Instrumented Motors Prove Crucial in Unconventional Well Placement

摘要

Near-bit, instrumented motors are a transformative technology used for unconventional well placement. Near-bit sensors are located closer to the bit compared to traditional measurement while drilling (MWD) sensors, which are normally>20 ft behind the bit, thus allowing the opportunity for exiting thin bed formations before a formation change can be observed on the logs. These tools are also instrumental when choosing the formation tops for each new boundary drilled. The gamma-at- bit-inclination sensor system provides at-bit azimuthal gamma ray and inclination measurements for improved geosteering and optimum well placement. This paper describes the geosteering capabilities of a newly released 6 3/4-in. sensor in different formations. In a single run, the gamma-at-bit-inclination sensor system successfully delivered a hole section of 4, 952 ft (2, 248 to 7, 200 ft) in 43. 5 drilling hr, with an average rate of penetration (ROP) of 114 ft/hr in depleted shale and sandstone formations on the Gulf of Mexico (GOM) continental shelf, eliminating additional bottomhole assembly (BHA) changes; a 4, 043-ft (7, 442 to 11, 485 ft) lateral in 23. 5 drilling hr with an ROP of 172 ft/hr in Oklahoma City (OKC), Oklahoma; and 4, 781 ft (479 to 5, 260 ft) in 37. 75 drilling hr at an ROP of 127 ft/hr in the Woodford shale of the Mississippi Lime, with zero non- productive time (NPT) or health, safety, and environment (HSE) incidents. The use of near-bit, instrumented motors allows remaining in the zone of unconventional plays longer. To date, a total of more than one million feet has been drilled using a smaller near-bit, 4 3/4-in. instrumented motor, and running with larger- sized tools has proven successful. Instrumented motors previously had limited drilling application; however, with the geosteering requirements for unconventional well placement, a greater range of applications for the measurements provided by the near-bit, instrumented motors has been identified.