云南金平长安金矿大倾角钻孔绳索取心施工技术

Wireline coring for large inclination boreholes in Chang’an Gold Mine, Jinping, Yunnan Province

摘要:

金平长安金矿区矿体以硫化矿形式赋存于砂岩中，属于埋藏较深、倾角较陡、勘查难度较大的金矿。矿区的勘查钻孔设计范围为：方位70°～250°、倾角30°～75°、孔深100～800 m。针对该矿区地层呈现硬、碎、漏复杂情况，钻孔设计倾角大、孔斜要求高等特点，采用了新型设备（XDJ4型全液压岩心钻机）钻孔及低粘、低密度、润滑性好的冲洗液护壁方法，采取“控制钻机安装”、“减速法”或“小径导向增压纠斜法”等措施进行控斜及纠斜。有效地解决了易斜、易漏等斜孔施工问题，保质保量按期完成了施工任务，取得了很好的经济和社会效益。本文总结了该矿区大倾角钻孔施工中的部分经验和存在问题，为同类工程施工提供了较好的参考。

Abstract:

The ore bodies of Jinping Chang’an Gold Mine exist in sandstone in the form of sulphide deposits, which has the characteristics of deep burial, steep dip and difficult exploration. In the design of exploration boreholes in the mining area, the azimuth ranges from 70° to 250°, the inclination from 30° to 75°, and the borehole depth from about 100m to 800m. In view of the complex situation of hard, broken and leaking formation, and with the large designed inclination and strict requirement on hole deviation in this mining area, a new type of drilling equipment (XDJ4 full hydraulic core drilling rig) was adopted for drilling with flushing fluid of low viscosity, low specific gravity and good lubricity for borehole wall protection. Control and correction of borehole deviation were carried out by taking measures such as control of drilling rig installation, deceleration method, small diameter pilot drilling followed with correction of deviation by increase of WOB. As a result, the construction difficulties such as easy deviation and leakage were effectively solved, and the project was completed with high quality and full quantity as well as on schedule, achieving good economic and social benefits. This paper summarizes some experience and existing problems in the construction of large inclination boreholes in this mining area, which provides good reference for the construction of similar projects.