Research and Analysis on Drilling-while-casing and Fracturing Drainage in Soft and Low Permeability Coal Seams

Abstract:

In order to improve the drilling depth and the permeability of soft and low permeability coal seams, a new technique including underground casing-while-drilling and horizontal hydraulic fracturing is proposed. The paper discusses the feasibility and execution steps of this technology based on the borehole design and stress analysis. It is possible that this technique becomes a new technology to solve the gas drainage difficulties in soft and low permeability coal seams.