海上油田单筒双井套管切割技术

Single Slot Dual Wells Casing Cutting Technology for Offshore Oil Field

陈国宏 石佳乐 黄毓祥 倪益民

CHEN Guohong SHI Jiale HUANG Yuxiang NI Yimin

中海油能源发展股份有限公司工程技术分公司, 天津 300450; 中国石油集团川庆钻探工程有限公司川东钻探公司, 重庆 401120

Energy Technology Drilling&Production Company, CNOOC, Tianjin 300452, China; Chuandong Drilling Company. Chuanqing Drilling Engineering Co. Ltd., CNPC, Chongqing 401120, China

海上油田低效井治理措施中，浅层拔套管侧钻技术是一项简单有效的方法，但当前海上油田老平台单筒双井日趋增多，常规单筒单井浅层切割拔套管技术因浅层防碰问题已无法满足作业要求。此文撰写主要目的即通过当前技术和工具解决上述难题。主要技术方法和思路为，套管切割决策树论证分析、套管切割点防碰分析和水力割刀优选；依据中海油定向井防碰标准对割点防碰分离系数、中心距等参数进行三维定量分析，确保割刀在极限偏心状态时作业零风险。同时根据切割套管尺寸、层数和磅级优选组合最佳水力割刀型号，并预备合适的磨铣工具以应急需；该项技术在渤海蓬莱及多个油田成功应用，不仅开创了单筒双井浅层切割拔套管的先例，同时也大大降低了作业成本和风险。在气井或高气油比井作业时，建议对两口井弃置或进行下部临时封堵[1]，防止因人员误操作和数据误差引起的“割伤”邻井事故。该项技术未来可在单筒三井和深水丛式井进行尝试和推广。

Among the treatment measures for inefficient Wells in offshore oil fields, the lateral drilling technology of shallow casing retrieve is a simple and effective method. However, due to the increasing number of old platforms with single barrel and double wells in offshore oil fields, the conventional single-barrel single-well shallow cutting and casing retriveve technology has been unable to meet the operational requirements due to the problem of shallow layer collision prevention. The main purpose of this article is to solve these problems with current technologies and tools. The main technical methods and ideas are as follows:casing cutting decision tree demonstration analysis, casing cutting point anti-collision analysis and hydraulic cutter optimization; According to CNOOC directional well collision prevention standard, three-dimensional quantitative analysis is carried out on the separation coefficient and center distance of cutting point collision prevention, so as to make it absolutely safe once cutter operates in the limit eccentric state. At the same time, according to the cutting casing size, layer number and pound grade, the optimal combination of hydraulic cutter type is optimized, and suitable milling tools are prepared to meet the urgent needs. The successful application of this technology in several oilfields in Bohai Bay not only creates a precedent of single-barrel double-well shallow cutting and casing pulling, but also greatly reduces the operating cost and risk. In the case of gas well or high gas-oil ratio well operation, it is suggested to abandon two wells or temporarily seal the lower part of them to avoid the accident of "cutting" adjacent wells caused by personnel's misoperation and data error. In the future, this technology can be tried and popularized in single-barrel wells and deep-water cluster wells.

https://doi.org/10.3969/j.issn.1008-2336.2019.04.069