The Research Of Shale Gas Adsorption Model Under High Temperature And High Pressure

How to accurately characterize the high temperature and high pressure adsorption process of shale is a key problem to be solved in the process of evaluation of shale adsorption capacity and reserves?It is important to study the development of shale gas reservoir and the study of unstable seepage flow model by shale gas high temperature and high pressure adsorption significance?However,most of the shale gas adsorption studies have a relatively low temperature and pressure on the actual temperature and pressure of most shale gas reservoirs in China?For shale gas,relatively low adsorption of shale gas at high temperature and high pressure?The gas is affected by high temperature and high pressure?The commonly used isothermal adsorption model is not suitable for high temperature and high pressure?For the description of shale gas high temperature and high pressure adsorption process,the error of shale adsorption capacity is larger?For this reason,this paper takes WY shale gas reservoir as an example to study the high temperature and high pressure adsorption of shale gas,and reveals the mechanism of shale high temperature and high pressure adsorption from microscopic point of view?Shale gas in different pore size of the adsorption method is different,due to shale pore size is small,adjacent microporous adsorption of gas molecules to absorb potential potential overlap,adsorption potential energy is larger?And the microporous surface area is huge,when the shale gas into the pores,not a layer of adsorption on the micro-hole,but the volume filled until the microporous saturation,the adsorption method is different from the monomolecular layer,multi-molecular layer adsorption?The method according to the microporous adsorption theory is called the microporous volume filling method;when the microporous adsorption is saturated,the shale gas begins to adsorb with the shale in the large pores?In the medium and large pore adsorption process,the adsorption potential is relatively small,the force field range is about the size of the molecular diameter,each with the adsorption capacity of the location can only adsorb a gas molecule?When the gas molecules into the hole,large pore field within the scope of the occurrence of single molecular layer adsorption?Finally,based on the theory of microporous filling and the theory of monolayer adsorption,the phase characteristics of shale gas under high pressure are considered,and the high temperature and high pressure adsorption model of shale gas is established?The model parameters were determined by MATLAB software,and the model accuracy was analyzed by combining the experimental data of high temperature and high pressure adsorption of shale gas?The results show that the physical parameters of the model are clear,the precision of the data fitting is high,the interference of the free gas content can be avoided,the adsorption capacity and reserves of the shale can be accurately evaluated,and the high temperature and high pressure adsorption process of the shale gas is accurately and the calculation method is simple?...