9,600

5 11.5–21.0 5.563 4.439 9,720 9,950

5-1/2 14.0–23.0 6.050 4.950 8,750 9,050

7 23.0–38.0 7.656 6.276 8,650 9,000

7-5/8 20.0–39.0 8.500 6.969 8,650 9,000

8-5/8 24.0–44.0 9.625 8.017 8,000 8,400

9-5/8 32.3–53.5 10.625 8.921 7,700 8,100

10-3/4 32.7–55.5 11.750 10.050 6,950 7,350

11-3/4 38.0–65.0 12.750 11.000 6,600 7,000

13-3/8 48.0–72.0 14.375 12.615 5,850 5,850

16 65.0–109.0 17.000 15.250 4,950 4,250

18–5/8 87.5–117.5 20.000 17.755 5,400 5,050

20 94.0–133.0 21.000 19.125 4,250 3,150

Insert Float Valve Type 900 FThe Davis Insert Float Valve Type 900 F is available for

use in wells of moderate depth using API 8 round shortthread or buttress casing.Davis Insert Fill-Up Valve Type 904 F

Like the Type 900 F, the Davis Insert Fill-Up Valve Type904 F is available for use in moderate depth wells, usingAPI 8 round short-thread or buttress casing. This valveallows continuous fill of the casing as it is run into thehole. A drop-ball converts the 904 F into a conventionalback-pressure valve.

Data for Davis Standard Stock Float Equipment manufactured from K-55 grade materialand threaded with API Round-8 or Buttress Connections

Standard stock Davis Float Equipment meets or exceeds the burst and collapse ratings of N-80 Grade Casing for most weights withinthe range shown for each size.NOTE: All burst and collapse pressure ratings are calculated in accordance with API Bulletin 5C3, Sixth Edition, October 1, 1994.

Davis-Lock Thread LockingCompound

The Davis-Lock thread locking com-pound is a strong epoxy-based compound for use on all threadedconnections to prevent back-off andloosening of joints. The one-poundkit contains the base, catalyst andapplicator.Davis API Modified ThreadCompound

This Davis thread compound con-forms to the specifications of APIBulletin 5A2. It is recommended foruse on casing, tubing, and in linepipe.Davis Non-Metallic ThreadCompound

This Davis thread compound hasbeen formulated as an environmen-tally safe replacement for API modi-fied thread compound that will meet

or exceed the listed performanceobjectives in API Bulletin 5A2.Davis Super-Seal Thread Compound

Davis developed the Super-Sealthread compound to provide long-lasting, high pressure sealing on allAPI threaded joints, especially tubing

and casing. The compound containsmolydisulfide and TFE resin for ahigh-pressure seal. Joints coated withDavis Super-Seal hold better andmake up easier with less torque andstill break clean without damage.

7

Insert Float ValveType 900 F

Insert Float Fill-Up ValveType 904 F

Davis Insert Float Valves

Davis Thread Compounds

8

Pack-Off Head Assembly

Type 501 DVT-PVTS

Drill Pipe Bowl and Slips

Stop Collar

Drill PipeCentralizer

Casing

Tag-In AdapterType B-122C

Tag-In Float CollarType 700 T-PVTS

Down-Jet Float ShoeType 501-PVTS

9

Davis Inner-String Cementing EquipmentExcellent cement jobs at reducedcosts have boosted inner-stringcementing equipment to the fore-front of operator popularity. Daviswas among the first to offer theinner-string systems, and continuestoday to have the most complete lineof systems available in the industry.

Davis equipment is designed with ataper in the top of the concrete toguide the adapter on the bottom ofthe inner-string into the receiverincorporated in the float shoe or col-lar. All three styles of adapter-to-receiver adjoinments engage dual-seal mechanisms to prevent fluidleakage. The primary seal consists ofelastomer seals compressed in asmooth bore. The 45° bearing faceeffected when the adapter andreceiver adjoin creates the secondaryseal.

Davis offers three proven systemsfor inner-string cementing: the Tag-Insystem, the Screw-In system, and theLatch-In system. The equipment usedin these systems can be manufacturedin virtually any size and thread, andas single or double-valve float shoes(with or without ports), float collars,and baffle collars.

An option available when orderingDavis inner-string equipment is alatch-down wiper plug. This plug fol-lows the cement and wipes the drillpipe. Once properly latched down,the plug and latch mechanism act tocheck back pressure, giving additionalassurance that cement will beretained in the desired position andthe inner-string (drill pipe) can beimmediately pulled out of the hole.

Davis is the only company thatstocks in local inventories all theaccessory items required to performinner-string cement jobs in a timelyand efficient manner. These itemsinclude a set of drill pipe bowl andslips, a false rotary plate, and a cen-tralizer to center the drill pipe insidethe casing.Davis Tag-In Equipment

Tag-In float equipment incorpo-rates a receiver built into the floatequipment (shoe or collar) thatreceives an adapter made up to thebottom of the inner string (usuallydrill pipe). The tapered concrete finisharound the receiver guides theadapter into it. The Type B-122-C Tag-In Adapter is engaged to the receiverby straight-in movement, No rotationis required. Once engaged, a primary

and secondary seal are effected.Disengagement of the seal isachieved by picking the adapter upand out of the receiver. Once again,no rotation is required.

A popular choice of equipment forinner-string cementing larger diame-ter casings, from both onshore andoffshore rigs, is the Davis Type 501-PVTS Float Shoe and the Type 700 T-PVTS Tag-In Float Collar. This equip-ment provides all the benefits thatcome with inner-string cementingthrough a float collar, including theoption to run one or more shoe jointsand the option to displace cementbelow the float collar without creat-ing a “wet shoe.”

For those preferring to inner-stringcement through a shoe, Davis offers

the Type 501 DVT-PVTS Double-Valve,Down-Jet, Tag-In Float Shoe. Thisfloat shoe incorporates all the fea-tures and benefits built into the 501-PVTS Float Shoe and the Type 700 TTag-In Float Collar.Pack-Off Head Assemblies

Davis also has available the largestand most complete inventory of cas-ing to drill pipe pack-off heads in theindustry, if well hydraulics dictate theuse of one when inner-string cement-ing. These heads are designed to sealthe drill pipe/casing annulus andallow pressure to be applied to it.This pressure serves to offset pumppressure that creates collapse loadingwhenever inner-string cementingoperations are conducted.

The Three Adapters of the Davis Inner-String Systems

Davis Latch-DownWiper PlugThis plug is optional withDavis Tag-in and Screw-insystems whether cementingthrough a shoe or collar. Itis available for all drill pipesizes and can be manufac-tured from non-metalliccomponents if drilling outwith a PDC bit is intended.

10

Type 501 DVS-PVTS

Type 700 L-PVTS

Type 700 S-PVTSScrew-In Assembly

Type 501 DVSLP-PVTSScrew-In Shoe withHanger Assembly

Drill Pipe

Port

Davis ConductorCasing Hanger

Davis Drive PipeLanding Ring

Drive Pipe

Conductor Casing

Screw-In Adapter

Type 501 DVSLP-PVTSDouble Valve,Down-Jet, Screw-InFloat Shoew/Latch-Down Plug

11

Davis Screw-In EquipmentScrew-In float equipment allows

the adjoining of the inner-string tothe casing at the float equipment.This adjoinment supports the load ofthe casing, allowing it to be loweredto bottom and inner-string cementedwhile being reciprocated. The equip-ment incorporates a strong receiverbuilt into the float equipment (shoeor collar) that is capable of handlingloads up to 300,000 pounds. Adjoin-ment between the Type B-120-BAdapter and the receiver is accom-plished by applying left-hand rotationto the inner-string. No torque isrequired. Once the receiver andadapter are engaged, primary andsecondary seals are effected betweenthe two. Disengagement is attainedby applying right-hand rotation tothe inner-string while gradually pick-ing it up.

Davis Screw-In equipment has cre-ated a whole new realm of economi-cal uses with regard to its multipleapplications. Among them:

1. Offshore, running and landing ofthe conductor casing string at eitherthe mudline or the production deck.The string can be landed in tensionby utilizing a Davis Drive PipeLanding Ring and Davis ConductorCasing Hanger. (See graphic oppositepage). This allows the operator toeffectively seal off the conductor/drive pipe annulus. A second option isto allow the casing string to be land-ed on bottom or free standing incompression. Either application cansave the operator rig time and relat-ed costs by eliminating the need fornippling-up well control equipmenton the conductor casing string.

When conductor casing is suspend-ed on a landing ring, at either themudline or the production deck, thetapered top of the Davis casing hang-er serves as an aid in protecting andguiding the bits to be used for thenext hole section into the top of theliner. In addition to this, Davis cancustomize the top of the casing hang-er to receive most brands of conven-tional mudline suspension or well-head housing equipment.

When conductor casing is set onbottom in compression, Davis offersthe Type B-125 bit guide (see photo)that screws into the top of the liner.In addition, Davis manufactures afluted casing hanger that is designedto land on this bit guide and suspendsurface casing. Most brands of con-ventional, modular mudline suspen-

sion equipment can then be placed inthe surface casing string for the pur-pose of landing and suspending ensu-ing casing strings.

2. Reciprocating full strings of cas-ing while inner-string cementing. Thisapplication has proven extremelyeffective on geothermal wells wherethe absence of cement voids in theannulus is exceptionally critical ifeventual casing collapse is to beavoided.

3. Setting a large-diameter liner toeliminate the cost of an expensive,conventional liner hanger, and realiz-ing all the benefits inherent in inner-string cementing.

As with all Davis inner-stringequipment, the Screw-In style is avail-able in several models including theType 700 S-PVTS for those who prefercementing through a float collar, andthe Type 501 DVS-PVTS for those whoprefer cementing through a floatshoe.Davis Latch-In Equipment

Davis also offers Latch-In equip-ment for inner-string cementing. Itacts similar to Tag-In equipment withthe additional feature of positivelylocking the adapter into the receiver.The Type B-113 Adapter is engagedto the receiver by straight-in move-ment. No rotation is required.Disengagement is accomplished byrotating the drill pipe one turn to theright and picking up on it. This action“un-jays” the collet that locks theadapter in place and allows it to com-press and release from the receiver.

The adapter can also be releasedwithout damaging it by pullingapproximately 40,000 pounds overthe inner-string weight. This action

results in a safety sleeve beingsheared out of the receiver. This back-up release feature should only beused if necessary.

Davis Latch-In equipment can beused when cementing from floatingdrilling vessels. It can also be used ifunusually high pump rates are antici-pated during cementing operations.The Latch-In mechanism will act toanchor the inner-string to the casing,eliminating the possibility of hydrauli-cally pumping or “lifting” it out.

The Latch-In style of inner-stringequipment is available in severalmodels including the Type 700 L-PVTSFloat Collar. This model provides theoperator with all the benefits thatcome with inner-string cementingthrough a float collar, including theoption to choose several shoe jointsand the option to overdisplacecement below the float collar withoutcreating a “wet shoe.”Davis Special Inner-StringCement Equipment

Davis has available, in either a shoeor collar, open-ended equipment thatcan be used to conduct inner-stringcementing operations. The design ofthis equipment makes its use advan-tageous particularly when large-diam-eter/thin-walled casings of the typecommonly run in storage wells arebeing cemented. The equipmentincorporates two receivers, one toreceive the standard Tag-In adapterand one to receive a special latch-down wiper plug that followscement.

A popular choice for this applica-tion is the Davis Type 601 TLP Down-Jet, Tag-In Guide Shoe with Latch-Down Plug receptacle. Its open-endedfeature allows casing to self-fill as it isrun in the well. This eliminates thetime that would normally be requiredto manually fill the casing. Once cas-ing is on bottom, the inner-string isrun and seal engagement occurs byuse of the standard Tag-In adapter. ADavis Pack-Off Head Assembly isoften rigged up at this point. At theconclusion of cement displacement,the special latch-down wiper plug islanded and locked into the shoe.Once latched, this plug provides theback-pressure check that is necessaryto retain cement in the desired position.

Type B-125 Bit Guide

Davis Extended Reach EquipmentDavis Flotation Collar*

The patented Davis Flotation Collar(DFC) is designed for use in runningcasing in substantially horizontal well-bores. Incorporated into the casingstring, the device serves as a tempo-rary barrier inside the casing. In sodoing, it allows the portion of thestring below it to be filled with air(no fluid) and the portion above it tobe filled with drilling fluid.

Floating the bottom portion of thecasing reduces the drag against thewellbore, while filling the upper por-tion with drilling fluid adds weight tothe casing string to push it into thehole. This feature facilitates runningcasing in highly deviated wells and, inmany cases, permits successful casingruns that would otherwise beextremely difficult if not impossible.

Once the opening sleeve is activat-

ed by casing pressure, allowing thedrilling fluid to displace the air in thelower section of the casing string,normal cementing operations canbegin immediately. Additional pres-sure on the bottom cementing plugreleases the DFC assembly so that itcan be pumped down to the float col-lar. The top cementing plug displacesthe cement and lands and seals onthe bottom cementing plug/DFCassembly.

Unlike earlier devices that must beset inside the casing and thenretrieved after landing the casing(requiring one round trip of the drillpipe and spacing the top of the lastcasing joint at the rotary table), theDavis Flotation Collar is installed inthe same manner as a float collar.

Applying pressure to the inside ofthe casing string is all that is required

to release the trapped air at the bot-tom of the casing string. This pressureis adjustable at time of manufactureto accommodate different pressurerequirements.

The Davis Flotation Collar is self-contained and requires no other run-ning, setting or retrieving tools. Theinner sleeves of the device provide agood seal for the cementing plugagainst the float collar, and they areeasily drilled out with either PDC orconventional rock bits when drillingthe float equipment.

*Davis-Lynch does not warrant that use of the DavisFlotation Collar in a Selective Flotation System is freefrom infringement of any patented methods. Use of theDavis Flotation Collar in such a system may, for example,require permission from Unocal under U.S. Patent4,986,361.

12

Mud-filledcasing

DavisFlotation

Collar

Air-filledcasing

DavisSpecial Application

Float Collar

DavisSemi-RigidCentralizer

DavisSpecial Application

Float Shoe

Mud

Davis Flotation Equipment Package

13

1.Davis Flotation Collar (DFC)

Bottom portion of casing is run dry (not filledwith fluid), with DFC installed at desired

depth. Casing above the DFC is filled withdrilling fluid as casing run continues to

desired depth.


Casing pressure is increased until the openingsleeve shifts down to permit fluid and air to

swap. After a fluid stabilization period, the casing is filled with drilling fluid.


Bottom cementing plug is launched ahead ofcement. After landing on the bottom sleeve,

it pushes both DFC sleeves ahead of thecement to the float collar below.


Bottom cementing plug and sleeves land andseal on the float collar. Bottom cementing

plug ruptures, and cement is pumpedthrough and out of the float equipment.


Top cementing plug is displaced and seals onbottom cementing plug/DFC assembly

at the float collar.

Opening Sleeve

Seal

Plug

CirculatingPorts

BottomSleeve

ShearBalls

BottomPlug

Seal

BottomPlug

Casing

FloatCollar

BottomPlug

TopPlug

Casing

FloatCollar

Casing Size Hole Size Product Bow O.D. Starting Force (In Lbs) Restoring Force (In Lbs)(In Inches) (In Inches) Number (In Inches) API Davis API Davis

4-1/2 6 0450-NW2C 7-1/8 464 361 464 3000+4-1/2 6-1/4 0450-NW2C 7-1/8 464 251 464 11404-1/2 6-1/2 0450-NW3C 7-5/8 464 355 464 20704-1/2 7-7/8 0450-NW4C 9-1/8 464 264 464 1040

5 6-1/4 0500-NW1C 7-1/8 520 175 520 6505 6-1/2 0500-NW2C 7-5/8 520 273 520 3000+5 7-7/8 0500-NW4C 8-1/8 520 190 520 10205 8-1/2 0500-NW4C 9-5/8 520 360 520 1650

5-1/2 7-7/8 0550-NW3C 8-5/8 620 240 620 6505-1/2 8-1/2 0550-NW4C 10-1/8 620 520 620 12105-1/2 8-3/4 0550-NW4C 10-1/8 620 227 620 13105-1/2 9-7/8 0550-NW5C 11-1/8 620 280 620 11805-1/2 12-1/4 0550-NW6C 13-5/8 620 240 620 680

7 8-1/2 0700-NW2C 9-5/8 1040 720 1040 3000+7 8-3/4 0700-NW3C 10-1/8 1040 795 1040 3000+7 9-7/8 0700-NW4C 11-5/8 1040 720 1040 1910

7-5/8 9-7/8 0758-NW3C 10-3/4 1056 550 1056 14678-5/8 11 0858-NW3C 11-3/4 1440 400 1440 14708-5/8 12-1/4 0858-NW5C 14-1/4 1440 1120 1440 18509-5/8 12-1/4 0958-NW8C 14-3/4 1600 1389 1600 217510-3/4 12-1/4 1034-NW2C 13-3/8 2040 511 1020 218510-3/4 13-1/2 1034-NW4C 15-3/8 2040 645 1020 138510-3/4 14-3/4 1034-NW5C 16-3/8 2040 660 1020 129011-3/4 14-3/4 1134-NW4C 16-3/8 2160 624 1080 141111-3/4 15-1/2 1134-NW5C 17-3/8 2160 940 1080 153013-3/8 17-1/2 1338-NW5C 19 2400 830 1220 2330

16 20 1600-NW5C 21-5/8 2600 844 1300 157016 22 1600-NW6C 24-1/8 2600 1161 1300 2530

18-5/8 22 1858-NW5C 23-1/4 3500 2010 1750 3000+18-5/8 24 1858-NW6C 26-3/4 3500 740 1750 1850

20 24 2000-NW5C 25-5/8 3760 1360 1880 193020 26 2000-NW6C 28-1/8 3760 1220 1880 2200

14

Davis “NW” Type Centralizer Dimension and Performance Data

Davis Non-Welded Centralizer*Davis offers a full line of patented,

non-weld centralizers. The centraliz-ers feature a unique interlockingadjoinment between the end collarand bow spring, which makes for astrong singular unit. Davis Type “NW”centralizers are designed to exceedthe performance requirements of APISpecification 10D for both startingand restoring forces. (See data tablethis page)

Other design features of the Type“NW” centralizer include:• Bow springs made of an alloy steelwhich are heat treated and temperedto a hardness to ensure proper andconsistentspring charac-teristics.• End collarhinges that arefolded to theinside. This actsto minimizethe collarstretch thattends to occurwhen centraliz-ers encounter

tapers common to some pipe connec-tions.• A reinforcing rib stamped into theend collar. This acts to strengthen itand ensure maintenance of its roundconfiguration during transport.• Several different spring bow heightsthat are available to accommodatemost any casing-to-hole configura-tion.• Centralizers with built-in stopdevices as well as those for unusualsizes available on request.

Davis Close-Tolerance Bow SpringCentralizer

In applications for running casingin close tolerances or slim holes, Davisoffers a special type bow spring cen-tralizer for these requirements. Toprovide optimum performance inclose-tolerance holes, these centraliz-ers feature low starting forces andhigh restoring forces. Centralizersconsist of a solid type end collar forslipping over the pin end of casingjoint. Some features/benefits include:• Designed to meet or exceed APISpecification 10D for starting andrestoring forces.

• Available with setscrews incorporat-ed for integralstop, or can be runbetween stopdevices for applica-tions when casingis to be rotated.• Typical applica-tions include: 5-inch casing inside6-inch hole, 7 5/8-inch casinginside 8 1/2-inchhole, and 9 5/8inch casing inside10 5/8-inch hole.Other sizes areavailable upon request.

Davis Non-Welded Semi-RigidCentralizer (SRC)

This Davis product features unique-ly profiled bows that simultaneouslyprovide the operator with those fea-tures found desirable in both springbow and rigid centralizers. The resultis a centralizer that far exceeds theperformance standards set forth inAPI Specification 10D.

Davis Cementing Enhancement Devices

*U.S. Patent No. 4,909,322

15

Davis “SR” Type Semi-Rigid Centralizer Dimension and Performance DataCasing Size Hole Size Product Bow O.D. Starting Force (In Lbs) Restoring Force (In Lbs)(In Inches) (In Inches) Number (In Inches) API Davis API Davis

4-1/2 6 0450-SR1C 6.06 464 171 464 4000+4-1/2 6-1/4 0450-SR2C 6.38 464 <150 464 4000+4-1/2 6-1/2 0450-SR3C 6.63 464 <150 464 31804-1/2 7-7/8 0450-SR7C 7.88 464 <150 464 3000

*5 6-1/2 0500-SR1C 6.56 520 <150 520 4000+5 7-7/8 0500-SR6C 8.00 520 <150 520 35855 8-1/2 0500-SR8C 8.68 520 <150 520 4000+

5-1/2 7-7/8 0550-SR4C 7.88 620 <150 620 17205-1/2 8-1/2 0550-SR6C 8.50 620 <150 620 29105-1/2 8-3/4 0550-SR7C 8.88 620 <150 620 25405-1/2 9-7/8 0550-SR9C 9.68 620 <150 620 4000+

*7 8-1/2 0700-SR1C 8.63 1040 <150 1040 4000+7 8-3/4 0700-SR2C 8.88 1040 783 1040 4000+7 9-7/8 0700-SR6C 10.00 1040 <150 1040 4000+

7-5/8 9-7/8 0758-SR4C 10.00 1056 <150 1056 4000+*8-5/8 11 0858-SR5C 11.00 1440 276 1440 4000+8-5/8 12-1/4 0858-SR8C 12.31 1440 <150 1440 4000+9-5/8 12-1/4 0958-SR5C 12.38 1600 683 1600 4000+

**10-3/4 12-1/4 1034-SR1C 12.38 2040 <150 1020 4000+10-3/4 13-1/2 1034-SR5C 13.50 2040 <150 1020 4000+10-3/4 14-3/4 1034-SR9C 15.00 2040 777 1020 4000+11-3/4 14-3/4 1134-SR6C 14.81 2160 180 1080 4000+11-3/4 15-1/2 1134-SR8C 15.50 2160 180 1080 4000+13-3/8 17-1/2 1338-SR9C 17.63 2400 410 1220 4000+

16 20 1600-SR9C 20.25 2600 745 1300 4000+18-5/8 22 1858-SR7C 22.06 3500 <150 1750 4000+

20 24 2000-SR9C 24.25 3760 605 1880 4000+20 26 2000-SR10C 26.13 3760 757 1880 4000+

*Starting force derived from testing over stop collars. **Starting force derived from testing over stop collars, recommended running only over a stop device.

As with the standard Davis Non-Welded Centralizer, the bows of theSRC are manufactured from alloysteel which is heat treated and tem-pered. During assembly they areadjoined to the end collars by theDavis patented interlocking method.

The design of the SRC’s bows pro-duces centralizers that have startingforces far below API maximums alongwith very low drag forces. The springcharacteristic of the bows allows theSRC to compress in order to getthrough tight spots and severedoglegs that may be present down-hole.

While the manufacture of thebows produces characteristics normal-ly associated with standard springbow centraliz-ers, the dou-ble-crestedprofile of theSRC bow pro-vides restoringforces that farexceed thosestandards setforth in APISpecification10D andwhich are nor-mally associat-ed with rigid

centralizers.The SRC is ideally suited for run-

ning in horizontal and highly deviat-ed wells where low running forcesare a must. It can be run over casingconnections or stop collars and, ifrequested, can be manufactured witha built-in stop device.

Davis Non-Welded TurbolizerThis is a centralizer with metal fins

installed on the bows to help induceturbulence in the cement slurry dur-ing pumping operations. Like thespring bows, the fins are made ofheat-treated alloy steel. This makesthem flexible, which minimizes dam-age while moving downhole.

The Davis Turbolizer incorporatesthe same non-welded end collar-to-spring-bowinterlockingadjoinment asthe Davis cen-tralizer.Turbolizersare availablein the samesizes and bowheights ascentralizers.

As with theDavis central-izer, turboliz-

ers can be manufactured with abuilt-in stop device. These items areavailable on special order.

Davis Cement BasketA simple, economical type of annu-

lar packoff, theDavis CementBasket is com-monly usedin situationswhereporous orweak for-mationsrequirehelp in sup-porting acement col-umn. It is con-structed of thin steel petals arrangedin an overlapping pattern and rein-forced by spring steel ribs. Its designallows cement to flow in an upwarddirection, yet helps to prevent it fromfalling downward.

The basket is easily installed by slid-ing it over the pin end of a casingjoint, prior to make-up of the joint.Travel range can be limited by a stopring or by couplings. Available in sizes4 1/2” and larger, the Davis CementBasket is most effective when central-ized and placed into a gauged sectionof the hole.

Casing Size Hole Size Product Bow O.D.(Inches) (Inches) Number (Inches)

4 1/2 6 0450-RAC 5 3/44 1/2 6 1/4 0450-RAC 5 3/44 1/2 6 1/2 0450-RBC 6 1/84 1/2 7 7/8 0450-RFC 7 5/8

5 6 1/2 0500-RAC 6 1/45 7 7/8 0500-REC 7 3/45 8 1/2 0500-RFC 8 1/8

5 1/2 7 7/8 0550-RCC 7 5/85 1/2 8 1/2 0550-REC 8 1/45 1/2 8 3/4 0550-RFC 8 5/85 1/2 9 7/8 0550-RIC 9 5/8

7 8 1/2 0700-RAC 8 1/47 8 3/4 0700-RBC 8 5/87 9 7/8 0700-REC 9 3/4

7 5/8 9 7/8 0758-RCC 9 3/48 5/8 11 0858-RCC 10 3/48 5/8 12 1/4 0858-RGC 12 1/89 5/8 12 1/4 0958-RDC 12 1/810 3/4 12 1/4 1034-RAC 1210 3/4 13 1/2 1034-RDC 13 1/410 3/4 14 3/4 1034-RHC 14 5/811 3/4 14 3/4 1134-REC 14 1/211 3/4 15 1/2 1134-RGC 15 1/413 3/8 17 1/2 1338-RHC 17 1/4

16 20 1600-RHC 19 7/816 22 1600-RJC 21 7/8

18 5/8 22 1858-REC 21 3/818 5/8 24 1858-RIC 22 3/4

20 24 2000-RHC 23 7/820 26 2000-RJC 25 7/8

Davis Non-Welded Rigid CentralizerThis Davis product features the

patented adjoinment between endcollar and spring bow first introducedin the Davisnon-weldedbow centraliz-er, along withall the featuresthat operatorsdemand in arigid centraliz-er. Theseinclude thereduction indrag associatedwith runningpipe in deviat-ed and hori-zontal wells,the ability to provide optimum con-centricity during casing cementingoperations, and the ability to func-tion equally well in either open orcased hole.

These centralizers are offered in awide assortment of bow sizes toaccommodate most casing-to-holeconfigurations.

Davis Stop CollarsDavis offers two designs of stop

collars: a friction-grip type and a set-screw type. The friction grip type ishinged and incorporates a nut/boltassembly which, when tightened,

draws the stop collar into a frictiongrip around the circumference of thepipe. It is manufactured from steelthat meets ASTM A 569 specifica-tions.

The set-screw type is a one-piece

model that slips on the pipe and isheld in place by tightening setscrews against the casing. It is manu-factured from steel that meets AISIM 1020 specifications. This designoffers superior holding capabilityand is especially applicable in closetolerance situations.

Davis stop collars are stocked in allpopular sizes ranging from 4 1/2″ to20″ Unusual sizes are available onrequest.

Davis Spherical Stand-Off Device*A new product that Davis is intro-

ducing is a spherical shaped stand-off device. This device is designed topromote positive stand-off, and sig-nificantly reduce the drag forces thatare normally associated with otherpositive stand-off devices.Features/benefits include:• Spherical curvature of the blades in

the vertical direction significantlyreduces drag, prevents the bladesfrom having “plowing effect,” andreduces build up of cuttingsaround stand-off device.

• Spherical curvature of the bladesaround the circumference preventsedge of blades from embeddinginto formation for applicationswhen casing is rotated.

• Blade shape and spacing of bladesallows for optimum flow areaaround the blades of the device.

• Aluminum material prevents dam-age to the OD of the casing or pre-vious casing strings, and reducesfriction.

• Special high performance coatingfurther prevents damage to casingstrings and prevents galvanic corro-sion. Coating also reduces tendencyfor cuttings to adhere to blades ofdevice and reduces friction.

• Designed for both common andclose tolerance applications.

• Utilized on applications for rota-

16

Stop Collar

Davis also offers a premium one-piecestop-collar, with set screws for superiorholding capability.

Spherical Stand-Off Device

Davis “R” Type Rigid Centralizer Dimension Data

17

tion or reciprocation.Contact your local Davis represen-

tative for more information.

*Patent pending

Davis Solid Body Flow DiverterThe Davis Solid Body Flow Diverter

(SBFD) provides a rigid means of hold-ing casing off the well bore. Withblades placed at an angle, it creates aswirling motion that promotes morecleansing action for mud removal,more circulating area, and sufficientcontact with the bore wall to providecentralization and prevent wall stick-ing.

SBFDs can be installed to remainstationary or move freely on the cas-ing. Length of movement is deter-mined by placement of stop devicesor by couplings where applicable. Instationary positions, SBFDs will nor-mally provide stand-off to allow circu-lation all around the casing string.When allowed to move freely, theyserve as a series of bearings duringreciprocation to reduce frictionaldrag.

Available in most casing/hole sizeconfigurations, the SBFDs have beensuccessfully used to:• Maintain centralization through

positive stand-off.• Enhance the effects of mud-wash

pumped ahead of cement slurries.• Aid in the removal of gelled mud

from the annulus.• Reduce torque required for casing

Solid Body Flow Diverter

rotation.• Create a spiral turbulence around

the casing to promote uniformcement bonding.

Davis Centralizer ApplicationAnalysis

Davis will, on request, run a com-puter-analyzed program that will rec-ommend centralizer placement andproject casing stand-off. All that isrequired are some simple pipe andwell data, including casing size, casingweight, casing seat, hole size, mudweight and, when deviation is pre-sent, full survey data, including kick-off point, rate of build and final devi-ation. Since centralization is most crit-ical through the cemented interval,anticipated top of cement is also

requested.With these data, the computer can

be set up to run the spacing/stand-offprograms in two different modes. Thefirst and most effective mode is “vari-able spacing.” In this program, therelevant well data are entered andthe computer calculates the numberof centralizers to run, and how tospace them, in order to meet whatev-er percent stand-off the customerdesires for cement emplacement.

The second mode is “constant spac-ing.” Using the same data requiredfor the variable spacing mode, thisprogram calculates what stand-offcan be expected when the customerrather than the computer dictates thenumber of centralizers to be run, andat what spacing they will be run.

18

DAVIS STAGE CEMENTING COLLARS AND EQUIPMENTFor over 20 years, Davis stage cement-ing collars have been used by opera-tors for their special applications.Now Davis offers three stage collardesigns: a mechanically opened tool,a hydraulically opened tool, and amechanically opened tool with abuilt-in inflatable packer.

Type 778 MC MechanicalStage Cementing CollarWhile now established as a field-proven tool, this tool continues to bethe subject of research and develop-ment to find new materials for fasterdrill-out time, greater PDC bit drilla-bility and better metal-to-metal seal-ing. Features of the 778 MC StageCementing Collar include:• Tools can be made from material

stationary throughout operation,minimizing chances of their beingdamaged.• The pressure-relief design preventsfluid trapping and compressionbetween the opening device and theclosing plug during the closing phaseof the tool’s operation.• The closing sleeve is held in theclosed position by an internal lockring.• Both the opening and closingsleeves lock against rotation for easydrill-out.• A minimum amount of aluminumand rubber are the only materialsencountered during drill-out.

Plug sets for four different cement-ing applications are available (pp. 20, 21).

grades up to 135,000 psi minimumyield, including material suitable forsour gas service.• All parts are custom fitted and sub-jected to extensive quality controlstandards for maximum performancedownhole.• The connection that adjoins thestage collar body and the bottom subeffects a metal-to-metal seal andengages a back-up elastomer seal, thetwo of which are designed to providegas-tight pressure integrity.• No welds are used on any portionof the tool.• The reduced length of the tool min-imizes the effect of bending stresses.• The seals providing internal and ex-ternal pressure integrity are housedin the stage collar body and remain

Running PositionPin and Box threads are identical to the casing threads. Stage collar integral connection is designed for gas tightness.Seals on opening sleeve provide internaland external pressure integrity across the fluid ports.

Opened Position Opening device has landed and, afterpressure is applied, the lower set of shearmechanisms is broken and the sleeveshifts downward to uncover the fluidports. Pumping operations can now be conducted through the stage collar.

Closed PositionThe closing plug has landed and, afterpressure is applied, the upper set of shearmechanisms is broken and the sleeveshifts downward, shutting off the fluidports. Double seals above and below theports provide pressure integrity.

Opening Sleeve

ClosingSleeve

ClosingPlug

DoubleSeals

LockRing

Fluid Ports

BrokenShearMechanism

Free-FallOpeningDevice

BrassShear Mechanism

Anti-RotationFeature

BodyConnectionwithMetal-to-MetalSeal andElastomerBack-up

19

Running PositionPin and Box threads are identical to the casing threads. Stage collar integralconnection is designed for gas tightness.Seals on opening sleeve provide internaland external pressure integrity across the fluid ports.

Opened Position Pressure is applied against the landed and sealed first-stage plug, breaking thelower set of shear mechanisms to allow the sleeve to shift downward and uncoverthe ports. Pumping operations can now be conducted through the stage collar.

Closed PositionThe closing plug has landed and, afterpressure is applied, the upper set of shearmechanisms is broken and the sleeveshifts downward, shutting off the fluidports. Double seals above and below the ports provide pressure integrity.

This stage collar features an openingsleeve with area differences on oppo-site ends that allows it to be manipu-lated hydraulically. The closing sleeveis identical to the one contained inthe Davis Type 778 MC MechanicalStage Cementing Collar. The develop-ment and introduction of this modelwas spurred on by the tremendousupswing in horizontal drilling activitythat has occurred in recent years. Thehydraulic-opening feature makes thistool’s use very practical in horizontalwells.

The elimination of the need to usea mechanical opening device has sev-eral other merits. Casing runs in high-ly deviated wells can now be two-

Type 777 HY Hydraulic-OpeningStage Cementing Collar

stage cemented without having touse continuous displacement typeplugs. In certain applications, linersrun with drill pipe can be run in con-junction with one or several inflat-able packers and used to isolate andselectively cement certain casingintervals. Slotted or pre-drilled linercan be run below a Davis inflatablepacker/hydraulic stage collar assem-bly, allowing cement to be pumpedabove the packer and isolated fromhighly sensitive producing zones.

Along with all the features inher-ent in the 778 MC Stage CementingCollar, the Type 777 HY offers:• Effective differential area on theopening sleeve that generates a high

opening force while requiring onlyoptimal pressure to do so.• The ability to open immediatelyupon the completion of first-stagecement displacement.• Opening pressure values that can beadjusted at the time of assembly toassure that all inflatable packers orother hydraulic tools present in thecasing string will be triggered at thecorrect juncture. (See SpecificationTable on page 22)

DifferentialOpeningSleeve

ClosingSleeve

Fluid Ports

BrokenShear Mechanism

BrassShear Mechanism

BodyConnection withMetal-to-Metaland ElastomerBack-up

Closing Plug

Double Seals

Lock Ring

Shouldered Anti-RotationFeature(Not shown)

20

DAVIS STAGE CEMENTING COLLARS AND EQUIPMENT

Two-Stage Cementing with theType 778 MC using a First-StageSealing Plug, Free-Fall OpeningDevice, and Closing Plug

1. A Davis float shoe and float col-lar along with the Type 778 MCStage Collar, are installed in thecasing string and the casing is runto bottom.

2. Circulation is established andfirst-stage cement is mixed andpumped.

3. The first-stage sealing plug islaunched and cement is displaced.At the conclusion of displacement,the first-stage sealing plug landsand effects a seal against the Davisfloat collar. No baffle is required.

4. The free-fall opening device isdropped and allowed to gravitateto position. Pressure is applied tothe casing and the stage collar isopened.

5. Circulation is established andsecond-stage cement is mixed andpumped.

6. The closing plug is launched andcement is displaced. At the conclu-sion of displacement, the closingplug lands and effects a seal in thestage collar. Pressure is applied tothe casing and the stage collar isclosed.

Two-Stage Cementing with theType 778 MC using a By-Pass Plug,Shut-Off Plug and Baffle, Free-FallOpening Device, and Closing Plug*

1. A Davis float shoe and float col-lar along with the Type 778 MCStage Collar, are installed in thecasing string and the casing is runto bottom. The yellow shut-offbaffle is installed in the casingstring at least (1) one joint abovethe Davis float collar. If API threadsare run (8RD or Buttress) the bafflecan be installed in the “J” sectionof a coupling. If premium threadsare run, a separate baffle collarmust be run.

2. After the hole is conditioned,the by-pass plug with the yellownose piece is launched ahead offirst-stage cement. This plug willpass through the shut-off baffleand land on any Davis manual- orself-fill float collar. Once landed,approximately 50 psi will invertthe wipers on the by-pass plug andallow cement to pass.

3. After cement is mixed andpumped, the shut-off plug islaunched and cement is displaced.At the conclusion of displacement,the shut-off plug lands and effectsa seal in the shut-off baffle.

4. The opening of the stage collarand the ensuing second-stagecementing and closing of the stagecollar are carried out identically tothat described for two-stagecementing with first-stage sealingplug.

*NOTE: When using the Type 777 HY Hydraulic-OpeningStage Collar, the standard plug sys-tem is a first-stage shut-off baffle,a first-stage shut-off plug, a con-tingent opening device, and a clos-ing plug. A first-stage latch-in plugwith a special Davis float collar isavailable on request.

Stage Cementing Plug Systems

Closing Plug Closing Plug

Free-FallOpening Device


First StageShut-Off Plug

Shut-Off BafflePainted Yellow

By-Pass Plug

Painted Yellow

First StageSealing Plug

21

Continuous Two-Stage Cementingwith the Type 778 MC using a By-Pass Plug, Pump-Down OpeningPlug, and Closing Plug.

In this application, the by-passplug follows first-stage cementand it is advisable to run a mini-mum of two joints between thefloat shoe and float collar.

1. After first-stage cement is mixedand pumped, release the by-passplug and begin displacing. Oncethe calculated volume of displace-ment fluid between the stage col-lar and the float collar has beenpumped, less a pre-determinedamount acting as a safety buffer,release the pump-down openingplug.

2. As the pump-down openingplug approaches the stage-collar,slow the pump rate to 1–2bbls./min. Once the plug has land-ed in the opening seat (indicatedby a pressure increase), apply pres-sure to the casing to open thestage collar.

3. Once the stage collar is open,second-stage circulating, cement-ing, and closing operations may becarried out as previously described.

Three-Stage Cementing with theType 778 MC and the Type 778MC-3S Stage Cementing Collars

The Type 778 MC-3S stage collar isidentified by its red markings andis always run as the lower of thetwo tools. Its free-fall openingdevice and closing plug are alsoidentified by their red markings.The upper stage collar is alwaysthe Type 778 MC and the free-fallopening device and closing plugfor it are standard.

The first-stage sealing plug isstandard and will pass throughboth stage collars and land andseal on any manual- or self-fillDavis float collar.

First-, second-, and third-stagecementing and displacing opera-tions, including opening and clos-ing both tools, are carried out aspreviously described.

Closing PlugClosing Plug



Pump DownOpening Plug

First StageSealing Plug

By-Pass Plug

Painted Yellow

Red Nose Piece Closing Plug

THIR

D S

TAG

ESE

CO

ND

STA

GE

FIR

ST S

TAG

E

Painted Red


Opening Closing Type 778 MC Type 778MC3SNominal Drill-Out Overall Opening Closing Opening ClosingCasing Maximum Wt. Range I.D. Length Pressure Force Pressure Force Seat ID Seat ID Seat ID Seat ID

Size (In.) Diameter (Lbs.) (Inches) (Inches) (PSI) (Lbs.) (PSI) (Lbs.) (Inches) (Inches) (Inches) (Inches)2 7/8 3.660 6.4–7.8 2.440 24.75 1000 4,676 1500 9,636 1.750 2.125

3 1/2 4.380 7.7–10.2 2.930 24.75 1200 8,107 1500 15,481 1.750 2.12512.7–14.1

4 1/2 5.562 9.5–13.5 3.950 27.25 1200 21,000 1500 25,000 2.750 3.062 2.250 2.500

5 6.090 11.5–15.0 4.300 27.25 1200 26,000 1500 33,000 2.750 3.250 2.250 2.500

5 1/2 6.625 14.0–17.0 4.892 27.38 1200 32,000 1500 39,000 3.750 4.062 2.750 3.06220.0–23.0 4.810

6 5/8 7.875 20.0–28.0 6.030 28.50 1200 45,000 1500 57,000 4.625 5.000 3.750 4.187

7 8.275 17.0–23.0 6.276 28.50 1200 49,000 1500 62,000 4.625 5.125 3.750 4.25026.0–29.0 6.20032.0–38.0 6.004

7 5/8 8.937 26.4–33.7 6.825 28.88 1200 59,000 1500 74,000 4.750 5.550 3.750 4.250

8 5/8 10.125 24.0–32.0 8.000 29.00 1000 71,000 1200 85,000 5.750 6.750 4.750 5.250

9 5/8 11.125 32.3–40.0 8.921 29.50 1000 78,000 1200 94,000 7.000 7.750 5.750 6.50043.5–53.5 8.600

10 3/4 12.375 40.5–45.5 9.950 30.88 1000 100,000 1200 120,000 8.000 8.750 7.000 7.500

11 3/4 13.375 42.0–54.0 10.825 30.88 1000 114,000 1200 137,000 8.000 8.750 7.000 7.500

13 3/8 15.000 54.5–61.0 12.515 30.88 900 133,000 1000 148,000 10.500 11.250 8.000 9.75068.0–72.0 12.415

16 18.000 65.0 15.125 32.38 500 90,000 700 126,000 13.125 14.00075.0–84.0 14.880

18 5/8 20.800 87.50 17.755 32.88 400 99,000 600 149,000 14.500 16.000

20 22.000 94.0–133.0 18.730 32.88 400 110,000 600 165,000 16.000 17.500

22 24.000 114.8–170.2 20.500 34.63 400 135,000 600 228,000 18.000 19.000

22

Specification TablesDavis Type 778 MC and Type 778 MC-3S (Three Stage)

Note: 4 1/2” thru 6 5/8” have 4–1” Ports. 7” thru 13 3/8” have 6–1 1/8” Ports. 16” thru 20” have 10–1 1/8” Ports.22” has 12–1 1/8” Ports.

Davis Hydraulic-Opening Stage Cementing Collar Type 777 HY

*Standard opening pressure. Other pressures available on special order.Note: 4 1/2”, 5” and 5 1/2” have 4–1” ports. 7” thru 13 3/8” have 6–1 1/8” ports. 16” thru 20” have 10–1 1/8” ports.

Opening* ClosingNominalCasing Maximum Weight Drill-Out Overall Opening Closing Opening

Size Diameter Range I.D. Length Pressure Force Pressure Force Seat I.D. Seat I.D. Pressure(Inches) (Inches) (Lbs.) (Inches) (Inches) (PSI) (Lbs.) (PSI) (Lbs.) (Inches) (Inches) w/Free Fall

Device (PSI)

3 1/2 4.380 7.7–10.2 2.930 24.75 2000 6,716 1500 15,481 1.375 2.125 120012.7–14.1

4 1/2 5.562 9.5–13.5 3.950 27.25 3000 14,000 1500 25,000 2.500 3.125 1100

5 6.090 11.5–15.0 4.300 27.25 3000 18,000 1500 33,000 2.625 3.250 1100

5 1/2 6.625 14.0–17.0 4.892 27.38 3000 23,000 1500 37,000 3.060 4.062 120020.0–23.0 4.810

7 8.275 17.0–23.0 6.276 28.50 2600 28,000 1500 57,000 4.250 5.125 100026.0–29.0 6.20032.0–38.0 6.004

7 5/8 8.937 26.4–33.7 6.825 28.88 2600 41,000 1500 68,000 4.250 5.500 1000

8 5/8 10.125 24.0–32.0 8.000 29.00 2500 48,000 1500 84,000 5.375 6.750 1000

9 5/8 11.125 32.3–40.0 8.921 29.50 2400 50,000 1500 111,000 6.300 7.750 100043.5–53.5 8.600

10 3/4 12.375 40.5–45.5 9.950 30.88 2300 63,000 1500 130,000 7.000 8.750 1000

11 3/4 13.375 42.0–54.0 10.825 30.88 2300 94,000 1500 156,000 7.000 8.750 1000

13 3/8 15.000 54.5–61.0 12.515 30.88 2000 96,000 1200 161,000 8.000 11.250 90068.0–72.0 12.415

16 18.000 65.0 15.125 32.62 1850 116,200 700 140,740 10.250 14.000 64075.0–84.0 14.880

20 22.000 94.0–133.0 18.730 32.63 600 143,500 600 188,500 13.500 17.500 160

Opening Closing Maximum Recommended Differential Pressure (PSI)Across Packer in Various Hole Sizes (In.)

Nominal Type Weight Drill-Out Maximum Pressure Force Pressure Force Opening ClosingCasing Number Range I.D. Diameter (PSI) (Lbs.) (PSI) (Lbs.) Seat I.D. Seat I.D.

Size (In.) 778-100 (Lbs.) (Inches) (Inches) (Inches) (Inches) 1000 1500 2000 2500 3000 3500 4000

4 1/2 450-575 9.5–13.5 3.950 5 3/4 900 16,000 1500 26,000 2.750 3.125 10 3/4 10 1/4 9 3/4 9 1/4 8 3/4 8 1/4 7 3/4

5 500-638 11.5–15.0 4.300 6 3/8 900 20,000 1500 33,000 2.750 3.250 11 1/4 10 3/4 10 1/4 9 3/4 9 1/4 8 3/4 8 1/4

5 1/2 550-700 14.0–17.0 4.892 7 1500 39,000 1500 39,000 3.438 4.062 12 11 1/2 11 10 1/2 10 9 1/2 920.0–23.0 4.658

6 5/8 663-800 20.0–28.0 6.030 8 900 34,000 1500 57,000 4.250 5.000 13 12 1/2 12 11 1/2 11 10 1/2 10

7 700-825 23.0–26.0 6.276 8 1/4 1500 61,000 1500 62,000 4.625 5.125 13 1/4 12 3/4 12 1/4 11 3/4 11 1/4 10 3/4 10 1/429.0–35.0 6.200

7 5/8 763-900 26.4–33.7 6.825 9 1/16 900 44,000 1500 74,000 4.750 5.500 14 13 1/2 13 12 1/2 12 11 1/2 11

8 5/8 863-1025 24.0–32.0 7.980 10 1/4 900 58,000 1500 95,000 5.750 6.750 15 1/4 14 3/4 14 1/4 13 3/4 13 1/4 12 3/4 12 1/4

9 5/8 963-1125 32.3–40.0 8.921 11 1/4 900 70,000 1500 117,000 7.000 7.750 16 1/4 15 3/4 15 1/4 14 3/4 14 1/4 13 3/4 13 1/443.5–53.5 8.600

10 3/4 1075-1275 40.5–45.5 9.950 12 3/4 800 80,000 1200 120,000 8.000 8.750 17 3/4 17 1/4 16 3/4 16 1/4 15 3/4 15 1/4 14 3/455.5–65.7 9.600

13 3/8 1338-1575 54.5–61.0 12.515 15 3/4 600 89,000 1200 178,000 10.250 11.250 22 1/4 21 3/4 21 1/4 19 3/4 19 1/4 18 3/4 18 1/468.0–72.0 12.415

Davis Packer Stage Cementing Collar Type 778-100

23

NOTE: Packer stage collars equipped with six cement ports.1 1/4” diameter on sizes 7” and above, and 1” diameter onsmaller sizes. Standard seal length of inflatable packer elementsis 36 inches. For special sizes or varying seal lengths consult yournearest Davis representative. Total length of packer stage collaris approximately 120” depending on type threads used.

With simple changes to tool IDs and plug and tripping deviceODs, all three Davis stage collar designs–the mechanical, thehydraulic and the mechanical with inflatable packer, are madereadily available for three-stage applications. See tables forstandard sizes. Contact your Davis representative for availabilityof sizes not shown.

This widely accepted Davis productcombines an inflatable packer and astage cementing collar into a singularunit. The stage collar portion of thistool uses the same sleeve andmechanical systems as the field-proven Davis Type 778 StageCementing Collar.

The packer portion of this tool usesthe same element design as the field-proven Davis Type 100 Integral CasingPacker. This element consists of aninnertube housed and protected bycontinuous, mechanically end-anchored, spring-steel reinforcingstrips that are leafed on top of eachother. These strips are encased in anoil-resistant outer rubber. Expansion isobtained by injecting fluid into theinnertube. This injection forces partialun-leafing of the steel strips which inturn stretches the outer rubber untilit effects a full-length seal against the

bore it is run in, whether cased oropen hole.

While the packer is expanding, thebottom end of the element is drawnup on a ratchet-type locking mecha-nism. This feature is intended to keepthe element mechanically expandedso it can provide some form of sup-port in the event of hydraulic failure.

Once inflation pressure is reached,simultaneous sealing of the fluidinjection inlets and opening of thecementing ports occur. This actionallows the immediate introduction offluid to the annulus after the packeris set. The inflation of the packer alsoserves to center the tool in the well-bore, leading to uniform distributionof cement as it exits the casing.

Although the combination packerstage collar serves two purposes, it isonly one tool. This means that it canbe serviced by one person, which

eliminates the cost of the second per-son who would be required if a stagecollar and inflatable packer were indi-vidually purchased from two separatecompanies.

The Davis Type 778-100 PackerStage Cementing Collar has multipleapplications. It can be used to:• Keep the hydrostatic head of sec-ond-stage cement off first-stagecement.• Keep the hydrostatic head of sec-ond-stage cement off pressure sensi-tive zones below it.• Keep cement from falling aroundpre-drilled or slotted liners.• Selectively place cement acrosswidely separated zones of interest.• Prevent gas migration that can ruinprimary cement jobs and lead toannular gas problems at the surfaceand expensive squeeze work.

Type 778-100 PackerStage Cementing Collar*

*U.S. Patent No. 5,024,273

24


The Type 778-100 Packer Stage Cementing Collar

Running in HoleShows packer stage cementing collar in running position with opening and closingsleeves pinned in place. Lower section ofsplit-type opening seat isolates inflate passage preventing premature inflation of the packer.

Inflating ElementThe free-fall opening device enters split-type opening seatshearing the the pins in the lower section. This allows lower section to move down exposing the inflatable packer element tothe fluid and pressure inside the casing. Fluid enters the packerelement through the double-seal in the free-fall opening deviceand the split-type opening seat and inflation passage in the tool body.

DrillableClosing Seat

Inflate-LimitValve

Inflate Passage


OptionalPump-DownOpening Plug

Double Lock Rings

Closing Sleeve

Opening Sleeve

Drillable Split-TypeOpening Seat

Shear Pin

Protected Seals

Shear Pin

Shear Pin

Anti-Rotation Lug

Steel ReinforcedInflatable Packer

Ratchet-TypeBottom Sub

Ratchet-TypeBottom Sub

Customer-SpecifiedCasing Mandrel

Pump-Down Opening PlugA pump-down opening plug canbe used in lieu of the free-fallopening device. It is applied inhorizontal wells and directionalwells where deviation at thepacker stage collar exceeds 30°.

25

NOTE:As the bottom sub of thepacker is drawn upwards, aratchet-type lock mecha-nism prevents downwardmovement. Should thepacker lose inflate pres-sure, this feature isdesigned to keep itmechanically set againstthe cased or open hole.

Opening Cement PortsWith the free-fall opening device in place, pressureapplied to the casing shears the pins in the openingsleeve and moves it downward to the open andlocked position. This movement seals off the inflatepassage and permanently traps the correct inflatepressure in the packer. The inflate-limit valve in thefree-fall opening device insures that the correctinflate pressure is achieved but never exceededwhen opening tool.

Closing Cement PortsOnce cement has been displaced and the closing plugseats in the closing sleeve, additional pressure isapplied to the casing. This pressure shears the pinsand allows the closing sleeve to travel downward toits final closed and locked position. The pressurerequired to do this varies with the tool size and thetype of job performed.

Cementing Ports

Closing Plug

OptionalLock-DownClosing Plug

Lock-Down Closing PlugAn optional lock-down closing plugis available on sizes 4 1/2” through7”. The plug locks into the closingseat of the the tool. This featureacts as a secondary cement checkand is particularly applicable whenthe packer stage collar is run aboveslotted or open-ended pre-drilledliner and the possibility of fluidflow into the casing exists.

26

Davis Inflatable PackersThe Davis line of inflatable packersfeatures a weldless design that pro-vides a strong and effective seal. Theyare available for virtually all drilling,completion and workover require-ments, as well as for pipeline testingand repair and offshore platforminstallation.

Inflatagrip Longseal* PackersThese Davis Packers, available with

20- or optional 40-foot length seals,provide a positive seal against fluid orgas movement in the annulus of ver-tical, deviated or horizontal wells.They are recommended for use wherenaturally occurring fracture systemsand high permeability streaks requirea longer seal for more positive zoneisolation. Mud- or cement- filledInflatagrip Longseal Packers will con-form to and seal in washed-out, ellip-tical or other irregularly shaped well-bores. They are of the limited steel ribreinforcing type in that the ribs donot extend completely from one endof the seal to the other. This featureallows the non-reinforced center por-tion of the packer to expand and sealin larger, irregularly shaped wellboresand still be retained at the ends bythe overlapping steel Inflatagrip rein-forcing ribs.

Features/Benefits of Types 202 and402 Inflatagrip Longseal Packers:• Patented Inflatagrip® end reinforc-ing metal ribs anchor against wall ofwell for positive end containmentduring and after inflation.

• Reinforcing metal ribs mechanicallyattached at each end of the element,along with the single durometer rub-ber element, assure a uniform infla-tion between the metal ribs to dis-place a maximum amount of mudfrom the seal area.• Mechanical anchoring of reinforcingmetal ribs in end subs, together withthe Inflatagrip feature, greatlyimproves the pressure differentialholding ability of the packers.• Dual inflation valve system provides56% greater inlet area for the infla-tion fluid than dual valve systems ofcompetition.• Longer reinforcing ribs bonded to arubber cover, in addition to surfacepreparation of the mandrel, minimizeany wadding of packer element dur-ing running.• Premium threads are availableinternally throughout the packers,eliminating the need for welding orthe use of crossover sub.• No welding or epoxy, which mightcause premature failure, is used inmanufacturing Davis packers.Unique Application Large DiameterInflatagrip Longseal Packers

Davis sales/engineering personnelhave designed and implemented amethod on several wells in a deepwa-ter-drilling environment, whichemploys the Inflatagrip LongsealPackers for the purpose of containingtroublesome shallow salt-water flows.This system has been utilized on 20”and 16” casing strings at the presenttime. Packer placement, inflationpressure settings, and the use of spe-cialty float equipment to receive adrop ball have been instrumental inthe success of this method. For morecomplete details please contact yourlocal Davis representative.

Inflatagrip Longseal* PackerTypes 202 and 402

*Patented

sk

Text Box

®Registered Trademark of Davis-Lynch, LLC U.S. Patent No. 4,829,144

27

Packers with Continuous ReinforcingThe inflatable element of these

packers has steel strips that run fromend to end of the seal and aremechanically attached to end subs.Available in standard 3-, 7- and 10-foot lengths, the continuous strip ele-ment will centralize the casing in thewellbore and withstand maximumdifferential pressure. It can be inflat-ed with water, mud or cement. The 7-and 10-foot elements may be pre-ferred for added seal length in frac-tured or highly permeable zones orwhere packer placement is critical forsuccess.

The inflatable element consists of aninnertube protected by the continu-ous, mechanically end-anchored,spring-steel reinforcing strips. Thesestrips are totally encased in an oil-resistant outer rubber. Expansion isachieved by injecting fluid into theinnertube. The fluid expands thestrips, stretching the outer rubberand effecting a full-length sealagainst the bore wall, in cased oropen hole.Inflatagrip® Feature

When it is desirable for a continu-ous reinforced packer to act as ananchor, Davis recommends its patent-ed Inflatagrip system, which consistsof raised grippers stamped into thesteel reinforcing strips. The gripperscan be profiled so that, whenexpanded and in contact with thewellbore, they prevent axial or rota-tional movement, in either cased oropen hole. The grippers are heattreated to a hardness that enablesthem to bite into P-110 grade casing.The anchoring mechanism can bebuilt into any Davis continuous rein-forced packer regardless of diameter.

1.Mechanically end-anchored spring-steelreinforcing strips give tremendous pull-out resistance force. For a 5 1/2-inchcasing packer, for example, the calcu-lated pull-out force is in excess of690,000 pounds.

2.Spring steel strips are continuous fromend to end in all seal lengths of theinflatable element, providing superiorstrength throughout. For a 5 1/2 inchcasing packer, for example, the calcu-lated tensile force through the centersection of the packer is in excess of500,000 pounds.

3.The Inflatagrip® anchor system is avail-able on all sealing element lengths.This anchoring mechanism can be usedin both casing and open hole and theteeth oriented to prevent axial or rota-tional movement.

Inflatable Casing Packer

sk

Text Box

®Registered Trademark of Davis-Lynch, LLC U.S. Patent No. 4,829,144

Diameter Maximum Recommended Differential Pressure (psi)of Across Packer in Various Hole Sizes (Inches)

Nominal Casing TypeSize Packer No.

(Inches) (Inches) 100– 1000 1500 2000 2500 3000 3500 4000

3 1/2 4.25 350-425 9.00 8.50 7.50 6.50 5.50 5.25 4.754 1/2 5.75 450-575 10.75 10.25 9.75 9.25 8.75 8.25 7.754 1/2* 5.63 450-563 9.75 9.00 8.00 7.25 6.75 6.50 6.00

5 6.38 500-638 11.25 10.75 10.25 9.75 9.25 8.75 8.255* 6.13 500-613 10.25 9.75 9.25 8.75 8.25 7.50 7.00

5 1/2 7.00 550-700 12.00 11.50 11.00 10.50 10.00 9.50 9.005 1/2* 6.75 550-675 11.00 10.50 10.00 9.50 8.50 8.00 7.506 5/8 8.00 663-800 13.00 12.50 12.00 11.50 11.00 10.50 10.006 5/8* 7.75 663-775 11.25 10.75 10.25 9.75 8.75 8.25 8.00

7 8.25 700-825 13.25 12.75 12.25 11.75 11.25 10.75 10.257* 8.06 700-806 12.00 11.00 10.50 10.00 9.00 8.75 8.50

7 5/8 9.00 763-900 14.00 13.50 13.00 12.50 12.00 11.50 11.007 5/8* 8.88 763-888 13.00 11.50 11.00 10.50 10.00 9.50 9.258 5/8 10.25 863-1025 15.25 14.75 14.25 13.75 13.25 12.75 12.259 5/8 11.25 963-1125 16.25 15.75 15.25 14.75 14.25 13.75 13.2510 3/4 12.75 1075-1275 17.75 17.25 16.75 16.25 15.75 15.25 14.7513 3/8 15.75 1338-1575 22.25 21.75 21.25 19.75 19.25 18.75 18.25

16 18.00 1600-1800 28.00 26.50 25.00 23.50 22.00 20.50 19.5018 5/8 20.88 1863-2088 33.00 31.25 29.50 27.75 26.00 24.25 22.50

20 23.00 2000-2300 36.00 34.00 32.00 30.00 28.00 26.00 24.0022 25.00 2200-2500 30.00 29.00 28.00

Davis Integral Casing Packer Type 100

*Special clearance

28

Davis Type 100 Integral Casing PackerThe Type 100 is a permanent, steel-rein-forced packer that is run as an integral partof the casing string. The mandrel throughthe packer is the same size, weight, andgrade as the casing. The packer is threadedwith connections identical to those of thecasing string.

The Integral Casing Packer is availablewith a single sealing element, or with dualstraddle elements. It can be run in a multi-tude of arrangements for numerous appli-cations. When inflated, the packer element

will effectively seal between concentric cas-ing strings or between casing and openhole.

This packer can be used to:• Control wellbore migration of gas andfluid.• Separate multiple zones.• Prevent unwanted water intrusion.• Allow gravel packing of multiple zones.• Reduce hydrostatic pressure during stagecementing.• Centralize casing.

Type 100 Integral Casing Packer1. Inflation Control Valves2. Knock-Off Plug3. Rubber innertube4. Rubber Outer Cover

5. Flexible Steel Reinforcing6. Sliding Seal7. Mandrel (Casing Sub)8. Screen

1

2

8

3

4

5

6

7

Packer Selection TableThe Packer Selection Table shows maximumrecommended differential pressure acrossthe Integral Casing Packer for any givencalipered hole size. For pressure or holesizes falling between the cited values, themethod of interpolation for an approxi-mate value can be used.

The sizes tagged with asterisks aretermed “Special Clearance.” They are used

where the combination of casing diameterand drilled hole size requires that the diam-eter of the packer be reduced. Thesereduced OD sizes are available through spe-cial order.

For casing sizes smaller than 3 1/2” andlarger than 20”, please consult your Davisrepresentative.

Casing Size Casing Weights Casing Size Casing Weights(Inches) (Lbs/ft) (Inches) (Lbs/ft)

4 1/2 11.60, 12.60, 13.50 10 3/4 40.5, 45.5, 51, 55.5

5 15, 18, 20.3 11 3/4 47, 54, 60, 65, 66.7, 71

5 1/2 15.5, 17, 20, 23 11 7/8 71.8

7 17, 20, 23, 26, 29, 32 13 3/8 54.5, 61, 68, 72, 77

7 5/8 24, 26.4, 29.7, 33.7, 39, 42.8 13 5/8 88.2

7 3/4 46.1 16 65, 75, 84, 94, 109

8 5/8 24, 28, 32, 36 18 5/8 87.5, 94.5, 97.7, 106, 117.5

9 5/8 40, 43.5, 47, 53.5 20 94, 106.5, 131, 133, 163

9 7/8 62.8

Fill and Circulate (FAC) Tool Available Sizes

Other sizes not listed above available on request

Davis Fill and Circulate Tool*The Davis Fill and Circulate (FAC) Tooloffers operators the safest and mostefficient means to fill or circulate cas-ing strings at desired rates as they arebeing run. In the fill position, fluid ispumped through the mandrel andthe mud saver valve as the casing isbeing lowered into the well. In thecirculate position, the sealing ele-ment, slightly larger than the ID ofthe casing, is lowered into the casingand forms a seal between the FACTool and the casing. Pressure appliedto the casing for fluid circulationcauses the fluid to enter an areabehind the sealing element, energiz-ing it to seal against fluid by-pass.

Features of the Davis FAC Tool are:• Fluid pressure-energized sealing ele-ment that is easily inserted into cas-ing, and seals more firmly as pressureincreases.• Tapered aluminum gauge ringbelow the sealing element protectsagainst thread damage and acts tocentralize the tool in the casing.• Mud-saver valve that retains the sta-tic head of the mud and preventsmud from dripping onto the rig flooras tool is being raised into the der-rick.• Flexible steel-reinforced rubber hosewith brass guide cone gives addedflexibility for inserting the FAC Toolinto the casing. Rubber insert onguide cone absorbs impact blows tocasing during stabbing, filling, andcirculating.• Reverse flow through the checkvalve allows any pressure trappedbelow the FAC Tool to be releasedprior to removal from casing.

adapted for use with several sizes ofcasing strings by changing the sealretainer ring, sealing element, andgauge ring.• Available with optional push-platefeature to aid in running casing tobottom.

*Patented

A

B

C

D

E

F

G

Fill Position Circulate Position

A. Drill Pipe Connector Sub B. Seal Retainer Ring C. Sealing ElementD. Gauge Ring E. Flexible Hose F. Mud Saver Sub and Valve

G. Guide Cone

• No “hands-on” manipulation of theFAC Tool is required to change fromthe fill to the circulate mode, or viceversa.• The sealing element is easilychanged by a single break at theretainer sub.• The same basic tool body can be

29

Box 262326Houston, Texas 77207-2326

24 Hours: 281-485-8301Fax: 281-485-6814

International Fax: 281-485-9836E-mail: [email protected]: www.davis-lynch.com

For a complete list of worldwide representatives and distribution locations, please visit our website

or contact our headquarters in Houston, Texas

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Equipment Catalog No. 20 - Davis-Lynch Casing Equipment

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