青海共和干热岩GR1井钻井工艺技术

The Drilling Technology for the GR1 Well in Hot-Dry Rock of Gonghe,Qinghai Province

本文介绍了青海共和县恰卜恰镇干热岩勘探孔GR1井的钻探施工概况以及采用的关键技术。通过对孕镶金刚石全面钻头技术、耐高温聚合物防塌钻井液技术、大直径螺杆复合钻进技术、底喷式聚晶取心钻头技术、壁钩式套铣打捞技术等难点的研究,解决了干热岩钻探碎岩效率低、钻进速度慢、钻井液高温稳定性及护壁与携岩能力差等难题,形成了一套适用于深部大口径干热岩钻探工艺技术,有效降低干热岩钻井与成井成本,对提高干热岩资源利用的经济可行性意义重大。共和盆地GR1干热岩勘探孔在地下3705. 42m深处探获温度达到236℃以上的干热岩,这是我国首次在青海共和盆地钻获高温优质干热岩体,实现了我国干热岩勘查重大突破。

This paper presents the situation of drilling-site construction and the key techniques used in the drilling of the dry-hot rock exploration hole GR1 at Qiabuqian town,Gonghe county,Qinghai province.We have conducted research on the difficult problems such as the impregnated diamond full-scale drilling bit,high temperature resistant polymer anti-collapse drilling fluid,large-diameter screw compound drilling,bottom-jet polycrystalline coring bit and the wall hook type milling and salvage.We have also tackled problems of low efficiency,slow drilling speed,high temperature stability of drilling fluid and poor wall protection and cuttings carrying capacity of the dry-hot rock drilling.And a set of drilling techniques for deep large-diameter dry-hot rock have been developed.The cost of dry-hot rock drilling and well completion has been reduced effectively.It is of great significance for improving the economic feasibility in utilization of dry-hot rock resources.The hot-dry rock s temperature at a depth of 3705.42 m in the exploration drilling hole GR1 is above 236℃.This is the first time that China has obtained high temperature and high quality dry-hot rock mass at Gonghe basin of Qinghai Province,showing a major breakthrough in the exploration of dry-hot rock in our country.