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Mubadala Petroleum planned to drill a complex Extended Reach Well (ERD) from an existing platform. To reach the required geological targets, the preferred wellpath was required to pass within close proximity of an adjacent oil producer that had a resultant separation factor (SF) of 0.70. A SF of less than 1.0 presents a mathematical possibility of well collision due to overlapping Elipses of Uncertainties (EOU). As such there was the likelihood of the inability to drill the well with a consequencial impact to the Mubadala business plan. A novel solution was by implemented by utilizing High Inclination Drilling with Gyro (HIDWG) tool to safely manage and mitigate the risk of well collision. The Jasmine field is a mature, complex oil field containing multiple stacked sandstone reservoirs, largely having individual oil and gas water contacts that have been on production since 2005. One of the major challenges is safely and economically accessing the remaining bypassed oil. Wellpath collision is an ever increasing risk as the ageing assets become more congested, which could lead to property damage and losses of production. Collision avoidance is gauged with a SF that takes into account the well depth, toolface, and the error model of the electronic survey tool. A conventional Bottom hole Assembly (BHA) with Measurement While Drilling (MWD) tool was initially considered, however the proximity calcuations yielded a SF of 0.7, and the well could not be drilled according to the company's drilling standard. To manage the risk and safely drill the well, the survey error uncertainty needed improvement. Instead of a conventional MWD, a High Inclination Drilling with Gyro (HIDWG) tool was utilized to reduce the survey error uncertainty to yield higher precision drilling control at depth in excess of 10,000 feet and at an inclination higher than 70 degrees. As a result of the BHA upgrade, the SF was instantly improved from 0.70 to 1.0, the collision risk was reduced to an acceptable level, and the well design was compliant with the drilling standard. Furthermore, the HIDWG was utilized for the first time in the Gulf of Thailand. Mubadala Petroleum successfully executed the ERD well utilizing the HIDWG, in combination with an Advance Hybrid Rotary Steerable System (RSS). The HIDWG tool provided an all-inclusive real-time surveying solution that delivered highly accurate surveys and with the Advance Hybrid Rotary Steerable System (RSS)'s precise drilling control throughout the intervals of close proximity with other wells. This paper explains how the HIDWG tool provided an inclusive surveying solution that could deliver both high accuracy surveys and precision drilling control throughout the zones of anti-collision concern of the ERD well. The chosen solution enabled the ERD well to be drilled to the required target successfully and allowed production to be established as planned. |
