SPE DISTINGUISHED LECTURER SERIESis funded principally

through a grant of the

SPE FOUNDATIONThe Society gratefully acknowledges

those companies that support the programby allowing their professionals

to participate as Lecturers.

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

Exploration & Production Technologydelivering breakthrough solutions

Recent Advances in Complex Well Design

Phil Pattillo, BP EPTG - Houston

3

Overview

• New loads and limitations

− Thermal effects – annular pressure build-up

− Designing with limited casing bore

− Extreme landing tools

• Beyond “API designs”

− Probabilistic design considerations

− ISO 10400

Annular Pressure Build-up (APB)

5

Annular Pressure Buildup (APB)

• Origin of APB loads

• Mitigating APB

− Principles and solution categories

− Specific well construction tools

16 in. casing collapse from APB during circulation

6

The origin of APB

What do we do about this hydrocarbon

bearing zone?

20"

16"

Mud Line

TOC?

7

APB depends on

• Mechanical and thermal properties of fluid

• Flexibility of the confining boundary

• Temperature increase

Considering the fluid component,

∆−∆=∆ p

CTVV

ffff

1α

8

Mitigating APB

Brute Force

• Thick-walled casing

Fluid Properties

• Foam spacer

• Fluids with low psi/F

• Cement entire annulus

Control the Load

• Vacuum Insulated Tubing (VIT)

• Nitrogen blanket

• Gelled brine

• Connection leak integrity

• Initial annulus pressure

Container Flexibility

• Vent the annulus

− Active path to surface

− Relief mechanism

− Formation fracture/TOC

− Rupture disks

− Grooved casing

• Annulus communication

• Syntactic foam

• Avoid trapped pressures external to annulus

9

Mitigating APB

Fluid Properties

• Foam spacer

• Fluids with low psi/F

• Cement entire annulus

10

Mitigating APB

Container Flexibility

• Vent the annulus

− Active path to surface

− Relief mechanism

− Formation fracture/TOC

− Rupture disks

− Grooved casing

• Annulus communication

• Syntactic foam

• Avoid trapped pressures external to annulus

11

Container Flexibility

• Vent the annulus

− Active path to surface

− Relief mechanism

− Formation fracture/TOC

− Rupture disks

− Grooved casing

• Annulus communication

• Syntactic foam

• Avoid trapped pressures external to annulus

Mitigating APB

12

Mitigating APB

Control the Load

• Vacuum Insulated Tubing

• Nitrogen blanket

• Gelled brine

• Connection leak integrity

• Initial annulus pressure

5100

5150

5200

5250

5300

5350

5400

5450

5500

5550

5600

80 90 100 110 120 130 140

Temperature, Deg F

Mea

su

red

Dep

th, f

t.

GelledBrine 2

GelledBrine 1

Connection

Outer Tube

Inner Tube

Vacuum Annulus

Tubing “A” Annulus

Weld

ConnectionConnection

Outer TubeOuter Tube

Inner Tube

Vacuum AnnulusVacuum Annulus

Tubing “A” AnnulusTubing “A” Annulus

Weld

13

5100

5150

5200

5250

5300

5350

5400

5450

5500

5550

5600

80 90 100 110 120 130

Temperature, Deg F

Me

as

ure

d D

ep

th, f

t.

Gelled Brine 1

Gelled Brine 2

Mitigating APB – Vacuum Insulated Tubing (VIT)

Connection

Outer Tube

Inner Tube

Vacuum Annulus

Tubing “A” Annulus

Weld

ConnectionConnection

Outer TubeOuter Tube

Inner Tube

Vacuum AnnulusVacuum Annulus

Tubing “A” AnnulusTubing “A” Annulus

Weld

Designing within wellbore limitations

15

36"

22" (224.0 ppf X-80)

13-5/8" (88.20 ppf HCQ-125)

9-7/8" (62.8 ppf C-110)

7" (38.0 ppf C-110)

28"

11-7/8" (71.80 ppf P-110)

18" (117.0 ppf N-80)

16" (97.0 ppf P-110)

RISK

DE

PT

H

36"

22"(Surface Casing)

13-5/8" (Deep Protective Casing)

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

7" (Production Liners)

28"

11-7/8" (Drilling Liners)

18", 16"(Drilling Liners)

Deepwater HPHT wells, maintaining hole size

• Geometric constraints

− Minimum → production tubulars, SSSV

− Maximum → 18-3/4 in. bore

• Possible solutions

− Riserless drilling

− Managed pressure drilling

− Designer muds

− Revisit casing risk profile

− Probability x consequence

− Recovery

− Empirical validation

− Solid expandable liners

16

Maintaining hole size - example

• 8-1/2 in. hole on bottom

• Production tubulars with 18,000+ psi internal yield

• 5-1/2 in. tubing

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

• Clearance outside tieback for APB mitigation (syntactic foam)

36”

28”

22” 224.0 ppf (1.000” wall) X-80

18” 117.0 ppf (0.625” wall) N-80

16” 97.0 ppf (0.575” wall) P-110

13-5/8” 88.20 ppf (0.625” wall) HCQ-125

11-7/8” 71.80 ppf (0.582” wall) P-110

9-7/8” 62.80 ppf (0.625 wall) C-110

7” 38.0 ppf (0.540” wall) C-110

36”

28”

22” 224.0 ppf (1.000” wall) X-80

18” 117.0 ppf (0.625” wall) N-80

16” 97.0 ppf (0.575” wall) P-110

13-5/8” 88.20 ppf (0.625” wall) HCQ-125

11-7/8” 71.80 ppf (0.582” wall) P-110

9-7/8” 62.80 ppf (0.625 wall) C-110

7” 38.0 ppf (0.540” wall) C-110

36 in.28 in.

22 in.

18 in.

16 in.

13-5/8 in.

11-7/8 in.

9-7/8 in.

7 in.

36”

28”

22” 224.0 ppf (1.000” wall) X-80

18” 117.0 ppf (0.625” wall) N-80

16” 128.6 ppf (0.781” wall) Q-125

13-3/4” 58.20 ppf (0.400” wall) P-110

12-1/4” 51.60 ppf (0.400” wall) P-110

10-3/4” 108.70 ppf (1.047” wall) C-110

7” 42.70 ppf (0.625” wall) CRA-125

11-3/4” ppf 126.20 (1.109” wall) C-110 x 10-3/4” ppf 108.70 (1.047” wall) C-110

36”

28”

22” 224.0 ppf (1.000” wall) X-80

18” 117.0 ppf (0.625” wall) N-80

16” 128.6 ppf (0.781” wall) Q-125

13-3/4” 58.20 ppf (0.400” wall) P-110

12-1/4” 51.60 ppf (0.400” wall) P-110

10-3/4” 108.70 ppf (1.047” wall) C-110

7” 42.70 ppf (0.625” wall) CRA-125

11-3/4” ppf 126.20 (1.109” wall) C-110 x 10-3/4” ppf 108.70 (1.047” wall) C-110

Or SET?

36 in.28 in.

22 in.

18 in.

16 in.

13-3/4 in.

12-1/4 in.

10-3/4 in.

7 in.

Tieback

Extreme landing loads

18

Landing strings and slip crushing

• Landing string static loads approaching 1.5 mm lbs

− Impulse load during tripping

− Heave induced excitation

• Applicability of Reinhold-Spiri

− To current systems?

− To other slip problems?

19

Understanding slip systems

• Strain gauged samples indicate

− Non-uniform loading

− Worst loading may be between inserts

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

22000

24000

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1

w0, in.

pL, l

b/in

NUMBER OF LINE LOADS = 3

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

AXIAL TENSILE LOAD = 100,000 lbAXIAL TENSILE LOAD = 300,000 lb

AXIAL TENSILE LOAD = 500,000 lb

AXIAL TENSILE LOAD = 700,000 lb

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

AXIAL TENSILE LOAD = 900,000 lb

A Simple Model - n Line Loads

Probabilistic design considerations

21

Detailed inspection data

22

Application – calculation of cross-sectional area

23

Application – detailed collapse prediction

• Line pipe samples

− X65, D/t 16-18+

• Detailed input

− Wall, diameter

− Axial, hoop σ-ε coupons

− Residual stress

• Full scale tests

− Pressure with bending

− Collapse, propagation

• Excellent results (<3% no bending, 0-9% with bending)

24

Probabilistic advantage using rupture disks

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

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

− Wide uncertainty of casing rupture and collapse pressures

− Cannot count on outer string failing first

7” Production Liner

Consider ifshoe plugs

ABC

Pipe Performance Uncertainty

16"

MIY

P R

atin

g

9-7

/8"

Col

llaps

e R

atin

g

9-7/

8" H

igh

Col

laps

e R

atin

g

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

Pressure (psi)

16" Barlow

16" Rupture

9-7/8" API Collapse

9-7/8" Tamano Collapse

Pipe Performance Uncertainty

16"

MIY

P R

atin

g

9-7

/8"

Col

llaps

e R

atin

g

9-7/

8" H

igh

Col

laps

e R

atin

g

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

Pressure (psi)

16" Barlow

16" Rupture

9-7/8" API Collapse

9-7/8" Tamano Collapse

Pressure

API API

Actual

Collapse

Burst

DiskF

req

uen

cy

25

ISO 10400 (New API 5C3)

Probabilistic properties (from performance or production data)

Details, derivations, performance property tables

Annexes

Identical to existing formulasCollapse, connections, mass, elongation, etc.

8-17

All newDuctile rupture7

von Mises yield

Axial yield, internal yield pressure as special cases

Triaxial yield6

Introduction, symbols1-5

CommentsSubjectClause

26

Conclusions

• No lack of challenging problems

− Continuing research on annular pressure mitigation

− Rethinking old solutions

• Design stretch via probability

− Increasing support from standards