(1. College of Petroleum Engineering，China University of Petroleum，Qingdao，Shandong 266580，China；2. State Key Laboratory in Heavy Oil，China University of Petroleum，Qingdao，Shandong 266580，China)
Abstract：A pseudo threshold pressure gradient was introduced into the Biot equation to study the low-frequency vibration stimulation in low permeability reservoir. The solution of the governing equation from Laplace transform and Durbin discrete method verified that the low-frequency vibration stimulation resulted in seepage enhancement and pressure increase. Laplace transform with respect to the time，the iterative elimination and the order lowering of non-homogeneous differential equation were employed to solve the governing equation. Numerical analysis based on the expressions and fitting properties of rock from Yanchang field was carried out with the Matlab programming. Examples with the porous media saturated with water phase，or with oil phase under different vibration frequency were given to analyze the change in seepage rate，pressure，porosity，solid strain and swelling shrinking ratio of the fluid. The results showed that the seepage velocity and porosity were increased obviously in the injection side by the low-frequency vibration stimulation. There existed an optimum vibration frequency in the range of 10 to 30 Hz to reach the biggest increase in porosity and permeability，which agreed with experiment results.
2016, Vol. 35 
