基于井壁稳定与改造效率的井眼轨迹优化设计

Research on wellbore trajectory optimization design based on wellbore stability and fracturing efficiency

在渤中地区井漏、阻卡、溢流等井下复杂事故频繁发生,造成了经济损失。研究井眼轨迹优化方法,降低井漏等风险,提高压裂改造效率,确保区块快速投产。主要完成:通过分析渤中X井,获得安全密度窗口;地应力方位影响裂缝起裂程度,控制压裂方位。方位角150°时,水平段钻进安全密度窗口最大,钻井安全;方位角140°~170°有助于压裂增产,最终优选钻井方位155°。使用兰德马克软件优化设计渤中X井井眼轨迹,实际钻井作业中无井壁失稳发生,压裂后测试产量达到同产层邻井5倍。

In the Bozhong area,downhole complicated accidents such as leakage,blockage and overflow occur frequently. Trying to optimize well trajectory, improve and reduce lost circulation and other risks, to achieve safe drilling of horizontal wells, to ensure rapid commissioning of the block. The main accomplishments are as follows,through the analysis of a well in Bozhong, the safe density window is obtained.The orientation of in-situ stress affects the degree of fracture initiation and controls the orientation of fracture. When the azimuth is 150°, the drilling density window increases to maximum. The azimuth of 140°~170° is helpful to fracturing and stimulation. Choose the optimum drilling azimuth is 155°. Landemark software is used to optimize the well trajectory of a well in Bozhong area, no wellbore instability occurs in drilling operation, and after fracturing, the production is 5 times higher than the adjacent well in the same layer.