STRATEGIC DECISION ANALYSIS TO ACCELERATE PLUG & ABANDONMENT PROJECT AT SUMATRA BLOCK

• Main Author: Budi Utomo, Santoso
• Format: Theses
• Language: Indonesia
• Subjects: Manajemen umum
• Online Access: https://digilib.itb.ac.id/gdl/view/53548
• Institution: Institut Teknologi Bandung

Asset and site restoration become a critical process for any oil and gas exploration and exploitation operation. It is a mandatory for any production operator to ensure the ex-location of an oil or gas well are fully recovered as environmental-friendly habitat. One of the initial process of the asset and site restoration is well’s subsurface plug and abandonment operation. The main objective of subsurface plug and abandonment operation is to set a mechanical barrier (cement plugs) inside and outside wellbore to ensure sealing between each hydrocarbon zones and between hydrocarbon zones to surface. During the last 3 years, PT. Pacific Oil Company ( not a real name) has been actively conducted plug and abandonment projects as per government rules and regulations. The challenge came in lately for 2019 plug and abandonment project. There was a long discussion on the project approval process because the government decided not to extend the permit for the company to continue operate the concession block. After those long discussion and approval process, the project was approved to be executed in 2020. Then another challenge came to complete the project in a shorter duration due to handover process from the company to the new operator. In the previous years, the duration of the project was about 9-10 months. For this project, the company management gave the target to complete the project less than 7 months. The project team conduct a brainstorm session to gather any ideas how to achieve the management direction. The project team used conceptual framework of why tree analysis and conducted a thorough review to generates the possible alternatives. By conducting a brainstorm session in the team meeting and discussion, there are 5 major elements that may have impact to the project schedule: work program/procedures, organization capability, tools and services, well’s equipment and materials, and environmental. Based on several focus group discussions, it is concluded that the most significant and direct impact on accelerating the plug and abandonment project is by adding new unit to execute the project. To add a new unit, the project team select 3 (three) possible alternatives: Add new rig, Reallocate workover/well service rig, combine rig and coil tubing unit. There were 3 (three) decision criteria for this process: Project schedule uncertainty, Impact to production, Total cost of action. Then the project team used analytic hierarchy process to compare each alternative and calculate 2 the best alternative for the project execution. The final calculated scores are Add new rig (0.339), Re-allocate workover/well service rig (0.292), combine rig and coil tubing unit (0.369). Based on the final calculated score, the selected alternative was using a combination of rig and coil tubing unit to execute plug and abandonment project. The proposed alternative will require low efforts to achieve the project schedule target but maintaining the production target and keep the total cost under budget. It was proven that the combination of rig and coil tubing unit can accelerate the completion of plug and abandonment project. During the implementation period, the project team conducted verification and validation of the decision. It was found that there was a challenging issue on the scheduling strategy, especially on the location preparation. So, the schedule was mixed between the normal wells and the hybrid wells, whichever location ready first. However, the overall result was good for the company.