Research of influence laws of fluid properties on elastic parameters of fractured low permeability reservoir rocks based on digital core

Key words:  well logging  fractured low permeability reservoir  rock properties  elastic modulus  digital core  finite element method

Abstract:

In order to investigate the effects of fracture and fluid properties on the elastic parameters of fractured low permeability reservoirs, the digital cores of low permeability reservoirs were constructed by X-ray CT. The transversely isotropic digital cores with parallel penny shape cracks were firstly constructed using digital image processing technology, then the elastic parameters of the cores were calculated by an extended finite element method, and lastly the effects of fracture and fluid properties on the elastic modulus were studied. The results show that with fixed crack aspect ratio and density, the longitudinal wave anisotropy linearly decreases with the increase of the fluid bulk modulus. With fixed crack density and fluid properties, the elastic moduli of fractured low permeability reservoir rock show a linear relationship with increasing crack aspect ratio. And with fixed crack aspect ratio and fluid properties, the elastic moduli of fractured low permeability reservoir rock show a linear relationship with increasing crack density.