asm houston chapter - full-scale testing of composite pipeline repairs for use … · 2017. 2....

Full-scale Testing of Composite Pipeline Repairs for Use in Advanced Applications

ASM Houston Chapter Seminar: Materials Selection and Corrosion Management in Oil Field Environments

Date: 7 February 2017 Prepared by: Colton Sheets

Associate

SES Document No.: xxxxxxx-EN-PT-01 (Rev 0)

2an employee-owned company

Presentation Purpose

• Provide an overview of recent studies investigating the use of composite repairs for advanced applications. Additionally will touch on the development of composite repairs and future investigations.

• Outline Composite repair overview

Industry standards

Design philosophies

Recent studies

Future work

Summary

Questions


Composite Repair Overview

• Composite materials are used to add strength to damaged pipelines

• Although originally used for repairing corrosion, suitable applications and use of composite materials has expanded

• Long-term performance continues to be the primary concern for our industry

• Our knowledge is increasing rapidly

• Full-scale destructive testing is essential for us to understand how these repair systems work

Armor Plate Pipe Wrap


Composite Repair Overview: Components of a Repair System

Composite material

Damaged pipe material

Keys to proper reinforcement of damaged

pipelines:

• Load transfer material stiffness

• Stiffness of composite wrap

• Quality installation and materials

Load transfer material


Composite Repair Overview: Target Applications of Repairs

• Gas and Liquid Pipelines

• Water Pipelines

• Small Utility Lines

• Chemical Plants

• Gas Plants and Refineries

• Offshore Facilities

Furmanite

Clock Spring


Composite Repair Overview: Uses of Composite Materials

(repair and structural reinforcement)

• Metal wall loss (due to corrosion)

• Plain dents

• Mechanical damage (dents with a gouge)

• Re-rating pipeline system to achieve higher operating pressures

• Reinforcing sections like branch connections


Composite Repair Overview: Composite Design Fundamentals

• Strength and stiffness of the composite material

• Environmental effects (e.g. cathodic disbondment, temperature, acids and alkalines)

• Effects of loading including pressure (both static and cyclic)

• Mechanics of load transfer from pipe to wrap

• Long-term performance issues

• Consistency in application and quality control in manufacturing


Composite Repair Overview

• Composites widely accepted and used in repairing non-leaking transmission pipelines

• Plants use composite materials, including repair of leaks

• Since 1994, Stress has tested more than 25 different composite repair systems

• Much of the early funding provided by manufacturers, although more recently operators providing much of the funding

• Although composite repair systems can be specifically designed for unique applications, the ASME PCC-2 Standard, Repair of Pressure Equipment and Pipe (Part 4 – Nonmetallic and Bonded Repairs) has provided a common basis for evaluating composite technology


Industry Standards

• ASME PCC-2 (and ISO 24817)

• Part 4 – Nonmetallic and Bonded Repairs

• Committee is active and standard is developing to meet industries’ needs

• Key benefit to industry is uniformityand establishing minimum design requirements

• Operator/end user involvement is key

(2006, 2008, 2011, and 2015 editions)


Industry Standards: Repair Design Philosophy

• Within ASME PCC-2 there are three basic approaches for determining the minimum required thickness for a particular composite material in repairing corrosion:

Section 3.4.3 Pipe Allowable Stress

Section 3.4.4 Repair Laminate Allowable Strains

Section 3.4.5 Repair Laminate Allowable Stresses Determined by Performance Testing

• The standards only permit a reduction in repair thickness when accompanied by confidence in performance (i.e. reward for rigor)


ASME PCC-2 Equation Number

ASME PCC-2 Equation

Calculated Values (see Notes below for variable values)

(3) sc

smin P-P

E

E

2s

Dt

0.787 inches

(6)

s

cc

min st 2

D P

E

1t

0.306 inches

(11)

lt

smins f

1st-

2

D Pt 0.138 inches

Industry Standards: Repair Design Philosophy

Notes (input variables used in above equations)

Es 30 x 106 psi (steel pipe modulus)

Ec 4.5 x 106 psi (composite laminate modulus)

s 42,000 psi (pipe Minimum Specified Yield Strength, or SMYS)

P 1,778 psi (MAOP)

Ps 1,000 psi (de-rated operating pressure due to presence of corrosion)

t 0.375 inches (pipe nominal wall thickness)

εc 0.25% (allowable long-term composite strain from ASME PCC-2 Table 4)

f 0.5 (Service Factor from ASME PCC-2 Table 5)

slt 50,000 psi (long-term composite strength based on ASME PCC-2 Appendix V directives)

ts 0.188 inches (remaining pipe wall thickness due to corrosion)

Repair of 12.75-inch x 0.375-inch, Grade X42 pipe with 50% corrosion

Stress-based

Strain-based

1,000 hour

test based


RECENT JOINT INDUSTRY STUDIES


Joint Industry Studies: Crack Reinforcement

1 2

3 4

Pipe I.D.

Pipe O.D.


Joint Industry Studies – Crack Reinforcement

• Driven by increasing interest in using composite repair systems to reinforce non-leaking, crack defects.

• Although not widely accepted, this technique has received approval from regulatory bodies in specific cases.

• Can crack reinforcement follow the same path as corrosion reinforcement?

Have the necessary test data and analysis

Characteristics of an acceptable design

Calculate required repair thickness / stiffness



• Concerns over long-term performance

Sustained and cyclic loads

Are composites able to slow fatigue growth?

• Sustained load

Burst test 50% WT

• Cyclic loads

Three (3) 15% WT

Three (3) 50% WT

• Cycle pressure range

10% to 72% SMYS

124 psi to 892 psi



• Burst samples failed in pipe outside of repair Reached tensile strength of

pipe

• 10 of the 26 fatigue samples reached runout of 250,000 cycles Mostly 50% WT notch

samples

• Minimum recorded cycles 15% Notch – 41,350

(Unreinforced – 24,325) 50% Notch – 11,765

(Unreinforced 532)


Joint Industry Studies: Wrinkle Bend Reinforcement


Joint Industry Studies – Wrinkle Bend Reinforcement

• A common technique in the U.S. (1930’s – 50’s) used to change a pipeline’s angle or elevation

• Often produced many closely spaced wrinkles

• Highly variable – no standard method for creating

• Can lead to cracking due to ground movement, thermal cycles


Joint Industry Studies – Wrinkle Bend Reinforcement

• Pressurize sample to 810 psi (72% SMYS) Pressure held between 750-850 psi

throughout test

• Cycled sample between -400 and 600 kip·ft bending moments (min/max moments) until through wall crack developed at wrinkle Axial stress range of ≈60 ksi Range determined from unreinforced test

results


Successfully Wrinkle Bend Reinforcement


Joint Industry Studies - Findings

• Composite repair systems have demonstrated ability to improve the performance of complex pipeline anomalies, opening the door for non-traditional repairs that are not addressed by industry standards

Both cyclic pressure fatigue life and ultimate failure pressure of simulated crack-like defects were increased when reinforced using composite repair systems

Every participating manufacturer extended the fatigue life of wrinkle bend anomalies

• Full-scale testing is essential to validating not only applications, but specific technologies

Not all systems are created equally when reinforcing complex anomalies

• Operators have many options when addressing integrity concerns


CONTINUED WORK


Continued/Future Work – Offshore Installations

• Offshore GoM installations currently restrict composite repairs to be effectively coatings

• What is the long-term performance of a structural offshore repair? Topsides, splash zone, subsea?

• 10,000-hr simulated study underway to investigate effects of subsea environment on composite repairs

• Intentional simulated delaminations introduced into the repairs


Continued/Future Work – Crack Reinforcement

• Continued crack growth studies

• Significant amounts of data collected

• Can we move toward standardization of crack reinforcement repairs?

0

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

0 50,000 100,000 150,000 200,000 250,000 300,000

Co

mp

osi

te S

tiff

ne

ss F

acto

r (E

*t =

lb/i

n)

Cycles to failure (n)

Crack Reinforcement Testing50% Samples | Composite Stiffness Factor | Runout = 250,000 cycles


Summary

• Composite repair technology continues to adapt to address more complex and technical challenges.

20 years ago corrosion reinforcement was not standardized

• Industry-wide performance studies allow for shared learning and investigation of new applications for existing technologies.

Makes complex full-scale testing more feasible

Adds to the existing body of research addressing the capabilities of composite repairs

• Results show promise but still significant work required before advanced applications can be implemented to existing standards.


Questions?

Colton Sheets

Associate

[email protected]

Office: 281-955-2900

Stress Engineering Services, Inc.

13800 Westfair East Dr.

Houston, TX 77041

mailto:[email protected]


Thank You!

asm houston chapter - full-scale testing of composite pipeline repairs for use … · 2017. 2....

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