Fracture imaging using Image Point transform and midpoint imaging of RVSP data

Abstract

An Image Point (IP) transform integrates along a hyperbolic path and converts data to a point in the IP domain so that the reflection events are accumulated to the image point for given sources in the IP domain. In addition, the image point by definition is uniquely determined and the midpoints between sources and the image points always lie on the reflector surface. Exploiting these two facts, the image point transform technique for Vertical Seismic Profile (VSP) to reverse VSP (RVSP) data is expanded to suggest a new method called the midpoint imaging method for imaging reflectors such as fractures. Applying the transform with synthetic data for Two-dimensional (2-D) models with single reflector and two reflectors, we confirm and demonstrate that the reflection events are clearly identifiable in the IP domain. The midpoint imaging method can successfully image the reflector surfaces and the dip information even with only two shot records in a simple case.