APPLICATIONS, DESIGN, AND KEY SUCCESS FACTORS FOR MOTORIZED ROTARY STEERABLE SYSTEM

Drilling oil and gas well is always a costly affair, and there has been a continuous push to reduce the cost by improving the well construction rate. In early times, well used to be vertical. When the need to drill directional wells arose, technology such as positive displacement motors with bent housing and rotary steerable systems (RSS) wereintroduced and drilled several directional wells. But both these technologies have some drawbacks. To perform directional work in the well with the Motor, sliding needs to be done which can cause a risk of stuck pipe. A Rotary steerable system (RSS) resolves the stuck pipe event to a great extent since directional work can be done in rotation mode. But the RPM available at the bit is only surface RPM (SRPM). To Counter this problem, the industry has developed the latest drilling technology that has the best of both technologies. The BHA consists of a Motor and an RSS. The motor provides extra RPM at bit and RSS does the directional work without any need for sliding. This technology has revolutionized the drilling envelope. These days Motorized RSS (MRSS) BHA has become a go-to BHA when a drilling engineer wants to achieve difficult well trajectories with drilling efficiencies. This paper discusses the various applications of this BHA along with Design and key success factors.