Prediction Of The Sweet Spot Zone Of Late Permian CBM In Block B Of Bowen Basin

As a self-generating and self-storage non-conventional natural gas energy,CBM has the advantages of cleanliness and economy.Its development and utilization is of great significance to relieve energy pressure,reduce greenhouse gas emissions and reduce coal mine accidents.It is of great significance for efficient development of CBM to carry out research on physical parameters of CBM reservoir and establish three-dimensional geological model to predict dessert area.This paper focuses on the Late Permian RCM coal seam group and FCCM coal seam group in Block B of Bowen Basin,combines the geology and logging data of the basin,completes the standardization of logging curves and fine identification of coal reservoir according to the logging response characteristics of coal seam"two high and two low"and core description data of the whole well section,and determines the upper limit value of coal-rock density in the study area is 1.8g/cm~3 and the thickness of each single coal seam.Based on the result of fine interpretation of single well and standard well,fine division and contrast of coal reservoir of single coal seam level are completed by marker layer contrast method and coal seam characteristic contrast method,and spatial distribution characteristics of each coal seam are defined.Based on the data of core analysis of coal seams,the core location of coal seams and the physical parameters of coal reservoirs are analyzed,the influencing factors of gas content,permeability,ash-humidity and other parameters of coal seams are analyzed,and the characterization relationships between gas content and parameters such as buried depth of coal seams,ash-humidity and core density,logging density and core density,and permeability and buried depth of coal seams are determined.Based on the above work,the geological model of CBM in Block B has been established.Fault model and stratification model are established by utilizing the results of logging stratification and previous research on seismic interpretation.Attribute model is established by utilizing the results of analysis of physical parameters of coal reservoir,including density model,gas content model,ash and humidity model,permeability model,etc.According to the cumulative frequency distribution of peak gas production of developed wells in Block B,the peak gas production of high,medium and low production areas in Block B is determined.According to the relationship between peak output of CBM and CBM content,permeability,thickness and buried depth,it is clear that CBM content,permeability and buried depth are the main factors controlling dessert area.Combining production data and main control factors of dessert area,the division standard of dessert area in Block B was put forward and the dessert area forecast was completed.