多分支井地热系统注采性能室内实验研究

Laboratory-Scale Experimental Study on the Injection-Production Performance of a Multilateral-Well Enhanced Geothermal System

宋先知 李嘉成 石宇 许富强 曾义金

SONG Xianzhi LI Jiacheng SHI Yu XU Fuqiang ZENG Yijin

油气资源与探测国家重点实验室（中国石油大学（北京）），北京 102249 中国石油新疆油田分公司工程技术研究院，新疆克拉玛依 834000 西南交通大学地球科学与环境工程学院，四川成都 611756 中国石化石油工程技术研究院，北京 102206

State Key Laboratory of Petroleum Resources and Exploration (China University of Petroleum (Beijing)), Beijing, 102249, China Research Institute of Engineering Technology, PetroChina Xinjiang Oilfield Company, Karamay, Xinjiang, 834000, China Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan, 611756, China Sinopec Research Institute of Petroleum Engineering, Beijing, 100101, China

多分支井地热系统利用分支井眼强化注采性能进行地热开采，为了研究该系统不同参数对注采效果的影响规律，开展了多分支井流动传热实验。基于搭建的地热多分支井室内实验系统和人工岩样，开展了地热多分支井注采性能评价实验，研究了不同参数对分支井注采能力的影响规律，对比了多分支井系统与单井开式系统的注采效果。研究发现：降低注入温度，可以增大多分支井地热系统的注入压力，提高其注入能力；增加分支井眼数量和长度，可减小多分支井系统的注入压力，并提高出口排量，提高系统的注采能力；多分支井系统的注采能力明显优于单井开式系统，更适用于地热资源的开采与回注。研究表明，多分支井可以提高地热系统的注采能力，研究结果为多分支井地热系统的现场应用提供了理论依据。

Instituting a multilateral-well enhanced geothermal system is a novel method to enhance fluid injectivity and productivity for geothermal development by using lateral wells. To study the influencing laws of different factors of the system oninjection-production performance, fluid flow and heat transfer experiments for multilateral-well were conducted. Experiments were performed to evaluate the injection-production performance and investigate the effects of different factors on the injectivity and productivity of lateral wells based on the multilateral-well enhanced geothermal experimental system and artificial rock samples. In addition, the injection-production performances of a multilateral well and a single vertical well were compared. Results indicated that decreasing the injection temperature can increase injection pressure and improve injectivity of the system, while increasing the number of lateral-wells and length can decrease the injection pressure and increase the outlet flow rate.The injection-production performance of the multilateral-well enhanced geothermal system is much better than that of the single-vertical-well geothermal system, and is more suitable for the development and injection of the geothermal energy. Findings prove that multilateral well can enhance the injectivity and productivity of the geothermal system, providing a theoretical foundation and guidance for field applications of the multilateral-well enhanced geothermal system.

国家重点研发计划项目“热储内多场耦合流动传热机理与取热性能优化”（编号：2018YFB1501804）、国家自然科学基金优秀青年科学基金“油气井流体力学与工程”（编号：51822406）、高等学校学科引智计划（111计划）项目“深部地热资源开发基础研究”（编号：B17045）和北京高校卓越青年科学家计划（编号：BJJWZYJH01201911414038）联合资助

https://doi.org/10.11911/syztjs.2021019