Physical seismic modeling of a vertical fault

Jessie Marie Arthur, Donald C. Lawton, Joe Wong

Detecting faults and subsequent deformation zones is significant in geotechnical engineering applications, seismic hazard assessment in earthquake studies, and the petroleum industry for reservoir potential where faults act as a conduit to migrate or trap hydrocarbon flow. Fault identification is also important in shale gas development to design better productive reservoir stimulation by accounting for the slow slip of pre- existing faults during hydraulic fracturing.

This study shows seismic physical modeling results of a shallow vertical fault zone with slight vertical throw. Several physical model prototypes are created with materials which range in velocity and density to best simulate host rock and a deformed fault zone. 2D marine seismic data is acquired and processed at the University of Calgary Seismic Physical Modeling Facility. Physical model materials tested include plaster, sandstone, limestone, lard, wax, and liquid acrylic.

The post-stack imaged results are compared and it can be seen that the fault zone is resolved in both zero offset and common source data from physical modeling. An interesting by-product from the physical modeling acquisition was the identification of ghost reflections captured below the primary reflections, which can be used in ‘mirror imaging’, to provide better illumination of the fault zone.

The modeled fault zone images show a likeness to real 2D seismic data collected over a recent ruptured surface fault in New Zealand.