地层压力对致密砂岩气藏水平井生产影响一体化模拟OA

Tight sandstone gas reservoirs in narrow channels represent a critical replacement domain for natural gas production in the Sichuan Basin.However,variations in original formation pressure exist among different channels,directly affecting the selection of favorable channels and overall development efficiency.To clarify the controlling effect of formation pressure on the production performance of gas wells,this study focuses on the Shaximiao Formation of the Tianfu Gasfield in the Sichuan Basin and employs an integrated geology-engineering approach to analyze how original formation pressure in different channel types influences the stable production capacity,reserve activation,and ultimate recovery factor of volume-fractured horizontal wells.The results indicate the following:① Production from volume-fractured horizontal wells exhibits a two-zone seepage characteristic,consisting of a near-well stimulated zone and a far-well matrix zone.The seepage capacity of the stimulated zone is primarily governed by fracturing scale,whereas fluid flow in the matrix zone is dependent on the original reservoir properties.② Under identical fracturing conditions,as the formation pressure coefficient increases from 0.4 to 1.8,the single-well activated reserves of three typical channel types increase by 5-6 folds,while both the stable production rate and ultimate recoverable reserves of gas wells rise by approximately 7 folds.③ The controlled radius of the stimulated zone remains relatively stable(210-230 m),with an ultimate recovery degree ranging from 45％to 83％that increases with rising formation pressure.In contrast,the drainage radius of the matrix zone varies substantially(50-600 m),with an ultimate recovery degree of 29％-37％.Channels with superior physical properties have larger controlled reserves in the matrix zone but a slightly lower recovery degree.Through integrated geology-engineering simulation,this study establishes a quantitative relationship between formation pressure and key development indicators of volume-fractured horizontal wells.This provides a theoretical basis for determining the minimum economic pressure required for the efficient development of narrow-channel tight sandstone gas reservoirs and optimizing development technical strategies.