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those companies that support the programby allowing their professionals

to participate as Lecturers.

And special thanks to The American Institute of Mining, Metallurgical,p g gand Petroleum Engineers (AIME) for their contribution to the program.

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Recent Advances in Complex Well DesignRecent Advances in Complex Well Design

Phil Pattillo BP EPTG - HoustonPhil Pattillo, BP EPTG - Houston

Overview

• New loads and limitationsNew loads and limitations

− Thermal effects – annular pressure build-up

Designing with limited casing bore− Designing with limited casing bore

− Extreme landing tools

• Beyond “API designs”

− Probabilistic design considerations

− ISO 10400

3

Annular Pressure Build-up (APB)

Annular Pressure Buildup (APB)

• Origin of APB loadsOrigin of APB loads

• Mitigating APB

− Principles and solution categories

− Specific well construction tools

16 in. casing collapse from APB during circulation

5

The origin of APB

Mud LineMud Line

What do we do about 20"

16"this hydrocarbon bearing zone?

16

TOC?

6

APB depends on

• Mechanical and thermal properties of fluidMechanical and thermal properties of fluid

• Flexibility of the confining boundary

• Temperature increase• Temperature increase

Considering the fluid component,

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⎢⎡ 1

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⎢⎢⎣

⎡Δ−Δ=Δ p

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7

Mitigating APB

Brute Force Container Flexibility• Thick-walled casing

Fluid Properties

y• Vent the annulus

− Active path to surface

− Relief mechanismFluid Properties• Foam spacer

• Fluids with low psi/F

• Cement entire annulus

Relief mechanism

− Formation fracture/TOC

− Rupture disks

− Grooved casing• Cement entire annulus

Control the LoadV I l t d T bi (VIT)

− Grooved casing

• Annulus communication

• Syntactic foam

A id t d t l• Vacuum Insulated Tubing (VIT)

• Nitrogen blanket

• Gelled brine

• Avoid trapped pressures external to annulus

8

• Connection leak integrity

• Initial annulus pressure

Mitigating APB

Fluid PropertiesFluid Properties• Foam spacer

• Fluids with low psi/F

• Cement entire annulus

9

Mitigating APB

Container Flexibility• Vent the annulus

− Active path to surface

− Relief mechanism

− Formation fracture/TOC

− Rupture disks− Rupture disks

− Grooved casing

• Annulus communication

• Syntactic foam

• Avoid trapped pressures t l t l

10

external to annulus

Mitigating APB

Container Flexibility• Vent the annulus

− Active path to surface

− Relief mechanism

− Formation fracture/TOC

− Rupture disks− Rupture disks

− Grooved casing

• Annulus communication

• Syntactic foam

• Avoid trapped pressures t l t l

11

external to annulus

Mitigating APB

Outer Tube

Inner Tube

Outer TubeOuter Tube

Inner Tube

Connection

Vacuum Annulus

Weld

ConnectionConnection

Vacuum AnnulusVacuum Annulus

Weld

80 90 100 110 120 130 140Temperature, Deg F

Tubing “A” AnnulusTubing “A” AnnulusTubing “A” Annulus

Control the Load• Vacuum Insulated Tubing

Nitrogen blanket

5100

5150

5200

5250

5300th, f

t.

GelledBrine 2

• Nitrogen blanket

• Gelled brine

• Connection leak integrity

5300

5350

5400

5450

5500

Mea

sure

d D

ept

GelledBrine 1

12

Co ect o ea teg ty

• Initial annulus pressure5550

5600

Mitigating APB – Vacuum Insulated Tubing (VIT)

Temperature, Deg F

5100

5150

80 90 100 110 120 130

Gelled Brine 2

5200

5250

5300pth,

ft.

Connection

Outer Tube

Inner Tube

ConnectionConnection

Outer TubeOuter Tube

Inner Tube

5300

5350

5400

easu

red

Dep

Vacuum Annulus

Weld

Vacuum AnnulusVacuum Annulus

Weld

5450

5500

5550

Me

Gelled Brine 1

Tubing “A” AnnulusTubing “A” AnnulusTubing “A” Annulus

13

5600

Designing within wellbore limitations

Deepwater HPHT wells, maintaining hole size

RISK

36"

• Geometric constraints

36"

22" (224.0 ppf X-8

28"

18" (117.0 ppf N-8

36"

22"(Surface Casing)

28"− Minimum → production tubulars,

SSSV

− Maximum → 18-3/4 in. bore18 (117.0 ppf N 8

16" (97.0 ppf P-11

DE

PTH

18", 16"(Drilling Liners)

• Possible solutions

− Riserless drilling

− Managed pressure drilling13-5/8" (88.20 pp

11-7/8" (71.80 pp

H

13-5/8" (Deep Protective Casing)

11-7/8" (Drilling Liners)

Managed pressure drilling

− Designer muds

− Revisit casing risk profile

9-7/8" (62.8 ppf C

7" (38.0 ppf C-110

9-7/8" (Production casing or tiebacks)

7"

− Probability x consequence

− Recovery

− Empirical validation

15

7" (Production Liners)

− Empirical validation

− Solid expandable liners

Maintaining hole size - example

• 8-1/2 in. hole on bottom

• Production tubulars with

36 ���

28 ���

22 ���

36 ���

28 ���

22 ���

18,000+ psi internal yield

• 5-1/2 in. tubing

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• 9-3/8 in. upper tieback drift (subsurface safety valve)

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• Clearance outside tieback for APB mitigation (syntactic foam)

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Extreme landing loads

Landing strings and slip crushing

• Landing string static loadsLanding string static loads approaching 1.5 mm lbs

− Impulse load during trippingtripping

− Heave induced excitation

• Applicability of Reinhold-pp ySpiri

− To current systems?

T th li bl ?− To other slip problems?

18

Understanding slip systems

• Strain gauged samples indicateindicate

− Non-uniform loading

− Worst loading may be between inserts

14000

16000

18000

20000

22000

24000AXIAL TENSILE LOAD = 100,000 lb

AXIAL TENSILE LOAD = 300,000 lb

AXIAL TENSILE LOAD = 500,000 lb

AXIAL TENSILE LOAD = 700,000 lb

A S����� M���� � � L��� L����

4000

6000

8000

10000

12000

14000

p L, l

b/in

NUMBER OF LINE LOADS = 3YOUNG'S MODULUS = 30x106 psiPOISSON'S RATIO = 0.3YIELD POINT = 100,000 psiWALL THICKNESS = 0.5 inMEAN RADIUS = 3.0 in

AXIAL TENSILE LOAD = 900,000 lb

19

0

2000

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1w0, in.

AXIAL TENSILE LOAD FOR PIPE YIELD (WITH pL = 0) = 942,500 lb

Probabilistic design considerations

Detailed inspection data

21

Application – calculation of cross-sectional area

22

Application – detailed collapse prediction

• Line pipe samplesLine pipe samples

− X65, D/t 16-18+

• Detailed input

− Wall, diameter

− Axial, hoop σ-ε coupons

− Residual stress

• Full scale tests

− Pressure with bendingPressure with bending

− Collapse, propagation

• Excellent results (<3% no

23

(bending, 0-9% with bending)

Probabilistic advantage using rupture disks

• Disk pressures have tight,ABC

Disk pressures have tight, controlled tolerances (± 5% on rupture pressure)

• Contrast with 12 5% wall

Consider ifshoe plugs

• Contrast with 12.5% wall tolerance and 10-30 ksi tensile strength variation for casing body 7” Production Linercasing body

− Wide uncertainty of casing rupture and collapse pressures

7 Production LinerPipe Performance Uncertainty

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9-7/

8" C

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8" H

igh

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Pipe Performance Uncertainty

MIY

P R

atin

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9-7/

8" C

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ing

9-7/

8" H

igh

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API API

A�����D���

�collapse pressures

− Cannot count on outer string failing first

16" M 16" Barlow

16" Rupture

9-7/8" API Collapse

9-7/8" Tamano Collapse

16" M 16" Barlow

16" Rupture

9-7/8" API Collapse

9-7/8" Tamano CollapseC�������

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24

7,500 10,000 12,500 15,000 17,500

Pressure (psi)

7,500 10,000 12,500 15,000 17,500

Pressure (psi)P�������

ISO 10400 (New API 5C3)

Clause Subject Comments

1-5 Introduction, symbols

6 Triaxial yieldvon Mises yieldAxial yield, internal yield pressure as special casesas special cases

7 Ductile rupture All new

Collapse connections8-17 Collapse, connections, mass, elongation, etc. Identical to existing formulas

AnnexesDetails, derivations, performance property Probabilistic properties (from

25

Annexes performance property tables performance or production data)

Conclusions

• No lack of challenging problemsNo lack of challenging problems

− Continuing research on annular pressure mitigation

Rethinking old solutions− Rethinking old solutions

• Design stretch via probability

− Increasing support from standards

26