Method and device increasing efficiency of drilling directional wells

摘要

The main independent controllable parameters in drilling oil and gas wells are the weight on bit and the frequency of bit rotation. When drilling deep directional wells with horizontal sections of the wellbore, the weight comes to the bottomhole with a delay due to increased frictional forces during the movement of the drill string to the bottomhole. This complicates the drilling control procedure. There are the methods of autonomous control of the weight on bit using electrical drilling, downhole motor, and the bit feeders. The research has shown that all known methods can generally only supplement the conventional method of creating weight on bit - transmitting the weight of the compressed part of the drilling tool and formation of hydraulic force on the downhole motor shaft. Each of those methods has certain shortcomings and does not solve the problem entirely. This paper presents the method and the device that are most effective for drilling directional wells. It is achieved by generating an additional weight on bit in the device, transferring this weight and the part of the force from the drill string through the upper end of the downhole motor shaft to the bit. Reduction of the frictional forces of the drill string against the borehole wall is carried out by the constant transmission of the bit axial vibrations from the upper end of the shaft of the downhole motor to the drill string and by adjustment of the axial vibrations parameters.