Simulating suspended solids generated during offshore pipelines installation and trenching

A consortium of petroleum companies in Malaysia is currently embarking on a project to develop oil and gas reserves offshore Sabah, Malaysia in Teluk Kimanis. Oil transport pipeline will be installed to transport hydrocarbons from the offshore platform to the plant located near the coast of Kimanis. It is anticipated there will be suspension of solids in the sea during the installation of the pipelines and offshore trenching activities. There were concerns that the suspended solids (SS) generated from these activities might cause negative impact to the marine ecosystem in Pulau Tiga Marine Park, for which an Environmental Impact Assessment (EIA) is needed for mitigation. This paper presents a brief exposition of this EIA study, with particular reference to model simulations on hydrodynamic regimes and SS in the Teluk Kimanis. Model simulations show that the SS plumes are visible only in the immediate vicinity of the SS release location, within a radius of 3-4 km. Hence, there is no possibility that the released SS will ever reach the Pulau Tiga Marine Park, which is located at more than 20 km away. Further, the SS concentration generated in the vicinity of the pipeline trenching will quickly decay to low levels one day after the discharge is discontinued.