--> ABSTRACT: Application of Stratigraphic Simulation to AVO Analysis, by S. A. Bouman; #91021 (2010)

Datapages, Inc.Print this page

Application of Stratigraphic Simulation to AVO Analysis

BOWMAN, SCOTT A

Analysis of AVO anomalies in seismic data is a valuable tool for locating gas reservoirs. However, to establish the importance of the anomalies, it is necessary to calibrate to known data or make an educated estimate of rock properties in the seismic profile. Stratigraphic simulation provides a technology for predicting the lithofacies and the presence of hydrocarbons from a limited dataset. Required input includes two-way travel time horizon data from workstation interpretations, horizon ages and depths from well logs and check shot surveys, and estimated paleobathymetric profiles for each horizon. This information is automatically "inverted" by adjusting the depositional and tectonic process inputs, to determine a best-fit model for the given observations.

Predicted rock properties including density, porosity, fluid type, pressure, and temperature are used to describe the physical state in a synthetic seismic profile that calculates the response of both the P- and S-waves. A distribution of Vp and Vs can be calculated from the stratigraphic model using the White-Boltzman equation. Values of the bulk modulus of the matrix and framework material (which vary as a function of lithology, age, depth, and porosity), and pore filling fluid are adapted to account for porosity-depth, and velocity observations. Porosity is modeled as a function of depth or overburden stress. Density is calculated as a function of mineral type and porosity. An impedance/reflectivity model can be determined from the distribution of velocities. The fluid content, as calculated by the fluid-flow model, can also determine the interval velocity.

AAPG Search and Discovery Article #91021©1997 AAPG Annual Convention, Dallas, Texas.