低固相高润滑双聚钻井液体系在地热井施工中的应用

Application of a low solid phase, high lubricating anddouble polymer drilling fluid system in geothermal well drilling

摘要:

在河南省兰考地区地热井施工中，二开井段深度超过1500 m，采用普通膨润土钻井液体系无法满足地热井施工及对含水层保护的要求，且容易造成卡钻事故。为了解决生产实际问题，研究设计了一种地热井施工用低固相高润滑双聚钻井液体系，通过现场4口井中的应用，钻井过程顺利，有效解决了井眼携砂能力不强、泥岩地层井壁不稳定、砂岩地层失水量大、泥皮厚等问题，4口井均未发生任何井下复杂情况和事故，说明该钻井液体系对兰考地区地层的适应性较好，能够满足该地区钻井工程的需要，对兰考地区地热井施工具有很好的指导意义。

Abstract:

In geothermal well drilling in Lankao where the depth of the second well section is more than 1500m, the common bentonite drilling fluid system can not meet the requirements, and it is easy to cause sticking incidents. In order to solve the drilling problems, a kind of low solid phase, high lubricating and double polymer drilling fluid system was designed for geothermal well drilling. Field application in 4 wells showed that the drilling process was smooth, which effectively solved the problems such as poor sand carrying capacity, unstable well wall in mudstone formation, large water loss in sandstone formation, thick mud cake, etc. None of the 4 wells met any difficult situation and incident. The drilling results indicate that the drilling fluid system has good compatibility with the formation characteristics in the Lankao area and can meet the needs of drilling works, providing good guidance for geothermal well drilling in the Lankao area.