非牛顿流体孔隙介质弹性波动方程

重油、聚合物和压裂液等非牛顿流体普遍存在于油气勘探和开发过程中,研究孔隙尺度非牛顿流体流动及其对地震波场的影响具有重要意义.Biot理论忽略了流体黏性系数及剪切应力的非线性变化,虽然可用于描述完全饱和固体与经典牛顿流体在波场作用下的相互作用,但是对于非牛顿流体孔隙填充物来说不准确,因此需要研究含非牛顿流体效应的孔隙介质...

Elastic wave equation for porous media saturated with non-Newtonian fluid

Non-Newtonian fluids like heavy oil, polymer and fracturing fluid are common in oil and gas exploration and development. The Biot theory ignores the nonlinear changes in the fluid viscosity coefficient and shear stress. Although it can be used to describe the interaction between fully saturated solids and classical Newtonian fluids under the action of wave field, it is not correct for the pore filling of non-Newtonian fluids. After establishing a fractional order derivative Maxwell model of non-Newtonian fluid, we found that there was a significant difference in the features of wave field propagation between regular wave equation and elastic wave equations in porous media saturated with non-Newtonian fluid. Resonance phenomenon exists in wave dispersion and attenuation. Such special effects have not been found in wave field dispersion and attenuation in porous media satura-ted with Newtonian fluid. At the same time, the rheological parameters and fractional derivatives of the constitutive relations of non-Newtonian fluids have obvious effects on the fluid-solid coupling. Numerical results show that the wave equation with non-Newtonian fluid effect is more accurate to predict the P wave velocity of heavy oil sandstone. Non-Newtonian constitutive relation brings new changes to fluid-solid coupling mechanism,which cannot be ignored for the influence on wave field dispersion and attenuation. This study explored the petrophysical model for field seismic survey. The results are useful to other related fields, such as seismic exploration of dense oil reservoir, and micro seismic simulation in cracked reservoirs filled with fracturing fluid.