50495081 Basic Well Control
-
Upload
2motivated -
Category
Documents
-
view
82 -
download
10
description
Transcript of 50495081 Basic Well Control
1
IDPT Basic WCIPM
Well Engineering ModuleBasic Well Control
IPM IDPT
IDPT Basic WCIPM
• Module Contents
• Objectives and Introduction
• Well Control Fundamentals CD (Self Study)
• WC Incident root causes and IPM Standards
• Primary, Secondary and Tertiary Well Control
• Well Control Mathematics and the “U” Tube
• Kick Causes and Prevention
• Well Control Equipment (HP, LP, BOP, Accumulator, MGS)
• Shut In and Well Kill procedures
• Well Control reporting (Kick reporting, Kill Sheets, etc..)
Basic Well Control
2
IDPT Basic WCIPM
• Module Objectives
• At the end of this lecture and completion of the WCF CD YOU will be able to:
• Define the terms “kick” and “Blowout”
• Perform basic Well Control calculations
• Understand the causes of Well Control incidents
• State primary, secondary and tertiary Well Control procedures
• Understand Well Control Equipment
• Describe the Shut In and Kill methods
• Explain the reporting procedures for Well Control incidents
Basic Well Control
IDPT Basic WCIPM
“A catastrophic well control incident could
put IPM out of business”
- Antonio J. CampoIPM President
3
IDPT Basic WCIPM
• Introduction
• In simple terms, a kick can only occur when the formation pressure exceeds the mud hydrostatic pressure
• The resultant positive differential pressure is transferred intothe wellbore and there is an influx of formation fluids
• If the well is shut in after determining that a kick has occurred then the well can be killed under controlled conditions
• Blow-outs occur when the kick (influx) can not be controlled and there is an emission of wellbore and/or formation fluids at surface
• The rig crew must be fully trained and alert at all times in order to take immediate action to bring the well under control.
Basic Well Control
IDPT Basic WCIPM
• An uncontrolled Kick !
Basic Well Control
Workover RigLand WellRussia
Cause: >Proper equipment not deployed>Poor practices>Lack of training
4
IDPT Basic WCIPM
Basic Well ControlCan turn into this:
Or this:
IDPT Basic WCIPM
Well Control Incidents - Root Causes
• Lack of knowledge and skills of rig personnel• Improper work practices• Lack of understanding of Well Control from certification
training• Lack of application of policies and standards • Poor contractor & supplier management• Inadequate Risk Management & Management of
Change
5
IDPT Basic WCIPM
IPM StandardsStandards
3 HSE4 Quality28 Engineering
IDPT Basic WCIPM
IPM StandardsReference Title InTouch #
IPM-PO-QAS-001 Corporate QHSE Policy 3286066IPM-PO-QAS-002 Engineering Policy 3286067IPM-ST-QAS-001 Document Formatting Standard 3274817IPM-ST-QAS-002 Project Bridging Document 3286070IPM-ST-QAS-003 Glossary of QHSE Definitions 3286072IPM-ST-QAS-004 Management of Change 3286073IPM-PR-QAS-001 Document Numbering and Control Procedure 3274819IPM-FO-QAS-001 Management of Change Form 3286075IPM-CORP-S004 Indemnity and Risk 3286076IPM-ST-HSE-001 Gas Detection Service and Equipment 3286077IPM-ST-HSE-002 Life Saving and Evacuation Equipment 3286078IPM-ST-HSE-003 Simultaneous Operations 3286079IPM-PR-HSE-004 Hygiene in Camps and Accommodations 3286082IPM-PR-HSE-005 Preparation of a Simultaneous Operations Manual 3286083IPM-ST-WCI-001 Well Engineering Management System (WEMS) 3286084IPM-ST-WCI-002 Information to be Kept on Location 3286085IPM-ST-WCI-003 Kick Detection Equipment 3286086IPM-ST-WCI-004 Well Control Equipment Testing Requirements 3286087IPM-ST-WCI-005 BOP Stack and Diverter Minimum Requirements 3286088IPM-ST-WCI-006 Well Control Certification 3286089IPM-ST-WCI-007 Consensus of Well Control Procedures 3286090IPM-ST-WCI-008 Well Control Drills 3286091IPM-ST-WCI-009 Casing Liner and Tubing Pressure Testing 3286092IPM-ST-WCI-010 Minimum Chemical Stocks 3286093
6
IDPT Basic WCIPM
IPM Standards (2)Reference Title InTouch #
IPM-ST-WCI-011 Kick Tolerance 3286095IPM-ST-WCI-012 Barriers 3286096IPM-ST-WCI-013 Authority during Well Operations 3286098IPM-ST-WCI-014 Agreement on Specific Well Control Procedures 3286099IPM-ST-WCI-015 Well Shut-in Method 3286101IPM-ST-WCI-016 Well Control Method 3286103IPM-ST-WCI-017 Kick Detection 3286104IPM-ST-WCI-018 Kick Prevention 3286106IPM-ST-WCI-019 Constant Bottomhole Pressure 3286107IPM-ST-WCI-020 Reporting of Kicks 3286108IPM-ST-WCI-021 Shallow Gas Risk Assessment and Contingencies 3286109IPM-ST-WCI-022 Well Control while Running Casing 3286110IPM-ST-WCI-023 Leak Off Test or Shoe Test 3286111IPM-ST-WCI-024 Procedures for Radioactive Sources 3286112IPM-ST-WCI-025 Casing and Tubing Design 3286113IPM-ST-WCI-026 Temporary and Permanent Abandonment 3286114IPM-ST-WCI-027 Wellbore Surveying and Collision Avoidance 3286115IPM-ST-WCI-028 Well Control Briefing Standard 3286116IPM-PR-WCI-002 Contingency Stripping Procedure 3286117IPM-PR-WCI-003 Testing of Cement Mixing and Pumping Equipment 3286118IPM-PR-WCI-004 Operational Requirements for Cement Slurries 3286119IPM-PR-WCI-005 Cement Placement 3286120IPM-PR-WCI-006 Setting and Verification of Cement Plugs 3286122IPM-PR-WCI-007 Survey Program PreparationIPM-PR-WCI-008 Technical and Operational Integrity 3303422
IPM-REF-WCI-001 Derivation of Kick Tolerance Calculation 3286124
IDPT Basic WCIPM
• The primary formula for Well Control
• U-Tube principles
• The calculation of pressures in the Static and Dynamic U-Tube conditions
Basic Well Control
7
IDPT Basic WCIPM
Well Control
• Primary Well Control :• The use of the Mud Weight to provide sufficient pressure to
prevent an influx of formation fluid into the wellbore
• Secondary Well Control:• Control Kick with Mud Weight and BOP Equipment
• Tertiary Well Control:• An Underground Blowout – to avoid a surface blowout
IDPT Basic WCIPM
Well Control Math
Volume:
1 gallon = If MW = 10 ppgP = 10 lb. = 0.52 psi
19.23 in2
Gradient = Change = 0.52 psi/ft
If MW = 1 ppgP = 1 lb. = 0.052 psi
19.23 in2
Gradient = Change = 0.052 psi/ft
Ht: 1
ft.
Area: 19.23 in2
G = 0.052 x MW(psi/ft) (ppg)
230.75 in3
8
IDPT Basic WCIPM
Well Control Math
MW: 10 ppg
Dept
h -f
t
G = 0.052 x MW(psi/ft) (ppg)
HP = G x D(psi) (psi/ft) (ft)
Pres
sure
-psi
0
1
2
3
0
0.52
1.04
1.56Only TVD is Considered
Not MD
IDPT Basic WCIPM
How vs Why
Given:• Gas Kick taken while
drilling at 6000 ft• Well Shut-In• MW = 10 ppg• Kill MW = ???
SIDPP =
SICPP =
600 psi
900 psi
9
IDPT Basic WCIPM
How vs Why
How to calculate KMW:
KMW = (0.052 x 10 x 6000) + 6006000 x 0.052
KMW = 11.923 = 12 ppg
Why KMW is 12 ppg:
G10 = 0.052 x 10 = 0.52 psi/ft
HP10 = G x D = 0.52 psi/ft x 6000ftHP10 = 3120 psiPzone = HP10 + SIDPP = 3120 + 600Pzone = 3720 psi
Gkill = Pzone = 3720 = 0.62 psi/ftD
KMW = Gkill = 0.62 =11.923 ppg=12 ppg6000
0.052 0.052
KMW = (0.052 x MW x D) + SIDPPD x 0.052
IDPT Basic WCIPM
How vs Why
What is the significance of the 600 psiSIDPP?Why was the Drill Pipe gauge pressure used in the calculation rather than the SICP gauge pressure?Why do we round up to 12 ppg for the KMW?
SICPP =900 psi
SIDPP =600 psi
10
IDPT Basic WCIPM
The ‘U’-Tube
An arrangement of pipes in which the two legs are attached at the bottom
The Pressure at Point A = Pressure at Point B
A B
IDPT Basic WCIPM
The Well as a ‘U’-Tube
The ‘U’-Tube Can
Be Either:• Static• Dynamic Pressure Contributors:
• Pump Pressure
• DP Friction Loss
• Bit Pressure Loss
• Annular Pressure Loss (ECD)
• Back Pressure from Choke
What are the Pressure
Contributors?
11
IDPT Basic WCIPM
Static ‘U’-TubeGiven:• Shut-In after Gas Kick• Depth: 10,000 ft• MW: 10 ppg• BHP: ??• Avg Grad Ann: ??• EMW: ??• How Big was the Kick??
SIDPP = 500 psi
SICP = 700 psi
– 8-1/2” Vertical Well– 5 Stands 6-3/4”DC
P1 = P2
IDPT Basic WCIPM
Static ‘U’-Tube
BHP = SIDPP + HPDSBHP = 500 + (0.052 x 10 x 10,000)BHP = 5700 psi
BHP = SICP + HPAHPA = BHP – SICP HPA = 5700 – 700 = 5000 psiGA = HPA = 5000 psi = 0.5 psi/ft
D 10,000 ft
EMWA = GA = 0.5 = 9.6 ppg0.052 0.052
Note that BHP: P1 = P2
SIDPP = 500 psi
SICP = 700 psi
P1 = P2
12
IDPT Basic WCIPM
Static ‘U’-Tube
Height of Influx = SICP - SIDPPGMud - GInflux
= 700 psi - 500 psi(10 ppg x 0.052) - GInflux
Gas Influx: < 0.2 psi/ft Water Influx: > 0.4 psi/ftWorst Case: Assume Gas Influx = 0.1 psi/ft
= 700 - 500 = 200 psi 0.52 psi/ft – 0.1 psi/ft 0.42 psi/ft
Height of Influx = 476.2 ft (TVD)
Kick Size = Height of Influx (MD) x Annular Volume (5 Stands of 6-3/4” DC in 8-1/2” Hole)= 476.2 ft x 0.0259 bbl/ft
Kick Size = 12.4 bbls
IDPT Basic WCIPM
Dynamic ‘U’-Tube
Given:• What does the CDPP
measure?• How are DP losses
calculated?• How are Annular pressure
losses calculated?
P1 ≥ P2
CDPP psi
CCP psi
13
IDPT Basic WCIPM
DS Pressure Loss
• Step 1: Obtain the following dimensional parameters• Drill pipe ID ddp – inches• Drill pipe Length Ldp – feet• Drill collar ID ddc – inches• Drill collar Length Ldc – feet• Plastic Viscosity PV – centipoise• Yield Point YP - lb/100ft2
• Step 2: Calculate the average fluid velocity (ft/sec):• Drill collars: Vdc = GPM/(2.448 x ddc
2)• Drill pipe: Vdp = GPM/(2.448 x ddp
2)
IDPT Basic WCIPM
DS Pressure Loss
• Step 3: Calculate the frictional pressure loss:• Drill collars:
PLdc = [(PV x Vdc x Ldc)/(1500 xddc2)] + [(YP x Ldc)/(225 x ddc)]
• Drill pipe:PLdp = [(PV x Vdp x Ldp)/(1500 xddp
2)] + [(YP x Ldp)/(225 x ddp)]
• DSPL = PLdc + PLdp
14
IDPT Basic WCIPM
Dynamic ‘U’-Tube
Given:• Depth: 10,000 ft• MW: 10 ppg• Circ DPP (CDPP): 2000 psi• Circ CP (CCP): 500 psi
• (backpressure)
• DS Pres Loss (dPDS): 1300 psi• Anl Pres Loss (dPA): 200 psi• BHP: ???
P1 ≥ P2
CDPP = 2000 psi
CCP = 500 psi
IDPT Basic WCIPM
Dynamic ‘U’-Tube
BHP = CCP + HPA + dPA
= 500 + (0.052 x 10 x 10,000) + 200BHP = 5900 psi
BHP = CDPP + HPDS - dPDS
BHP = 5900= 2000 + (0.052 x 10 x 10,000) - 1300
OR
P1 ≥ P2
CDPP = 2000 psi
CCP = 500 psi
15
IDPT Basic WCIPM
Problem #1
THE ‘U’ –TUBE1/2 hour
IDPT Basic WCIPM
10 9.7
+350
156
0
SICP = 0 psi (overbalanced U-Tube)
BHP = SICP + HPAnn= 0 + (0.052 x 10 ppg x 10,000 ft)
BHP = 5200 psi
SITP = BHP - HPTub= 5200 – (0.052 x 9.7 ppg x 10,000 ft)
SITP = 156 psi
Zone Overbalance = BHP – Zone Pressure= 5200 – 4850 psi
Zone Overbalance = 350 psi
Problem #1
16
IDPT Basic WCIPM
+650
156
370
CTP = 156 psi (Held Constant)
CCP = dPAnn+ dPTub= 300 + 70
CCP = 370 psi
BHP = CCP + HPAnn - dPAnn= 370 + 5200 – 70
BHP = 5500 psi
Zone Overbalance = BHP – Zone Pressure= 5500 – 4850 psi
Zone Overbalance = 650 psi ( 300 psi above Shut-In)
Problem #1
IDPT Basic WCIPM
+623
0
370 L
CTP = 0 psi (U-Tube Balanced)(Choke Fully Open)
CCP = dPAnn + dPTub= 300 + 70
CCP = 370 psi (Pressure Loss in U-Tube)
Volume of 9.7 ppgAnn = Volume of 10 ppg TubL x CapacityAnn = (10,000 – L) x CapacityTubL x 0.0986 = (10,000 – L) x 0.02
= 200 – L x 0.020.1186L = 200L = 1686 ft10,000 – L = 8314 ft
BHP = CTP + HP9.7 + HP10 - dPT= 0 + (0.052 x 9.7 ppg x 1686 ft) + (0.052 x 10 ppg x 8314 ft) + 300= 0 + 850 + 4323 + 300
BHP = 5473 psi
Zone Overbalance = BHP – Zone Pressure= 5473 – 4850 psi
Zone Overbalance = 623 psi
Problem #1
17
IDPT Basic WCIPM
+650
0
402 L
CTP = 0 psi (HPTub Greater than HPAnn)(Choke Fully Open)
BHP = CTP + HPT + dPT = 0 + 5200 + 300
BHP = 5500 psi
Zone Overbalance = BHP – Zone Pressure= 5500 – 4850 psi
Zone Overbalance = 650 psi
Volume of 9.7 ppgAnn = Volume of 10 ppg TubL x CapacityAnn = 10,000 x CapacityTubL x 0.0986 = 10,000 x 0.02L = 2028 ft10,000 – L = 7972 ft
BHP = CCP + HP9.7 + HP10 - dPAnnCCP = BHP - HP9.7 - HP10 + dPAnn
= 5500 - (0.052 x 9.7 ppg x 2028 ft) + (0.052 x 10 ppg x 7972 ft) + 70= 5500 - 1023 - 4145 + 70
CCP = 402 psi
Problem #1
IDPT Basic WCIPM
0
526
+650
CTP = 0 psi (HPTub Greater than HPAnn)(Choke Fully Open)
BHP = 5500 psi (Same as (#4))
Zone Overbalance = 650 psi (Same as (#4))
CCP = BHP – HPAnn + dPAnn= 5500 - (0.052 x 9.7 ppg x 10,000 ft) + 70= 5500 - 5044 + 70
CCP = 526 psi
Problem #1
18
IDPT Basic WCIPM
+494
0
370
CTP = 0 psi (U-Tube Balanced)(Choke Fully Open)
CCP = 370 psi (Pressure Loss in U-Tube)
BHP = CTP + HPTub + dPTub= 0 + 5044 + 300
BHP = 5344 psi
Zone Overbalance = BHP – Zone Pressure= 5344 – 4850 psi
Zone Overbalance = 494 psi
Problem #1
IDPT Basic WCIPM
0
100
200
300
400
500
600
0 1 2 3 4 5 6
370402
526
370
156
CTP/
CCP
-psi
Tubing Volumes
Problem #1
19
IDPT Basic WCIPM
0
100
200
300
400
500
600
700
800
900
1000
0 1 2 3 4 5 6
Tubing Volumes
650 650
623494
Over
bala
nce
-psi
Problem #1
IDPT Basic WCIPM
Kicks – Cause
There is ONE condition that allows a kick to occur:
The pressure in the wellbore becomes less than the pressure in the formation
20
IDPT Basic WCIPM
Kicks – Causes and Prevention
Cause Best Prevented By: Most Common
Least Common
1. Failure to keep hole full of proper weight fluid
Measurement of fill-up volume when tripping -
2. Drilling into zones of knownpressure with mud weight too low
Good engineering & well procedures and an alert, questioning attitude by WSS -
3. Drilling into unexpected, abnormal formation pressure
Careful engineering, proper well design -
Trip Tank!!
STUDY OFFSET WELLS
READ THE PROGRAM
IDPT Basic WCIPM
Kicks – Causes and Prevention
Most Common
Least Common
Careful engineering, proper well design -Case off Loss Circ ASAP!
5. Unloading mud by pulling balled assembly
Measurement of fill-up volume when pulling drill string – TRIP TANK!
6. Mud weight high enough to drill, but not to trip
4. Lost Circulation (Fluid Level, not rate of loss is critical in well control)
Measurement of fill-up volume when pulling drill string – TRIP TANK!
Cause Best Prevented By:
21
IDPT Basic WCIPM
Uncontrolled Kicks = Blowouts
Don’t Let it Happen
IDPT Basic WCIPM
Well Control Equipment
• Trip Tank
• LP and HP Well Control Equipment
• BOP Configuration and testing
• Accumulator, Manifold and Mud Gas Separator
22
IDPT Basic WCIPM
Well Control Equipment - Overview
HIGH PressureLOW Pressure
Pump
Trip Tank
Choke
Accum
Gas Buster DegasserSuction
MudStorage
Mud Mixing PVT
BOP StackWell Head
DP
To Pump
CSG
IDPT Basic WCIPM
Well Control Equipment
What is the most important piece of well control equipment on the rig?
The Trip Tank
23
IDPT Basic WCIPM
Surface BOP Stack Configuration
Choke Line HCR
TOP RAMS
BLIND RAMS
BOTTOM RAMS
ANNULAR
BOTTOM RAMS
Kill Line
VR Plug Installed in
Casing Head
Replace with Double Gate (Pipe Rams – Blind Rams) in Selected Cases
IDPT Basic WCIPM
Sub-Sea BOP Stack Arrangement
BLIND RAMS
BOTTOM RAMS
UPPER ANNULAR
LOWER RAMS
BOTTOM RAMS
MIDDLE RAMS
BOTTOM RAMS
UPPER RAMS
BOTTOM RAMS
SHEAR RAMS
LOWER ANNULAR
LMRP CON
Stack Connector
Outer Choke
Inner Choke
Inner Choke
Outer Choke
Inner Choke
Outer Choke
Inner Choke
Outer Choke
24
IDPT Basic WCIPM
Pressure Test Frequency
During the first trip after the14-day interval with a maximum interval of 21 days or before as specified by local regulationsPrior to installation where possibleAfter installation of wellhead and BOP assembly and prior to drillingWhen any component change is madePrior to drilling into a suspected high pressure zoneAt any time requested by the Operator’s Drilling RepresentativeAfter RepairsPrior to the initial opening of the drill stem test toolsWhen bonnets have been opened solely for the purpose of changing rams prior to running casing, a body test to ensure the integrity of the bonnet seals will suffice
The pressure tests of all blowout preventers, wellhead components and their connections, BOP operating unit, choke manifold, kill and choke lines, standpipe manifold, kelly and kelly cocks, safety valves and inside BOPS shall be made:
IDPT Basic WCIPM
Accumulator Bottle
Bladder Assembly
Shell
Fluid Port Assembly
25
IDPT Basic WCIPM
Accumulator Sizing
PRECHARGEVOLUME AT
ACCUMULATOR OPERATING PRESS
MIN OPER PRESS 200 psi ABOVE
PRECHARGE PRESS
USABLE VOLUME
- MOST ALL MODERN ACCULULATORS ARE 3000 psi WORKING PRESSURE
Non
-Fla
mm
able
Gas
1200 psi
1000 psi
Acc
umul
ator
Fl
uid
3000 psi
IDPT Basic WCIPM
Accumulator SizingSLB STANDARD
SPECIFICATION:
• Close all (rams and annular) functions and Open all HCRs valves• Open all (rams and annular) functions and Close all HCRs valves• Close Annular• Open choke line remote operated valve
The accumulator volume of the BOP systems should be sized to keep a remaining stored accumulator pressure of 1380 kPa (200 psi) or more above the minimum recommended precharge pressure after conducting the following operations (with pumps inoperative):
26
IDPT Basic WCIPM
EXAMPLE:
BOP Equipment: 1 Annular + 3 Rams + HCR Valve
Usable Volume (UV): = 133 Gal
Closing Volume (CV): 20 + (3 x 10) + 1 = 56 Gal
Nominal (Bottle) Volume (NV): 2 x UV = 266 Gal
Opening Volume (OV): 20 + (3 x 10) + 1 = 56 GalClosing Volume (CV): 20 = 20 GalOpen Choke Line Valve (OV): 1 = 1 Gal
Accumulator SizingSLB STANDARD
IDPT Basic WCIPM
Accumulator Sizing
Calculation of Usable (Bottle) Volume
1.676.670Liquid Vol
10,00010,00010,000P x V
8.333.3310Gas Vol
120030001000Pressure
UseableOperatingPre-Charge
UV = 6.67 – 1.67
UV = 5
1 2 3Non
-Fla
mm
able
Gas
3000 psi
1200 psi
1000 psi
Acc
umul
ator
Fl
uid
USABLE VOLUME
27
IDPT Basic WCIPM
Hydraulic Pumps
SPECIFICATION:
• Closing annular preventer (excluding diverter) on minimum size drill pipe being used
• Opening hydraulic operated choke line valve• Obtain a minimum of 1380 kPa (200 psi) pressure above accumulator precharge
pressure on closing unit within two (2) minutes or less
The unit will include one (1) electric pump and two (2) back-up air pumps for accumulator charging. With the accumulator system removed from service, the pumps should be capable of:
IDPT Basic WCIPM
Choke and Standpipe Manifold
At least three flow paths must be provided that are capable of flowing well returns through conduits that are 76.14 mm (3”) nominal diameter or larger. At least one flow path:
• Shall be equipped with a remotely controlled, pressure operated adjustable choke. Simplified choke manifolds without remote control choke may be acceptable on light rigs with 2-3k psi stacks.
• Shall be equipped with a manually operated adjustable choke.• Must permit returns to flow directly to the pit, discharge manifold or other
downstream piping without passing through a choke. Two gate valves with full rated working pressure must be provided in this unchoked path.
28
IDPT Basic WCIPM
Float Valves
SPECIFICATION:
• Prevent sudden influx entry into the drill string• Prevent back flow of annular cuttings from plugging bit nozzles
Either plain or ported floats are acceptable
Float valves must be used while drilling and opening hole prior to setting surface casing or any time the posted well control plan is to divert and can also be used in deeper sections of the hole. They:
IDPT Basic WCIPM
Mud-Gas Separator
From Choke
Impi
ngem
ent
Plat
e
Baffle Plates
1. Diameter and length controls the amount of pressure in separator
2. Height and diameter and internal design control separation efficiency
Drain Line w/Valve
Vent Line
No Valves!!
MUD
GA
S
3. Height of ‘U’-Tube (D) and distance from bottom of separator to top of ‘U’-Tube controls fluid level and stops gas from going out of the bottom
Siph
on B
reak
erD
dNo
Valv
es!!
Mud
29
IDPT Basic WCIPM
Exercise - MGS Design
IDPT Basic WCIPM
EXAMPLE:Well Depth: 10, 000’
Hole/CSG Size (12-1/4” x 13-3/8”): 0.125 bbl/ftDrill Pipe (5”, 19.5#): 0.025 bbl/ft
MW: 12 ppg KMW: 14 ppg
Kick Vol: 50 bbl
Kill Speed: 3 BPM
Well Killed by Driller’s Method Csg Press when gas reaches surface: 1987 psiCsg Press when gas out: 1057 psi
Avg Gas Rate during 1st minute of venting: 3,202 MCF/DAvg Gas Rate during last minute of venting: 1,722 MCF/DAvg Gas Rate while venting: 2,462 MCF/D
Exercise - MGS Design
30
IDPT Basic WCIPM
0 5 10 15 20
Pressure Loss in 100 ft
0 5 10 15 20
5
1
0
1
5
2
0
2
5
30
Gas Flowrate – MMSCF/D
Upst
ream
Pre
ssur
e –
psi
4” ID 6” ID
8” ID10” ID
12” ID
Gas Temp = 75º F
Downstream Pressure = Atmospheric
Exercise - MGS Design
IDPT Basic WCIPM
DIVERTERS
Well Control Equipment
Are NOT Well Control Equipment
31
IDPT Basic WCIPM
Diverters
• Diverter Requirements
• Diverter Procedures
IDPT Basic WCIPM
Designed to direct UNCONTROLLED flow away from personnel
• Major weaknesses of the Diverter:1) Plugging:
A large number particles of this size: Can bridge off these flow paths:
2) Erosion:• Gas/Sand mixtures flowing through diverter lines have been measured
to erode though steel at the rate of 8”/hour
• Water mixtures have been measured at 16”/hour
NO RELIABLE MEANS EXIST TO ELIMINATE THESE PROBLEMS
Diverters
8” 12”
1/4 -1/2”
32
IDPT Basic WCIPM
Diverter Configuration
Surface
Casing Shoe
Riser
Diverter
Entry
Diverter Line
Flow Line
IDPT Basic WCIPM
SLB Diverter Requirements Land, Swamp Barge & Jack-Up
Relief Lines• At least two relief lines installed to permit venting at
opposite ends or sides of the rig• On Land a single line is permissible
• The relief line shall be at least 8” (203 mm)• No other lines into or out of diverter lines or housing
33
IDPT Basic WCIPM
SLB Diverter Requirements Land, Swamp Barge & Jack-Up
Relief System• The diverter relief system shall be inserted with a minimum number of
bends and all lines well secured. Each diverter relief line will be equipped with a pressure-operated full opening, unrestricted valve. The operating sequence of the diverter will be as follows:• Open selected valve• Close diverter
These functions shall be interlocked. A means of switching flow from one vent to the other without closing in the system must beprovided.
IDPT Basic WCIPM
SLB Diverter Requirements Land, Swamp Barge & Jack-Up
Relief System• Special care should be taken to protect pipe bends form erosion. This may
include:• Use of long radius pipe bends• Providing extra metal thickness at bends• Sleeve-type connections shall not be used in the diverter system• A power-operated valve must be installed to automatically shut off mud returns
to the pits when the diverter is closed, if the mud return line and diverter relief outlet from the well is a common outlet or the mud return line connects below the diverter head
34
IDPT Basic WCIPM
SLB Diverter Requirements Land, Swamp Barge & Jack-Up
Relief System• Special care should be taken to protect pipe bends form erosion. This may
include:• Use of long radius pipe bends• Providing extra metal thickness at bends• Sleeve-type connections shall not be used in the diverter system• A power-operated valve must be installed to automatically shut off mud returns
to the pits when the diverter is closed, if the mud return line and diverter relief outlet from the well is a common outlet or the mud return line connects below the diverter head
IDPT Basic WCIPM
Shut-In Procedure while Drilling
Paths on Choke Manifold Closed (Hard Shut-In), Float in Drill string
2. Raise string to shut-in position (time permitting)3. Stop the pumps and flow check; if well flows,
proceed without delay to next step4. Close annular/ open remote controlled choke line valve (HCR)5. Notify man in charge6. Check space out and close pipe rams and locks7. Bleed off pressure between pipe rams and annular (if possible)8. Record annulus and drill pipe pressure and pit gain
1. Stop rotation
35
IDPT Basic WCIPM
4. Notify man in charge
Shut-In Procedure while Tripping
1. Set slips below tool joint (No tool next to shear ram)2. Install full opening safety valve and close same3. Close annular/open remote controlled choke line valve (HCR)
between safety valve and top drive) and open safety valve6. Read annulus and drill pipe pressure and pit gain
5. Make up kelly or top drive (insert a pup joint or single
Paths on Choke Manifold Closed (Hard Shut-In), Float in Drill string
IDPT Basic WCIPM
Hard Shut-In vs. Soft Shut-In
Hard Shut-InAdvantages:
• Influx stopped in shortest possible time• Quick and simple procedureDisadvantages:• Perceived pressure pulse or ‘Water Hammer’ effect that is
thought to damage formation
36
IDPT Basic WCIPM
Hard Shut-In vs. Soft Shut-In
Soft Shut-InAdvantages:
• Perceived pressure pulse is reducedDisadvantages:• A larger influx is obtained due to the delay in fully shutting
the well in• More complex due to requirement of ensuring valve
alignment before closing BOP
IDPT Basic WCIPM
Hard Shut-In vs. Soft Shut-In Conclusions
Soft Shut-In• Little improvement to pressure pulse• Significant effect from additional influx
Hard Shut-In• ‘Water Hammer’ smaller than shut-in pressure rise• Formation exposed to lower net pressure• Results favor Hard Shut-In
• Minimum confusion, Less influx volume, Lower annular pressure
• Safety of personnel and equipment without risk to well
37
IDPT Basic WCIPM
Well Kill ProceduresCONSTANT BHP WELL CONTROL METHOD
Circulate Gas Out Holding Constant BHP
P1 = P2
IDPT Basic WCIPM
Well Kill Procedures
• 4 Methods• Drillers Method
• Circulate kick out• Then pump kill weight mud
• Wait and Weight Method• Mix KW mud (Well shut in) and pump into wellbore.
• Volumetric, Lubricate and Bleed• When circulation is a problem
• Bullheading
38
IDPT Basic WCIPM
ADVANTAGES
Driller’s Method
• Simplicity – Less calculations are required than Wait and Weight• Can start circulation immediately – Effect of gas migration reduced• Removes influx and stabilizes wellbore pressure at earliest possible time• Viable option if limited barite is available
DISADVANTAGES• Method will require at least two circulations • Under certain conditions the highest shoe pressure• Two circulations may cause damage to Well Control Equipment
IDPT Basic WCIPM
Wait and Weight Method
• In some circumstances, it generates the lowest pressure on the formation near casing seat.
• In a long open hole section, it is the least likely method to induce lost circulation.
• Requires one less circulation, therefore less damage to Well Control Equipment
• Defacto standard for majority of our clients
• Requires longest waiting period prior to circulation. In a case where a significant
amount of hole is drilled prior to encountering the kick, the cuttings may settle out
and plug annulus
• Gas migration is a problem while the density of the system is increased
ADVANTAGES
DISADVANTAGES
39
IDPT Basic WCIPM
Well Control Incident Reporting
• All WC Incidents will be reported in QUEST within 24 hours of the incident.
• The QUEST entry shall be accompanied by a Well Control Incident Report
IDPT Basic WCIPM
Well Control Incident Reporting
40
IDPT Basic WCIPM
Well Control Incident Reporting
IDPT Basic WCIPM
Well Control Incident Reporting
41
IDPT Basic WCIPM
• Now you should be able to:
• Define the terms “kick” and “Blowout”
• Understand the causes of kicks and blowouts
• Describe primary, secondary and tertiary WC procedures
• Perform basic WC calculations
• Describe the necessary equipment for Well Control
• Be able to report a WC incident in Quest
• Fill out a killsheet.
Basic Well Control