安塞低渗油田水平多分支井钻井技术

针对安塞油田低渗透油藏地质特征,结合分支井开发方式的适应性及其技术特点,通过对分支井井身结构优化、钻头选型、轨迹控制、分支井眼侧钻、地质导向、摩阻扭矩分析等技术的研究和应用,成功完成了安塞油田第1口水平多分支井-杏平1井。该井完钻井深5068 m,水平位移1574.22 m,主水平段长1203 m,水垂深比1.16。在只能使用常规钻井设备及导向工具等难题下,成功采用低边侧钻技术在主水平段内侧钻了7个分支井眼,分支井眼总长2300m,累计打开目的储层3503 m,并实现了多次重入钻井,初步形成了适合安塞油田地质特点的分支井钻井技术。

Technology for drilling multilateral horizontal wells of Ansai low permeability oilfields

Through analyzing the geological characteristics of the oilfield of low permeability, and the adaptability of the method of developing multilateral wells, as well as the technical characteristics of the method, Well Xingping-1, the first multilateral horizontal well of Ansai Oilfield, is successfully completed, based on the research and application of such techniques as the optimization of multilateral well structure, bit selection, trajectory control, branch hole sidetracking, geosteering, friction and torque analysis. The well is finished with the depth being 5068m, the horizontal displacement 1574.22 m, the main horizontal section 1203 m long, the ratio of vertical water depth 1.16. With the use of conventional drilling equipment and steering tool, the low-side sidetracking technique is successfully applied to the main horizontal section. As a result, seven branch holes are drilled, which are 2300 m long in total, as well as 3503 meters of target reservoirs are opened. What's more, reentry into drilling wells is realized for many times. Multiple-well drilling techniques, suitable for the geological characteristics of Ansai Oilfield, have come into being preliminarily.