Simulation Of Fracturing Fluid Flowback In Shale Gas Reservoir

There is a process of fracturing fluid flowback in shale gas Wells after large scale hydraulic fracturing,which is one of the most important links in the management of hydraulic fracturing.Only by realizing rapid and effective flowback of fracturing fluid after fracturing,can the expected effect of fracturing be guaranteed.However,the obvious characteristic of fracturing fluid flowback in shale gas Wells is that the flowback rate of fracturing fluid is not high,and a considerable part of fracturing fluid can' t be flowback in the formation,which affects the effect of stimulation.In this paper,the distribution area of fracturing fluid after fracturing in shale gas wells and the influencing factors of flowback process were studied,aiming to provide theoretical basis for the control of fracturing fluid flowback.In this paper,fluid in the flowback process of shale gas wells after fracturing includes shale gas and fracturing fluid,and the fluid distribution area mainly includes shale matrix and fracture system.According to the research status at home and abroad,the reasons for the retention of fracturing fluid in shale reservoirs are summarized,and the distribution region division and regional characteristics of shale fracturing fluid are described.Then four types of models were established through the commercial simulator CMG to consider the possibility of different fracturing fluid distributions.Each model is described in detail,and the sensitivity of factors that may affect flowback such as capillary pressure,height and permeability are studied.Then the factors that may affect the flowback were studied by plotting the flowback correlation factor curve for each type.And the results were explained from the perspectives of flowback and retention of the injected fracturing fluid.Finally,the local grid encryption technology of CMG is used to establish the flowback model of shale fracturing fluid for different fracture forms,such as single plane fracture,complex fracture,reticular fracture and different cluster number,and obtain the relevant laws of flowback.