SALT, SEDIMENT, AND TAR INTERACTIONS AND THE ORIGIN OF TAR BEDS IN THE GREEN CANYON AREA OF THE GULF OF MEXICO

The Gulf of Mexico (GOM) has massive faults, salt domes, oil seeps, tar mounds, tar mats, and several other geologic features. When tar is encountered while drilling, it is known to cause an increase in drilling costs and in most cases will prolong the completion times for wells. The study of the origin of tar and its relation to the formation of tar beds will help reduce the risks involved in drilling in a tar zone. Tar is known to occur in petroleum basins as tar mats however; tar has also been identified on the surface of the seafloor as mounds. The Cenozoic structural history of the GOM Basin is directly related to the mobilization of Jurassic salt due to the increase in sediment load on the salt. It is suggested that this Jurassic salt is the main cause for the expulsion of tar via faults to the ocean floor.

This study aims to provide evidence or refute previous understanding of the origin and migration of tar seeps/mounds in the Green Canyon of the Gulf of Mexico.

Three-dimensional seismic reflection data from the study area has been licensed from WesternGeco for the purpose of this study, which will allow for surface mapping and detailed analysis of these tar mounds. In conclusion, a model will be developed to explain the occurrence of tar in the GOM. Tar mounds most likely exist in other areas of the Green Canyon and the resulting model from this study will help explain their migration paths and further assist in the understanding of their origin.