Control azimuth of the directional equipment to operate directional drilling

During directional drilling,the drilling trajectory needs to be adjusted by using directional devices to reach the target successfully.However,the field engineers usually use simple directional devices,such as an elbow sub,to conduct long-distance directional drilling during practical directional drilling.They control setting angles only based on subjective experience.As a result,only a feasible range is obtained,which has a negative effect on the trajectory adjustment speed.Deviation and azimuth angles needed can be gotten on the basis of many times of revision.In this paper,a new method is discussed to control directional drilling only by changing the azimuth angle of directional devices and as a result an optimum approach to calculating the azimuth angle of directional devices is achieved.The approach is to get the first vector from the present point to the level of target and the second vector from the present point to the target,and then the difference of the first vector from the second vector is a new vector.The horizontal projection of the new vector determines the azimuth angle of directional devices to operate directional drilling.The new method is simple and practical to change the azimuth of wellbore immediately and stably,so as to reach the target successfully either in the mode of increasing or decreasing inclination.