Abstract Neogene shelf, slope, canyon, and slope-to-basin-floor transition plays in the southern Laguna Madre–Tuxpan (LM-T) continental shelf reflect a variety of structural and stratigraphic controls, including gravity sliding and extension, compression, salt evacuation, and lowstand canyon and fan systems. The Neogene in the LM-T area was deposited along narrow shelves associated with a tectonically active coast affected by significant uplift and erosion of carbonate and volcanic terrains. This study characterizes 4 structurally defined trends and 32 Neogene plays in a more than 50,000-km 2 (19,300-mi 2 ) area linking the Veracruz and Burgos basins. Copyright © 2009 by The American Association of Petroleum Geologists. Reprinted from AAPG Bulletin, v. 89, no. 6, (June 2005), pp. 725 – 751. DOI:10.1306/13191099M903340 The Cañonero trend in the southern part of the LM-T area contains deep-seated basement faults caused by Laramide compression. Many of these faults are directly linked to the interpreted Mesozoic source rocks, providing potential pathways for vertically migrating hydrocarbons. In contrast, the Lankahuasa trend, north of the Cañonero trend, contains listric faults, which detach into a shallow horizon. This trend is associated with thick Pliocene shelf depocenters. The dominant plays in the Faja de Oro–Náyade trend in the central part of the LM-T area contain thick lower and middle Miocene successions of steeply dipping slope deposits, reflecting significant uplift and erosion of the carbonate Tuxpan platform. These slope plays consist of narrow channel-fill and levee sandstones encased in siltstones and mudstones. Plays in the north end of the LM-T area, in the southern part of the Burgos basin, contain intensely deformed strata linked to salt and shale diapirism. Outer-shelf, slope, and proximal basin-floor plays in the Lamprea trend are internally complex and contain muddy debris-flow and slump deposits. Risk factors and the relative importance of play elements vary greatly among LM-T plays. Reservoir quality is a critical limiting play element in many plays, especially those in the Cañonero trend directly downdip from the trans-Mexican volcanic belt, as well as carbonate-rich slope plays adjacent to the Tuxpan platform. In contrast, trap and source are low-risk play elements in the LM-T area because of the abundance of large three-way and four-way closures and the widespread distribution of organic-rich Upper Jurassic Tithonian-age source rock. The potential for hydrocarbon migration in LM-T plays is a function of the distribution of deep-seated faults inferred to intersect the primary Mesozoic source. Their distribution is problematic for the Lankahuasa trend, where listric faults sole out into the Paleocene. Seal is poorly documented for LM-T plays, although the presence of overpressured zones and thick bathyal shales is favorable for seal development in middle and lower Miocene basin and slope plays. Reprinted from AAPG Bulletin, v. 89, no. 6, (June 2005), pp. 725–751.

ABSTRACT Reservoir sandstone geometry of tide-dominated depositional sequences in the Lower Misoa Formation (lower Eocene), together with multiple northwest-trending normal faults, exerts a strong influence on fluid distribution and poorly swept areas in the VLA-6/9/21 Area in north-central Lake Maracaibo. An integrated reservoir-characterization study by the Bureau of Economic Geology (BEG) and Maraven, S. A., identifies depositional and structural controls on bypassed oil in poorly swept areas adjacent to elongate pathways of water encroachment along depositional axes within sparsely drilled, fault-bounded compartments. The upper C6 to C3 Members consist of multiple tide-dominated depositional sequences, 30.5 to 91.5 m (100 to 300 ft) thick, bounded below by tidal-ravinement surfaces and capped by flooding surfaces. Each sequence contains multiple parasequences composed of 50- to 100-ft (15.2- to 30.5-m), predominantly upward coarsening, pervasively burrowed sandstones, eroded by cross bedded sandstones. Limited accommodation space resulted in tidal ravinement and erosion of older genetic stratigraphic units. Detailed depositional modeling of these depositional sequences provides a framework for understanding and predicting reservoir drainage patterns and distribution of remaining oil.