Treatment of drilling sticking and burial in horizontal grouting laterals

Abstract:

In recent years, the directional drilling technology for Ordovician limestone water control grouting has developed rapidly, leading to sharp increase in the number of multi-lateral ultra deep horizontal grouting holes. In drilling of horizontal grouting holes, there are many common problems, such as large amount of formation leakage, sudden mud loss, long open hole sections at small-diameter, complex hole trajectories of the horizontal section; great difficulty in control, strict error allowance, expensive directional instruments and tools, etc.; and relatively high drilling risk due to proneness to drill pipe sticking incidents. Once the sticking incident occurs, it will take a long period to deal with it with great difficulty. The traditional sticking treatment method doesn’t work well for such incidents in horizontal grouting holes. With use of the air compressor, compressed air was supplied to destroy the sand settling structure in the horizontal hole, and blew the settled sand out of the hole or into the formation fractures; thus realizing successful treatment of sticking and burial in drilling of horizontal grouting holes. The preventive measures for sticking and burial incidents in drilling of horizontal grouting holes are summarized.