Application of AVO to thickness prediction of thin sand

Abstract

Oil and gas are the resource buried in deep underground. The purpose of petroleum exploration is to delineate the sand body saturated with the oil or gas. The thickness of sand is an important property of sand layer in the reservoir research. In the oilfield of Eastern China, the thickness of sand body is usually very thin and below ten meters, so it is very hard for us to estimate the real thickness of sand body because its thickness is far less than the resolution limit of seismic wavelet in exploration. For further discussion of the problem, we probed into how to use the method of amplitude versus offset (AVO) to predict the thickness of sand body in this paper. Firstly, a set of thin sand models with different thickness are made; then, the prestack gathers of the models are simulated with the reflectivity method; after that, AVO attributes of prestack gathers are analyzed; next, the relationship between AVO attributes and the thickness of thin sand are established; finally, the relationship is used for the prestack gathers of the entire seismic data, and the thickness of thin sand of study area are estimated.