黄36井区油页岩段水平井快速钻井技术

黄36井区长8目的层水平井钻井施工过程中,针对长7油页岩段长、井斜大,长4+5地层承压能力低,钻井液密度达不到平衡油页岩坍塌压力所需要的密度,导致油页岩易垮塌以及PDC钻头滑动困难、造斜段机械钻速低等问题,从单纯通过防漏堵漏提高钻井液密度转变为降低排量提高钻井液密度,同时通过减小油页岩交变应力、控制油页岩段井斜来提高坍塌压力,使用牙轮钻头造斜等方法,降低了坍塌几率,并有效提高了机械钻速。该水平井快速钻井技术能有效解决窄密度窗口的问题,提高施工效率,降低钻井成本。

Fast drilling technology for horizontal wells in oil shale segment of Huang 36 Well Area

In regard of the problems of easy collapse of oil shale, difficulty in sliding of PDC drill, and low rate of penetration in deflecting segment, due to long length and steep well deflection of Chang 7 oil shale segment, low load bearing capacity of Chang 4+5 stratum, and failure of drilling fluid density to meet the required density for balancing collapse pressure of oil shale during drilling for horizontal wells of Chang 8 target stratum of Huang 36 Well Area, density is raised by lowering displacement from pure plugging and leakage prevention, and collapse pressure of oil shale segment is improved by lowering alternating stress of oil shale and controlling well deflection of oil shale segment. In addition, the method of deflecting by roller bit is adopted to lower collapse probability and effectively improve rate of penetration. The method effectively solves the problem of narrow-density windows, facilitates guaranteeing drilling safety, improves construction efficiency and lowers drilling cost.