Successful of SK305 Artificial Reefing Decommissioning Project

Abstract

Abstract This paper will discuss on recent SK305 decommissioning project which had completed in November 2017. These two platforms had been total removal and been an artificial reef at Sarawak water in Malaysia. This paper will share on activity and best practices from early stage until completion which divided into phases Engineering, Preparation, Removal and Disposal and Post Decommissioning /Reefing activity. Preparation activities needed for decommissioning and reefing project start with Baseline survey at reef location, underwater inspection, and topside inspection. During the Engineering stage, facilities integrity checks, removal engineering and Transportation engineering been carried out. Cutting basis and cutting equipment been developed and identified. Performed reefing engineering to ensure lowering of the facilities is in control condition and reefed facilities are stable. Topside and jacket removal via single lifting accordingly been execute follows the procedure and engineering for smooth execution. Post decommissioning survey been carried out to assess the successful of the project. Baseline inspection, underwater inspection had provided some information to the contractor on the scope and reveal some of the uncertainties about the decommissioning project. Engineering study is critical when to ensure safe operation. Observed that actual operation is similar to the engineering's simulation where team had follow the engineering accordingly. Reefing engineering performed to ensure the facilities been placed at the right location and position. During offshore execution removal of facilities there are challenges we faced malfunction of the cutting/dredge equipment had led to use back up plan and innovative solution to utilized other available equipment available onboard (Diamond wire cutter, abrasive water jet internal cutter, dredger, soil plug removal, airlift, cutting torch etc.). Sequence of cutting also need to be consider to minimize the pinch effect of the facilities. Decommissioning Safety Case been developed for this project to registered and to close the remedial action plan which will help project not to oversight any critical activity and aspect that had been identified. Finally, the post decom/reefing survey had been carried and the result observed new marine growth and numbers of fishes at reefed platform and had concluded the successful of this decommissioning reefing project. This paper should be an interest to those who will exploring abandonment and decommissioning project which considering reefing as one of the decommissioning option. This paper will share on it process on materializing reefing of 2 platforms through Engineering, Preparation, Removal and Disposal (EPRD) approach contract. The novelty in this paper is on assurance that been made by Company via baseline and post reefing survey to ensure environment aspect been consider.