川南下寒武统筇竹寺组井研—犍为地区瘦身井优化评价研究

Optimization and Evaluation of Slimming Wellbore Structures for the Qiongzhusi Formation of Jingyan-Qianwei Area, Southern Sichuan Basin

何龙 何新星 张玉胜 严焱诚 刘伟 朱礼平

HELong HEXinxing ZHANGYusheng YANYancheng LIUWei ZHULiping

中国石化西南油气分公司, 四川 成都 610041 中国石化西南油气分公司石油工程技术研究院, 四川 德阳 618000 中国石化西南油气分公司非常规油气勘探开发管理部, 重庆 永川 402160

Southwest Petroleum Branch, SINOPEC, Chengdu, Sichuan 610041, China Petroleum Engineering Technology Institute of Southwest Petroleum Branch, SINOPEC, Deyang, Sichuan 618000, China Unconventional Oil and Gas Exploration and Development Management Department of Southwest Petroleum Branch, SINOPEC, Yongchuan, Chongqing 402160, China

川南下寒武统筇竹寺组井研—犍为地区上部地层存在压力体系复杂、井壁失稳、部分地层可钻性差等问题，钻井周期长，建井成本高。针对上述问题，通过统计分析，应用已钻井资料建立了井研—犍为区域的三压力与复杂地层剖面，优化一二开必封点，形成常规井身结构方案。提出了采用$\phi$190.5 mm井眼完钻的瘦身方案，通过水力学与管柱力学分析开展了瘦身井身结构的适应性评价，单井实施瘦身结构井一二开采用$\phi$127.0 mm钻杆，三开采用$\phi$127.0 mm+$\phi$114.3 mm钻杆，平台井工厂实施瘦身结构井一二开采用$\phi$139.7 mm钻杆，三开采用$\phi$127.0 mm+$\phi$114.3 mm钻杆，井斜角不超过90°时能够实施水平段长3 000 m的钻井。应用常规井身结构方案，实际钻井周期相比前期缩短21.68%，若采用瘦身井身结构，单井预期可降低成本180万元。研究技术成果可为筇竹寺组页岩气下步钻井工程设计提供重要优化方向，有望从源头上降低建井成本，促进井研—犍为筇竹寺组页岩气资源的高效开发与规模建产。

There are some issues in the upper strata of Qiongzhusi Formation of Jingyan-Jianwei Area, southern Sichuan Basin, such as complex pressure systems, wellbore instability, and poor drillability, etc, which lead to prolonged drilling cycles and high well construction costs. To deal with these issues, we established the tri-pressure profile and complex formation sections in the Jingyan-Jianwei Area by analyzing data of drilled wells. The necessary sealing points for the first and second were optimized, and a conventional wellbore structure scheme for this region was formulated. Based on the goal of cost reduction, a slimming scheme with a $\phi$190.5 mm wellbore for well completion was proposed. Through hydraulic and pipe string mechanical analyses, the adaptability evaluation of the slimming wellbore structure was conducted. For single-well implementation, the first and second spuds of the slimming structure well employ $\phi$127.0 mm drill pipes, and the third spud adopts $\phi$127.0 mm+$\phi$114.3 mm drill pipes. For platform well, the first and second spuds of the slimming structure well utilize $\phi$139.7 mm drill pipes, and the third spud adopts $\phi$127.0 mm+$\phi$114.3 mm drill pipes. When the well deviation angle is less than or equal to 90°, a horizontal well with a horizontal section length of 3 000 m can be implemented. By applying the conventional wellbore structure scheme, the actual drilling cycle was shortened by 21.68% compared to the previous stage. If the slimming wellbore structure is adopted, it is expected that the cost of a single well can be reduced by 1.8 million yuan. The research and technical achievements can offer significant optimization directions for the subsequent drilling engineering design of the Qiongzhusi Formation shale gas, and are anticipated to reduce the well construction costs, facilitating the efficient development and large-scale production of shale gas resources in the Qiongzhusi Formation of Jingyan-Jianwei Area.

10.11885/j.issn.1674 5086.2024.12.16.02