The Success Case of the Decontamination of Production Sealines in the Gulf of Thailand

Abstract Oil and Gas Pipelines usually contain many contaminants from their long operational services in production. Prior to abandonment of a pipeline at the end of production, the environmental impact due to decommissioning must be assessed in order that the best pipeline decommissioning option, i.e. leave-in-place or by total removal, can be selected. In case of leave-in-place is selected, the decontamination of pipeline shall be performed so that the contaminant concentration is less than an acceptable level. PTTEP have developed own technologies to cover all scopes of decontamination works including contaminant measurement in pipeline since 2015. R&D were performed through technical survey, proof-of-concept, prototype testing, field testing to full deployment to 3 pipelines. The R&D were performed with academic/research institutes, contractors/manufacturers and government bodies. The R&D were divided into 3 main activities: Decontamination Methodology, Decontamination Chemical, Intelligent Sampling Pig. In 2021, PTTEP commenced the full decontamination using these own developments on three pipeline in the Gulf of Thailand to support the option selection of pipeline decommissioning. In this report, the summary of the overall pipeline decontamination process including the technology trial of all 3 R&D activities of three pipelines are described.