Study On Gas-water Two-phase Steady-state Capacity Of Horizontal Wells In YD Gas Reservoirs

As the demand for natural gas increases, the development of unconventional gas resources has been put on the agenda gradually. Especially the low permeability or tight gas reservoir has become the main force of domestic natural gas production. But since the special characteristics of reservoir and seepage mechanism in low permeability or tight gas reservoir, it results in the low natural productivity of gas well. The prospective development results cannot be achieved by adopting conventional developing methods. The development of this reservoir needs to use horizontal well cooperated with multistage hydraulic fracturing technology.This paper targeted YD gas reservoir, which is a low permeability and tight gas reservoir. Based on sufficient investigation and research on the production of fractured horizontal wells and gas-water two phase flow, the author defined gas-water two phase generalized pressure that considered the effect of stress sensitivity in gas reservoir and gas slippage effect, used the conformal mapping method and superposition principle of potential to build the production model of fractured horizontal wells under the condition of gas-water two phase flow. Combined with the actual situation of hydraulic fracturing, the author introduced the local coordinate system to build the production model of inclined fractures. Meanwhile, the gas-water flow in horizontal wellbore bad been taken into account, which gave rise to a new production model coupling seepage in gas reservoir and gas-water flow in horizontal wellbore. Finally, the actual data of YD gas reservoir had been used to prove the accuracy of three models by the calculation program. Besides, the influence rules of the reservoir parameters, fluid physical parameters and fracture parameters on fracturing horizontal well productivity had been analyzed in detail.The research of this paper is a beneficial supplement to fracturing horizontal production analysis theory system. This study not only has strong theoretical, but also has wide application prospect. The results of research provide theoretical basis for determining the reasonable working system of gas well. It also can provide reference for the same gas reservoir developed by fracturing horizontal wells.