Improving Efficiency, Cost, and Time in Offshore Well Operations Using the Selective Perforation Method: Application in Mahakam Offshore Campaign

Abstract The Mahakam Working Area consists of delta and offshore regions. Offshore interventions are usually done in campaigns, covering several wells on one platform using slickline, electricline, and coiled tubing units from an Accommodation Working Barge (AWB). Perforation is a common activity, but the traditional method—one gun for one reservoir in a single run—takes longer as more, thinner reservoir layers are targeted. This slows down production gains and increases costs. To address this issue, the selective perforation method is employed. This technique enables perforation of multiple reservoir targets in a single run, the operator able to make up 3 to 5 guns in one perforating gun assembly. The selective perforation method utilizes a unique electrical signal and address system to activate each perforating gun individually. The maximum number of guns in a single run is constrained by the pulling weight capacity of the electricline wire and the height limitations of the Pressure Control Equipment (PCE) stack-up. The selective perforation method offers a solution by simplifying the preparation of perforating gun sub-assemblies. With this method, perforation of three or more reservoir targets can be carried out selectively in a single run, thus reducing operational duration. By utilizing a unique address signal, the selective perforation method enables individual activation of each gun in the perforating assembly, allowing for a longer gun string and targeting more intervals in one run. The implementation of this method from January 2023 to May 2024 was successfully carried out on 110 wells, achieving a cost saving of IDR 62.98 billion. This study highlights the novel application of the selective perforation method in the Mahakam Working Area. The innovation lies in its capability to perforate multiple reservoir targets in a single run by assembling and selectively activating up to 3 to 5 perforating guns using a unique electrical signal and address system. As demonstrated in recent Mahakam field implementations, this method significantly reduces intervention duration and costs, while expediting production gains from targeted wells. This case study serves as a valuable reference for other operators seeking to optimize offshore well interventions, particularly in regions with similar operational constraints and challenges.