水敏性复杂地层深孔绳索取心钻进工艺研究与应用

Research and application of deep hole wireline core drilling technology in water-sensitive complex formations

宝山矿区地质构造较复杂,存在多个断裂破碎带,地层软硬互层交替,炭质页岩厚度大,遇水膨胀,钻孔缩径严重,钻进过程中易发生粘附卡钻、坍塌及埋钻等事故,属于典型的水敏性地层。针对该类地层在钻进过程中出现的这些问题,通过优化钻孔结构、合理钻具级配,采用金刚石绳索取心钻进工艺和低固相钻井液护壁技术,适当控制回次进尺长度和回次进尺时间等措施,保证了钻孔孔壁的稳定性及工程安全,有效地解决了水敏性地层钻进中出现的问题,加快了施工进度,取得了较好的钻进效果,使项目得以顺利完成。本次钻探施工完成了钻探进尺9500余米,达到了地质找矿目的,取得了较好的经济和社会效益。此外,希望适用于该矿区的钻进工艺方法对其他相似水敏性复杂地层的钻探施工具有一定的参考意义。

The geological structure in Baoshan mining area is relatively complex with multiple fractured zones and alternating layers of soft and hard strata.The thickness of the carbonaceous shale is large,and it expands when encountering water,causing serious borehole shrinkage.During drilling,accidents such as sticking,collapsing and burying are prone to occur,making it a typical water sensitive formation.In view of these problems that occurred during the construction process in this type of formation,measures such as optimizing the drilling structure,reasonable drilling tool grading,using diamond wireline core drilling technology and low solid-phase drilling fluid wall protection technology,appropriately controlling the length and time of the s footage per round trip,etc.,were taken to ensure the stability and engineering safety of the drilling hole wall,the problems in the drilling of water-sensitive formations are effectively solved,the construction progress is accelerated,and the good drilling effect is obtained,so that the project can be successfully completed.More than 9,500 m of drilling was completed in this drilling project and the purpose of geological prospecting was achieved with good economic and social benefits,In addition,it is hoped that the drilling method applicable to this mining area will have certain reference significance for the drilling in other similar complex water-sensitive formations.