Optimum drilling design of high deviated directional wells and its application

The technology of high deviated directional well can be used to drill through a long shale gas reservoir, explore and control a wide range of gas-bearing area, and increase the production of single well and percentage recovery significantly. Based on the early exploration of vertical drilling, through the optimum design of well structure, borehole trajectory, drill assembly, friction torque, drilling fluid system, cementing technique, we selected the drilling scheme of high deviated directional well suitable for the efficient development of shale gas, established the formation pressure profile of Baojing area and completed the bit type selection. By applying the deviation control while drilling vertical straight well, compound drilling within building up section, and rotating steering drilling technique within the target section, two high deviated directional shale gas wells were constructed successfully with the drilling rate of shale formation being 100%. The technology system developed here which is for the efficient high deviated directional drilling, obviously increase the rate of penetration, shorten the drilling cycle, and achieve the goals of safe and efficient drilling, and thus provide a reference on the future exploration and development of shale gas and coalbed methane in other areas.