SLGC / BCM
Operator: CABGOC/Chevron
Location: Block 0, offshore Angola

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The primary purpose of the Sanha Lean Gas Connection (SLGC) Project is to provide a Lean Gas Platform (LGP), subsea pipelines and structural capacity to deliver up to 480 MMscfd of gas, currently injected into the Sanha reservoir, to Angola LNG.

The SLGC is connected to the Sanha Condensate Complex for gas gathering and then forwarding it to Angola LNG via the Congo River Crossing (CRX) pipeline.

Lean Gas Platform comprises a Booster Compression Module (BCM), which is the top deck of the platform. The primary purpose of the BCM is to provide compression of up to 600 MMscfd of gas from CRX segment A, Mafumeira South Project (MSP) platform, and tie-in provision for a potential, future Malembo Gas Supply 2 (MGS2) project.

The facilities included:

  • A new fixed-leg jacket platform – LPG – to provide pressure let down valves for lean gas from Sanha, flow metering, gas chromatograph and moisture analyzer, cold flare overpressure protection system and integrate key processes and utilities;
  • 2 x 20” risers and Gas Pipelines to transport gas coming from CRX Segment A to CRX Segment B for onward transmission to ALNG;
  • A piping tie-in connection from the 20” CRX segment A pipeline to the inlet of future eductor system and the BCM;
  • 16” riser and gas pipeline to receive gas from MSP subsea skid and associated pig receiver/launcher;
  • Piping tie-in connection from the MSP pipeline to the inlet of future eductor system and the BCM
  • An instrument air generation package (sized to feed the Booster Compression Nitrogen Generation package);
  • Inter-connecting bridge from LGP to SCC to provide access;
  • Pressure relief and vent system with associated flare/vent boom cantilevered off LGP;
  • Brownfield tie-in work on the SCC for SLGC, including ESS, IC&E, communications, fire & gas, piping and structural modifications.
  • Module structure and substructure (for installation) that contain all BCM equipment and comprise the top deck of LGP, including: compressor trains with suction scrubbers and discharge coolers, nitrogen generation package, electrical building (including MCCs, MV Switchgear, and ASDs) and pedestal crane;
  • Brownfield tie-in work on the SCC for BCM, including 4160V switchgear modifications to include 2000A circuit breaker, installing compressor control panels, installing new integrated load shedding system, and installing associated cables across the inter-connecting bridge to and from electrical buildings.

 

 

General Services provided by SACOL on this project: Audit services as a legal requirement for official issuance of Operating License, including the issuing of a report on Commissioning and Start-up activities of the SLGC/BCM Project, located offshore on Block 0 – Angola.

1 – Chevron/CABGOC documentation reviewed:

  • Basis of Design (Platform & Pipelines);
  • Project Quality Management Plan;
  • Detailed Project Schedule (Fabrication / Assembly / Offshore Campaign / Commissioning / Start-Up);
  • Inspection and Test Plans;
  • NCR Management procedure and Registers;
  • Project HSE Plan.

2 – Project activities witnessed and audited:

  • Testing (FAT) – Line Pressure Test at 9000 psig (17 lines) / 5560 psig (28 lines) – at Sonamet yard in Lobito, Angola
  • Risers Fabrication – 20″ CRX-A Riser – at Sonamet yard in Lobito, Angola
  • Deck Erection – Diagonal Braces Welding – at Sonamet yard in Lobito, Angola
  • Compressor Pre-Alignment Check – at Sonamet yard in Lobito, Angola
  • Riser Completion – 20″ CRX-A Riser – at Sonamet yard in Lobito, Angola
  • Jacket Completion – Drift Test (Post Fabrication) – at Sonamet yard in Lobito, Angola
  • Booster Compression Module (BCM) – FAT Completion – at Sonamet yard in Lobito, Angola
  • Compressor Installation Completion (Loop Check on Compression Trains) – at Sonamet yard in Lobito, Angola
  • Jacket Load-Out – at Sonamet yard in Lobito, Angola
  • Jacket Installation (Preparation, Lift & Installation) – offshore Block 0, Angola
  • BCM (Installation & Completion Works) and Bridge Installation – offshore Block 0, Angola
  • LPG Gas Export, CRX A Riser Topside (Hook-Up Riser) – offshore Block 0, Angola
  • System 270 Gas Export & Metering (Commissioning – CTP) – offshore Block 0, Angola
  • PCP Platform (System 700 – Fire & Gas System) – offshore Block 0, Angola
  • System 230 Gas Compression (Train A CTP – Commissioning) – offshore Block 0, Angola
  • Start Up Event #2 at LGP (20-A CRX Gas Import Pipeline – Start-Up) – offshore Block 0, Angola
  • BCM System Completion (Commissioning) – offshore Block 0, Angola
  • Start Up Event #3 at LGP (Compressors Load Sharing) – offshore Block 0, Angola

 

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