西藏谷露地热田ZK401高温地热井钻井工艺技术  

Drilling technology of ZK401 high temperature geothermal well in Gulu geothermal field,Xizang

作　　者：吴儒杰[1,2] 郑冉 张松 万汉平[1,2] 郝伟林 唐伟军[1,2] 张健 WU Rujie;ZHENG Ran;ZHANG Song;WAN Hanping;HAO Weilin;TANG Weijun;ZHANG Jian(Beijing Research Institute of Uranium Geology,Beijing 100029,China;CNNC Geothermal Exploration Technology Center,Beijing 100029,China;Center of Land Mining Rights Trading and Resource Reserves Evaluation,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1期117-128,共12页World Nuclear Geoscience

摘　　要：谷露地热田是西藏那曲—尼木地热带上的典型水热型高温地热田,安全、经济和高效的钻井工艺技术很大程度上决定了其高温地热资源的可开发利用潜力。ZK401井是在谷露地热田实施的一口优质高产探采结合井,地层以花岗岩类为主,其岩石硬度大,机械钻速低,钻头使用寿命短。自上而下揭露多层热储,其35~41m即可揭露124.8℃中温地热流体,汽水总量约40 t·h^(-1);50~320 m揭露超过120℃的中温热储,汽水总量约30~35 t·h^(-1);320~1320 m揭露186.9℃高温热储,汽水总量高达348 t·h^(-1),具有热储埋深浅、温度高,断裂构造发育,地层出水量大的特点,高温及水侵作用致使钻井液极易失效,井喷风险大,安全钻井难。为解决上述钻井施工难点,进行了高温地热钻井关键技术研究。通过采用异形齿PDC钻头和岩石热裂提速技术,使单只异形齿PDC钻头进尺较同规格牙轮钻头提高了23%~48%,使三开井段花岗岩类地层的平均机械钻速提升至3.18 m·h^(-1)。通过优化井身结构,采用简易控压钻井技术,利用低温清水作为二开及三开钻进循环钻井液,达到了及时发现并有效保护热储层和控制井喷风险的目的;实现了ZK401井在520 m揭露186.9℃高温热储且汽水总量达348 t·h^(-1)苛刻条件下的安全、持续钻进,且非生产时间较采用常规钻井技术的邻井缩短了37%,极大地降低了钻井成本,提高了高温地热资源的可开发利用潜力。为后续该区域乃至其他地区解决高温地热井钻井施工提供参考。The Gulu geothermal field is a typical hydrothermal high temperature geothermal field in the Naqu-Nimu geothermal belt of Xizang.The safe,economical,and efficient drilling technology largely determines the potential for the development and utilization of its high-temperature geothermal resources.ZK401 well is a high-quality and high-yield exploration and production combined well implemented in the Gulu geothermal field.The rock is mainly composed of granite,which has high rock hardness,low mechanical drilling speed,and short drill bit service life.Multiple layers of thermal storage were exposed from top to bottom,and the medium temperature geothermal fluid of 124.8℃was exposed from depth 35 to 41 m,and the total amount of steam and water is about 40 t·h^(-1).The medium temperature thermal storage of more than 120℃was exposed at the depth of 50 to 320 m,and the total amount of steam and water is about 30 to 35 t·h^(-1).320 to 1320 meters exposed 186.9℃high-temperature thermal storage,with a total amount of steam and water of up to 348 t·h^(-1).It has the characteristics of shallow thermal storage depth,high temperature,developed fault structures,and large formation water output.High temperature and water invasion can easily cause drilling fluid failure,high risk of blowout,and difficulty in safe drilling.In order to solve the above difficulties in drilling construction,the key technologies of high-temperature geothermal drilling were studied.Through the use of special-shaped PDC bit and rock thermal cracking technology,the penetration of a single special-shaped PDC bit was increased by 23%~48%compared with the same size cone bit,and the average mechanical drilling speed of the granite in the third drilling has been increased to 3.18 m·h^(-1).By optimizing the wellbore structure,adopting simple pressure control drilling technology,and using low-temperature clean water as as circulating drilling fluid for second and third drilling,the purpose of timely discovering and effective protection of thermal reserv

关 键 词：谷露地热田 钻井工艺 简易控压钻井 高温地热井 井喷 

分 类 号：P634[天文地球—地质矿产勘探] TK521[天文地球—地质学] TE921[动力工程及工程热物理—热能工程]