Specular Enhancement and Diffraction Imaging, Tools for Reducing Exploration and Development Risk

When evaluating an exploration prospect it is essential to build both an accurate structural framework at the prospect scale and an understanding of the faulting in the region. In many provinces, imaging problems severely limit our ability to map the subsurface and unless sub-optimal imaging is rectified and the structural understanding further enhanced by seismic attribute generation incorrect drilling decisions can be made.

We present a novel method for maximizing information from available seismic data. Within a ray based angle migration structural continuity is enhanced by weighting the specular energy of the recorded data directly at the subsurface image points. Additionally the specular energy is attenuated, thus emphasising diffraction imaged characteristics giving another volume to aid fault interpretation.

Using a data example from offshore Trinidad and Tobago we show how the specular weighted reflectivity data has better event continuity and fault definition over the conventional Kirchhoff PSDM. Additionally the resulting diffraction image volume gives a high resolution image of the complex faulting whose interpretability is enhanced by co-rendering with the specular weighted reflectivity volume.