无固相聚乙烯醇冲洗液在龟山铜金矿区的应用

Application of Solid-free PVA Polymer Drilling Fluid in Guishan Copper-Gold Ore District

摘要:

龟山深部铜金矿区含超厚风化破碎带，钻进过程中发生严重坍塌，导致起下钻以及扫孔困难。为此，选用了无固相聚乙烯醇冲洗液增强防塌能力。聚乙烯醇加量越大，冲洗液粘度越高，稳定岩心不发生崩散的能力越强，但是降失水能力差。使用FT-342能够显著降低失水量，并且具有良好的润滑性。使用该冲洗液钻穿ZK141钻孔714～834 m段破碎的炭质页岩及煤层，解决了钻杆内壁结垢的问题，起到了良好的防塌效果。

关键词:超厚风化层;聚乙烯醇冲洗液;防塌性;龟山铜金矿区

Abstract:

The deep copper-gold deposit in GUI Shan contains super thick weathered and fractured zone, severe collapse was encountered during drilling, which led to the difficulties of pipe tripping and hole cleaning. Therefore, the solid-free polyvinyl alcohol drilling fluid was used to enhance the collapse prevention ability.The experiment indicated that the higher the amount of polyethylene, the higher the viscosity of the drilling fluid, and the stronger the ability of stabilizing the core without disintegration. However, there is no obvious water loss-control ability. The use of FT342 can significantly reduce the water loss, and has good lubrication. This drilling fluid was used in drilling through the broken carbonaceous shale and coal seam during the section of 714～834m of ZK141 borehole, the scaling on the inner wall of drill pipe was solved with a good effect of preventing collapse.

Key words:super-thick weathering zone; PVA polymer drilling fluid; anti-collapse; Guishan copper-gold ore district