干热岩地应力测量评价方法与前沿挑战

可靠的地应力数据能够指导开发干热岩资源。本文针对干热岩深部储层地应力调查存在的困难,按照基于钻孔、岩芯和地质的三类调查手段,首先总结提出了适用于干热岩地应力测量与评价的方法,并指出了其基本原理、测试仪器、应用场景与存在的优缺点。然后,以我国青海共和干热岩试采工程为例,提出了干热岩地应力测量与评价模式,给出了储层地应力特征的主要认识,并验证其与工程开发结果的一致性。最后,总结了干热岩地应力测量方法的认识,指出了干热岩开发中与地应力相关的两大前沿科学问题,即储层裂缝控制与诱发地震,并对其发展趋势与挑战进行了展望。

An Overview of the Measurement and Evaluation Methods of In-situ Stress and Its Frontier Challenges in Hot Dry Rock

Reliable in-situ stress data can guide the development of hot dry rock (HDR) resources. In view of the difficulties involved in investigation of in-situ stress in deep reservoirs of HDR, this study summarizes and puts forward three types of investigation methods suitable for in-situ stress measurement and evaluation in HDR, based on borehole, core, and geology, and points out their basic principles, test instruments, application scenarios and advantages and disadvantages. Additionally, the HDR in-situ stress measurement and evaluation model is proposed taking the Gonghe HDR project in Qinghai, China, as an example. The main conclusions of the in-situ stress feature are shown, and its consistency with the result of hydraulic fracturing is verified. Subsequently, two frontier scientific issues related to in-situ stress in HDR development, namely reservoir fracture control and induced earthquake, are pointed out. Finally, the understanding of the in-situ stress measurement method of HDR is summarized, and its development trend and challenges are also assessed.