2013 Honorary Lecturer

Middle East & Africa

George Smith

University of Cape Town
Cape Town, South Africa

AVO in Exploration and Development

Abstract

Amplitude variation with offset, commonly called AVO, as an exploration and development tool has been around in the hydrocarbons business for about 30 years. In the early part of this period, the emphasis was perhaps more on the exploration phase, but as the science of reservoir characterization developed, attention moved more and more to the development and production phases.

During this period, starting in 1982 with Ostrander examining CMP gathers, we have seen approaches such as P- and S-wave reflectivity stacking, the fluid factor, intercept and gradient, crossplotting, partial stacks, NI and PR (normal incidence and Poisson's ratio), AVO classes, lambda-mu-rho, elastic impedance, AVO impedance, prestack inversion, geostatistics, attribute inversion, neural networks and many more used to derive information from the offset domain.

At the SEG Annual Meeting in 2012, there was only one oral session called "AVO", but AVO concepts were inherent in sessions on anisotropy, rock physics, reservoir characterization, seismic inversion, time lapse, interpretation, shale reservoirs and attributes. This shows the extent to which AVO concepts have become an integral part of the modern seismic world, permeating acquisition, processing, inversion and interpretation.

Have the applications of AVO in exploration, where data are relatively sparse, kept up with the increasingly sophisticated techniques used in the statistically more finely sampled development scenarios? This presentation will look at many published and unpublished examples to assess where we stand with AVO today.