Characterizing hydraulic fractures using the transient pressure surge effect

It has been demonstrated in both numerical modeling and lab experiments that a fluid-filled fracture can be a subsurface pressure amplifier to a weak driving force such as an incident seismic wave. We refer this phenomenon to as the transient pressure surge (PS) effect. PS is frequency dependent and can be a very useful for enhancing fracture systems because it may transiently enhance pore pressure and alter fluid flow patterns. In this paper, we use PS to infer fluid-filled fracture parameters. We develop a three-dimensional boundary element (BEM) method to study the seismic/geomechanical response of fluid-filled fractures with different sizes and apertures. We first review the previous modeling and lab evidence of the PS phenomenon and then present our new BEM modeling results. The PS effect could be used for imaging subsurface fracture systems and inverting for discrete fracture parameters for fracture characterization.