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Abstract: The Relationship Between Mud Volcanoes, Petroleum Migration and Accretionary Prisms; Lessons from the Caucasus, the Australian Margin and Venezuela

Paul Ware

Mud volcanoes have been widely documented in areas of overpressure where explosive expansion of trapped methane has occurred during argillokinesis. In an area with high sedimentation rate, such as the Gulf of Mexico, there may be no time for fine-grained sediment to de-water before being covered by impermeable material.

In an accretionary wedge this process is complicated by overthrusting of off-scraped material which increases the overburden pressure and provides many more avenues for the migration of fluids through the system. In some cases, such as is seen in the Caribbean, the fluids may escape directly to the surface (or seabottom) through high permeability beds. When this happens there may be no diapirism. In other cases, such as in Venezuela, the forearc may be the site of rapid, laterally-derived, sedimentation, and fluids from the overthrusted rocks may be forced to escape through several kilometers of recent deltaic sediments. Since these fluids may include petroleum, this has obvious exploration potential.

If there are no suitable reservoir rocks, such as in Timor, there may be no commercial accumulations. However, many giant fields are associated, world-wide, with mud volcanoes, such as those in Azerbaijan.

AAPG Search and Discovery Article #90951©1996 AAPG International Conference and Exhibition, Caracas, Venezuela