高5断块深层致密油水平井钻井关键技术实践

Practice of Key Technologies for Drilling Horizontal Well in Deep Tight Oil Reservoir of Gao 5 Fault Block

针对冀东油田高5断块深层致密油水平井钻井施工中出现的井壁易失稳、机械钻速慢、钻井周期长等技术难题,开展了致密油水平井钻井关键技术研究。综合考虑地层特征、钻井施工难度及钻井成本等因素,将高5断块深层致密油水平井优化为三开井身结构;依据致密油储层井位分布的特点、油层位置的空间变化,结合造斜点位置及工具造斜率的不确定性等因素,设计了“直-增-稳-增-稳-探层-水平段”七段制水平井井眼轨迹剖面;基于高5断块深部地层钻井工程地质特性分析结果,进行高效PDC钻头优化设计研究及配套提速工具的优选;针对深层致密油储层砂泥岩互层和井底温度高的特点,优选应用了高性能油基钻井液体系和地面降温处理系统。综上研究,逐步形成了一套适用于冀东油田高5断块深层致密油储层水平井钻井关键技术。目前已成功进行了首批6口井的钻井施工,最大完钻井深达到了5762 m,最长水平段1483 m,最短钻井周期为39.88 d。所得结论可为加快高5断块深层致密油储层开发进程提供技术保障,也为同类储层开发提供经验和参考依据。

In order to solve the technical problems such as wellbore instability,slow ROP and long drilling cycle occurred in the drilling process of deep tight oil horizontal wells in the Gao 5 fault block of Jidong oilfield,key technologies for drilling tight oil horizontal wells were studied.First,after having comprehensively taken into account factors such as stratigraphic characteristics,drilling construction difficulty and drilling costs,the deep tight oil horizontal wells in Gao 5 fault block were optimized into a three spud in casing program;second,based on the characteristics of well location distribution in tight oil reservoirs and the spatial changes in oil layer locations,combined with factors such as kick-off point position and uncertainty of tool build-up rate,a seven segment horizontal well trajectory profile of“vertical-build-hold-build-hold-exploration layer-horizontal section”was designed;third,based on the analysis of the geological characteristics of deep drilling engineering in the Gao 5 fault block,the research of efficient PDC bit optimization design and the optimization of supporting ROP improvement tools were conducted;fourth,aimed at the characteristics of sand-mudstone interbed and high bottomhole temperature in deep tight oil reservoirs,high-performance oil-based drilling fluid system and surface cooling treatment system were optimized and applied;fifth,based on the above researches,a set of key technologies suitable for drilling horizontal wells in deep tight oil reservoirs in the Gao 5 fault block of Jidong Oilfield were gradually formed.The first batch of 6 wells have been successfully drilled up to now,with a maximum total depth of 5762 m,a lonest horizontal section of 1483 m and a shortest drilling cycle of 39.88 d.The conclusions provide technical support for accelerating the development process of deep tight oil reservoirs in Gao 5 fault block,and also provide experience and reference basis for the development of similar reservoirs.