Prediction of a three-dimensional model volume ahead of the drill-bit using a hybrid seismic inversion - a real data example

摘要

Geohazards such as the abnormal pore-pressure, fracture gradient, and shallow water flow are important conditions to detect and analyze when planning (or drilling) a well. The most reliable tool, which can provide such information are the seismic waveform data, and inverting seismic data is the only way to retrieve subsurface lithology, which can then be linked to such geohazards ahead of the drill-bit. Here, we develop a hybrid seismic inversion method, combining a prestack waveform inversion (PWI) with an amplitude-variation-with-offset/angle (AVO/AVA) inversion. Applying our method to real data from the Rock-Springs uplift, Wyoming, USA we demonstrate that the method is capable of predicting the three-dimensional (3D) model ahead of the drill-bit. Although we use this inverted 3D model to identify the lithological and fluid properties for potential targets for carbon dioxide (CO_2) storage, we also show how the methodology outlined here could be applicable in predicting zones of hydrocarbon accumulations and detecting possible geohazards.