Study Of Fractured Horizontal Well Production Performance In Shale Gas Reservoir

Shale gas,an unconventional resource,has become a research focus in recent years with its huge exploration and development potential.Shale gas resources are abundant in China and have a good development prospect.It is of great significance to meet energy demand in China.Fracturing horizontal wells is the most effective technology for shale gas development.Its pressure dynamics and production dynamics analysis have important engineering significance.Shale gas reservoirs are self-generated,which are different from conventional gas reservoirs in terms of reservoir formation,seepage mechanism,and mode of storage.In this article,the pore characteristics,reservoir characteristics,and different shale gas seepage mechanism were analyzed.A triple-continuum model considering organic matter,inorganic pores,and microfractures was established.We assumed that there is only adsorbed gas in organic matter,and the adsorbed gas will resolve when pressure is low and diffused to the microfractures in a pseudo-steady state diffusion manner.Only the free gas is considered in the inorganic pores,and the free gas is darcy flow and diffused to the microfractures in a pseudosteady state flow.Only the free gas is considered in the microfractures,and the free gas is a darcy flow.Based on the establishment of the triple-continuum model,a multi-stage fractured horizontal well without considering the SRV was established.Perturbation theory and Laplacian transformation are used to solve the bottomhole pressure of the fracturing horizontal well.The effects of pressure-sensitive,adsorption characteristics of shale gas adsorption,and hydraulic fracture parameters on the pressure dynamics of shale gas reservoirs were analyzed.Based on the establishment of the triple-continuum model,a multi-stage fractured horizontal well considering the SRV was established.Perturbation theory and Laplacian transformation are used to solve the bottomhole pressure of the fracturing horizontal well.The effects of pressure-sensitive,Parameters of SRV on the pressure dynamics of shale gas reservoirs were analyzed.Based on the established single-phase triple-continuum model,a new model considered the gas-water flow in the inorganic pores and micro-fractures,only the shale gas in organic matter is established.Based on the new model,the equations of mass conservation were established,then simplified to volume conservation equations under standard conditions,discretized by the finite difference method,and linearized using the fully implicit method.On this basis,non-neighbor connections(NNC)are introduced to describe diffusion between different porosity.FORTRAN90 is used to complete the programming of the gas-water flow model for shale gas.A conceptual model was established and the program was verified for reliability.Establishing a conceptual model of fractured horizontal wells based on field data.Simulation using our own program,then shale gas-related geological parameters and corresponding fracturing parameters was analysised.