Salt-Sediment Interface Geometries and Kinematic Development of Traps Associated with Salt Stocks in Northern Gulf of Mexico Deepwater Subsalt Plays

Understanding the development of traps adjacent to salt stocks and ridges in north-central Gulf of Mexico (GoM) subsalt plays is a critical component in pre-drill prospect evaluation. The development of traps targeted in subsalt plays (both Miocene and Early Tertiary age reservoirs) involves interaction between sedimentation and salt movement. For traps developed adjacent to salt stocks and ridges, stratigraphic relationships observed in strata close to the trap and within the depocenter in which the trap resides, and structural geometries observed at the salt-sediment interface can provide information from which the kinematic evolution and timing of the structure can be inferred. An understanding of the trap evolution, with respect to hydrocarbon charge-timing, is one of the critical components in the petroleum system evaluation for any prospect. In this study, examples of constrained trap geometries, based on well and 3D seismic data from the northern GoM deepwater exploration trends are presented. Restoration of the case studies using different assumptions regarding deformation mechanisms (such as inclined-shear versus flexural-slip) illustrates the impact these assumptions have on the restoration and on pre-drill assessments (such as interpreted sediment isopachs at and in areas adjacent to the prospect).

AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California