苏里格致密气藏超长水平段水平井钻井完井关键技术

Key Technologies for Drilling and Completing Horizontal Wells with Ultra-Long Horizontal Sections in the Sulige Tight Gas Reservoirs

针对苏里格气田致密气藏超长水平段水平井钻井完井过程中循环泵压高、摩阻扭矩大、机械钻速低、井眼清洁困难、完井套管柱下入困难等问题,分析了超长水平段水平井钻井完井技术难点,进行了高效钻具和钻井设备优化配置、井眼轨道设计和井眼轨迹控制、水平段钻井提速和清洁,以及旋转导向钻井、强抑制润滑性水基钻井液和"旋转引鞋+套管"漂浮下入等技术研究,形成了苏里格致密气藏超长水平段水平井钻井完井关键技术。现场试验2口井,平均井深7 027 m,平均水平段长3 719.5 m,钻井周期50.93 d,取得了很好的效果。其中,靖50-26H1井完钻井深7 388 m,水平段长4 118 m,创造了当时长庆油田井深最深和国内陆上油气井水平段最长2项纪录。研究与试验结果表明,该技术可为苏里格致密气藏高效勘探开发提供技术支撑,也可为国内致密气超长水平段水平井安全高效钻井完井提供借鉴。

The drilling and completion of horizontal wells with ultra-long horizontal sections in the tight gas reservoirs of Sulige Gas Field is subject to problems such as high circulating pump pressure, large friction torque, low rates of penetration (ROP), difficult borehole cleaning, and difficulties in running the completion casing string. In response, the technical difficulties in the drilling and completion of such wells were analyzed. Research was conducted on technologies such as optimized allocation of high-efficiency drilling tools and equipments, borehole trajectory design and control, horizontal section drilling acceleration and cleaning, rotary steering system (RSS) drilling, strong inhibition and lubrication water-base drilling fluid, and “rotary guide shoe+casing” floating running, etc. The key technologies for drilling and completing horizontal wells with ultra-long horizontal sections in the Sulige tight gas reservoirs were developed and applied in 2 wells with an average well depth of 7 027 m and an average horizontal section length of 3 719.5 m. The drilling cycle was 50.93 d, which meant that the proposed technologies achieved a favorable effect. Between the two wells, the Well Jing50-26 H1, with a total depth (TD) of 7 388 m and a horizontal section length of 4 118 m, established the records as the deepest well in Changqing Oilfield and the longest horizontal section of onshore oil and gas wells in China at that time. The research and application show that the key technologies can provide technical support for the efficient exploration and development of the Sulige tight gas reservoirs and a reference for safe and efficient drilling and completion of horizontal wells with ultra-long horizontal sections in tight gas fields in China.