井筒布置及裂隙分布特征对增强型地热系统采热性能的影响  

Effect of wellbore layout and fracture distribution characteristics on heat recovery performance of enhanced geothermal system

作　　者：单丹丹[1] 李玮[1,2] 王艳 李卓伦 冯耀国[4] 逯广东 张弦[1] SHAN DanDan;LI Wei;WANG Yan;LI ZhuoLun;FENG YaoGuo;LU GuangDong;ZHANG Xian(College of Petroleum Engineering,Northeast Petroleum University,Daqing 163318,China;CNPC Drilling Engineering Technology Research Institute,Beijing 102206,China;Equipment Management Section,No.1 Drilling Engineering Branch,Bohai Drilling Company,Tianjin 300280,China;No.2 Oil Production Plant,PetroChina Daqing Oilfield Company,Daqing 163414,China)

机构地区：[1]东北石油大学石油工程学院,大庆163318 [2]中国石油集团钻井工程技术研究院,北京102206 [3]渤海钻探公司第一钻井工程分公司装备管理科,天津300280 [4]中国石油大庆油田有限责任公司第二采油厂,大庆163414

出　　处：《地球物理学进展》2023年第2期600-611,共12页Progress in Geophysics

基　　金：国家自然科学基金面上项目“万米深井PDC钻头冲击破岩机理及提速方法研究”(52274005);黑龙江省优势特色学科建设项目“基于钻井大数据的钻进优化和人工智能建模技术”(XK202001)联合资助。

摘　　要：增强型地热系统(EGS)是干热岩储层良好的渗流和传热通道,EGS由注入井、含裂隙储层、采出井所组成,因此井筒布置和裂隙分布特征将直接影响到流体的流动路径,进而影响着流体的流动和传热过程.本文旨在同时考虑井筒布置与裂隙分布特征对系统采热性能的影响,建立三维井筒与热储热流耦合数值模型,分析井网布置与井间距参数变化;以及裂隙条数、裂隙迹长等裂隙分布特征变化对系统采热的影响,并以4项采热评价指标来评估地热潜能.研究结果表明:(1)注入井井数的增加会提高生产质量流率,但却不会使热突破明显提前,使得热开采速率大大提高,对系统采热有利;(2)井间距的增大可以延长系统寿命,提高开采中后期生产质量流率以及热开采速率,有利于热能提取;(3)裂隙条数的增加会导致裂隙储层连通性增强,从而导致采出温度下降更快,生产质量流率提高更大,热开采速率也明显提高,进而缩短系统寿命,且储层热提取率增大,对地层开采程度会提高;(4)裂隙平均迹长越长,采出温度越高,生产质量流率也越大,越有利于实现商业化开采,同时系统热开采速率也越大,且不会降低系统寿命,储层热提取率随平均迹长增大而减小,说明储层被开采程度较低,裂隙的贡献更大.Enhanced Geothermal System(EGS) is a good seepage and heat transfer channel for dry hot rock reservoirs.EGS is composed of injection wells,fractured reservoirs and produced wells.Therefore,wellbore layout and fracture distribution characteristics will directly affect the flow path of fluid,and then affect the flow and heat transfer process of fluid.The purpose of this paper is to consider the influence of wellbore layout and fracture distribution characteristics on the thermal recovery performance of the system at the same time,establish a three-dimensional wellbore and heat storage heat flow coupling numerical model,analyze the influence of well pattern layout and well spacing parameter changes,fracture numbers,fracture track lengths and other fracture distribution characteristics on system heat production.The geothermal potential is evaluated with four heat recovery evaluation indicators.Research indicates:(1) The increase in the number of injection wells will increase the production mass flow rate,but it will not significantly advance the thermal breakthrough,which greatly increases the thermal recovery rate,which is beneficial to the system thermal recovery.(2) The increase of well spacing can prolong the service life of the system,improve the production mass flow rate and thermal recovery rate in the middle and late period of exploitation,and is conducive to heat energy extraction.(3) The increase of the number of fractures will lead to the enhancement of the connectivity of the fractured reservoir,resulting in a faster decline in the recovery temperature,a greater increase in the production mass flow rate,a significant increase in the thermal recovery rate,thereby shortening the life of the system,and an increase in the thermal recovery rate of the reservoir,which will improve the degree of formation exploitation.(4) The longer the average trace length of the fracture is,the higher the recovery temperature is,and the greater the production mass flow rate is,which is more conducive to the realization of comm

关 键 词：增强型地热系统 井筒布置 裂隙分布特征 采热性能 井筒与热储 热流耦合 评价指标 

分 类 号：P314[天文地球—固体地球物理学]