WORKOVER OPERATION IMPROVEMENT FOR WELLS WITH HIGH WELLHEAD ELEVATION AT “HUMAIRA” AREA

• Main Author: Budi Rudiantoro, Agung
• Format: Theses
• Language: Indonesia
• Subjects: Manajemen umum
• Online Access: https://digilib.itb.ac.id/gdl/view/55293
• Institution: Institut Teknologi Bandung

PT. Diamond Energy Indonesia (PT. DEI), located in Riau Province, is one of the largest oil producers in Indonesia. In responding to the dynamic fluctuations of oil and gas commodity prices in recent years, PT. DEI puts serious efforts to maintain oil production and reduce operational costs to assure their competitiveness in the oil and gas industry in the country. One of PT.DEI focus area is cost efficiency in the field of drilling and workover. One of the production assets operated by PT. DEI is the “Humaira” oil field where there are more than 2,000 oil and gas producer wells. Wells with high wellhead is the unique cases that become the subject of this project. The existence of wells with high wellhead elevation is due to the addition of a component to the wellhead (retrofit) which serves to improve the sealing ability of the installed wellhead design, or the subsidence of the soil surface of the well location due to erosion caused by rain or flooding. The high wellhead causes limited clearance of the rig working platform for installation of the blowout preventer (BO). Based on data during the period 2018 – 2020, there were an average of 51 cases per year related with wells with high wellhead and caused an additional annual workover cost of $1.48 MM. The Workover/Well service (WOWS) Department of PT. DEI seeks an effective solution to reduce the extra workover costs due to wells with high wellhead elevation issue. Root Cause Analysis was used to understand the root causes that contributes the extra workover costs refer to wells with high wellhead elevation. Interviews with Subject Matter Experts (SME) were conducted to explore alternative solutions covering technical, practical, safety and economic aspects. From the group discussion session, 8 possible alternative solutions were obtained, such as changing the wellhead design, altering the height of the working platform, using a class II 11” Blowout Preventer (BOP), utilizing side-outlet BOP, using 7-1/16” BOP class III, using concrete blocks to add rig elevation, soil backfilling to increase the rig carrier elevation, or maintaining current practice, which is combination of using 7-1/16” BOP class III and concrete blocks. The Kepner-Tregoe method was used to rank alternative solutions by considering the agreed objective criteria toward each alternative. From the eight possible alternative solutions, the use of BOP side-outlet as a substitute for drilling spool as to conduct well circulation was selected as the fit for purpose solution. With this solution, the problem of limited working platform clearance could be solved without compromising safety and compliance toward related industry standards. This solution is estimated to save workover costs due to additional equipment rental costs and potential production delays equivalent to USD 742,220.00 per year (P50 scenario).