Subsea Asia JG 11 6 08 - Championing the UK subsea … services subsea asia jg 11_6_08.pdf ·...

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SUBSEA ASIA 11 th June 2008 Advances in Subsea and Deepwater Pipeline Pre-commissioning SUBSEA ASIA Advances in Subsea and Deepwater Pipeline Pre-commissioning John Grover 11 th June 2008

Transcript of Subsea Asia JG 11 6 08 - Championing the UK subsea … services subsea asia jg 11_6_08.pdf ·...

SUBSEA ASIA 11th June 2008Advances in Subsea and Deepwater Pipeline Pre-commissioning

SUBSEA ASIAAdvances in Subsea and Deepwater Pipeline Pre-commissioning

John Grover

11th June 2008

SUBSEA ASIA 11th June 2008Advances in Subsea and Deepwater Pipeline Pre-commissioning

Introduction

The increasing number of subsea and deepwater developments brings new challenges where there are no surface connections to the pipeline available for pipeline testing and pre-commissioning.

Once constructed / installed such subsea and deepwater systems still have to undergo certain pre-commissioning and commissioning operations, from initial flooding, gauging & testing up to final start up.

SUBSEA ASIA 11th June 2008Advances in Subsea and Deepwater Pipeline Pre-commissioning

Objective

• Flooding and pigging subsea pipelines using a Remote Flooding Module

• Pressurisation using subsea hydrotest oump• Use of smart gauge tools (SGT) to gauge

pipelines – allows the gauging of lines with reduced bore & testing without pig recovery.

• Use of subsea data loggers to record pressures and temperatures

• Use of systems to transmit this data to surface real-time during the test period

• A look at the next generation of technologies for deepwater pipeline pre-commissioning

Whilst the provision of such services in shallow water and topside-to-topside developments is routinely achieved, providing the same services at water depths in excess of 1,000m poses many challenges. In this paper we shall review the unique challenges in providing such services deepwater, and then review current / planned technologies including:

SUBSEA ASIA 11th June 2008Advances in Subsea and Deepwater Pipeline Pre-commissioning

Oil Pipeline Pre-commissioning

Fill line with treated & filtered water

Run sufficient cleaning pigs to meet agreed cleanliness

Prove internal bore by running a gauge pig of caliper tool

Perform hydrostatic strength test

Optional caliper survey / OOS survey

Line ready for commissioning / lay up

1 2 3

4 5 6

SUBSEA ASIA 11th June 2008Advances in Subsea and Deepwater Pipeline Pre-commissioning

Gas Pipeline Pre-commissioning

Steps 1 to 4 as for oil pipelines – line tested

Dewater & swab line to remove bulk water – run desal slug

Dry line to an agreed “dewpoint”using dry air or vacuum

Optional caliper survey / OOS survey

Line ready for commissioning / lay up

1 2 3

4 5 6Purge & pack the line with nitrogen gas

April 4th, 2003 BP Equipment Presentation Andy Barden

April 4th, 2003 BP Equipment Presentation Andy Barden

SUBSEA ASIA 11th June 2008Advances in Subsea and Deepwater Pipeline Pre-commissioning

Challenges in Deepwater EnvironmentHydrotesting is a common requirement for all deepwater pipelines & flexibles – here we review the unique challenge this brings subsea:

1. Large diameter line from surface vessel to deepwater PLET needed to flood the line with filtered, treated water

2. Long duration for water temperature to stabilise if surface water (say 25degC) used to flood line at 1000m WD (say 4degC)

3. Recovery of gauging tool to surface to verify mechanical condition prior to pressure testing

SUBSEA ASIA 11th June 2008Advances in Subsea and Deepwater Pipeline Pre-commissioning

Challenges in Deepwater EnvironmentHydrotesting is a common requirement for all deepwater pipelines & flexibles – here we review the unique challenge this brings subsea:

1. Large diameter line from surface vessel to deepwater PLET needed to flood the line with filtered, treated water – use of RFM eliminates the need for large diameter subsea downlines. Also SHP allows line to go straight in to hydrotest again saving timeand reducing risk

2. Long duration for water temperature to stabilise if surface water (say 25degC) used to flood line at 1000m WD (say 4degC) – the RFM floods the line using ambient temperature water meaning no stabilisation time

3. Recovery of gauging tool to surface to verify mechanical condition prior to pressure testing – the SGT (Smart Gauge Tool) allows results of gauging survey to be annunciated via a pingerand can then be left in for the test saving 1 recovery run

SUBSEA ASIA 11th June 2008Advances in Subsea and Deepwater Pipeline Pre-commissioning

RFM Overview

SUBSEA ASIA 11th June 2008Advances in Subsea and Deepwater Pipeline Pre-commissioning

RFM Overview

• Small, compact, light 4.2m x 3.2m x 2.5 / 6,000kg• Fully meets specifications• Chemicals on board, introduced by venturi• Filtration on board• Instrumentation onboard• Range of pipeline sizes, set to desired flowrate/pig speed

• Additional hydro-test capability if desired• Particularly beneficial in deepwater• ROV friendly - ROV Engineers Involved in Design

SUBSEA ASIA 11th June 2008Advances in Subsea and Deepwater Pipeline Pre-commissioning

SHP Overview

• BJ designed hydraulically driven test pump operated by ROV

• Various flows and pressures available, determined by available ROV power but circa 35 litres/minute to 600 Barg

• Eliminates the need for and downline• Can be fitted to RFM Boost Pump skid or stand alone skid

• Saves time vs. down-line deployment

PipelineNomial

bore (inches)

Length (metres)

Vol/bar (litres) Bar/min ex SHP Test Pressure

(bar)

Vol to test pressure (litres)

Time to test pressure (hours)

TS-WI-FL-01 12 9553 31.83 0.94 431 114523 7.62

TS-P-FL-01 10 9577 21.71 1.38 431 9921 5.20

TS-P-FL-02 10 9248 20.96 1.43 431 9580 5.02

TS-T-FL-01 8 9553 13.57 2.21 431 6210 3.25

TS-GL-FL-01 8 9479 13.47 2.23 431 6162 3.23

SUBSEA ASIA 11th June 2008Advances in Subsea and Deepwater Pipeline Pre-commissioning

SGT Overview

Developed using patented sensor / pressure vessel unit. Uses a segmented urethane disc to supplement the existing aluminiumgauge plate. by recording the number of deformations beyond the given tolerance. For deepwater pipelines this means the following:

• Smart gauge is run at flooding stage prior to hydrotest and is received in laydown head

• ROV / surface hydrophone picks up the signal and immediately confirms the success of the gauging run

• Hydrotest can then proceed without removal of the laydown head to inspect the gauge plate

• Fixed gauge plate is then rechecked upon final removal of the laydown head

SUBSEA ASIA 11th June 2008Advances in Subsea and Deepwater Pipeline Pre-commissioning

Subsea Data-logger Overview

• Can be connected to 4 lines at once saving time

• Monitors pipelines during hydrostatic test

• Records pressure and temperature

• Allows vessels to carry out other work

• Recovered and downloaded when convenient

• Deployed and recovered by ROV

• Can be linked to surface via BJ Update™ system

Video

SUBSEA ASIA 11th June 2008Advances in Subsea and Deepwater Pipeline Pre-commissioning

Subsea Operation

V

SUBSEA ASIA 11th June 2008Advances in Subsea and Deepwater Pipeline Pre-commissioning

Future DevelopmentsDEVELOPMENT

• Remote closing of valves at discharge end of pipeline under test

• Improved pig detection for both launch and receive

• Real time transmission of test data to surface using acoustic telemetry

BENEFIT

Saves 1 vessel move and 1 ROV deployment = $ and time saving

Removes need to “over-pump”during any subsea pigging operation = $ saving & environmental benefit

Already under field trials (BJ Update™) and soon operational –means vessel can work elsewhere during test = $ saving & improved vessel utilisation

SUBSEA ASIA 11th June 2008Advances in Subsea and Deepwater Pipeline Pre-commissioning

Summary & Conclusions

1. System design has a major impact on how a line can be tested andcommissioned – in Asia we are seeing many using complete subsea architecture with few permanent surface connections

2. The biggest risk in deepwater pipeline operations is making and maintaining the connection between the vessel and subsea connection

3. The cost of any support vessel required to support subsea pre-commissioning far outweighs the cost of the subsea pre-commissioning spread

4. Today it is possible to flood, gauge and hydrotest a deepwater pipeline without the use of any down-line – at BJ Services alone this technique has been successful employed on over 100 pipelines

5. As ROV size and hydraulic power increases it will be possible to run larger pumps improving flooding and testing time

6. Combining remote valve closing, remote data transmission and guaranteed pig location we can further reduce the risk whilst improving the efficiency of deepwater pipeline pre-commissioning