Research and Application of Closed-Loop Electronic Control Variable Diameter Stabilizer in Directional Drilling

That multiple adjustments of the inclination rate for orientation in sliding orientation caused by frequent operations leads to a decrease drilling efficiency during procedure of drilling directional wells. This paper introduces a new type of closed-loop electro-controlled variable diameter stabilizer that can achieve efficient and precise adjustment of the rate, providing a new solution for the construction of long inclined sections in drilling directional wells. This equipment consists of sensors, control circuits, motors and reducers, lithium-ion batteries, and the variable-diameter mechanism. It has an independent control system, and the outer diameter of the variable-diameter mechanism can be switched to three positions according to drilling design requirements. During rotary drilling, the bottom hole assembly has the same ability to increase and decrease the inclination in the inclined section, the stable section, and the decreasing section as the RSS tool, and reduces the time for sliding drilling as well. The equipment has been applied to 5 wells with special physical properties. On-site test data indicates that the equipment can achieve a diameter change range of 206-212mm. That, the diameter change results can be monitored in real-time by surface instruments, achieved visualization. In horizontal section drilling operations, the drilling speed reached more than 80% that of RSS, but the operating cost and maintenance cost are less than 5% of it. Excluding ultra-large inclination increase, decrease, and stabilization well sections, in drilling operation of the horizontal section, the equipment can surpass RSS drilling speed and achieve a more inclination rate. This closed-loop electro-controlled variable diameter stabilizer uses electro-controlled components as control devices. Its novel variable diameter structure offers high precision in diameter adjustment. Additionally its visualization function makes operation simple and efficient. This technology expands the existing directional drilling equipment and provides new ideas for simple and efficient directional drilling.