Coupled Seepage Model Of Shale Reservoir Based On Sound Field

Shale gas reservoirs have the characteristics of low productivity and fast descent,so it is very important to study the ways to improve their recovery.At present,ultrasonic as a way to promote shale gas desorption and increase production capacity,is still in the primary research stage.In this paper,based on the interaction between the seepage field and the sound field,the shale gas coupling seepage model under the acoustic field is established and shale gas production capacity evaluation method under the action of sound field is also established.Firstly,the influence of the sound field on the seepage field of the shale is studied from the aspects of adsorption,desorption and diffusion.Then,the coupled seepage model based on the acoustic field is established.After the differential equation,the Newton-Lapson iterative method can be used to solve the problem.The results show that the shale gas production with sound field is slower and the production time is longer in the later stage of the flow,and the smaller the attenuation coefficient of the ultrasonic,the slower the production decreases.The greater the ultrasonic power,the greater the amount of shale gas desorption;There is a threshold for the attenuation coefficient of the ultrasonic wave.When it is larger than the threshold,the effect of ultrasonic waves on the reservoir is weak and almost negligible..Finally,the examples are analyzed and the results show that the prediction curve under the action of sound field compared with the actual production curve,in the middle and late decline,the prediction curve decreases slowly,the sound field effect for the promotion of shale gas production has a certain effect.Based on the theory of acoustic rock to promote the theory of shale gas production,this paper establishes a method for evaluating the productivity of shale gas reservoir under the action of sound field,which lays a foundation for improving the recovery of shale gas reservoir.