A Dynamic Model For Fluid Flow In A Borehole Fracture

Abstract

The attenuation of Stoneley waves by a borehole fracture are closely related to fluid flow in the fracture. We consider the dynamic response of a viscous fluid in a horizontal fracture to the oscillating pressure excitation of Stoneley waves at the fracture opening. A dynamic model has been developed to describe the fluid motion in the fracture. This model relates both viscous shear effects at the fracture surface and the acoustic wave propagation in the fracture fluid. The dynamic conductivity is derived to characterize the fluid conduction in the fracture. This model is applied to study Stoneley wave attenuation across a borehole fracture, and is found to agree well with laboratory fracture modeling data.