Thinking of CBM exploration with high dip angle and "open air" dual characteristics:A case of Xinjiang CBM reservoir
Given the large reserves and high gas content of CBM reservoirs in Xinjiang,a small number of CBM wells have sustained high and stable production,and most wells have low or even no gas production.As a result,it is difficult for Xinjiang CBM industry to increase storage and production with high quality.It cannot reach large-scale development and utilization conditions and cannot give play to potential resource advantages.Based on the practical knowledge analysis,combined with the research results of CBM reservoirs in China and abroad,the author believes that the spatial occurrence characteristics of CBM reservoirs with high dip+"open air"and the technical scheme of this feature are not compatible with one of the main factors restricting Xinjiang coalbed methane industry.In view of the significant difference between the characteristics of the CBM reservoir with high dip+"open air"and the low-dip CBM reservoir,the author puts forward the reasons and solutions to be optimized in the process of exploration and development of CBM reservoirs with dual characteristics from four aspects:1)The sealing property of the reservoir and its relationship with the gas content of CBM reservoirs should be studied using hydrogeology and hydrogeochemistry research methods;2)The standardization of reservoir physical parameters provides accurate basis for reservoir understanding and reservoir reconstruction decision;3)The identification of coalbed methane genesis can avoid one-sided understanding of the regional sweet spot selection,enrichment law,and evaluation CBM reservoirs;4)Objective and scientific reserve calculation method is a direct method to improve the quality of achievement transformation and reduce the error of regional gas storage.It is necessary to standardize the parameters of CBM reservoirs with dual characteristics and objectively identify the accumulation mechanism.
Xinjiang coalbed methaneincrease storage and productionlarge-scale development and utilizationspatial occurrence characteristicsstandardization ideasaccumulation mechanism