干热岩储层裂缝扩展及采热一体化数值模型  

Integrated Numerical Model of Fracture Propagation and Production in Dry Hot Rock Reservoir

作　　者：考佳玮 杨康 谭鹏 陈作 Kao Jiawei;Yang Kang;Tan Peng;Chen Zuo(SINOPEC Research Institute of Petroleum Engineering Co.,Ltd.,Beijing 102206,China;Petroleum Engineering Supervision Center,Northwest Oilfield Branch Company,SINOPEC,Luntai 841600,Xinjiang,China;CNPC Engineering Technology R&D Company Limited,Beijing 102206,China)

机构地区：[1]中石化石油工程技术研究院有限公司,北京102206 [2]中国石油化工股份有限公司西北油田分公司石油工程监督中心,新疆轮台841600 [3]中国石油集团工程技术研究院有限公司,北京102206

出　　处：《吉林大学学报(地球科学版)》2025年第2期575-586,共12页Journal of Jilin University:Earth Science Edition

基　　金：国家自然科学基金项目(52192621)。

摘　　要：为准确评价干热岩储层压裂及其注采热效果,本文建立了一种流-固-热耦合的干热岩水力裂缝扩展数值模型,可以模拟干热岩复杂压裂裂缝形态,并进行注采热分析。以青海省共和盆地干热岩为研究对象,基于其地质力学参数特征建立了2个算例,并开展了干热岩多井压裂及采热过程模拟。结果表明:干热岩起裂裂缝受非均匀应力场扰动呈体积裂缝特征,水力裂缝遇天然裂缝可激活并形成复杂裂缝形态;多井间压裂裂缝可通过天然裂缝连通,为注采热提供超过95%的流动换热通道;注采热时,流体主要沿着贯通裂缝流动,形成换热优势通道,导致注采热初期出口温度降幅较大,在前3 a,出口水温下降幅度达30~50℃,后期降速趋于平缓;提升压裂裂缝复杂性可增大有效换热面积,配合以合理的井位及注采参数提升换热效果,实现干热岩的高效开采。To simulate hydraulic fracturing and heat injection and extraction effect in hot dry rock reservoir,we established a thermo-hydro-mechanical coupling hydraulic fracture propagation and heat transfer model for simulating the complex fracturing fracture morphology of dry hot rock and conducting injection-production thermal analysis.Taking the hot dry rock(HDR)in Qinghai Gonghe basin as a reference,we constructed two case considered the geo-mechanical parameter characteristics and simulated the multi-well fracturing and heat recovery process,the numerical results of fracturing and heat injection and recovery show that:In HDR,the fracture initiation is influenced by the non-uniform stress field,exhibiting volumetric fracture characteristics.Fractures created through multi-well fracturing connect via natural fractures,providing over 95%of the heat exchange flow channels for heat injection and production.During heat injection and production,fluid mainly flows along the connected fractures,forming dominant heat exchange channels.This leads to a significant decrease in outlet temperature during the initial stage of heat injection and production,with the outlet water temperature dropping by 30-50℃within the first three years,followed by a gradual slowdown in the later stages.Enhanced fracture complexity can increase effective heat transfer area,while optimized well placement and injection-production parameters improve thermal efficiency,enabling sustainable geothermal energy exploitation.

关 键 词：干热岩 水力裂缝扩展 天然裂缝 采热 流-固-热耦合 非连续离散裂缝模型 换热 青海共和盆地 

分 类 号：P314[天文地球—固体地球物理学]