Structural segmentation, salt sheet provinces and hydrocarbon distribution of Louisiana Shelf, Gulf of Mexico

An integrated study of seismic, well and field data of Gulf of Mexico greatly improves understanding structure, sedimentation and hydrocarbons of Louisiana shelf, which has significant implication in hydrocarbon exploration.; Diapirism and detachment are two distinct structural styles and exclusive to each other in distribution. They are formed with low and high sediment-influx respectively, reflecting sedimentation control on structural development during early stage of salt withdrawal. In turn, structural influence on basin sedimentation is reflected by that paleoshelf-edges are straight and coincide with major faults in detachment trend and sinuous and wrap around salt diapirs in diapir trend.; Five-order structural segmentation reflecting the interplay of salt with sedimentation in different scales are defined. The first order is four tectonic provinces of Texas shelf, western Louisiana shelf, eastern Louisiana shelf and Texas-Louisiana slope in the Gulf of Mexico. The second order is three structural trends along the inner, middle and outer western Louisiana shelf province. The third order is three salt-fault families along the outer western Louisiana shelf trend. The fourth order is the salt-wall corridors within each salt-fault family. The fifth order is the single salt sheet.; Two salt sheet provinces characterized Louisiana shelf-coast area. Paleogene salt sheets beneath the present lower coastal plain and inner shelf are fed from Jurassic Louann salt and emplaced in three regional Paleogene transgressive surfaces during deposition episodes of Houston Embayment. Neogene salt sheets beneath the outer shelf and slope areas are fed from both Paleogene salt-sheets and Louann salt and emplaced mainly in Pliocene sediments during deposition episodes of Mississippi Embayment.; Uneven distribution of discovered hydrocarbons within different order structural segments in terms of reservoir attribute, geological age and depositional style reflect the significant impact of structure and sedimentation on hydrocarbon accumulation. Sand bodies tend to be thin and widespread for detachment style and thick and isolated for diapir style. The “sandwich” reflection pattern identified underneath the inner shelf suggests a sandy-shaly-sandy section related to Miocene depocenter-shifting and implies great hydrocarbon potential in lower Miocene deepwater sediments. Subsalt minibasins under salt-fault families hint at depositional fairways for subsalt exploration.