Elastic least-squares migration for quantitative reflection imaging of fracture compliances

To quantitatively image fractures with high resolution, we have developed an elastic least-squares migration (LSM) algorithm coupled with linear-slip theory, which accurately addresses seismic wave interaction with thin structures. We derive a linearized waveform inversion using the Born approximation to the boundary integral equation for...

Quantitative imaging of fractures around a borehole using linear slip theory and elastic least-squares migration

Single-well reflection imaging using sonic logging data successfully locates fine-scale structures around a borehole including fractures. In order to achieve accurate and quantitative estimation of fracture properties with high resolution, we propose to couple least-squares migration with linear slip theory. The proposed least-squares...

Enhanced characterization of fracture compliance heterogeneity using multiple reflections and data-driven Green's function retrieval

The spatial heterogeneity along a fracture is a key determinant for fracture-associated mechanical and hydraulic properties of the subsurface. Laboratory experiments have been performed to test the applicability of the nonwelded interface representation to predict the frequency- and angle-dependent elastic response of a single fracture. The...

AVO inversion for a non-welded interface: Estimating compliances of a fluid-filled fracture

Though well known for layer boundaries, the use of amplitude-versus-offset (AVO) variations for non-welded boundaries like fractures is not yet investigated. Depending on the seismic wavelength used, fractures can be regarded as thin, compliant zones in rocks, in different scales. We explore the potential of multiangle AVO inversion of P-P and P...

Laboratory estimation of fracture compliance of a fluid-filled fracture using AVO response of a nonwelded interface

We explore the potential of multi-angle AVO inversion of P-P and P-S reflections from a fracture to estimate fracture proper- ties. Although AVO analysis of welded interface like geologi- cal layer boundaries is common, the use of AVO variations for nonwelded boundaries like fractures is yet to be investigated. We conduct laboratory experiments...

Characterization of heterogeneous fracture compliance using multiple reflections coupled with data-driven Green's function retrieval

The spatial heterogeneity along a fracture is a key determinant for fracture-associated hydraulic properties. We propose a new method to estimate the heterogeneous compliance distribution of a fracture from the reflection response at the fracture surface. For this purpose, we formulate a data-driven approach for Green's function retrieval based...

Nonlinear imaging condition and the effect of source illumination: Imaging fractures as nonwelded interfaces

Fluid flow through a fractured reservoir is often controlled by the large fractures. Seismically imaging these large fractures has the potential to illuminate their hydraulic properties.We derived a nonlinear imaging condition considering a medium containing nonwelded interfaces such as fractures for high-resolution fracture imaging. This was...

Non-linear imaging condition to image fractures as non-welded interfaces

Hydraulic properties of a fractured reservoir are often controlled by large fractures. In order to seismically detect and characterize them, a high-resolution imaging method is necessary. We apply a non-linear imaging condition to image fractures, considered as non-welded interfaces. We derive the imaging condition from the general correlation...

Power spectral density of the heterogeneous fracture compliance from scattered elastic wavefields

Using the scattered elastic wavefield, a method to derive the power spectral density (PSD) of the heterogeneous compliance distribution, along the plane of a single fracture, is formulated. The method involves estimation of the stress field at the fracture depth from the scattered wavefield followed by least-squares optimization of the PSD of...

Inverse scattering solution for the spatially heterogeneous compliance of a single fracture

Characterizing the spatially heterogeneous fracture compliance through use of elastic waves has the potential to illuminate the hydraulic and mechanical properties along a fracture. We formulate the inverse scattering problem to estimate the heterogeneous compliance distribution along a single fracture embedded in a homogeneous background. For...