Development and Field Test of Electronically Controlled Half-WayRotary Steerable Drilling Tool

The half-way rotary steerable drilling technology separates the torque of the lower drilling tool from the upper drilling tool so that the upper drill string can be rotated and achieve bit feed at low speed, while the lower drilling tool performs conventional sliding directional drilling. In this way, the trajectory control ability of steerable drilling and the extension ability of horizontal sections can be greatly improved at a low cost. Based on this technology, an electronically controlled half-way rotary steerable drilling tool was developed. The tool was installed near the drill bit end of the drill string of conventional sliding directional drilling. The ground signal transmission device sent a negative pulse sequence command of the drilling fluid. After receiving the command, the tool performed the drill string torque separation and combination actions. It should be pointed out that the control of the anti-torque after torque separation is the key technology of the tool. Usually, the friction torque between the drill string and the well wall is used to counteract the anti-torque, but when the torque surges, the anti-torque cannot be balanced. The electronically controlled half-way rotary steerable drilling tool can effectively resist the anti-torque and stabilize the tool face by adding an anti-torque-resistant stabilizer and a torque absorption and energy storage assembly. The field tests results of four wells with the electronically controlled half-way rotary steerable drilling tool applied show that the tool can greatly alleviate the support pressure, reduce friction and drag, and improve the transmission efficiency of weight on bit (WOB). The tool has the ability to control the anti-torque. After the torque is separated, the tool face remains stable, and the rate of penetration (ROP) is improved. Therefore, the tool can be widely promoted and applied.