水平井油管钻磨复合桥塞技术及应用

Composite bridge plug drilling and milling technology by tubing in horizontal well and its application

针对连续油管钻磨复合桥塞存在成本高、易卡钻等问题,结合长庆致密油藏地层压力低的特点,提出了水平井中采用油管输送工具钻磨复合桥塞。改进了一种平底磨鞋;兼顾转速和扭矩优选了性能稳定、使用寿命长的螺杆;按实现功能和尽量简化的原则组配形成了国产化的钻磨工具组合;依据环空止动返速模型设计了最小施工排量;以偏心环空压耗计算为重点得到最大施工泵压;针对水平井难以精确计算钻压的问题,提出了按螺杆最大许用钻压控制悬重同时限制泵压压降的钻压施加方法。该技术在长庆油田进行了8口井的现场试验,一趟钻最多钻除复合桥塞13个,单个桥塞平均钻磨时间小于120min,单个桥塞最快钻磨时间40 min,性价比不低于连续油管作业。

In view of high cost and easy pipe sticking when drilling and milling composite bridge plug using coiled tubing and in conjunction with the characteristics of low formation pressure of Changqing tight reservoirs, this paper presents a technique of drilling and milling composite bridge plug with tubing-conveyed tool in horizontal wells. A lfat milling shoe was improved; long-life screw with stable performance was optimized while considering both RPM and torque; a drilling and milling tool assembly with localization was made by the principle of realizing functions and simplicity. The miminum construction displacement was designed as per annular slip velocity model. The maximum drilling pump pressure was obtained by calculating eccentric annular pressure loss. In order to accurately calculate bit pressure in horizontal wells, the technique of adding bit pressure was proposed as per the maximum allowable bit pressure of screw to control suspension weight while controlling the pump pressure drop. This technology was ifeld tested in 8 wells in Changqing oilifeld, and a maximum of 13 composite bridge plugs were drilled out in one run; the milling time for single bridge plug was less than 120 min and the fastest time for drilling and milling one plug was 40 min, so its performace-price ratio is no less than that of coiled tubing.