Study on Capillary Pressure Measuring Technology of Coal Bed Methane Well

The paper introduced the basic principle and technical status of the capillary measurement and the key problems of the coal bed methane well capillary pressure measuring, analyzed the problems possibly occurred in the coal bed methane well measurement and solutions and discussed the development orientation to i mprove the capillary measuring technology of the coal bed methane well.According to the coal bed methane well, a circular space moving type and a concentric fixed ty pe pressure transmission cylinders and the pressure measuring system were designed.A pressure measuring plan was provided to fundamentally solve the difficult prob lems of the flowing pressure variation measurement in the coal bed methane well.The pressure measuring system could have a comprehensive accuracy up to 0.06% u nder the 2 m water column pressure, which was obviously improved than the pressure measuring accuracies of other technologies.