Study on Coal Rock Stress Sensitivity of Different Cleat Directions in Ordos Basin
REN Fei
LI Xin-zi
ZHANG Sui-an
Abstract：Coal stress-sensitivity has serious impacts on the value of permeability during coalbed methane development, meanwhile, the permeability change would directly determine the success or failure of commercial exploitation of coalbed methane resources. The experi-mental studies have done for permeability change with different effective stress in different directions of coal in the Laokengkou mine of southeastern margin of Ordos Basin,such as parallel face cleats,vertical face cleats and vertical bedding.The comparative analysis of coal permeability loss value accompanying direction changes during the pressurization and step-down process was done.The results showed that the phases of stress sensitivity were varied in different coal cleat orientation,where the strong stress sensitivity phase for parallel to the face cleats focuses on the effective stress was less than 8 MPa range,vertical cleats and vertical bedding planes concentrated in less than 6 MPa,4 MPa respectively.Considering the impacts of stress sensitivity during drainage for coalbed methane wells in nearly 200 m deep coal seam should carefully extraction,reducing amplitude of permeability reduction and time schedule,were proposed.Based on the permeability advantage of face cleats,the well network layout is the long axis of well network paralleling to the face cleats.
Keywords：coal rock bodystress sensitivitycleat directionpermeability losscoalbed methane well drainagewell pattern optimization
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 21-25 )