长庆某区块长63大斜度井钻井地质设计关键技术优化  

Optimization of key techniques for drilling geology design of highly-deviated wells in Chang 63 objective interval of a block,Changqing Oilfield

作　　者：郑杨 ZHENG Yang(Geology Design Center of GWDC Mud Logging Company,CNPC,Panjin,Liaoning 124010,China)

机构地区：[1]中国石油长城钻探录井公司地质设计中心

出　　处：《录井工程》2020年第3期23-27,共5页Mud Logging Engineering

摘　　要：长庆某区块大斜度井是长庆油田2018年产能建设项目的重要开发部署,其主要开发目的层位为延长组长63。根据该区块延长组长63的地质特征,结合大斜度井的工程要求,在对大斜度定向井钻井地质设计关键技术的优化中,重点针对地层预测技术、地层压力预测技术两项关键技术进行科学优化。地层预测方面:制定“三靶点”轨迹,保证入窗井斜角在60°~86°范围;进行地质建模,确保靶点深度预测准确。压力预测方面:利用基于地层正常压实理论的伊顿指数法分别计算出地层孔隙压力、地层破裂压力和地层坍塌压力,再采用改进等效深度法绘制三压力剖面图,对设计井进行区域压力预测。通过该区块大斜度井设计预测靶点情况统计发现,设计52口井,符合48口,预测深度符合率为92.3%,较2018年以前的符合率90%有大幅度提升;地层压力数据能为钻井施工提供更准确的技术支撑,减少钻井过程中的井下事故发生率,最大程度地确保安全施工和高效开发,实现了该区块单井产量和产建效益“双提升”。The highly-deviated wells in a block of Changqing Oilfield is an important development deployment of the productivity construction project of Changqing Oilfield in 2018.The main development objective interval is Chang 63 reservoir of Yanchang Formation.According to the geologic characteristics of Chang 63 objective interval in this block and the engineering requirements of highly-deviated wells,in the optimization of the key techniques of drilling geology design for highly-deviated directional wells,the key techniques of formation prediction and formation pressure prediction are focused on scientific optimization.In terms of formation prediction,formulate the three-target-point trajectory to ensure that the inclination angle of window entry is within 60°-86°,and carry out geologic modeling to ensure the accuracy of target point depth prediction.In terms of pressure prediction,the Eaton index method based on the normal formation compaction theory is used to calculate the formation pore pressure,formation fracture pressure and formation caving pressure respectively,and then the improved equivalent depth method is used to draw the three pressure profile to predict the regional pressure of the planned well.Statistics on the design and prediction target point of highly-deviated wells show that 52 wells are designed,48 wells are consistent,and the prediction depth coincidence rate is 92.3%,which is greatly improved compared with the coincidence rate of 90%before 2018.The formation pressure data can provide more accurate technical support for drilling construction,reduce the downhole accident rate in drilling process,maximize the safety of construction and efficient development,and improve the single well yield and productive construction benefit in this block.

关 键 词：大斜度井 钻井地质设计 建模 关键技术 地层预测 压力预测 优化 

分 类 号：TE132.1[石油与天然气工程—油气勘探]