地热井砂岩热储回灌堵塞机理及解堵研究  

Blocking Mechanism and Solution of Sandstone Thermal Storage Reinjection in Geothermal Wells

作　　者：刘斌[1,2,3] 王江峰 李红岩[1,2,3] 王鹏涛 张杰 LIU Bin;WANG Jiangfeng;LI Hongyan;WANG Pengtao;ZHANG Jie(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Sinopec Green Energy Geothermal Development Co.,Ltd,Xianyang 712000,Shaanxi,China;Geothermal University-Enterprise Joint Research Center of Shanxi“Four Subjects and One Joint”,Xianyang 712000,Shaanxi,China;Southwest Petroleum University,Chengdu 610500,China)

机构地区：[1]西安交通大学能源与动力工程学院,西安710049 [2]中石化绿源地热能开发有限公司,陕西咸阳712000 [3]陕西省“四主体一联合”地热能校企联合研究中心,陕西咸阳712000 [4]西南石油大学,成都610500

出　　处：《建筑节能（中英文）》2024年第6期9-15,共7页Building Energy Efficiency

基　　金：四川省重点研发计划资助项目“中深层地热能高效取热关键技术研究及应用”(2023YFS0355)。

摘　　要：地热井回灌是制约水热型地热持续开发的“卡脖子”难题,特别是砂岩热储的回灌更为艰难。为揭示制约砂岩热储回灌过程中面临的堵塞难题,以陕西关中渭河盆地某“一采一灌”模式砂岩地热井为例开展试验研究,探究砂岩热储回灌过程中的4类堵塞机理,并提出相应解堵措施。结果表明:碳酸盐类、部分铝硅酸盐类和铁类矿物沉淀受温度影响较大,地层温度的升高会加速其化学堵塞的形成;随温度的上升,悬浮物堵塞和化学堵塞会构成协同效应。同时悬浮物颗粒布朗运动速度也因温度上升而增大,使堵塞更严重;回灌产生气体堵塞的原因主要是:大体积气泡进入储层内部难、气泡直径与底层喉道大小相当;腐生菌和铁细菌是成微生物堵塞的主要微生物。通过加入阻垢剂可有效防止化学堵塞,采取多级过滤可减缓物理堵塞,在回灌系统中加入自动排气装置可防止气体堵塞,对尾水进行灭菌处理降低微生物堵塞风险。经过现场回暖季试验,采取的解堵措施应用于目标地热井后的回灌率达100%,降低了回灌过程中可能发生的堵塞对回灌带来的不良影响。Geothermal well recharge is a bottleneck that restricts the sustainable development of hydrothermal type geothermal,especially the recharge of sandstone thermal storage is more difficult.In order to reveal the blockage that restrict the process of sandstone thermal storage and reinjection,an experimental study is conducted using a sandstone geothermal well in the “one extraction,one irrigation” model in the Weihe Basin of Guanzhong,Shaanxi Province as an example to explore the four types of blockage mechanisms in the process of sandstone thermal storage and reinjection,and corresponding blockage removal measures are proposed.The results show that the precipitation of carbonates,some aluminosilicates and iron minerals is greatly affected by temperature,and the increase of stratum temperature will accelerate the formation of chemical blockage.With the increase of temperature,suspension blockage and chemical blockage will constitute a synergistic effect.Meanwhile,the Brownian motion velocity of suspended particles also increases with the increase of temperature,which makes the blockage more serious.The main reasons for gas blockage caused by recharge are as follows:it is difficult for large volume bubbles to enter the reservoir,and the bubble diameter is equivalent to the size of the bottom throat.Saprophytic bacteria and iron bacteria are the main microorganisms that cause microbial blockage.Adding scale inhibitors can effectively prevent chemical blockage,adopting multi-stage filtration can slow down physical blockage,adding automatic exhaust devices in the recharge system can prevent gas blockage,and disinfecting the tail water can reduce the risk of microbial blockage.After on-site warm-up season testing,the measures taken to remove blockages are applied to the target geothermal well,resulting in a 100% reinjection rate,reducing the negative impact of possible blockages on reinjection during the reinjection process.

关 键 词：砂岩地层 地热开发 回灌井 堵塞机理 解堵技术 

分 类 号：TU83[建筑科学—供热、供燃气、通风及空调工程] P314[天文地球—固体地球物理学]