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7/21/2019 P&P Hand Out
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1
WELL CONTROL
It Is An Influx Of Formation Fluid Into The Well.
What Is A Kick?
2
WELL CONTROL
An Uncontrolled Exit Of The Formation Fluids At The Surface
What Is A Blowout?
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WELL CONTROL
Pore Spaces
Grains
What Is Formation Pressure?
All Formations We Drilled Consists of Rock
Grains and Pore Space.
Formation Fluid Pressure Is the Pressure of
the Fluids That Exist in Pore Space
4
WELL CONTROL
Preventing A Kick
PRIMARY MUD HYDROSTATIC
What Is Well Control?
Shutting In The Well After A Kick Has Been Taken
OR
SECONDARY BLOW OUT PREVENTERS
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5
WELL CONTROL
PRIMARYPREVENTION
TAKE KICK
SHUT IN WELL
SECONDARY
KILL WELL
Well Control?
6
WELL CONTROL
How Can You Prevent A Kick?
KNOW WHAT CAUSES A KICK
USE CORRECT RIG PRACTICES
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WELL CONTROL
MUD HYDROSTATIC FALLS
FORMATION
PRESSURE
OR
MUD
HYDROSTATIC
FORMATION PRESSURE RISES
8
WELL CONTROL
Causes Of Kicks
Kicks Occur When
“ Under Balance ”
Under Balance Is Caused by :
2. Increase in Formation Pressure.
1. Mud Hydrostatic Reduction.
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WELL CONTROL
What Causes Mud Hydrostatic To Drop?
Pressure = Mud Wt X Constant X TVD
Reduce Mud Weight Reduce Length
Of Mud Column
?
?
?
?
?
?
10
WELL CONTROL
Running Into Bubbles
Mud Hydrostatic Reduction.
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WELL CONTROL
Hole TVD 10,000ft (81/2”)Hole cap. 0.0772 bbl/ft
Dc / hole cap. 0.03 bbl/ft
Mud wt. 11 ppg
Formation gradient. 0.56 psi/ft
Influx size 10 bbls while POOH (Swabbing)
Gas gradient 0.1 psi/ft
What is effect on BHP when run back to the bottom
Example
12
WELL CONTROL
Circulating Hole Clean
Mud Hydrostatic Reduction.
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WELL CONTROL
Drilled Gas
Gas in the Well Bore
Mud Hydrostatic Reduction.
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WELL CONTROL
Effect of Gas Expansion
Example:-
well depth 7000’
mud wt. 11 ppg
influx (gas) volume 1 cu. Ft
Calculate vol. Of gas @ 6000’, 5000’, 4000’, 3000’,
2000’, 1000’, 500’, 250’ and @ surface
gas Pressure @7000’ = 11 X .052 X 7000=4000 psi
Vol. Of gas @6000’ =1.16 cu.ft
@5000’ = 1.39 cu.ft @4000’ = 1.75 cu.ft
@3000’ = 2.33 cu.ft @2000’ = 3.5 cu.ft
@1000’ = 7.00 cu.ft @500’ = 14.0 cu.ft
@250’ = 28.0 cu.ft @125’ = 56.0 cu.ft
@surface = 272 cu.ft
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WELL CONTROL
Swabbing
Mud Hydrostatic Reduction.
16
WELL CONTROL
Main Causes:
Momentary reduction in BHP due to reduction in
hydrostatic force cased by the upward suction action
of the drill string, which can allow a small invasion
into well bore.
Swabbing
1. Pulling Pipe Too Fast2. High Viscosity Mud
3. Small Collar to Hole Wall Clearance
4. Balled-Up' Bit
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WELL CONTROL
Pumping Light Mud
Mud Hydrostatic Reduction.
Bottom Hole Pressures
psi
18
WELL CONTROL
Loss of Barite
Centrifuge
Shakers
Desilters
Poor Mud/Settling
PitHole
What Can Reduce Mud Weight ?
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WELL CONTROL
Losses
20
WELL CONTROL
Losses
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WELL CONTROL
Rig Floor
Flowline
Pull Out Without Filling The Hole
Mud Hydrostatic Reduction.
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WELL CONTROL
Casing Cap = Annular Cap + Pipe Cap + Metal Disp.
** All Capacities In bbls/ ft.
Pressure or Level Drop Per Foot Pulled
Mud Grad X Metal Displacement
( Casing Cap - Metal Displacement)Dry Pipe =
Mud Grad X Metal Disp. + pipe Cap
Casing Cap - Metal Disp. + Pipe Cap
Wet Pipe =
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WELL CONTROL
Mud Weight = 12 ppg
Metal Disp = .0075 bbls / ft.
Pipe Cap = .0177 bbls / ft.
Casing Cap = .076 bbls / ft.
Stand Length = 93 ft.
Calculate Pressure Drop When
A) Pulling One Stand Dry.
B) Pulling One Stand Wet.
Example
24
WELL CONTROL
Mud Grad X Metal Displacement
( Casing Cap - Metal Displacement)Dry Pipe =
Answer
Mud Grad X Metal Disp. + pipe Cap
Casing Cap - Metal Disp. + Pipe CapWet Pipe =
12 X 0.052 X 0.0075
(0.076 - 0.0075)
= 6.8 psi
=
12 X 0.052 X (0.075 + 0.0177)
0.076 - (0.075 + 0.0177)
= 28.78 psi
=
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WELL CONTROL
720 Ft Of 8” Drill Collars.
D.C. Capacity = .0077 bbls / ft.
D.C. Displacement = .0546 bbls / ft.
Mud Weight = 15 ppg.
Casing Capacity = .1497 bbls / ft.
Calculate.
A. Drop in Mud Level when all collars are pulled
from the hole without filling the annulus.
B. Drop in Bottom Hole Pressure.
Example
26
WELL CONTROL
Rig Floor
Flowline
Failure of Float collar
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WELL CONTROL
Example
A13 3/8 String Casing Is Run Into The Hole With Conventional Float. The
Driller Did Not Fill The Casing For Fourteen 40 ft Joints. If Float Were To
Fail At This Point, And Mud U-tubes Up Inside The Casing, Calculate The
Effect On Bottom Hole Pressure.
Data:-
Casing Capacity = 0.152 bbls/ft
Annular Capacity = 0.1238 bbls/ft
Mud Weight = 12.6 ppg
Answer
Hydrostatic Pressure Loss If Casing Float Fail =
Mud Gradient X Casing Capacity X Differential Height
(Casing Capacity + Annular Capacity)
0.665 X 0.152 X 14 X40
( 0.152 + 0.1238)= 205 psi
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WELL CONTROL
Key Prevention Practices.
Do Not R.I.H. Too Fast.
Monitor Trip Tank.
Always Fill Hole With Correct Mud.
Monitor ECD.
Keep Viscosity Down To Acceptable Level.Keep Casing Full.
Know What Mud Is In Hole.
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WELL CONTROL
Causes Of Abnormal Pressure
Under Compaction
Faulting
Sand Lens
Salt Dome
Artesian
Gas Cap
Leaks Around Casing
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WELL CONTROL
Under Compaction (Trapped Water)
Permeable Layers Trap Water.
Fluid Pressure Rises Steeply
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WELL CONTROL
+ +
+ +
++ ++
+
+++
Sand Lens
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WELL CONTROL
Sand A00
Sand A0
Faulting
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WELL CONTROL
Salt Domes
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WELL CONTROL
0’
500’
Spring
Underground
water level
Rain
1000’
Artesian Effects
Calculate Mud Weight To Balance?
Formation Water = .433 psi/ft
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WELL CONTROL
7000’
8000’
.465 psi/ft
Normal Pressure
Gas Cap Effect
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WELL CONTROL
Calculate the pressure at top of the reservoir
Pressure at 8000’ = 8000 X .465 = 3720 psi
Height of reservoir = 8000 – 7000 = 1000’
Ph of the reservoir = 1000 X 0.1 = 100 psi
Pr at 7000’ = 3720 – 100 = 3620 psi
E.M.W. at 8000’ = 3720 / .052 / 8000/ = 8.94 ppg
E.M.W. at 7000’ = 3620 / .052 / 7000 = 9.94 ppg
In trapped gas reservoir, the highest point of the reservoir
usually has the highest pressure. Due to gas less dense
than formation water.
Example
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WELL CONTROL
Leaks Around Casing
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WELL CONTROL
Revision:
KICKS OCCUR WHEN
“ UNDERBALANCE ”
Causes Of Kicks
UNDERBALANCE IS CAUSED BY :
MUD WEIGHT REDUCTION.
DROP IN MUD LEVEL.
INCREASE IN FORMATION PRESSURE.
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WELL CONTROL
Monitor Trips - In And Out
Circulate Bottoms Up If In Doubt Of Hole Condition
Monitor Well At All Times
Trip Carefully In And Out
Pump Out If Tight Hole
Circulate Through Choke If A Lot Of Gas Is Expected
Keep Mud In Good Shape
Always Keep Hole Full
Double Check Effect Of Lightweight Mud/Pills
Pump Good Cement
Kick Prevention
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WELL CONTROL
What Is Warning Signs
Information From the Well That
Tells You That the Well May Be Getting
Close to Being “Under Balanced”
Your Safety Margin Is Getting Less.
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WELL CONTROL
1. ROP ChangesOverbalance Less
Softer Rock
2. Hole condition
Squeezing Rock
Torque / Drag / Fill
3. Data from Mud
Gas
Cuttings
Temperature
Kick Warning Signs
Chlorides
Shale Property
Trip Monitor
42
WELL CONTROL
Improper Fill up or Displacement During Trips
Connection Gas
Increased Background Gas
Increased Drilling Rate
Flowline Mud Temperature Increase
Increased Chloride Content of Mud
Increased Drill String Torque
Increased Drill String Drag
Increased Number and Size of Cuttings
Decreasing Shale Density
Major Warning Signs
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WELL CONTROL
Sometimes Called ‘Fast Break’
A Sudden Increase in R.O.P
How Much
How Far to Drill ?
What About a Decrease in R.O.P ?
What Is a Drilling Break
What Affects ROP
WOB
RPM
Bit Type
Hydraulics
Rock Type
Overbalance
44
WELL CONTROL
Geolograph Chart
Increasing
Drill Rate
(ROP)
9850’
9855’9860’
9.00
9.15
9.30
Increased Drilling Rate
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WELL CONTROL
Increased Drill String Torque
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WELL CONTROL
Drilled cuttings
‘Knocked Off’,
Heaving Shale Cuttings
Cuttings Size and Shape
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WELL CONTROL
Cause of Connection Gas
BHP=
6864 psi
BHP=
7114 psi
7000 psi 7000 psi
11 ppg
mud
12000’
Annular
Pressure Loss
= 250 psi
Mud Static
Kick Can Occur Mud Circulating Formation Under ControlConnection Gas being Circulated to Surface
Formation Pressure
0
psi3000
psi
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WELL CONTROL
Normal
Pressure
Abnormal
Pressure
Temperature Increase
9500’
9700’
9900’
10100’
9600’
9800’
10000’
10200’
Flow Line Temperature Graph
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WELL CONTROL
Shale Density Graph
Normal
Pressure
Increasing
Formation Fluid
Pressure
Increasing Shale Density
9500’
9700’
9900’
10100’
9600’
9800’
10000’
10200’
Normal Trend Line
Shale
Shale
Shale
Sand
Sand
Sand
Abnormal Pressure Zones Exhibited a DECREASINGShale Density with DEPTH
50
WELL CONTROL
Surface Kick Indicators
Excess Flow From the Well When Tripping
Return Flow Rate Increase When Pumping
Pit Gain
Drilling Break
Decreased Pump Pressure/increased SPMFlow From Well With Pumps Off
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WELL CONTROL
First : Shut the Well In
Second : Choose and Use a Kill Method to
Restore the Mud Hydrostatic
Pressure to Level That Re-Establishes
Primary Control
What Action to Take?
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WELL CONTROL
Shut In MethodsHard
Soft
Reason for Shut In
To Prevent Blowout
To Allow Pressure Reading to Be Taken for
Kill Mud
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WELL CONTROL
Flow / Pit Alarms Not Set (Properly)
Drill Too Far After Drilling Break
Lack of ‘Shut In’ Training
Lack of Maintenance & Testing
Waiting for Instructions
Accumulator Unit Not Working
Not Monitoring Trips
Low Level of Crew Awareness
Shut In Practices
Things That Delay Shut In.
54
WELL CONTROL
Soft Method
Raise Kelly/Top Drive Until Tool Joint Is Above Rotary
Table
Shut Down Mud Pumps
Open Choke Line Valve (HCR) at Stack
Check That Adjustable Choke Is Open
Close Annular Preventer *
Close Adjustable Choke
Record Shut in Pressure and Pit Gain
* API Soft Shut in States BOP
(It Does Not Specify an Annular)
Line up With Remote Choke Opened.
Drilling
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WELL CONTROL
Soft Method
Install and make up the fully opened SAFETY VALVE in
the Drill String.
Close the Safety Valve
Open Choke Line Valve (HCR) at Stack
Check That Adjustable Choke Is Open
Close Annular Preventer *
Close Adjustable Choke
Pick up and make up Kelly?Top Drive
Open Safety ValveRecord Shut in Pressures and Pit Gain
* API Soft Shut in States BOP
(It Does Not Specify an Annular)
Tripping
Line up With Remote Choke Opened.
56
WELL CONTROL
Hard Method
Line up With Remote Choke Closed.
Drilling
Raise Kelly/Top Drive Until Tool Joint Is Above Rotary
Table
Shut Down Mud Pumps
Close Ram Preventer *
Open Choke Line Valve (HCR) at Stack
Record Shut in Pressure and Pit Gain
* API Soft Shut in States BOP
(It Does Not Specify a Ram)
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WELL CONTROL
Hard Method Tripping
Install and make up the fully opened SAFETY VALVE in
the Drill String.
Close the Safety Valve
Close Ram Preventer *
Open Choke Line Valve (HCR) at Stack
Pick up and make up Kelly?Top Drive
Open Safety Valve
Record Shut in Pressures and Pit Gain* API Soft Shut in States BOP
(It Does Not Specify a Ram)
Line up With Remote Choke Closed.
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WELL CONTROL
Hard
Quicker
Less to Remember
Smaller Influx
Soft
Slower
Checks if choke line is Clean
Larger Influx
Reduces Water Hammer Effect
Hard V’s Soft
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WELL CONTROL
Problems
1. Shallow Gas
Many Rigs That Are Burned up Suffered
Shallow Gas Kicks
2. Losing the Hole and a Re-drill
Top Hole Drilling
60
WELL CONTROL
Shallow Gas
200 ft
Wind Direction
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WELL CONTROL
SIDPP Shut In Drill pipe PressureSICP Shut In Casing Pressure
Pit Gain
SIDPP
Tells You Under Balance Inside Drill String
SICP
Tells You Under Balance Inside Annulus
Pit GainTells You Size of Influx at Shut in
Shut in Data
62
WELL CONTROL
Why Are They Different?
Mud in Annulus Is Contaminated
Therefore Less Hydrostatic
SIDPP V’s SICP SIDPP
Influx Height
Pump
SICP
Choke
Manifold
psi0
0psi
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WELL CONTROL
Increase SPM = Increase PSI
Approximate Effect Is :
= Old Pump Pressure X
Pressure V’s Strokes
New SPM
Old SPM
2
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WELL CONTROL
Pressure V’s Drilling Fluid Density
New M.Wt
Old M.Wt
Increase M. Wt = Increase PSI
Approximate Effect Is:
= Old Pump Pressure X
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WELL CONTROL
Kill Mud
Kill Mud Weight
SIDPP
TVD X 0.052
+ Present Mud Wt.
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WELL CONTROL
Initial and Final Circulating Pressure
I.C.P. = Slow Circulating Pressure + SIDPP
F.C.P. = Slow Circulating Pressure X
Kill M.Wt
Old M.Wt
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WELL CONTROL
Pressure Exerted on the Bottom of the Hole.
B.H.P = Mud Hydrostatic
+
Back Pressure Held at Remote Choke
+
Annular Pressure Loss (APL)
Bottom Hole Pressure
68
WELL CONTROL
Slow Pump Rate
Normally 1/2 - 1/4 Drilling SPM
Why Kill Well at Slow Rate?
How Are They Taken?
When Are They Taken?
How Are They Used in Kill Process?
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WELL CONTROL
1. Size Of Choke And Choke Lines.
2. Minimize Excess Pressure Exerted On
Formations During The Kill.
3. To Allow Kick Fluid To Be Handled At Surface.
4. To Reduce The Chance Of Overloading The
M.G.S.
5. Allow Choke Operator Time To Make
Necessary Choke Adjustments.
6. Ability To Mix Kill Mud.
7. To Reduce Damage To The Pump
Causes Effect the Choice of SCR
70
WELL CONTROL
When Should Be Taking SCR ?
1. At Beginning of Each Shift.
2. After Mud Properties Changed .
3. When Long Sections of Hole Are Drilled
Rapidly (500 Ft).
4. When Returning to Drilling After Kill.
5. When Changed B.H.A (Nozzles, D.C, Motor….)
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WELL CONTROL
SCR’ s Should Be Read On The Drill Pipe
Pressure at The Remote Chock Panel.
SCR’ s Should Be Taken With The Bit Near The
Bottom.
Where To Read Standpipe Pressure.
When Recording SCR
72
WELL CONTROL
High
PermeabilityLow
Permeability
Time For Build How Long For Shut In Pressure To Stabilize?
psi
600
psi
600
Time
P r e s s u r e
Fast
P r e s s u r e
Time
Slow
Casing Pressure Casing Pressure
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WELL CONTROL
Why?Gas Is Light And Will Migrate (Percolate) Up Hole
Speed Of Migration?
Depends On Mud Wt + Mud Viscosity
How Can I See Migration?
Steady Rise In Surface Pressure After Initial Stabilization
Gas Migration
74
WELL CONTROL
Time
SIDPP or SICP
Migra tion
Shut In Pressure
Gas Migration
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WELL CONTROL
psi
600
psi
600
0
0
Float in Drill String
Pump Slowly Down Drill
Pipe And Watch Build Up
Time
500
SIDPP
Time
600
SICP
How To Find SIDPP?
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WELL CONTROL
psi0
0
Clean Annular
psi psi
psi0
0
Annular Loaded
With Cutting
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WELL CONTROL
Bit off Bottom
psi0
0psi
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WELL CONTROL
Packed Off
psi0
0psi
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1. Drill 10 - 15 Feet Rat Hole
2. Test Surface Equipment
3. Circulate To Condition Mud
4. Pull Inside Casing
5. Shut In Well
6. Pump 1/4 - 1/2 Bbl/Min Into Well*
7. Plot Pressure Rise
8. When Pressure Rise Slows Down Or Stops; Shut Down
Pump
9. Measure Pressure Where Pressure Rise Slows Down
10.Monitor Stable Pressure Then Bleed Back Pressure
* Varies With Company Policy
Leak Off Procedure
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WELL CONTROL
Volume Pumped
P u m p P
r e s s u r e
Trend LineLeak Off Pressure Point Of Leak Off
Leak Off Test (L.O.T.)
How Is Formation Strength Measured?
Fracture Pressure = Mud Hydrostatic psi + LOT psi
Formation Integrity Test
Pressure Up To Agreed Pressure Without Any Leak-off
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WELL CONTROL
Fracture Pressure
Can Be Called “ Breakdown” Or “ Max. Allowable ”
= (L.O.T ÷ Shoe TVD ÷ .052) + Mud Wt. ppg
= (Mud Wt. ppg X .052 X Shoe TVD) + L.O.T.
Fracture Mud Weight
MAASP
Difference Between Pressure That Will Fracture The
Rock And The Mud Hydrostatic Pressure
= (Fracture Mud Wt - Current Mud Wt) X .052 X Shoe TVD
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WELL CONTROL
MAASP = Leak Off At Time Of Leak Off Test
If Mud Weight Is Increased The Hydrostatic On
Shoe Increases
Therefore
Margin Between Mud Hydrostatic And Fracture
Gets Less.
This Margin Is Called M.A.A.S.P.
MAASP V’s Leak Off
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WELL CONTROL
Well Condition Required For Accurate Leak Off Test.
Drill Out The Casing Shoe And Approximately
5 – 15 Ft Into New Formation.
Circulate The Mud To Get Same Weight All
Way Around.
Good Pressure Test Of Surface Equipment.
Calibrated Pressure Gauges.
Accurate T.V.D Of Casing Shoe.
Accurate Volume Of Mud Pumped.
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WELL CONTROL
Mud Hydrostatic
Friction Losses In Annulus
Bridging/Packing Off In Annulus
Shutting In Well With Pumps Running
Kicks And The Kill ProcessChoke Line Friction
What Exerts Pressure On The Formation?
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WELL CONTROL
What Can Increase The Risk Of ExceedingMAASP
Incorrect Casing Shoe Setting Depth
Unexpected High Pressure
Large Kick Size
Low Fracture Pressure
Long Open Hole Sections
Gas Migration
Bad Kill Practices
Too Much Safety Margin
Choke Line Friction Loss
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WELL CONTROL
Principle Of Kill Method
One That Maintains Correct AndConstant Bottom Hole Pressure
Restore Primary Control
How ?
Clean Out Influx
Replace Old Mud With Kill Mud
At All Times
Maintain Correct Bottom Hole Pressure.
How ?
Use Approved Kill Method
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WELL CONTROL
Pressure Exerted on the Bottom of the Hole.
B.H.P = Mud Hydrostatic
+
Back Pressure Held at Remote Choke
+
Annular Pressure Loss (APL)
Bottom Hole Pressure
Most Times APL Is Small And Can Be Ignored.
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WELL CONTROL
Pressure Balance
BHP = Hydrostatic + Back Pressure
To Maintain Constant BHP!
Fluid Hydrostatic
Then
Choke Back Pressure
If
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WELL CONTROL
The Choke (Remote Or Manual) Is A DeviceFor Adjusting Back Pressure.
A Kick Is Due To Lack Of Mud Hydrostatic.
The Choke Provides A Back Pressure To
Compensate For Lack Of Mud Hydrostatic.
When Heavy Mud Is Pumped The Operator
Reduces Back Pressure.
Role Of Choke
90
WELL CONTROL
This Procedure Starts the Kill Correctly.
It Ensures That B.H.P Is Correct for the Kill.
It Can Be Stated That the Start up Procedure
“Calibrates” the Well Kill to Correct B.H.P.
How?
Bring Pump Up to Speed Holding Casing
Pressure Constant.
Start up Procedure
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WELL CONTROL
1st Clean Out Influx
2nd Circulate Kill Mud
After 1st Circulation
SIDPP = SICP
Driller’s Method
Two Circulation's
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WELL CONTROL
1st Circulation
Start up - Bring Pumps up to Kill Rate Holding
Casing Pressure Constant
When up to Speed Look at Drill Pipe Pressure.
Hold It Constant at This Value For Complete Circulation
On Completion of Circulation Shut DownThe Reverse of Start up Procedure
If Annulus Is Clean S.I.C.P Will Now Read S.I.D.P.P
If Annulus Is Not Clean Then S.I.C.P Will Be Greater
Than S.I.D.P.P
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WELL CONTROL
Start up - Bring Pumps up to Kill RateHolding Casing Pressure Constant
When up to Speed Maintain Casing Pressure
Constant Until Kill Mud Is at the Bit
With Kill Mud at Bit Switch to Drill Pipe Pressure and
Hold Constant Until Clean Mud Returns at Surface
It May Be Preferred to Use the Wait and Weight
Procedure for the 2nd Circulation.This Is in Case of Any Influx That Was Not Cleaned Out
in the1st Circulation
2nd Circulation
94
WELL CONTROL
One Circulation
Pump Kill Mud From the Start
Procedure
Start up - Bring Pumps up to Kill Rate
Holding Casing Pressure Constant
Once up to Speed the Drill Pipe Pressure Should
Equal I.C.P
Allow Drill Pipe Pressure to Fall From I.C.P to F.C.P
As Kill Mud Is Pumped to the Bit With Kill Mud at the
Bit Hold Drill Pipe Pressure Constant at F.C.P Until Kill
Mud Returns at Surface
Wait and Weight
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WELL CONTROL
ICP = SIDPP + SCR Pressure
FCP = SCR X
Step Down From Icp To Fcp
Using Either Graph Or Chart
Kill Mud
Old Mud
PSI
ICP FCP
Strokes From Surface To Bit
SIDPP
0Strokes From Bit To Surface
STKS PSI
0 1400
100 1350
200 1300300 1250
400 1200
500 1150
600 1100
700 1050
750 1025
ICP
Strokes To Bit FCP
96
WELL CONTROL
Following A Choke Adjustment The Drillpipe Gauge
Takes Longer To React Due To Length Of System
Kill Mud Only Does Good When Going Downhole.
Therefore Re-zero Stroke Counter
Calculated ICP Is Only A Guideline. Actual (True) ICP Is
Seen At Start Up
If Actual ICP Is Different Then Recalculate Graph Or
StepDown
Things To Watch
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97
WELL CONTROL
Comparison of Killing Methods
Ease of Calculation ( Driller Method )
Lower Annulus Pressure ( Wait & Weight)
Shortest Circulating Time (Wait & Weight )
98
WELL CONTROL
Drillers And Wait & Weight Only Work With Bit Below
The Influx.
Problems May Be:-
Unable To Use Pump
Hole Plugged
Bit Above Influx
In These Situations It May Be Necessary To Use
Other Well Control Techniques
Volumetric
Stripping
Combined Volumetric/Stripping
Non-Routine Techniques
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WELL CONTROL
Volumetric Method
Circulation Not Possible
Plugged string.
Pipe out of hole.
Pump is shut-down or unavailable
and there is a float in the string.
Circulation Not Recommended
Not at TVD off bottom).
Pipe stuck
Not possible to strip.
Applications
100
WELL CONTROL
To keep BHP constant
Bleed mud through choke maintaining SIDPP constant
BHP =Ph d/p (no change) + SIDPP (constant)
= Constant
Bad practice
Due Hold casing Pressure Constant
BHP = Ph Ann. + SICP
= Ph Ann (decrease to bleed mud) + SICP (constant)
= Decrease
Volumetric Method
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101
WELL CONTROL
Well Control ProblemsIndicators of Mechanical Failures
Changes In Drillpipe And Casing Pressures During
Well Control Variations Can Indicate Potential
Mechanical Problems
Blockages
String
Annulus
Choke
Washouts
String
Choke
Surface Equipment Failure
Losses
Hydrates
Common Kick Problems
102
WELL CONTROL
Loss of Circulation
Plugged Choke
Choke Washout
Plugged Nozzle
Nozzle Washout
String Washout
Problem DP psi Csg psi BHP
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WELL CONTROL
Bad Practices
Incorrect Start Up
Changing SPM
Holding Wrong Pressure
Not Using Graph/Step Down
Not Pumping Correct Mud
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WELL CONTROL
A. Use Correct “Start Up”
B. 1. Maintain Correct SPM
2. Correct Pressure V Strokes
3. Correct Mud Wt
How Do You Know That The B.H.P Is:
A. Correct ?
B. Constant ?
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WELL CONTROL
Procedure
Correct Action
wrong Action
Effective on BHP
Brining up pump to kill speed
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WELL CONTROL
Procedure
Correct Action
wrong Action
Effective on BHP
Driller Method (1st Circulation)
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WELL CONTROL
Procedure
Correct Action
wrong Action
Effective on BHP
(2nd
Circulation) While Pumping Kill Mud To Bit
108
WELL CONTROL
Procedure
Correct Action
wrong Action
Effective on BHP
(2nd Circulation) While Pumping Kill Mud From
Bit to Surface
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109
WELL CONTROL
Procedure
Correct Action
wrong Action
Effective on BHP
W&W Method (While Pumping Kill Mud To Bit)
110
WELL CONTROL
Procedure
Correct Action
wrong Action
Effective on BHP
Increase Pump Speed
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111
WELL CONTROL
Procedure
Correct Action
wrong Action
Effective on BHP
Decrease Pump Speed
WELL CONTROL
Procedure
Correct Action
wrong Action
Effective on BHP
W&W Method (While Pumping Kill Mud From Bit
To Surface)