一开次钻穿不同岩性不同压力系统地层的探索

杨税务潜山带位于渤海湾盆地廊固凹陷，储层埋藏深，钻遇地层复杂，建井周期长，钻探成本高。针对杨税务潜山井优化井身结构、缩短建井周期这一技术难点进行了攻关，在对地层压力剖面分析、奥陶系潜山碳酸盐岩漏失以及石炭—二叠系复杂地层井壁失稳机理研究的基础上，逐步形成了敏感性泥页岩井壁稳定技术、潜山碳酸盐岩防漏技术、超高温深井尾管固井技术，以AT2X1侧钻井为契机，利用较低钻井液密度一开次顺利钻穿石炭—二叠系复杂地层和奥陶系碳酸盐岩潜山储层，为该区块后续井井身结构由四开简化为三开做了有益尝试。AT2X1井的成功侧钻，为该地区潜山内幕钻探，一开次钻穿潜山内幕的府君山组，解决潜山内幕中徐庄组、毛庄组、馒头组等泥岩地层垮塌提供了技术借鉴。

Exploring to drill through the strata with different lithologies and pressure systems in one stage: A case study on the side-tracking Well AT2X1 in the Yangshuiwu buried hill belt

Yangshuiwu buried hill belt is located in the Langgu Sag of the Bohai Bay Basin, and it suffers the problems of deep reservoir, complex drilled strata, long well construction cycle and high drilling cost. A series of studies were carried out to optimize the casing program and shorten the well construction cycle of the wells in the Yangshuiwu buried hill belt. After the formation pressure profile was analyzed and the circulation loss in the Ordovician buried-hill carbonate rocks and the borehole instability mechanisms in the Carboniferous-Permian complex strata were studied, the borehole stabilization technology for sensitive mud shale, circulation loss technology for buried-hill carbonate rocks and the liner cementing technology for ultra high-temperature deep wells were formed gradually. Taking the side-tracking Well AT2X1 as an opportunity, the drilling fluid with lower density was used to drill through the Carboniferous-Permian complex strata and the Ordovician buried-hill carbonate reservoirs smoothly in one stage, which provides the beneficial trial for the subsequent simplification of four-stage casing program into the three-stage one. The successful side-tracking of Well AT2X1 provides the technical reference for drilling the internal buried hill in this area, penetrating the Fujunshan Formation inside the buried hill in one stage and solving the mudstone collapse problem of Xuzhuang Formation, Maozhuang Formation and Mantou Formation inside the buried hill.