世界典型高温地热田回灌经验及对谷露热田回灌井部署的启示  

Reinjection experience of world high-temperature geothermal field and the deployment of reinjection wells in Gulu geothermal field

作　　者：张松[1,2] 郑冉 郝伟林 胡先才[1,2] 万汉平 胡志华 高洪雷[1,2] 张健 吴儒杰[1,2] 唐伟军 ZHANG Song;ZHENG Ran;HAO Weilin;HU Xiancai;WAN Hanping;HU Zhihua;GAO Honglei;ZHANG Jian;WU Rujie;TANG Weijun(Beijing Research Institute of Uranium Geology,Beijing 100029,China;CNNC Geothermal Exploration Technology Center,Beijing 100029,China;Land and Mineral Rights Trading and Resource and Reserve Evaluation Centre of Xizang Autonomous Region,Xizang Autonomous Region,Lhasa 850011,China)

机构地区：[1]核工业北京地质研究院,北京100029 [2]中核集团地热勘查技术研究中心,北京100029 [3]西藏自治区土地矿权交易和资源储量评审中心,西藏拉萨850011

出　　处：《世界核地质科学》2024年第4期745-755,共11页World Nuclear Geoscience

摘　　要：地热尾水回灌是地热田开发过程中必不可少的环节,对热田开发具有重要意义。对世界上不同类型高温地热田回灌策略进行系统梳理,发现不同类型地热田常采取不同的回灌策略:气相为主的气液两相地热田常进行内场回灌;液相为主的气液两相地热田和水热型地热田常采用内场回灌与外场回灌相结合的方式。重点分析与谷露地热田相似的美国Brady Hot Spring地热田、Beowawe地热田和中国羊易地热田三个水热型高温地热田在生产过程中的回灌情况,对上述地热田在回灌过程中的回灌距离、回灌深度及回灌后对热田生产的影响进行总结。上述地热田多采用同构造回灌的方式进行回灌;一般无特定的回灌距离,常采用内场回灌与外场回灌相结合的方式进行;回灌目的层常选择渗透性好的断裂构造;回灌深度以大于500 m的深层回灌为主。这些热田在回灌过程中,为了达到良好效果,需要平衡生产区的压力下降和热突破之间的关系。结合谷露地热田实际地质情况,认为谷露地热田应该采取同构造回灌,且采用内场回灌与外场回灌相结合的深层回灌方式。初步在热田生产区1 km以外的位置选择3片回灌区域。其中回灌1区是主要回灌区域,位于热田生产区的北侧约1~1.5 km范围内。为了防止发生热突破,需要在回灌井实施过程中,进行回灌试验,尽早确定回灌井与生产区之间的水力联系。Reinjection is an essential part of geothermal exploration.This article reviewed the reinjection strategies of different high-temperature geothermal fields in the world and found that different types of geothermal fields had different reinjection strategies:two-phase geothermal system(vapour-dominated)usually adopts infield reinjection;two-phase geothermal system(liquid-dominated)and hot water systems take both infield and outfield reinjection.The reinjection situations of Brady Hot Spring and Beowawe geothermal fields in the United States,Yangyi geothermal field in China,which are similar to the Gulu geothermal field,were systematically analyzed.The reinjection distance,depth,and the impact on the geothermal field by reinjection were discussed.The above geothermal fields mostly adopt the same-structure reinjection method;no specific reinjection distance is used in all the fields,a combination of infield and outfield reinjection is often used;the reinjection target usually selects a fault with good permeability;the reinjection depth is mainly greater than 500 m.During the reinjection process,it is necessary to balance the relationship between the pressure drop in the production area and the thermal breakthrough.Considering the geological situation of the Gulu geothermal field,it is suggested that the Gulu geothermal field should adopt the same-structure for the reinjection and a combination method of infield and outfield deep reinjection.Three reinjection sectors areas more than 1 km away from the production area of the geothermal field were selected.Among them,Reinjection Area 1 is the main reinjection area,which is about 1 to 1.5 km to the north of the production area.

关 键 词：西藏 高温地热田 回灌经验 谷露地热田 回灌井 

分 类 号：P634[天文地球—地质矿产勘探] P314[天文地球—地质学] TE249[石油与天然气工程—油气井工程]