Study On Shale Gas Seepage Model Under Sound Field

Shale gas has abundant reserves and broad prospects for exploration and development in our country,but it is difficult to develop and the output decreases rapidly.As an effective method to promote the desorption and productivity of shale gas,ultrasound is still in the initial stage of research.Therefore,it is very meaningful to study the shale gas seepage model under the action of sound field.Firstly,the experiment of constant temperature adsorption and desorption of shale gas was carried out with self-designed instrument and device.It was proved that ultrasonic wave can reduce the molecular adsorption on shale surface,accelerate the desorption rate of the adsorbed molecules and shorten the time of pressure balance.Based on the consideration of ultrasonic exhaustion,slippage effect and stress sensitivity,a shale gas productivity model under acoustic field was established,and the slippage factors and stress sensitivity were found.Sensation has obvious influence on shale gas productivity.Ultrasound has no obvious effect in the early stage of shale gas exploitation,and reduces its productivity deceleration rate,prolongs production time,increases cumulative productivity and improves shale gas recovery rate in the late stage of exploitation.The seepage model under acoustic field is used to fit the history of horizontal production wells in Longmaxi Formation shale mining in the demonstration area.Compared with the actual production curve,the prediction curve under acoustic field decreases slowly in the middle and late stages of decline,which shows that the acoustic field has a certain effect on stimulating shale gas production.In this paper,a shale gas seepage model under acoustic field is established considering multiple factors,which has certain significance for improving shale gas recovery.