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2018 EJRNL PP XIAODONG HAN 1.pdf)u
Terbatas Suharsiyah
» ITB

An improved model based on Biot poroelastic theory is presented incorporating the initial seepage fow in the matrix. The proposed model quantifes wave propagation in the oil feld development process as VSP, transient well tests, and seismic production technology. Porosity variation, fuid–solid compressibility, and pseudo-threshold pressure gradient in low permeability reservoir are simultaneously considered, resulting in a modifed form of continuity and motion equations. Integrating the equations and decomposition for the fuid–solid displacements helps to derive the analytical wave vectors of the fast P, slow P, and S waves in porous media. The sensitivity of afecting factors, such as petrophysical parameter, fuid property, and vibration frequency, on the wave velocity and attenuation is subsequently evaluated. Furthermore, the Biot model can be considered a special situation when the initial fow rate in this model tends to zero. The increase in initial percolating rate, expressed by the ratio of initial fow rate and solid scalar potential, causes an obvious decrease in the fast P wave velocity and an increase in its quality factor. Propagation of the slow P wave and the S wave is scarcely infuenced. Low vibration frequency and low permeability also contribute to a large diference between the wave propagation parameters of the improved and Biot models. Cognition of the proportion in the inertia and viscosity efects is helpful in analyzing the complicated multiple mechanisms in wave propagation in the actual developed layer.