半潜式钻井平台水平井裸眼侧钻技术

Sidetracking technology for horizontal open hole on semi-submersible drilling platforms

注水泥塞侧钻是在原井眼一定位置注水泥填井,再侧钻出新井眼的钻井工艺。文昌某油田一口水平开发井因?215.9 mm井眼钻遇油层显示不理想,决定在裸眼注水泥塞后进行侧钻。为克服侧钻点深、地层强度高、半潜式平台升沉大等难点,采用了短保径、强侧向攻击性能的PDC钻头和Power Drive旋转导向工具,通过滑槽、造台阶及控时钻进等技术措施控制井眼轨迹,利用岩屑录井和近钻头井斜等资料及时监控侧钻实施情况,成功完成了侧钻作业。该侧钻井作业顺利,轨迹平滑,后续防砂筛管顺利下入,为今后半潜式平台水平井侧钻作业提供了较好的借鉴经验。

Sidetrack with cement plug is a drilling technology that dills a new wellbore after placement of cement plug in the origi-nal open hole. Due to unfavorable oil indications of the reservoir encountered by ？215.9 mm wellbore, a horizontal development well located in Wenchang Oilifeld was sidetracked after placing cement plug in the openhole. In order to overcome such dififculties such as large depth of sidetrack point, high formation strength, large heaving of semi-submersible drilling platform, etc., this sidetracking opera-tion was successfully completed by using short gage PDC bit with strong side attacking ability and rotating steering tool Power Drive to dill the sidetrack hole, using sliding groove, creating steps and controlled drilling to control the well trajectory, and using cuttings logging and near bit inclination to monitor the realtime sidetracking job. The successful execution of this sidetracking job, the smooth well trajectory and the successful runing of subsequent sand-control screens, provide useful references for the sidetracking operations for horizontal open hole from semi-submersible drilling platform in the future.