Slurry in use for directional drilling into clay band layer in horizontal

Abstract

A slurry used for clay layer of horizontal positioned drilling is prepared from alta-mud, soda ash, hydrolytic polyacrylonitrile, lubricant and water. the prepared slurry can prevent drilled hole from collapse and driller from seizing-up in course of horizontally positioned drilling.

Description

Technical field: [0001] The invention relates to a mud used for horizontal directional drilling in the field of geological exploration, and belongs to the mud used for horizontal directional drilling in clay layers. Background technique: [0002] The mud used in the horizontal directional drilling process has the functions of carrying and suspending cuttings, stabilizing the well wall, cooling and flushing the drill bit. At present, the mud used in the horizontal directional drilling process is composed of bentonite and water. The viscosity and shear force of the single-component mud are too high. During the drilling process, when the drill bit passes through the clay, or through loose, When the mud and shale layers are easy to hydrolyze and disperse or make slurry, the drilled cuttings will quickly disperse into fine particles and suspend in the mud. At this time, the density of the mud increases, and the viscosity shear force rises sharply, making the mud more and more Th...

AI Technical Summary

Problems solved by technology

At present, the mud used in the horizontal directional drilling process is composed of bentonite and water. The viscosity and shear force of the single-component mud are too high. During the drilling process, when the drill bit passes through the clay, or through loose, When the mud and shale layers are easy to hydrolyze and disperse or make slurry, the drilled cuttings will quickly disperse into fine particles and suspend in the mud. At this time, the density of the mud increases, and the viscosity shear force rises sharply, making the mud more and more The thicker it is or even completely loses its fluidity, the drilled and crushed cuttings cannot be removed and transported outside the hole in a timely and effective manner, so that hole collapse and drill sticking are prone to occur during drilling, back-expanding and back-dragging