白涧铁矿南区复杂地层钻探施工技术

Drilling technology for complex formation in the south area of Baijian Iron Mine

摘要:

邢台白涧铁矿南区地层岩石破碎、部分地层含角砾、胶结性差、漏失严重，钻探施工中存在掉块卡钻、缩径、坍塌、埋钻及孔内泥浆全部漏失等难题。通过优化钻孔结构、使用新工艺、新方法，合理选择钻进参数，采用绳索取心钻进配合预留技术套管，有效解决了上部煤系地层的坍塌问题；采用反丝套管的方法，极大地减轻了由于地层缩径、掉块引起的套管下不到位、起拔困难等风险；常规型绳索取心钻杆替代套管方法的采用，提高了含角砾、松散地层的穿过速度，减少了钻探工作量的报废，加快了施工进度；特别是高胎体双水口钻头的使用，提高了钻进效率，节约了钻探施工成本，项目得以如期完成。

关键词:破碎地层;钻孔缩径;钻孔坍塌;绳索取心钻进;高胎体双水口钻头

Abstract:

The formation in the south area of Baijian Iron Mine in Xingtai is broken， containing breccia locally， and with poor cementation and serious leakage； thus， leading to some drilling problems， such as sticking due to falling stones， borehole contraction， collapse， drilling string burial， full circulation loss. By optimizing the drilling structure， using new processes and methods， properly selecting drilling parameters， using wireline core drilling plus pre-set technical casing， collapse of the upper coal measure strata was effectively eliminated. The use of reverse-thread casing greatly reduced the risks in placement of casing and pulling out of casing caused by borehole shrinkage and falling stones. The adoption of conventional wireline coring drill rods instead of casing improved the drilling speed in breccia and loose formation， reduced drilling abandonment， and sped up drilling progress. Notably， the use of the high matrix double nozzle bit improved drilling efficiency， and saved drilling construction cost， allowing the project to be completed on schedule.

Key words:broken formation;borehole shrinkage;borehole collapse;wireline coring;high matrix double nozzle bit