非常规油气藏新一代体积压裂技术的几个关键问题探讨

Discussion on Several Key Issues of the New-Generation Network Fracturing Technologies for Unconventional Reservoirs

蒋廷学

JIANG Tingxue

页岩油气富集机理与有效开发国家重点实验室, 北京 102206 中国石化页岩油气钻完井及压裂重点实验室, 北京 102206 中石化石油工程技术研究院有限公司, 北京 102206

State Key Laboratory of Shale Oil and Gas Enrichment Mechanism and Effective Development, Beijing, 102206, China Sinopec Key Laboratory of Shale Oil and Gas Drilling and Hydraulic Fracturing, Beijing, 102206, China Sinopec Research Institute of Petroleum Engineering Co., Ltd., Beijing, 102206, China

体积压裂技术是实现非常规油气藏高效开发的关键，围绕有效改造体积及单井控制EUR最大化的目标，密切割程度、加砂强度、暂堵级数及工艺参数不断强化，导致压裂作业综合成本越来越高。为此，开展了新一代体积压裂技术（立体缝网压裂技术）的研究与试验，压裂工艺逐渐发展到“适度密切割、多尺度裂缝强加砂、多级双暂堵和全程穿层”模式。为促进立体缝网压裂技术的发展与推广应用，对立体缝网的表征、压裂模式及参数界限的确定、“压裂–渗吸–增能–驱油”协同提高采收率的机制、一体化变黏度多功能压裂液的研制、石英砂替代陶粒的经济性分析及“设计–实施–后评估”循环迭代升级的闭环体系构建等关键问题进行了探讨，厘清了立体缝网压裂技术的概念、关键技术及提高采收率机理，对于非常规油气藏新一代压裂技术的快速发展、更好地满足非常规油气藏高效勘探开发需求，具有重要的借鉴和指导意义。

Network fracturing technologies are the key to the efficient development of unconventional reservoirs. The degree of tight spacing, the intensity of proppant injection, the number of temporary plugging stages, and operation parameters are constantly optimized to maximize the effective stimulated reservoir volume (ESRV) and single-well estimated ultimate recovery (EUR), ultimately adding to the increasingly high comprehensive costs of fracturing operations. For this reason, new-generation network fracturing technologies (namely, three-dimensional fracture network fracturing technologies) were investigated and tested. Regarding the development of the fracturing process, a mode of “moderate tight spacing, high-intensity proppant injection to multi-scale fractures, multi-stage dual temporary plugging, and whole-process layer-penetrating” was gradually ushered into practice. Several key issues were discussed to further the development, promotion, and application of three-dimensional fracture network fracturing technologies. These issues involved the characterization of three-dimensional fracture networks, the determination of the fracturing mode and parameter boundaries, the synergistic enhanced oil recovery (EOR) mechanism of “fracturing-imbibition-energy enhancement-oil displacement”, integrated multi-functional fracturing fluids, the analysis of the economic efficiency of replacing ceramsite with quartz sand, and the establishment of a closed-loop system upgraded by cyclic iteration of “design-implementation-post-frac evaluation”. In this way, the concepts, key technologies, and the EOR mechanism of the three-dimensional fracturing technologies were clarified. Important reference and guidance can be provided by this paper for the rapid development of new-generation fracturing technologies for unconventional oil reservoirs and better fulfillment of the requirements for efficient exploration and development of unconventional reservoirs.

国家自然科学基金企业创新发展联合基金项目“海相深层油气富集机理与关键工程技术基础研究”（编号：U19B6003-05）资助

https://doi.org/10.11911/syztjs.2023023