Optimization of Abandonment and Site Restoration Appraisal for Offshore Post-Operational Activities

Abstract Abandonment and Site Restoration (ASR) appraisal delivers a certain impact for oil and gas working area economic value. As the field becomes mature, the economical calculation has to be considered carefully. PSC operators are challenged to remain committing to execute the ASR plan at the end of the contract. The ASR appraisal is utilized by the PSC operators to deposit the amount of the fund for the upcoming ASR that may be handled. Appraisal method used in this paper is constructed based on Minister of Energy and Mineral Resources' Regulation about Post-Operational Activities, Procedures 040 set by SKK Migas regarding ASR and general guidelines for drilling and workover operations and also supporting guidelines from SNI 6910:2022. Natuna Block B, Sampang and Madura Offshore are three offshore working areas in Indonesia operated by a PSC operator that will ended at 2027 and 2028. The upcoming ASR are recalculated based on the existing contract, the possible technology applied nowadays and the optimization strategy in the effort to reduce the operating cost for well Plug and Abandonment (P&A) and Facility decommissioning. By optimizing the utilization of jack up rig and HWU, adding the in situ rig to reef scenario to jacket decommissioning, an acceleration in write-off process, the appraisal recommending a significant reduction on ASR costs. Further technology for Well P&A and ASR are highly expected to maintain the business sustainability. The appraisal method discussed in this paper can be a model for assessing and optimizing ASR costs in oil and gas blocks at other operators.