Following a nine-month engineering phase, offshore operations on Dalia have just started, and PSL is using its pioneering combined subsea pigging unit (SPU) and subsea hydrotest unit (SHU) for flooding, pigging and pressure testing of subsea pipelines; the company will also carry out topside and umbilical operations for the Greater Dalia field, which is located 230 km offshore in water depth up to 1500m.
PSL reports that it won the contract as a result of the successful completion of a similar workscope on the Baobab field in the Ivory Coast for CNR International. On this project, PSL pioneered its SPU/SHU concept in what is believed to be a world-first use of this type of subsea technology to facilitate the flooding, pigging, and pressure testing of subsea pipelines.
PSL developed and has successfully used its SPU to pig and flood pipelines on a number of deep-water projects but hydro-testing was traditionally performed independently of flooding and pigging operations, using hoses and pumps operated from a surface vessel which had considerable cost implications for clients. The new technology means significant savings can be made because smaller crew sizes and less equipment are needed for SPU/SHU work. The reliance on a dedicated multi-service vessel (MSV) being on location during the operations is also greatly reduced.
PSL’s workscope on the Dalia development is a further ‘first’, as it combines MSV-based, flowline pre-tie-in pigging and hydrotesting using the SPU/SHU, unit and FPSO-based conventional post-tie-in pigging and hydrotesting. It also includes pre- and post-tie-in testing of subsea, electrical, and hydraulic control umbilicals and fly leads within the one contract.
A number of other West African projects similar to the scale and complexity of Dalia are expected to go out to tender in the next 18 months, and PSL is confident that the expertise and technology which has made Dalia a success will be of great interest to operators in this region.
While the SPU/SHU was originally developed for deepwater projects, PSL has tailored the technology for use in shallower waters, and is soon to complete its first North Sea job with Acergy on the Britannia Satellites. Also in the UKCS, PSL continues to develop a long-standing relationship with Technip, and has just completed a year-long pipeline contract for all of Saipem’s North Sea projects. The company is also engaged in pipeline pigging, leak testing, and nitrogen testing for ChevronTexaco on a contract that has been continuing for several years.
PSL is also exploring the potential of several new trunk pipeline contracts. Managing director, Doug Duguid, said: “Gas delivery lines from Norway and Europe in to the UK feature larger-diameter pipelines while another area of interest is the Mediterranean where lines are being installed to deliver oil and gas from North Africa to southern Europe. We have worked on a number of trunk line projects in the Far East and feel we can bring this knowledge and technical expertise to the North Sea. Allied to our excellent track record in smaller-diameter pipelines, we think we have a lot to offer this sector of the market.”
The company’s recent investment of $3.5m on new equipment underlines its commitment to providing customers with modern and fit-for-purpose equipment. Doug Duguid added: “Our company has a ‘can-do’ culture for a ‘must-have’ industry, and our investment in both equipment and people in our pipelines division reflects that attitude.” Competency and training programmes have always been of critical importance to PSL, and the company’s competency-management systems have recently been approved by OPITO, which is the body responsible on behalf of the offshore industry for ensuring the quality and content of key safety and emergency training.