This paper describes the pipeline design and construction engineering of a submarine pipeline bundle pulled from an onshore stringing yard to a new jetty in the Gulf of Thailand. The jetty is located approximately 6.5 km from the coast off Petchburi, in a water depth of 10.7 m Chart Datum. The pipeline bundle system comprises of three 16-inch diameter pipelines coated externally with corrosion protection coating and concrete weight coating as well as the associated risers. Two of the three pipelines are used to transport diesel and the third is used to carry mogas. The engineering design of the pipelines and risers is discussed, followed by key aspects of the pipeline installation. Design and field results are presented.
The pulling of a submarine pipeline or a bundle of pipelines from shore to a location offshore often adopts the Bottom-Pull Installation Technique. Using this method, individual pipe joints are aligned and welded into continuous pipe strings and pulled into the water using a pull winch or a pull vessel. The pipeline stringing operation can be carried out either at a fabrication yard onshore near the landfall area or on board a lay vessel. The method is especially useful in areas with logistics problems or in shallow water regions where the vessel approach to shore is limited by its draught. The first bundled pipelines bottom pull in Asia took place in Singapore in 1981 where the Caltex/PCS bundled six lines were pulled across Jurong Fairway between Singapore and Pulau Merlimau (RJBA 1980). Since then there have been a number of single line and bundle pulls in the region, especially in Malaysia, Indonesia and Hong Kong. This paper describes the bottom pull design and installation of the Petchburi Terminal Company's (PTC) bundled pipelines in the Gulf of Thailand (see Figure A).
