内插管式气举反循环钻进工艺在基岩地热井中的应用

随着地热资源被广泛利用,地热井各种钻井技术新方法不断应用,如何提高地热井施工效率、降低地热井施工成本是地热井项目钻探施工的关键。气举反循环钻进工艺被广泛应用于地热井钻探施工中,然而在基岩浅井和中深井地热项目施工中,使用常规气举反循环钻进工艺存在钻具重量大、结构复杂、双壁密封不严等问题,对钻机提升能力要求较高,中小型钻机难以满足,加大了施工成本。本研究在不改变常规中小型正循环施工钻探设备、钻具的条件下,提出了一种内插管式气举反循环钻进技术,并在沂南智胜汤泉1号基岩地热勘查井施工中进行了应用。试验表明:内插管式气举反循环技术施工工艺,可在无需更换原有钻探设备和钻具的基础上,通过加工部分钻具及部件,便可实现正反循环工艺之间的更换。更换后的气举反循环钻进工艺结构简单、钻具重量轻、双壁密封可靠、施工成本低,提高了设备利用率和钻进效率。在基岩浅井和中深井中,应推广应用内插管式气举反循环钻进工艺。

Application of Hanging Pipe Air-lift Reverse Circulation Drilling Technology in Geothermal Well Drilling

Accompanying with extensive use of geothermal resources, geothermal well drilling technology and new methods have been constantly used. How to improve the efficiency and reduce the cost of geothermal well construction is the key in geothermal well project drilling construction. Gas lift reverse circulation drilling technology is widely used in geothermal well drilling construction. However, in bedrock shallow well and medium deep well geothermal project construction, by using conventional gas lift reverse circulation drilling technology has some problems, such as heavy drilling tool, complex structure and loose double wall sealing. It requires high lifting capacity of drilling rig. Small and medium size drilling rig is difficult to meet the requirement, and the construction cost has been increased. In this study, without changing the conventional medium and small-sized drilling equipment and drilling tools, a kind of internal intubation gas lift reverse circulation drilling technology is used in the construction of Zhisheng Tangquan No.1 bedrock geothermal exploration well in Yi''nan. It is showed that the construction technology of internal intubation gas lift reverse circulation technology can realize the replacement of positive and negative circulation technology by processing some drilling tools and components without replacing the original drilling equipment and drilling tools. The replaced air lift reverse circulation drilling technology has the advantages of simple structure, light weight, reliable double wall sealing and low construction cost. It can improves the utilization rate of equipment and drilling efficiency. It is necessary to popularize the application of internal intubation gas lift reverse circulation drilling technology in bedrock shallow wells and medium deep wells.