Evaluation Of Fracturing Effect On Compact Sandstone Gas Reservoir In Middle Depression Of West SiChuan Basin

Most of gas reservoir's productivity capacity in Depression of West SiChuan Basin such as LuoDai J₃P, XinChang J₃P¹, J₃P², and JS₂ sandstone gas reservoir is below the industrial capacity standard, then, hydraulic fracturing is a very important measure for them to be put into production because of its compact strata, and a relatively large economic-society proceeds has been made in the tight clastic reservoir for many years. But, with the proceeding of gas exploration, hydraulic fracturing has been become more and more critical technology for increasing productivity. Basing on fractured well's information, analyzed the geologic factors which affect the gas well's fracturing effects according to analysis such as geology, logging, fracturing, well-testing and production data, and supply a recommended standard of fracturing choosing, appraising affecting extent between each geologic factor and fracturing effect using partial correlation + gray correlation method, assuring geologic factors' fracturing optimizing. Basing on the analysis of pump parameters, appraising affecting extent between each pump-geologic factor and fracturing effect using partial correlation + gray correlation method, and assuring affecting extent of fracturing effect on pump and geologic factors. According to analysis of stress, pump pressure and unstable well-testing, the article analyzed fracture's attitude and the relationship between each other fracturing model and fracturing effect; analyzed the relationship between propagation of fracture and fracturing effect using Nolte-Smith curve; computed length and width of fracture in each other fracturing model using pump data, and the first time evaluated fracture's roughness. According to analysis of well-testing information and geologic characteristics, the article analyzed the relationship between fracturing stimulation scale and fracturing effect from underground percolation point. According to the fracturing gas wells' geology and production characteristics, the fracturing gas wells have been divided into three categories, which are pure decline, purified decline and increase, forecasting fracturing wells' dynamic product using Arps decline curve, YuQitai's new increasing curve and the amended weng model, making the fracturing effect's evaluation more correct.