Unravelling Complex Petroleum Filling History of Great White Field by 4-D Integrated Petroleum Systems Approach

Abstract

The Great White field in deep waters Gulf of Mexico, USA, is the first development of the GoM Lower Tertiary Paleogene play. The Great White field is one of the largest structures in the Perdido Fold belt. The structure is comprised of a faulted anticline complex formed by a doubly-verging thrust configuration with a four-way closure and an overprint of extensional fault systems. The first exploration well drilled in 2002, found multiple stacked Paleogene pays. Lower GOR fluid was found in the Paleocene while higher GOR fluid was found in the overlying Eocene reservoir. Initially, a vertical stacked-pay charge model was proposed where the Paleocene fluid leaked into the Eocene reservoir. The lower GOR fluid in the Paleocene reservoir was explained by the mixing of fluids from the Tithonian and a less mature Cretaceous source. This study offers an alternate charge model. We suggest that the Eocene and Paleocene are charged laterally rather than invoking a vertical fill to leak model. This is supported by the measured Paleocene column height not exceeding its calculated sealing capacity – it is charge volume limited. Additionally, the higher GOR in the Eocene reservoir can be better explained by the timing of the uplift, around 4 million years ago. This new charge model is supported by geochemistry, sand distribution, and 4D thermal modeling.

AAPG Datapages/Search and Discovery Article #90291 ©2017 AAPG Annual Convention and Exhibition, Houston, Texas, April 2-5, 2017