Well Control

PETR 5000 Well Control S. H. Emadi, PhD

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Why Well Control is Imperative?

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Mud Window Density, ppg 0

5

10

15

20

25

0 Pore Pressure 2000

Fracture Gradient

4000

Depth, ft

6000

8000

10000

12000

14000

16000

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Mud Window Density, ppg 0

5

10

15

20

25

0 Pore Pressure 2000

Mud Density plus Trip Margine

4000

Fracture Gradient Fracture Gradient Mines Trip Margine

Depth, ft

6000

8000

10000

12000

14000

16000

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Mud Window • Trip Margin • Swabbing Pressure • Surge Pressure

• Riser Margin • Floating Rigs (e.g. Drill ship)

• Equivalent Circulating Density (ECD) PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Trip Margin • How quickly the drill string is run • Dimension of the wellbore • Dimensions of the drill string • Rheological properties of drilling fluid PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Well Control Equipment • • • • • •

Float Valve in the Bit Sub Kelly Safety Valve (Ball-Type Valve) Blow Out Preventer (BOP) Choke Manifold Kill & Choke Line Accumulator (Koomey Unit) PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Float Valve in the Bit Sub

Float Valve Bit Sub

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Kelly Safety Valve (Ball-Type Valve)

Kelly Safety Valve PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Different Valves • Ball-Type Valve

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Different Valves • Gate Valve

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Different Valves • Needle Valve

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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BOP Stack

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Annular Preventer • • • •

Made of Rubber Low Pressure Rating Can Seal every Shape Hydraulically Activated

Annual Preventer

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Pipe Ram

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Pipe Ram • Made of Rubber and Steel • High Pressure Rating • Can Seal Specific Pipe Size • Hydraulically/Hand Activated Pipe Ram

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Blind Shear Ram

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Blind Ram • Made of Steel • High Pressure Rating • Can be Closed on any Part of DP • Hydraulically Activated

Blind Ram

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Shear Ram • Made of Steel • High Pressure Rating • Can be Closed on any Part of DP • Hydraulically Activated

Shear Ram

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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BOP Stack

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Choke Manifold

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Choke Manifold • Set of Valves/ or Chokes • Used to Control the Pressure from the Well Head • Chokes • Fixed • Adjustable

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Accumulator

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Accumulator • Used to Hydraulically Operate Rams, Annular Preventer, and HCR • High Pressure Cylinders Store Gas (nitrogen) • Hydraulic Fluid • According to API RO53, reservoir tank should have a total volume at least two times of usable volume to close all BOP equipment. PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Causes of Kicks? • • • • • •

Insufficient BHP Improper Hole Fill up during Trips Swabbing Cutting of Mud by Formation Fluids Lost Circulation Abnormal Pressure Formations PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Abnormal Pressure Formations • Normal Pressure Gradient • Abnormal Pressure Gradient • Subnormal Pressure Gradient

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Abnormal Pressure Formations

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Abnormal Pressure Formations • Non-Permeable Formations • Dense Rocks • Thick Gas Sand

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Abnormal Pressure Formations • Reverse Faulting

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Abnormal Pressure Formations • Salt Diapirs

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Abnormal Pressure Formations • Erosion

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Abnormal Pressure Formations • Man-Made Abnormal Pressure

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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How to Detect Kicks? • • • • • • • •

Change in Mud Pit Level Change in ROP Change in MW Gas Content Change in SPP Change in Drilling Mud Properties d-exponent Analysis MWD - LWD PETR 5000 - S. H. Emadi, PhD - Spring 2015

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d-exponent 𝑅𝑂𝑃 log( ) 60𝑅𝑃𝑀 𝑑= 12𝑊𝑂𝐵 log( 6 ) 10 𝑑𝑏 Where ROP: ft/hr WOB: lbf 𝑑�𝑏: Bit Diameter, in PETR 5000 - S. H. Emadi, PhD - Spring 2015

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𝑑𝑐 -exponent MW also affects ROP. 𝜌𝑛 𝑑𝑐 = 𝑑 𝐸𝐶𝐷 Where 𝜌𝑛 : Normal Pore Pressure Gradient ECD: Equivalent Circulating Density

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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𝑑𝑐 -exponent Example: Calculate d and 𝑑𝑐 -exponent for the following well. ROP: 50 ft/hr WOB: 20,000 lbf RPM:100 𝑑𝑏 =8.5 in Solution 𝑅𝑂𝑃 50 log( ) log( ) 60𝑅𝑃𝑀 = 60 × 100 = 1.34 𝑑= 12𝑊𝑂𝐵 12 × 20,000 log( 6 ) log( ) 6 10 𝑑𝑏 10 × 8.5 𝜌𝑛 0.465 𝑑𝑐 = 𝑑 = 1.34 = 1.19 𝐸𝐶𝐷 10.1 × 0.052 PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Procedure for Determining 𝑃𝑝 from 𝑑𝑐 • Calculate 𝑑𝑐 over 10-30 ft intervals • Plot 𝑑𝑐 vs depth (Use data only from clean shale sections) • Determine the normal line for 𝑑𝑐 vs. depth plot. • Establish where 𝑑𝑐 deviates from the normal line to determine abnormal pressure zone. PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Procedure for Determining 𝑃𝑝 from 𝑑𝑐

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Properties of Gas and Gas Laws 16,000

P vs. V 14,000

12,000

P, psi

10,000

8,000

6,000

4,000

2,000

0 0

20

40

60

80

100

120

140

160

V, gal

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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MAASP • Maximum Allowable Annular Surface Pressure • Depends on: • Surface Equipment • Casing Resistance • Weakest Formation Fracture Propagation Pressure PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Kick Indicators • • • • • • •

Increase in ROP Increase in Gas Content Increase Chloride Content Change in the Size and Shape of Cuttings Decrease in SPP Increase in Return Drilling Fluid Temperature Increasing Flow at the Flow-Line (Positive Kick Indicator) • Increase in Pit Volume (Positive Kick Indicator) PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Kick Tolerance • What is kick tolerance? • Which factors affect on kick tolerance? • When we have to determine kick tolerance? Typical Values of Kick Tolerance Hole Size (in)

Kick Volume (bbl)

6” and smaller

10-25

8.5”

25-50

12.25”

50-100

17.5”

100-150

23”

250 PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Kick Tolerance

Circulation Of The Gas Influx Using The Drillers Method, Well Engineering and Construction, Hussain Rabia PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Kick Tolerance • 𝐹𝑃𝑃 = 𝑃𝑓 − 𝑃𝑔 − 𝑇𝐷 − 𝐻 − 𝐶𝑆𝐷 × 𝑀𝑊 • 𝐻=

0.052×𝑀𝑊× 𝑇𝐷−𝐶𝑆𝐷 +𝐹𝑃𝑃−𝑃𝑓

0.052×𝑀𝑊−𝐺

• 𝑉1 = 𝐻 × 𝐴 • 𝑃1 𝑉1 = 𝑃2 𝑉2 PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Kick Tolerance • 𝑀𝑎𝑥. 𝐷𝑃𝑆𝐼𝑃 = (𝐹𝐺 − 𝑀𝑊) × 𝐶𝑆𝐷 × 0.052 • Temperature Effect •

𝑃1 𝑉1 𝑇1

=

𝑃2 𝑉2 𝑇2

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Well Killing Procedure • As soon as any kick sign observed, Pickup drill string from bottom, stop pumping, and rotating. • Check the flow level in the wellbore (Check the flow line for back flow) • Close BOP • Calculate Pit Gain PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Well Killing Procedure • Start Recording Casing Shut In Pressure (CSIP) • Record Drill Pipe Shut In Pressure (DPSIP) • Calculate Kick Density • Determine Height of Kick • Determine Type of Influx PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Well Killing Procedure • Prepare Kill Mud Weight in Mud Pit • Make Decision What Killing Method has to be used. • Do Necessary Calculations (ICP, MAASP, …) • Start Killing Operation • Recording CSIP and DPSIP PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Well Killing Methods • Two Circulations or Drillers Method • One Circulation or Wait-andWeight Method-Engineer’s Method • Concurrent Method PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Well Killing Methods DPSIP

CSIP

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Well Killing Calculations 𝑀𝑊𝑘𝑖𝑙𝑙

𝐷𝑃𝑆𝐼𝑃 = 𝑀𝑊𝑐 + 0.052 × 𝑇𝑉𝐷

𝑃𝑓 = 0.052𝑀𝑊𝑐 × 𝑇𝑉𝐷 + 𝐷𝑃𝑆𝐼𝑃

𝑃𝑓 = 𝑃𝑚−𝑎𝑛𝑛 + 0.052 × 𝜌𝑘𝑖𝑐𝑘 × ℎ𝑘𝑖𝑐𝑘 + 𝐶𝑆𝐼𝑃 𝐼𝐶𝑃 = 𝑅𝐶𝑃 + 𝐷𝑃𝑆𝐼𝑃 𝑀𝑊𝑘𝑖𝑙𝑙 𝐹𝐶𝑃 = 𝑅𝐶𝑃 × 𝑀𝑊𝑐 𝑀𝐴𝐴𝑆𝑃 = 𝐹𝑃𝑃 − 𝑃ℎ−𝑎𝑛𝑛 PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Driller’s Method

Lake 2006 PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Driller’s Method

Lake 2006 PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Wait-and-Weight Method

Lake 2006 PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Wait-and-Weight Method

Lake 2006 PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Well Killing

Lake 2006 PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Well Killing

Lake 2006 PETR 5000 - S. H. Emadi, PhD - Spring 2015

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Well Killing Methods • Time required • Surface Pressure • Ease of implementation • FPP of Weak Formations

PETR 5000 - S. H. Emadi, PhD - Spring 2015

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