GRP High Pressure Pipelines for Australia- Why and How? -

• Composite Glass Reinforced Plastic (GRP) is particularly suited to high pressure pipelines in corrosive services. Glass Reinforced Epoxy (GRE) is fast becoming a material of choice for oilfield pipelines where it can provide a whole of field life service. Application of GRE to low pressure and non-corrosive services can be expected.

• AS 2885 is the recognised standard for high pressure petroleum pipelines and currently allows GRP as an “alternative material” but otherwise provides little guidance for its application. There is a need for an appropriate inclusion of GRP materials in AS 2885 to address various regulatory and technical issues associated with use of the material.

• A number of outstanding issues will need to be addressed for GRP to be widely accepted by regulators, designer, constructors and owners as a competitive AS 2885 pipeline material. Pipeline industry input to the subject is essential to identify and manage the risks inherent with the introduction of this “new” material and the benefits it can bring to the industry.

• APIA WA Chapter Seminar 23 June 2006 - Perth• Dennis Kirk-Burnnand – Senior Engineering Specialist• PCT Engineers, Level 4, 15 William St, Perth WA 6000 • tel: +61 8 6462 1900 fax: +61 8 6462 1919 web: www.pct.com.au• Sponsored by: Alinta Asset Management and FiberGlass Systems

GRP High Pressure Pipelines for AustraliaWhy and How?

• Agenda:

– Benefits and Need for GRP Pipelines– Current Application of GRE Pipelines– GRP Materials inclusion in AS 2885– Standards for Manufacture, Design and Installation– Basic Design Methodology for GRE Pipelines– Design and Construction Outcomes– Issues to be Resolved

Benefits and Need for GRP Pipelines• Difficult Services

– GRP is particularly suited to corrosive services such as well production fluids, wet or sour gas, produced water, waterflood and other corrosive fluids.

– Overcomes Internal and External Corrosion– Overcomes Difficult CP Conditions– Satisfies Tight Environmental Restrictions (e.g. History of Leaks, Installation Footprint)– Changing material prices (GRE vs CS vs HDPE) will affect the rate of GRE growth

• Whole of Life Solutions– With careful design and despite the difficult services GRP can provide a leak free, system for

in excess of 20 years. In many applications this constitutes a near maintenance free, whole of life solution. For other materials, such as CS, special coatings, tight quality assurance measures, continuous CP and chemical corrosion protection, regular inspections, pigging surveys, high maintenance and replacement may be necessary for the pipeline to last this long.

– However a successful GRE design requires a level of excellence in materials, manufacture, design, installation and maintenance. All these must be at a level comparable with that required by AS 2885 for steel pipelines. Backyard solutions will not always provide such an outcome.

• Cost Effective– Competitive Initial CAPEX (vs CS, PE) plus Low Ongoing OPEX (vs CS) will lead to GRE use

even in non corrosive and low pressure services (e.g. Dry Gas Transmission and Distribution Mains).

Current Application of GRE Pipelines• Glass Reinforced Epoxy (GRE) pipe is finding use in Australian high pressure

pipelines yet this material is not well addressed by the applicable Standards. As a consequence the regulatory framework and technical requirements for its use are not clear.

– High pressure GRP Pipelines have been used in Australia for around 20 years and will shortly total in excess of 1,200 km with operating pressures up to 10 MPa

– Current GRP pipeline applications in Australia include hydrocarbon production flowlines, field gathering systems, produced water handling/disposal and waterflood systems.

– Many of these pipelines come under the cover of AS 2885 but are typically non-registered pipelines within oil and gas production licence areas. As a consequence GRE has to date had a relatively low profile with State Regulators.

– Tightening environmental requirements, risk management processes and changing material prices are expected to lead to increased utilisation of GRP materials. The growth can be expected in the current service areas and through expansion into new areas such as Coal Seam Methane (CSM), Coal Mine Methane (CMM). For CSM and CMM applications GRE offers the prospect of high pressure wet gas gathering pipelines from infield production manifolds to centralised gas treatment facilities.

– The expected growth will inevitably lead to increased application of GRP on registered pipelines and the possibility of service on Pipeline Laterals, Transmission Pipelines and City Gas Reticulation Networks.

GRP Materials inclusion in AS 2885

• Petroleum pipelines in Australia rely heavily on AS 2885 which aims to be the “single and sufficient” Standard for high pressure pipeline design, construction and operation. For GRP to be an accepted component of this industry it is necessary to establish an appropriate technical framework for this material. Such a framework should demonstrably “meet the intent of AS 2885” which already provides well established and detailed technical criteria for steel pipelines.

• AS 2885 currently allows for the use of GRE as an “alternative material” and the current draft includes limited references to GRE and applicable Standards for pipe manufacture and design. Further detail is necessary to address the appropriate inclusion of GRE material as a real alternative for Australian pipelines and to provide guidance to manage the risks associated with its use on pipelines.

Standards for Manufacture, Design and Installation• Many national and international standards exist for GRE and several

have been considered including ASME B31.3 Section VII, API 15LR,API 15HR, UKOOA Specifications and Recommended Practices, Shell DEP 31.38.70.24 and ISO 14692 (developed from the UKOOA specifications and the Shell DEP).

• ISO 14692 has already been proposed as being the most appropriate Standard and is now included in the AS 2885 Draft to provide a technical framework for GRE pipeline manufacture, design, construction and maintenance.

• Other Standards already included are API 15HR as an alternative for pipe manufacture and AS 2566 for analysis of burial and road crossing loads.

• The ISO 14692 Standard is relatively new and includes a number of errors and issues yet to be resolved. Several issues noted during PCT’s design have lead to the ISO Committee being reactivated and significant revisions are likely to result.

• Refer to www.iso14692.co.uk

• Based on known failure conditions plus suitable design margins• Failure and Design Stress Envelopes - Anisotropic Material• Considers all stress inducing loads and Load Combinations • Stress Analysis using conventional tools Roark’s Formulas, Caesar II, FEA• Temperature, Fluid Type and Cyclic or Transient Loading correction factors• Anchors and expansion management via Expansion Loops & Elbows• High Thermal Expansion and Low Elastic Modulus• Strength of Pipe vs Joints vs Fittings• Support Spans and Deflections• Wall Thickness Calculation • Installation Curvature• Water hammer• UV Protection• Flotation• Static and Electrostatic Properties in Dry Gas service

Basic Design Methodology for GRE Pipelines

Ssa(0:1)

Ssh(2:1)

Tp1000

Plthp

Pq (=Plcl)

Psthp

Sqs

Sal(0:1)

Sfs

Salf

Pqf

Sh.sum.max

Sa.sum.left

Pd.max

0

20

40

60

80

100

120

140

160

0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0

Hoop Tensile Stress (MPa)

Axi

al T

ensi

le S

tres

s (M

Pa) Idealised Short Term Failure Envelope

Simplif ied Short Term Failure Envelope1000 hr Hydrotest Failure PressureLong Term Hydrotest Failure PressureSlope 2:1Slope 1:1Qualif ied Stress EnvelopeFactored Stress EnvelopeAllow able Sustained Load

f scale

A1.A2.A3f2=0.67

Pressure in Unrestrained Pipe Slope = 2:1

f1

1/10^2.2xG

Tested Failure Conditions

Sa.max for non pressure condition

Pd.max and Sh.max for unrestrained pipe condition

Slope = 1:1

Failure Envelope

Design Methodology 2:1

σsa(0:1)

σsh(2:1)

σsa(2:1)

σqs

σal(0:1)

σal(2:1)

σaf (0:1)

σf s

σaf (2:1)

σa,des (2:1)

σh,des

σa,des (0:1)

σh,sum

σap

σab

Hoop Tensile Stress (MPa)

Axi

al T

ensi

le S

tress

(MPa

)

fscale

A0, A1, A2, A3

f2

f3

KEY1 schematic representation of the short-term failure envelope2 idealized short-term failure envelope3 qualif ied long-term failure envelope at standard conditions4 factored qualif ied long-term failure envelope at project conditions5 long term design envelope

a For design Purposes, the shape should be based on actual measured data points

1a

2

3

4

5

Note:i) σsa(2:1) is the 97.5% low er confidence levelresult obtained in accordance w ith ASTM D1599 testingii) σsa(0:1) is the 97.5% low er confidence level result obtained in accordance w ith ASTM D2105 testingiii) σal(2:1) is the 97.5% low er confidence level result obtained in accordance w ith ASTM D2992 testing

σa, sum

Design Outcomes

Construction

Issues to be Resolved• Compressive Stress Envelope• Hazardous Area Rating at joints• Pipe Locating• Abrasion – Internal, External• Fire Damage• Long Term Limit for Short Term

Loading• Impact – Stone Damage• Gauging• Hydrotest x1.25 vs x1.5• Anchors on Above Ground Pipelines• Anchors on buried Pipelines• Anchor Design• Support Design• Local Support Stresses• Restrained Pipe Stresses – above

ground• Restrained Pipe Stress – buried

• Road Crossing Design to AS 2566• Fracture Control• MAOP Selection• Penetration Resistance• Release Rates• Third Party Protection Measures• NDT Technology and Methods• Field Repairs• Regulatory path to AS 2885 for each

State• Non petroleum pipelines in AS 2885

Issues to be Resolved• PCT Engineers and Australian businesses are leading the

way towards a brighter future for GRE as a credible high pressure pipeline material.

• The benefits in difficult applications are already clear and it is likely that GRE will find wider application in general pipeline services.

• Development of the regulatory framework and application of sound design practices are key elements of this growth but need involvement by the industry if the benefits are to be realised.