蔚县盆地中深层地热井钻井技术研究

Research on drilling technology of middle-deep geothermal well in Yuxian Basin

河北省蔚县盆地属于冀西北山间断陷盆地,地热资源丰富,开发利用程度较高。热储层为中元古界长城系—蓟县系,所钻遇地层构造复杂,断裂纵横,造成钻探施工难度大。针对蔚县盆地区域复杂、漏失、破碎地层,介绍了R1、DR1、DR2三口地热井钻井难点及钻井工艺,采用了相应的螺杆复合钻进、气举反循环钻进、破碎地层取心等关键技术措施,在满足地质设计要求的同时提高了钻进效率,有效地完成了钻井施工任务,为后续在该区域进行中深层地热钻探积累了经验。

The Yuxian Basin belongs to the fault subsidence basin in the northwest mountains of Hebei Province,with rich geothermal resources and high exploitation and utilization degree.The thermal reservoir is in the Changcheng System and Jixian System of the Mesoproterozoic Erathem,and the strata encountered are complicated in structure and criss-cross faults,which makes the drilling construction difficult.In view of the complex,leaky and fractured stratums in Yuxian Basin,the drilling difficulties and drilling technology of R1,DR1 and DR2 geothermal wells were introduced.The corresponding key technical measures such as screw composite drilling,gas lift reverse circulation drilling and coring of broken stratum were adopted to improve drilling efficiency while meeting the requirements of geological design,and effectively completed the drilling construction task.Experience had been accumulated for the subsequent middle-deep geothermal drilling in this area.