Simulation Of Physical Properties Of Deep Coal Reservoirs In The Fukang West Block

Most of the physical properties of low-rank coal reservoirs in Fukang West Block are concentrated in the shallow part,while the deep physical properties are relatively weak.This paper analyzes the porosity and permeability of deep coal reservoirs in the Fukang West Block by conducting characteristic experiments on coal samples,basic coal quality tests,high-temperature and high-pressure permeability and high-pressure isothermal adsorption on coal samples collected in the Fukang West Block The characteristics of gas content,discussed the variation law of the above characteristics with burial depth and its controlling factors,constructed a coal reservoir permeability and temperature-effective stress prediction model and a three-phase gas content evaluation model under different temperature and pressure conditions,and predicted Fu Permeability and gas content of coal reservoirs with different buried depths in Kangxi block.The following insights have been obtained: 1)Poor connectivity of low-rank coal reservoirs is good,and porosity and burial depth are negative exponential functions;2)Coal reservoir permeability and temperature show a negative exponential relationship with burial depth There is a negative logarithmic relationship,and the permeability of the coal reservoir gradually decreases with the increase of the burial depth;3)Under the triple effect of the negative effect of temperature on adsorption,the positive effect of coal rank and pressure on adsorption,the saturation adsorption of low-rank coal The conversion depth is up to 2900m;4)The content of free gas is between 0.05m~3/t-1.56m~3/t when the gas saturation is 100%,and the free gas content of deep coal reservoir is positively correlated with the burial depth,that is,the deeper the burial depth,the free gas The greater the content and the faster the increase,from 0.05m~3/t at 400 m to 1.56m~3/t at 3400m;5)The amount of water-soluble gas changes with the increase of the burial depth is small,showing a slow increase trend;6)The amount of adsorbed gas always occupies three-phase state The dominant position of gas volume,water-soluble gas volume accounts for a relatively low proportion of three-phase gas content,and the proportion of free gas volume in the deep part is higher than that in the shallow part;7)Verification with the measured gas content data of the buried depth of 3360 m shows that the relative error between the predicted value of the total gas content of the coal reservoir and the measured value is 7%,indicating that the prediction effect of the three-phase gas content evaluation model is good,and it has a deep effect on the development of deep coalbed methane in the Fukang West Block.This dissertation includes 37 illustrations,28 tables,and 106 references.