Main Controlling Factors Of Continental Shale Gas Content In Fuxin Basin

As the“coal capital”,coal resources in Fuxin are near exhaustion after hundreds of years of exploitation,and the study of shale gas research kicked off.However,due to the late start of the study,the geological conditions for formation of shale gas in the Fuxin Basin are weak,and the controlling factors for the gas content of the shale gas in the basin are not clear.This paper took the Fuye 1 well as a breakthrough to reveal the main gas bearing property of the continental shale in the Fuxin Basin.In addition,established a gas-bearing theoretical model to made a great contribution to the study of shale gas in Fuxin Basin.There are many factors affecting gas content,which are generally divided into external factors and internal factors.The external factors mainly include temperature,pressure,shale thickness,depth,etc.The internal factors are divided into organic geochemistry,mineral composition and reservoir properties,and further subdivided.The organic geochemical aspects include Organic carbon content and organic matter maturity,mineral composition mainly include the content of brittle minerals and clay minerals.Reservoir properties include pore permeability,pore type and pore structure,and pore structure includes parameters such as specific surface area,average pore size,and pore volume.Therefore,the main controlling factors of shale gasification need to be discussed hierarchically,and ultimately come down to the most basic parameters.The paper takes the fourth section of Shahai Formation and the Jiufotang group in Fuxin Basin as the research object,and uses the high-precision on-site desorption test of shale gas content as a means to combine the experimental results of organic geochemistry,reservoir properties,and petrology analysis.The main controlling factors for the gasification of continental shale in Fuxin Basin are organic carbon content,specific surface area,total pore volume,brittleness,and clay mineral content.From the quantitative point of view,the adsorption gas and free gas are established separately.The gas-bearing model.The gas model of free gas and adsorbed gas was verified and regression analyzed.The free gas content of the Shahai and Jiufotang formations in the Fuxin basin is ranged from 0.042 to 0.699 m~3/t,The average free gas content is 0.301 m~3/t,and the relative error is 0.18.The adsorption gas content is between 0.17-1.98m~3/t,the average adsorption gas content is 1.21m~3/t,the relative error is between 0.19-0.34,and the overall gas content is good.In general,the continental shale created in the Fuxin Basin The gas content quantitative model has good calculation effect,and the more independent variables are selected,the relative error of the prediction model will be reduced,and the model will be more stable.