煤矿水害治理多分支水平井精准定导向技术研究

Research on precise directional drilling technology for multi-branch horizontal wells in coal mine water hazard control

摘要:

多分支水平井注浆技术因其施工成本低、环境污染小、隔水效果好等特点，被广泛应用于煤矿水害治理中。但由于煤层底板普遍存在断层发育、目的层薄、破碎带聚集等复杂情况，施工时常出现泥浆漏失、顺层钻进困难、穿越断层易卡钻等难题，严重影响了注浆治理效果。针对这些问题，本文以安徽某煤矿为例，在对其地质特征进行分析的基础上，从定向轨迹设计、定导向设备选型以及井眼轨迹控制等方面展开研究，将定向钻进和地质导向技术结合，优化复杂地质条件下多分支水平井定导向技术，并成功应用于多分支水平井超前注浆改造工程中。现场应用表明，该技术提高了井眼轨迹控制的精确性，保证了目的层钻遇率，应用效果良好。

关键词:多分支水平井;煤矿水害治理;定导向技术;井眼轨迹控制;注浆改造

Abstract:

Multi-branch horizontal well grouting technology has been widely used in coal mine water hazard control due to its low construction cost， low environmental pollution and good water isolation effect. However， the coal seam floor generally is featured of complex conditions such as fracture development， thin target layers， and aggregation of fracture zones， often leading to problems such as mud leakage， difficulty in in-seam drilling， and easy sticking through the fractures during drilling operations and affecting the effect of grouting treatment seriously. In view of these problems， taking a coal mine in Anhui as an example， based on the analysis of its geological features， this paper studies directional wellbore trajectory design， selection of directional equipment and control of wellbore trajectory. Directional drilling and geo-steering technology were combined and successfully applied to the advance grouting treatment project with multi-branch horizontal wells. The field application showed that the technology improved the accuracy of wellbore trajectory control， ensured the target layer intersection rate， and had good application effect.

Key words:multi-lateral horizontal well;control of water hazards in coal mines;directional drilling technology;well trajectory control;grouting treatment