福建悠远矿区破碎地层绳索取心技术分析

以悠远矿区ZK303孔为研究对象,运用回归分析法对该孔的钻探进尺和井身质量数据进行了分析,认为该孔的极限完孔日期应在59d内,全井段的最大弯曲出现在780m;1 200m以上拟采用孕镶金刚石梯齿性钻头,以下采用PDC锯齿型钻头。依据扩散双电层理论,采用提高泥浆中Na+浓度来抑制水敏地层的水化分散,并结合适当次数的冲孔再钻进,这样既保证了井壁的稳定,又可大大提高钻速,从而获得良好的钻探效果和经济效益。此结果可为矿区其它钻孔的施工提供参考。

Analysis of Friable Strata Wireline Coring Drilling Technology in Youyuan Mine Area,Fujian

To take the ZK303 borehole in the Youyuan mine area as subject investigated,carried out drilling footage and borehole quality data analyses through regression analysis methods.Facts of completion of borehole should be within 59 days;maximum deviation might be at depth 780m;using impregnated diamond stepped borway bit above depth 1200m,and using PDC borway bit below have been considered.Based on diffused double layer theory,increase Na＋ concentration to restrain hydrate dispersion in water sensitive strata,combined with proper frequency flushing,thus can ensure wall stability and increase drilling rate,as a result,good drilling effect and economic benefit.The result can be a reference for other borehole operation in the mine area.