Analysis of time-lapse multicomponent seismic data from a potash mining area in Saskatchewan

Edward Andrew Nicol, Donald C. Lawton

Seismic anisotropy is a subsurface property that can have a severe impact on the quality of subsurface seismic imaging. In this study, a multicomponent, time-lapse seismic survey is interpreted to determine if seismic anisotropy exists in a potash mining area in Saskatchewan. The focus of this study is the Devonian Dawson Bay Formation which is made up of fractured carbonates and thus may allow fluid to propagate downward from an aquifer into the underlying Prairie Evaporite Formation. The seismic volumes were split into 4 azimuthally sectored sub-volumes that are made up of a stack of source-receiver ray paths covering a 45 degree sweep. Through interpretation and travel-time analysis of these data, it has been found that carbonates of the Dawson Bay exhibit azimuthal velocity anisotropy, possibly due to fractures, although it is not possible to determine the cause of the anisotropy with this analysis.