| dc.description.abstract | Explo - 1x is an exploration well located on the outermost part of Sisi Field or 1.92 km from the nearest existing platform with ±72-meter water depth. Explo - 1x will be drilled vertically using jack up rig for about 275 days (P50). The objective of drilling Explo - 1x is to prove the potential hydrocarbon prospect at U6 and MF7 layer interval with target depth at 5255 mTVD. Explo - 1x is the most expensive and challenging exploration well in offshore Mahakam history with narrow mud weight window and potential loss (depleted layer) issues. Narrow pore pressure and fracture gradient profile can lead into a complex casing configuration. Explo - 1x consumes around 61.5 MMUSD with a total of 7 sections to be drilled, with a tieback configuration on the production section and tight casing clearance. This paper will do a feasibility assessment of simpler casing with different perspectives and justification to reach the optimized well cost of Explo – 1x. All the details of proposed improvement will be considering casing point selection, mud weight selection, casing size, casing clearance and casing grade selection. In addition, the proposed design also considers the casing wear simulation to check the thickness reduction which will impact to the reduction of casing burst and collapse rating. The study is comprehensive which includes the hydraulics simulation side to support the feasibility of this configuration by determining the minimum and maximum flowrate, ECD while drilling simulation, and surge effect while running casing simulation. The result of this study assessment is successful to prove the feasibility of simpler casing configuration of Explo - 1x that comes up with 6 sections, contributing to the cost reduction of up to 5 MMUSD and duration up to 18 days. | en_US |
