METHOD OF INDICATING THE PRESENCE OF GAS HYDRATE AND SHALLOW GAS IN DEEPWATER ENVIRONMENT

摘要

A method for indicating the presence of free gas charged sands, and/or hydrates over free gas, and/or hydrates not over free gas, the method using well log data and a rock physics model. Velocity and density of background clays and sands are extracted from the well log data. The extracted velocities and densities are used to build a rock physics model. An AVO response is generated that is representative of free gas-charged sands. An AVO response is generated that is representative of hydrates over free gas-charged sands. An AVO response is generated that is representative of hydrates devoid of free gas. The generated AVO responses are used to construct an AVO crossplot diagram that is further used to distinguish deposits of free gas charged sands from hydrates over free gas, from hydrates not over free gas.