ATM

PETE 661

Drilling Engineering

Lesson 19

Kick Detection and Control

2ATM

Kick Detection and Control

Primary and Secondary Well Control

What Constitutes a Kick

Why Kicks Occur

Kick Detection Methods

Kicks while Tripping

3ATM

Kick Detection and Control

Shut-in Procedures

Soft Shut-in

Hard Shut-in

Water Hammer

4ATM

Kick Detection and Control

Read: ADE Ch. 6

Reference: Advanced Well Control Manual, SPE Textbook,

~2003...

Homework # 11 - due November 25

5ATM

Kick Detection and Control

The focus of well control theory is to contain and manage

formation pressure. Primary well control involves efforts at

preventing formation fluid influx into the wellbore.

Secondary well control involves detecting an influx and

bringing it to the surface safely.

6ATM

Kicks

A kick may be defined as an unscheduled influx of formation fluids.

Fluids produced during underbalanced drilling are not considered kicks

Fluids produced during a DST are not considered kicks

7ATM

Kicks

For a kick to occur, we need:

Wellbore pressure < pore pressure

A reasonable level of permeability

A fluid that can flow

8ATM

Kicks

Kicks may occur while: Drilling Tripping Making a connection Logging Running Casing Cementing N/U or N/D BOP, etc.

9ATM

Causes of Kicks

Insufficient wellbore fluid density

Low drilling or completion fluid density

Reducing MW too much

Drilling into abnormally pressured formations

Temperature expansion of fluid

Excessive gas cutting

10ATM

Causes of Kicks - cont’d

Reduction of height of mud column

Lost circulation because of excess static or dynamic wellbore

pressure

Fluid removal because of swabbing

Tripping pipe without filling the hole

11ATM

Causes of Kicks - cont’d

Excessive swab friction pressure while moving pipe

Wellbore collision between a drilling and producing well

Cement hydration

12ATM

Kick indicators

Indicator

Drilling break

Increase in mud return

rate

Pit gain

Flow w/ pumps off

Significance

Medium

High

High

Definitive

13ATM

Kick indicators Indicator

Pump pressure decrease/ rate increase

Increase in drillstring weight

Gas cutting or salinity change

Significance

Low

Low

Low

14ATM

Kick Influx Rate

This equation would rarely be strictly applicable in the event of a kick since fluid compressibility is not considered and transient relationships better describe influx flow behavior.

radius wellborer

radius drainage r

cosityinflux vis

wellboreat the pressure pore p

radius drainage at the pressure pore p

thickness,formation h

typermeabiliformation k

rate, flowinflux q

where

ln

w

e

w

e

we

we

rr

ppkhq

15ATM

Kick Influx Rate

Extremely important to detect a kick early, to minimize its

size.

If a kick is suspected,

run a flow check!!!

16ATM

Circulation path for Drilling Fluid

What goes in Must come out

unless a kick occurs…or…

As drilling proceeds, mud level in pit drops slowly.

Why?

17ATM

Set alarm for high or low flow rate

If a kick occurs, flow rate from the well increases - an early indicator

Mud Return Rate

18ATM

Pit Volume Totalizer, PVT shows pit gain or loss.

Pit level is a good kick indicator

System should detect a 10 bbl kick under most conditions onshore

19ATM

Kick size Under most conditions a 10 bbl kick

can be handled safely.

An exception is slimhole drilling, where even a small kick occupies a large height in the annulus.

In floating drilling, where the vessel moves, small kicks are more difficult to detect

20ATM

Mud pulse telemetry - pressure pulses detected at the surface

Compare signals

from drillpipe

and annulus

High amplitudepositive pulse

Low amplitudenegative pulse

21ATM

Acoustic kick detection

Gas in the annulus will attenuate a pressure signal, and will reduce the velocity of sound in the mud

22ATM

Minimum kick size that can be detected by an acoustic system

Temperature = 212 degrees F.Mud density = 16.7 lbm/galInflux rate = 32 gal/minPump rate = 317 gal/minCollar diameter = 6 inchesHole diameter = 8-1/2 inches

Pressure, psi

Kic

k vo

lum

e, b

bl

23ATM

Delta flow

indicator

24ATM

Delta flow indicatorDelta flow = qout - qin

Kick detected

Upper Alarm Threshold

Lower Alarm Threshold

Time

Del

ta F

low

In

dic

ato

r

25ATM

Delta flow indicator

Field Examples of Kick Detection and Final Containment Volumes using the Delta Flow Method

Hole Depth Influx Volume Volume Size ft. Rate Detected

Contained in. gal/min bbl bbl

5 7/85 7/85 7/8

15,77014,00517,152

35 760

0.720.701.00

2.01.55.0

26ATM

BOP stack

27ATM

BOP Control Panel

28ATM

Choke Manifold

29ATM

Choke panel

30ATM

If a kick is suspected

Lift the drillstring until a tool joint is just above the rotary table

Shut down the mud pumps

Check for flow

31ATM

If a kick is suspected

If flowing - shut the annular, open the HCR valve, and close the choke

Record SIDPP and SICP

Record pit gain and depth (MD and TVD)

Note the time

32ATM

Hard Shut-In

1. Assure beforehand the choke manifold line is open to preferred choke and choke is in closed position.

2. After a kick is indicated, hoist the string and position tool joint above rotary table.

3. Shut off pump

4. Observe flowline for flow.

33ATM

Hard Shut-In5. If flow is verified, shut the well in by

using annular preventer and open the remote-actuated valve to the choke manifold.

6. Notify supervisor (company drilling supervisor, toolpusher or rig manager).

7. Read and record shut-in drillpipe pressure (SIDPP).

34ATM

Hard Shut-In 8. Read and record shut-in casing

pressure (SICP).

9. Rotate the drillstring though the closed annular preventer if feasible.

10. Measure and record pit gain.

35ATM

Water hammer ?

Hard Shut-In

36ATM

Soft Shut-In

1. Assure beforehand choke manifold line is open to preferred choke and choke in in open position.

2. After kick is indicated, hoist string & position tool joint above rotary table.

3. Shut off pump.

37ATM

Soft Shut-In

4. Observe flowline for flow.

5. If flow is verified, open remote-actuated valve to choke manifold and close annular preventer.

6. Shut well in by closing choke.

7. Notify supervisor (company drilling supervisor, toolpusher, rig manager).

38ATM

Soft Shut-In

8. Read and record SIDPP.

9. Read and record SICP.

10.Rotate drillstring through closed annular preventer if feasible.

11.Measure and record pit gain.

39ATM

Larger Kick !

Soft Shut-In

40ATM

Example 5.1A kick is detected while drilling at 13,000 ft. The well is shut-in by the ram preventer in

5 seconds.

Determine water hammer load at surface if influx flow rate is 3.0 bbl/min, the mud’s acoustic velocity is 4,800 ft/s and mud density is 10.5 lbm/gal

1.

41ATM

Example 5.1, continued

For the same conditions:

Compute velocity assuming the annulus flow area corresponds to 5.0 in. drillpipe inside 8.921 in. inner diameter casing.

Ignore effect of influx properties on wave travel time and amplitude.

2.

42ATM

Example 5.1, continued

……………………. (5.2)c

ac g

vvp

43ATM

Example 5.1, continuedThe relationship is only valid if valve is fully

closed before the shock wave has time to make the round trip from surface to total depth. If this condition is not met, closure is defined as “slow” as opposed to “rapid” and resultant pressure surge will be lower.

Regardless of method, some pressure increase, however minor, cannot be avoided and the soft shut-in procedure may in fact be considered rapid in some cases.

44ATM

Example 5.1, cont’d

Solution: The time for the pressure wave to traverse the system is

t = dist/vel = (2)(13,000)/4,800 = 5.4 sec

Hence this would be characterized as a rapid shut-in and Equation 5.2 is appropriate.

c

ac g

vvp

45ATM

Example 5.1 cont’d

2. The velocity change in the annulus is computed as:

222

223

in )5-/4(8.921s/min) (60

)/ftin /bbl)(144ft .615bbl/min)(5 (3.0q

c

ac g

vvp

v = 0.94 ft/s

46ATM

Example 5.1 cont’dThe surface pressure increase is given by

equation 5.2

2

3

c s-lbf / ft-lbm 32.17

ft/s .ft/s ,gal/ft .lbm/gal 10.5

9408004487

psi. 76 lbf/ft 11,015 2c

c

ac g

vvp

47ATM

Off Bottom Kicks

Slugging of drillpipe

Hole fill during trips

Surge and Swab pressures

Kick detection during trips

Shut-In Procedures

Blowout Case History

48ATM

Off Bottom Kicks

Pbh = g1h1 + g2h2 = g2h3

Hydrostatic Balance

When stopping circulation, ECD is lost. Always check for flow.

“Slugging” of Drillpipe to prevent “Wet Trip”

… AFTER Flow Check

49ATM

Failure to keep the hole full

When pipe if removed from the wellbore the fluid level drops resulting in loss of HSP.

To prevent kicks the hole must be re-filled with mud.

50ATM

Nominal Dimensions-Displacement Factors for API Drillpipe

Outside Nominal Nominal Average Displacement Diameter Inside Weight Approximate Factor

in. Diameter, in. lbm/ft Weight bbl/ft

2-3/8 1.995 4.85 5.02 0.001821.815 6.65 6.80 0.00247

2-7/8 2.441 6.85 7.09 0.00258 2.151 10.40 10.53 0.00383

3-1/2 2.992 9.50 10.15 0.003692.764 13.30 13.86 0.005042.602 15.50 16.39 0.00596

51ATM

Nominal Dimensions-Displacement factors for API

DrillpipeOutside Nominal Nominal Average Displacement

Diameter Inside Weight Approximate Factorin. Diameter, in. lbm/ft Weight bbl/ft

4 3.476 11.85 12.90 0.004693.340 14.00 15.14 0.005513.240 15.70 17.13 0.00623

4-1/2 3.958 13.75 14.75 0.005373.826 16.60 17.70 0.006443.640 20.00 21.74 0.007913.500 22.82 24.33 0.00885

52ATM

Nominal Dimensions-Displacement factors for API

DrillpipeOutside Nominal Nominal Average Displacement

Diameter Inside Weight Approximate Factorin. Diameter, in. lbm/ft Weight bbl/ft

5 4.276 19.50 21.58 0.007854.000 25.60 27.58 0.01003

5-1/2 4.778 21.90 23.77 0.008654.670 24.70 26.33 0.00958

6-6/8 5.965 25.20 27.15 0.009885.901 27.70 29.06 0.01057

53ATM

Displacement Factors for High Strength Drillpipe

Outside Nominal Average Displacement Diameter Weight Approximate Factor

in. lbm/ft Weight, lbm/ft. bbl/ft

2-3/8 6.65 6.95 0.002532-7/8 10.40 11.01 0.00400

3-1/2 13.30 14.51 0.00528

15.50 17.02 0.00619

4 14.00 15.85 0.0057715.70 17.50 0.00637

4-1/2 16.60 18.65 0.0067820.00 22.40 0.0081522.82 25.21 0.00917

54ATM

Displacement Factors for High Strength Drillpipe

Outside Nominal Average Displacement Diameter Weight Approximate Factor

in. lbm/ft Weight, lbm/ft. bbl/ft

5 19.50 22.34 0.0081325.60 28.60 0.01040

5-1/2 21.90 25.14 0.0091424.70 28.13 0.01023

6-5/8 25.20 28.33 0.0103127.70 30.58 0.01112

55ATM

Displacement Factors for Heavy-Wall Drillpipe

Outside Nominal Connection Approx. Displacement Diameter Inside Weight Factor

in. Diameter, in. lbm/ft bbl/ft

3-1/2 2.063 NC38 23.20 0.008442.250 NC38 25.30 0.00920

4 2.563 NC40 29.70 0.01080

4-1/2 2.750 NC46 41.00 0.01491

5 3.00 NC50 49.30 0.01793

56ATM

Example 5.2Drill a well to 9,500 total depth with a 10.0

lbm/gal mud. 8.097 in. ID casing has been set at 1,500 ft.

Determine the hydrostatic pressure loss if ten 90 ft stands of 4 1/2 in., 16.60 lbm/ft Grade E drillpipe are pulled without filling the hole.

Also determine the losses after pulling ten

stands of drillpipe if the bit is plugged and after pulling one stand of 6 1/4 x 2 1/2 in drill collars.

57ATM

Example 5.2

Solution

The displacement factor for open drillpipe is obtained from Table 5.5 and the displacement volume is computed as:

Vd = (0.00644) (10) (90) = 5.80 bbl

58ATM

Example 5.2To determine the drop in fluid level, we must

have capacity factors for the drillpipe and annulus. These can be obtained directly from a published table or by calculation.

Inside Drillpipe:

Ci = 3.8262/1,029.4 = 0.1422 bbl/ft. and

Inside Annulus:

Cc = (8.0972 - 4.52)/1,029.4 = 0.04402 bbl/ft.

59ATM

Example 5.2These values are only approximate since the effect of the pipe upsets and tool joints are not considered. The mud level will fall by

h = 5.80/(0.01422 + 0.04402) = 99.6 ft.

and the corresponding hydrostatic pressure loss is

p = 99.6(10.0/19.25) = 52 psi.

60ATM

Example 5.2

Tripping out with a plugged bit implies the string is pulled wet and, if no mud falls back in the hole, the drillstring inner capacity is being evacuated along with the steel. The volume removed after pulling ten stands wet is

V = Vi + Vd = (0.00644 + 0.01422)(10)(90)

= 18.59 bbl

(inside drillpipe + steel in drillpipe)

61ATM

Example 5.2

The mud level drop in the annulus and pressure loss are thus

h = 18.59/0.04402 = 422.3 ft.

and

p = (422.3)(0.519) = 219 psi.

62ATM

Example 5.2

For drill collars, we compute the displacement factor and displacement volume as

Cd = (6.252 - 2.52)/1,029.4 = 0.03188 bbl/ft.

and

Vd = (0.0318) (1)(90) = 2.87 bbl.

63ATM

Example 5.2

The pressure loss is determined in the same manner as the open drillpipe case.

Ci = 2.52/1,029.4 = 0.00607 bbl/ft

Ca = (8.0972- 6.252)/1,029.4 = 0.02574 bbl/ft

h = 2.87/(0.00607 + 0.02574) = 90.2 ft

and

p = (0.519) (90.2) = 47 psi