Collaborative Well Planning as a Key to Efficient And Successful Complex Geological Sidetracks Planning And Monitoring in Overpressured Deepwater Environment: A Case Study From Malaysia's Fast-Track Deepwater Well

Abstract

The past decade has given rise to deepwater wells in Malaysia as exploration began to outreach deepwater geological targets. Major discoveries with significant amounts of oil and gas reserves have been made. However, this environment is known for hazardous subsurface conditions that pose numerous challenges to drilling operations. Hence, accurate well planning is essential in this environment. This paper describes the role of collaborative well planning (CWP) for the successful delivery of complex overpressured deepwater exploration side-tracks and discusses planning and well monitoring for B-3 ST1, an appraisal well offshore Sabah, Malaysia. The well was drilled to evaluate the presence of oil in a gas block discovered by the previous two (2) offset wells. These offset wells were drilled into overpressured zone with a myriad of wellbore issues, such as stuck pipes, losses, kicks, and running out of the drilling window, which finally led to early total depth (TD). Despite such issues, the well was intended to be a fast-track well, planned for less than two (2) months instead of the normal lead time of 12 to 18 months. The fast-track nature of the well requires meticulous designed well planning due to its hazardous nature and extremely condensed time frame. The CWP model and technology employed from PETRONAS Real Time Visualization Center (PRTVC) were used for Well B-3 ST1 to meet the objectives. The model combines all stakeholders from various departments into the decision room, while the technology helps display and collaboratively analyses all available data. Geological, well design and surface and subsurface hazards were carefully considered. The result was the primary well location, and six (6) geological side-track scenarios were accomplished in just one day. It is also worth noting that this CWP concept is the first of its kind applied in Malaysia. The CWP was used again during drilling wherein a multidisciplinary team was again gathered to monitor the well around the clock, which resulted in quick and well-informed decision making. Well B-3 was drilled with one successful cased hole sidetrack to geological target objectives without operation problems. The success has made B-3 ST1 a trendsetter in terms of efficient and safe deepwater drilling planning and operation.