The emerging Paleogene play: Deepwater Gulf of Mexico

摘要

The Paleogene Wilcox trend has emerged as an important frontier play in the deepwater Gulfof Mexico, as confirmed by several recent discoveries. The Wilcox trend is an onshore prolificproducer along the Gulf Coast region, but its potential in deepwater settings has beenrecently recognized.At Repsol, a regional evaluation of the Wilcox depositional system was conducted using 2Dseismic data sets and limited 3D surveys available from the western and central areas in theGulf of Mexico. Most of the area is characterized by the presence of allochthonous salt, thus,seismic imaging is generally poor. Mapping of both Upper and Lower Wilcox sequences ofmore than 35,000 square miles indicate a widespread distribution for the Wilcox strata. Theseanomalously thick and extensive sedimentary deposits extend 200 miles downdip from thepaleoshelf edge. Wilcox age-equivalent paleocanyons have been previously recognized andmapped along the Gulf coast, and they could have been the conduits for sediment transportand dispersal into the deepwater depositional environments.The Lower Wilcox records sand deposition in amalgamated channel a basin floor setting,whereas the Upper Wilcox seems to represent channelized sands in a slope setting. Thedeepwater interpretation was linked updip to the shelf area, and downdip into the abyssalplain to better understand the entire Wilcox depositional system. Regional isopachs showsthe major depocenters and three major source areas in Texas and Louisiana. The westernGulf of Mexico areas were sourced from the Rio Grande and the Houston Embayment. TheEastern Keathley Canyon and Walker Ridge areas were sourced from Louisiana, via theancestral Mississippi River.