软弱易冲蚀地层钻探施工技术

Drilling Technology in Soft Erosion Stratum

摘要:

钻探生产中经常遇到一些软弱易冲蚀地层，因这些地层岩石破碎、松软，在进入内管前往往易被冲洗液冲蚀，进入内管后也常常因卡簧卡不牢在打捞时掉落造成空管。因岩心采取率低往往造成钻孔报废。以贵州道真新民铝土矿矿区为例，分析了软弱易冲蚀地层岩心采取率低的原因；为提高该类地层岩矿心采取率，研制了无泵反循环超前侧喷绳索取心钻具，保证了岩矿心采取率，取得了很好的效果。

Abstract:

Soft erosion strata are often encountered in drilling construction; the cracked and soft rocks usually are eroded by slurry before entering the inner tube or drop out from inner tube because of unstuck core lifter. The low core recovery often results to borehole abandoned. The paper analyzes the causes of low core recovery in soft erosion stratum by an example of bauxite mines in Guizhou, an advanced side spray wire-line coring tool without pump is developed to ensure the core recovery with good effects.