Drilling Optimization in Mahakam Offshore Field Indonesia by Combining Multiple Shaped Geometry PDC Cutters and Motorized Rotary Steerable System Resulting in Step Change Performance and Substantial Value Creation.

Under the marginal remaining reserve condition, Pertamina Hulu Mahakam has been constantly initiating the ways to improve drilling efficiency thru sidetrack well. In the Q4 2022 to Q1 2023, sidetrack drilling campaign was conducted in existing Jempang Metulang (JM-1) platform, South Mahakam Field, which known as the most challenging among other Mahakam offshore fields. This paper provides a case study of performance improvement of five cased hole sidetrack wells (milling out 9-5/8in casing and drilling 8-1/2in hole section subsequently). The study started by analyzing main drilling problems in the field in which many offset wells experienced multiple BHA runs and severely low rate of penetration (ROP). The average OB ROP in the previous campaign was only 13 m/hr with maximum achievement 1,200-2,400 meters drilling interval per BHA run. In 2023 sidetrack drilling campaign, the main drilling objective is to achieve one-run to well TD, increase OB ROP and optimize well architecture design to drill with single 8-1/2in open hole. Several initiatives were then implemented of motorized RSS BHA utilization, fit-for-purpose bit selection design and proper job execution by applying optimum drilling parameter. The result of thorough improvement process follow-up shows a significant well cost reduction up to 10.4 MUSD including improvement 159% OB ROP with fastest value 40.6 m/hr. A new drilling record was achieved for longest 8-1/2in hole section of 3,346 meters in one run to well TD. On top of that, all the initiatives have been executed in a safe manner without any major operation issues and successfully unlock remaining marginal reserve to prolong the sustainability of Mahakam.