干热岩钻探关键技术探索

Study on Key Technologies of Dry Hot Rock Drilling

干热岩是国际公认的高效低碳清洁能源,近年来,随着国家对清洁能源勘探开发的提倡和支持,国内开展了一些干热岩勘探工作。干热岩钻探是前期获取地质资料进行资源量计算及后期开发利用的关键部分。现阶段国内在干热岩钻探工艺技术方面还没有形成体系,大多借用石油钻井行业及地质钻井行业的一些工艺技术,但干热岩钻探钻遇地层温度普遍较高,且大部分孔段均为坚硬的花岗岩地层,因此如何在高温环境下保持钻井液性能,保证其携带岩屑及维护孔壁稳定的功效,在坚硬的花岗岩层中如何提高钻进效率,实现高效钻进,钻遇破碎地层时如何维护孔壁稳定,实现护壁堵漏等问题,该文结合国内已施工的部分干热岩钻探工程,对国内干热岩钻探所采取的工艺技术进行了探索,研制了抗高温配方的钻井液,使用转盘回转+孔底动力钻具复合钻进,在钻井液中加入抗高温封堵剂,可有效提高干热岩钻探效率,以期促进干热岩钻探工艺技术的研究、应用和推广。

Dry hot rock is a highly efficient low carbon clean energy recognized by the international community.In recent years,accompanying with the advocation and support of the exploration and development of clean energy,dry hot rock exploration work has been carried out.It is a key part of obtaining geological data for resource calculation in the early period and development and utilization of dry hot rock in the later period.At present,systematic dry hot rock drilling technology has not been formed in our country.Some technology from the oil drilling industry and geological drilling industry have been used.But the formation temperature of dry hot rock drilling is generally high,and most of the drilling holes are in hard granite.Therefore,how to maintain the performance of the drilling fluid in a high temperature environment,to ensure that it carries the cuttings and maintains the stability of the hole wall,how to improve drilling efficiency and achieve efficient drilling in a hard granite layer,how to maintain the stability of the hole wall and achieve the wall plugging when drilling the fractured ground are difficulties.In this paper,combining with some practices of dry hot rock drilling projects which have been constructed in China,technology of dry hot rock drilling have been studied in order to promote the application of dry hot rock drilling technology.