Abstract

The economic demand for petroleum has lead to reevaluation and exploration for Austin Chalk fractured reservoirs. The geologic controls of (1) stratigraphic facies variation, (2) source bed presence and maturation, and (3) the existence of structural tectonic influences are similar in the Austin Chalk trend to those that exist in any fractured reservoir. Successful exploration for fractured reservoirs depends on prediction of the location of the fractures and their patterns. By reconstructing paleostress in the Austin Chalk trend, these fractures and exploration targets can be predicted. Areas of maximum fracturing are related to areas of maximum curvature of the potential reservoir rocks. In the case of the Austin Chalk trend, however, recognition of maximum curvature can be masked by regional dip.

In addition to the complex geological controls, this type of reservoir is extremely sensitive to complications induced by (1) drilling, (2) completion, (3) stimulation, and (4) production techniques. Logging techniques and recognition of these potential horizons are quite different from exploration for the more recognizable porous sand and carbonate reservoirs.