Sable Compression Facilities: Technical Overview
Authors: Stewart H.R. 
Published: October 2008

Introduction

The Sable Compression Platform is located in the North Atlantic offshore Nova Scotia Canada. It is part of the Sable Development Project that has been developed in phases. The first phase (Tier 1) was commenced in 1998 and completed in 1999 with gas flowing from the Tier 1 fields Thebaud, Venture and North Triumph. The next phase (Tier 2 Satellites) involved development of the Alma and South Venture fields, brought onstream in 2003 and 2004, respectively. In the final phase (Tier 2 Compression), central compression has been located at Thebaud in order to increase recovery of hydrocarbons as the fields decline. Gas production from the five fields flows through Compression and is transported via 26" pipeline to the onshore Goldboro gas plant (Ref 1). The Sable Compression project was sanctioned in October 2003, with fabrication commencing in January 2005, and the major offshore Hook Up and Commissioning (HUC) campaign executed from May through to October 2006. Start up was achieved on 14 November 2006. This paper will provide a technical overview of the project and will highlight some topical aspects of its design and execution.

Key Features -200 kms offshore29m waterdepthMax design wave ht: 21mVery dense sand foundation8 leg Jacket 2800 mtons8 No. 84" thru leg piles 3200 mtonsSingle lift topsides 7600 mtonsDesign temperature: -20C to +35CBridge 50m long & 320mtons

Figure 1 - Photograph of Thebaud Compression Platform viewed from the Southwest (available in full paper)

Execution Overview

The front end engineering design (FEED) including scoping engineering was completed by KSLO, a joint venture between SNC Lavalin and Aker Kvaerner, Inc. during 2002 and 2003. After a tender period, the majority of the Sable Compression Project was executed under a single Engineering, Procurement, Construction and Installation (EPCI) contract, awarded to Saiwoo Contracting (SW), a joint venture partnership between Daewoo Shipbuilding and Marine Engineering Co., Ltd. (DSME) and Saipem S.p.A. (Saipem). The SW scope was divided into five main work packages with DSME responsible for the topsides (Deck and Bridge) and offshore Hook-Up and Commissioning (HUC); and Saipem responsible for the Jacket and Piles, Transportation and Installation (T&I) and Brownfield fabrication and installation. Detailed design and engineering was subcontracted and split between AKI for the topsides, SNCL for the Brownfield tieins and Saipem for the jacket design and fabrication. One single project management team was established in Halifax and staffed with personnel seconded from DSME and Saipem, both expatriate and Nova Scotian.

The Company Brownfield "cut-ins" scope was identified to minimize and control interference and shutdown of the production operations. This scope, which included direct piping cut-ins to the existing Thebaud systems, was contracted to Accent Engineering for design, procurement and onshore fabrication with the offshore scope executed by Company. Interface management of the 'integrated' systems and facilities was performed by SW PMT (Project Management Team) and Company.