Numerical Simulation Of Flow Characteristics For Shale Gas

With the sustainable growth of the energy demand of human society, the storage of conventional oil and gas resources decreases rapidly, and the usage of unconventional oil and gas resources such as shale gas becomes much important. For the specialty mechanisms of shale gas on the storage and migration, the research of shale gas flow processes is of great importance for the development of shale gas.Flow characteristics of shale gas are studied in this paper, a computer program is designed on the perspective of numerical simulation. For the flow progress of the methane in the matrix, the pressure distribution and flow rate variation is studied on the constant pressure outlet condition and the impact of desorption to pressure and flux is obtained; by the definition of parameter modulus, the impact of compression coefficients of permeability, porosity and methane viscosity to flux is compared. For the overall exploit process of shale gas, a triple media flow model contains’ matrix-nature fractures-hydraulic fractures’ is used to establish the gas flow mathematical model, which is solved numerically. By the results, the impact of bottom-hole pressure, the hydraulic fractures length, the hydraulic number and Langmuir volume to gas production is analyzed. The results show that the presence of desorption can maintain reservoir pressure and improve the productivity of methane; the larger compress factor of porosity contribute higher initial gas production and faster gas production rate, the ability of stable production of lower porosity compress factor reservoir is stronger than which is higher. The outlet pressure may cause a great impact to shale gas production, the lower the pressure, the higher the flux is. Longer hydraulic fracture contributes higher flux but the growth rate decreases as the length become longer. The flux is higher as the number of hydraulic fractures increases but the yield-increasing effect decreases. The effect of Langmuir volume can be ignored in the early stage, but the ability of stable production is stronger for higher Langmuir volume reservoir after a certain time production.