Design, Operation and Maintenance of Subsea High Integrity Pressure Protection System and Subsea Automated Pig Launcher for Shallow Water Gas Condensate Field Development in Malaysia

Abstract

This paper provides an overview of design, operation, and maintenance of Subsea High Integrity Pressure Protection System (HIPPS) and Subsea Automated Pig Launcher (SAPL) in a shallow water gas condensate field development offshore Sarawak, Malaysia. It will outline the key technical drivers for the subsea field architecture development and technology qualification programme that was undertaken to manage the risk and uncertainties with deployment and operation of new subsea technology. The shallow water field hereby denotes as "Field K" is located approximately 200 km offshore Sarawak, Malaysia at water depth of around 80 meter. The field consists of two (2) subsea wells and is expected to deliver non-associated gas at rate of 200 MMscf/d to a Central Processing Platform (CPP), located approximately 5 km away from the wells. The field was initially planned to be developed using a wellhead platform but mid-way through the project, it was decided for Field K to be developed using Subsea Production System (SPS) with the following key requirements: - Meet production target of 200 MMscf/d Achieve production availability of 96% Diverless philosophy throughout the field life Utilize the procured 24 inch Carbon Steel (CS) pipeline with design pressure of 83 barg Implement safety protection system that complies to Safety Integrity Level (SIL) 4 requirement to safeguard downstream facilities from the wells Closed in Tubing Head Pressure (CITHP) of 240 barg. Operational pigging to be carried out every 3 months and intelligent pigging every five (5) year for the 24 inch CS pipeline Any new technology to be implemented shall reach minimum Technology Readiness Level (TRL) 5 as per API 17N prior to its installation. A subsea technology screening and gap assessment was performed using API 17N and Company Internal Standards, and it was decided for the field to be developed using two 7 in. horizontal subsea tree, with two unit of Subsea HIPPS on manifold and retrievable Subsea Automated Pig Launcher at Pipeline End Termination (PLET). The field commenced its operation in December 2012 and was able to meet all the field key requirements identified. It was also the first subsea shallow water field that was designed, build, and operated by the Company. The paper will also highlight the key lessons learned and best practices during design, operation and maintenance that can be shared with other Operators and Industry. The paper will outline the design, operational consideration, and necessary technology qualification program for new/modified subsea technology i.e., Subsea HIPPS and Subsea Automated Pig Launcher prior to deployment.