Innovative Instrumented Motor with Near-bit Azimuthal Gamma Ray and Inclination Improves Geosteering in Thin-bedded Formations

摘要

Drilling horizontal wells in thin-bedded reservoirs with the goal of achieving maximum contact with the reservoir is challenging. Staying within the payzone of the reservoir saves drilling and completion costs and improves recovery from the well. Informations that have high gamma ray contrasts, azi-muthal gamma ray and continuous inclination are typically used to aid the geosteering process. In a conventional drilling motor BHA, the relevant sensors are placed as far back as 40 ft to 50 ft (12 m to 15 m) behind the bit. Given this large bit-to-sensor offset, and shallow depth of investigation of gamma ray measurements, it becomes difficult to effectively geosteer the well to maintain maximum contact with the reservoir.