CBM reservoir parameter measurement based on the interference testing technology

In order to remedy the problem of point replacing surface in the results of traditional injection pressure drop test, a CBM reservoir parameter measurement method based on interference well testing was proposed. The basic principle, test method and data analysis basis were described. Taking a well group composed of a stimulation well and 4 observation wells in the south of Qinshui basin as example, the results of earlier injection pressure drop and historical fitting of the well group were compared to the results of interference well testing and analyzed. The results showed that the permeability of different measurement points of the well group approximated the permeability from historical fitting using production data and was higher than the permeability measured from injection pressure drop, but the permeability obtained by the three methods was of the same order of magnitude. The CBM interference well testing technology may reflect the characteristics of the regional permeability distribution of the tested well group consisting of 5 wells, at the southeast direction in the region, i.e the direction of development of the principal fracture, the permeability was higher. By combining the parameter values measured from the three methods, it can be known that the CBM interference well testing can get not only the parameter value of the discrete points, but also the regional connectivity of well group and advantageous seepage direction, the results are helpful to know the regional reservoir parameters, provide direct data basis for the layout of further well grid and production wells.