Anadarko Basin: Modeling the Megacompartments

J. Miles Maxwell, Changxing Qin, Judy Lunardini, Khaireddine Sakrani, Peter J. Ortoleva

CIRF.B3D, a three dimensional model of the generation of abnormal pressures and fluid migrations in the Anadarko basin, is presented. The model shows in detail how the sedimentary, stress and thermal history of the basin can lead to the development of the compartmented regions of abnormal pressure in the basin. Pressure seals are shown to arise by a combination of mechanical and pressure-solution mediated compaction. The latter in particular yields the tightly fitting fabrics that allow for the sub-nanodarcy permeabilities that can maintain significant pressure abnormalities on the 100 million year time frame.

The input to the CIRF.B3D model consists of a detailed sedimentologic and petrologic description of the basin, and of the reconstruction of its burial (tectonic and thermal) history. For this study of the Anadarko basin we used published data and our petrologic observations as well as those of Z. Al-Shaieb and J. Puckette of Oklahoma State University. The model then predicts the development of compartments defined as three dimensional domains isolated' from the surroundings by very low permeability seals. The results obtained are then compared in detail to the observations made on the Anadarko basin. The predictions made by our model are in good agreement with observed petrologic and pressure data.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995