ALBERT

Description: Lidar collects high-resolution spatial data, making it a popular tool for outcrop investigations; however, few of these studies utilize lidar's spectral capability. Lidar scanners commonly collect intensity returns (power returned/power emitted) that are influenced primarily by distance and target reflectivity, with lesser influence from angle of incidence, roughness, and environmental conditions. Application of distance normalization results in values that approximate target reflectivity. At the near-infrared wavelength of lidar, quartz-rich sandstones are more reflective than clay-rich mudstones. Scans of unweathered core and weathered outcrop were collected to investigate the relationship between lithology and lidar intensity. In unweathered, laboratory samples, intensity shows an inverse relationship to wt. % clay and are positively correlated to wt. % combined quartz, plagioclase, and K-feldspar. A similar relationship was also observed in scans of lightly weathered outcrop, although weathering and moisture diminished intensity contrast between sand-rich and shale-rich intervals. Thus, lidar intensity is a possible remote sensor of lithology, particularly in remotely located and inaccessible outcrops.

Description: The Heidrun field, located on the Halten Terrace of the mid-Norwegian continental shelf, was one of the first giant oil fields found in the Norwegian Sea. Traditional reservoir intervals in the Heidrun field lie within the Jurassic synrift sequence. Most Norwegian continental shelf fields have been producing from these Jurassic reservoirs for the past 30 yr. Production has since declined in these mature fields, but recently, exploration for new reservoirs has resurged in this region. The Jurassic rifted fault blocks form a narrow continental shelf in Norway, thereby greatly reducing the areal extent for exploration and development within existing fields. As the rift axis is approached farther offshore, these Jurassic reservoirs become very deep, too risky to drill, and uneconomical. This risk has prompted exploration in more recent years of the shallower Cretaceous, postrift stratigraphic succession. Cretaceous turbidites have been found in the Norwegian and North Seas, and the discovery of the Agat field in the Norwegian North Sea confirms the existence of a working petroleum system capable of charging Cretaceous reservoirs. These Cretaceous reservoirs were deposited as slope- and basin-floor fans within a series of underfilled rifted deeps along the Norwegian continental shelf and are thought to be sourced from the localized erosion of Jurassic rifted highs. We use three-dimensional seismic and well data to document the geomorphology of a deep-water, Lower Cretaceous wedge (Cromer Knoll Group) within the hanging wall of a rift-related half graben formed on the Halten Terrace offshore mid-Norway. Seismic attribute extractions taken within this Lower Cretaceous wedge reveal the presence of several lobate to elongated bodies that seem to cascade over fault-bounded terraces associated with rifted structures. These high-amplitude, elongated bodies are interpreted as deep-water sedimentary conduits that are time equivalent to the Cretaceous basin-floor fans in more distal parts of the basin to the west. These half-graben fills have the potential to contain high-quality Cretaceous sandstones that might represent a potential new reservoir interval within the Heidrun field.

Description: A 15,000-km2 (5792-mi2) three-dimensional seismic data survey that covers the shelf-slope transition of the eastern offshore Trinidad continental margin reveals the geometry and depositional history of the last maximum glacial lowstand shelf-margin succession. Despite the lack of well information at these shallow depths, the quality and continuity of the seismic data allow us to pursue a detailed seismic stratigraphic interpretation of the last lowstand margin succession. The basin-fill stratal architecture of the studied stratigraphic interval shows a great deal of lateral and vertical variability along the continental margin during the Pleistocene to Holocene. Three geomorphological elements controlled the character of the accommodation within the basin and were crucial in transporting, delivering, and storing sediment supply from shelf to slope areas: (1) the Columbus sedimentary pathway on the shelf, (2) bypass zones in the shelf-break region, and (3) deep-water depocenters. The location and geometry of these geomorphological elements within the basin are clearly controlled by underlying structures, transpressional to the north and gravity driven to the south. Migration of the paleo-Orinoco delta system across the shelf was also a key factor in defining the stratigraphic geometries that are observed within the shelf break. Development of shelf-edge versus outer-shelf deltaic systems on the continental margin was controlled by the nature of sediment supply at specific times, as well as by the availability of accommodation, although, to a lesser extent, to relative sea level fluctuations. The interpretation also showed that, for time-equivalent units, parts of the shelf-edge region could develop as an erosional margin (sediment bypass zones), whereas other parts of the shelf edge could behave as an accretionary margin (sediment accumulation). The sequence-stratigraphic interpretation that was attempted in this work also demonstrated that the characteristics of systems tracts can abruptly change along strike in the shelf-edge region for time-equivalent units. These changes can be misleading if a genetic interpretation is pursued only on the basis of the definition of system tracts in the shelf-edge region without the consideration of a complete regional framework.

Description: 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-km2 (19,300-mi2) area linking the Veracruz and Burgos basins. 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. William A. Ambrose is a stratigrapher specializing in clastic sedimentology. He received an M.A. degree from the University of Texas at Austin in 1983. He worked for the Research Planning Institute, Texas, from 1984 to 1986 and has been with the Bureau of Economic Geology since 1987, working on a variety of international and Gulf Coast reservoir-characterization and basin-analysis projects.Tim F. Wawrzyniec is a structural geologist specializing in kinematic analysis and geophysics. He received his Ph.D. from the University of New Mexico in 1999 and worked for Vastar and the Bureau of Economic Geology. In 2003, he joined the Department of Earth and Planetary Sciences at the University of New Mexico. Khaled Fouad has been a senior seismic interpreter at the Bureau of Economic Geology since 1997. He has more than 17 years experience as a seismic interpreter with various major oil companies. He received his B.Sc. degree in 1982 in Alexandria University, Egypt. He received his Diploma of higher studies in 1984 with honors from the same university. His experience includes the Gulf of Mexico, Maracaibo Basin, Vienna Basin, and the Gulf of Suez. Shinichi Sakurai is a petrophysicist and was employed by ARCO Technology & Operation Services before joining the Bureau of Economic Geology in July 2001. He also worked for Core Laboratories, Inc., and BP. He has served the Society of Petrophysicists and Well Log Analysts as a distinguished speaker, a technology committee member, and a symposium-organizing committee member. David Jennette has 15 years of industry experience in nonmarine, shelf, and deepwater reservoir prediction and characterization for ExxonMobil Upstream Research Company; since coming to the Bureau of Economic Geology, he has been involved in high-resolution digital outcrop capture and interpretation and play assessment and characterization of Petroleos Mexicanos' turbidite-dominated Veracruz basin. L. Frank Brown received his B.S. degree in geology and chemistry from Baylor University in 1951 and his M.S. degree and his Ph.D. from the University of Wisconsin in 1953 and 1955, respectively. In addition to serving as associate director and research professor for the Bureau of Economic Geology, Frank has worked for Standard Oil of Texas and has served as an associate professor at Baylor University and emeritus professor at the University of Texas at Austin. Frank has authored numerous publications and has received numerous awards. Edgar H. Guevara is a research scientist at the Bureau of Economic Geology; he previously worked in the Venezuelan petroleum industry. He holds geological degrees from the Universidad Central Venezuela and the University of Texas at Austin (M.A. and Ph.D.). He has more than 35 years of experience in geological studies and project coordination, particularly depositional systems and stratigraphy applications to petroleum exploration, reservoir characterization, and geoenvironmental studies. Dallas B. Dunlap is a geologist and database coordinator for the Bureau of Economic Geology. He received a B.S. degree from the University of Texas at Austin in 1997 and has been employed by the Bureau of Economic Geology since that time. He has worked on many international and domestic projects, focusing on subsurface mapping, modeling, and data management. Suhas C. Talukdar is a geologist-geochemist with 35 years of professional experience in industry, research, and teaching. He received a Ph.D. in 1973 from Rice University, Houston. His expertise is in petroleum geochemistry, basin modeling, petroleum system analysis, and hydrocarbon charge assessment. He is presently a consultant with the Bureau of Economic Geology and BaselineDGSI at Woodlands, Texas. Mario Aranda Garcia is a structural geologist with more than 20 years experience with Petroleos Mexicanos. He holds advanced degrees in geology from the Universidad Nacional Autonoma de Mexico and the University of Texas at Austin. He specializes in tectonics and fault modeling applied to exploration. He was Petroleos Mexicanos' principal investigator for the recent Bureau of Economic Geology–Petroleos Mexicanos joint research project on the offshore Laguna Madre–Tuxpan area. Ulises Hernández Romano is a geologist with Petroleos Mexicanos Exploración y Producción. He graduated with honors from the Universidad Nacional Autonoma de Mexico in 1995. In 1999, he obtained a Ph.D. in sedimentology from the Postgraduate Research Institute for Sedimentology, University of Reading, United Kingdom. He joined Petroleos Mexicanos Exploración y Producción in 1999 and currently is leading the offshore development team in the Poza Rica area. He is currently the vice-president of the Poza Rica section of the Asociacion Mexicana de Geologos Petroleros. Juan Alvarado Vega is a geologist with Petroleos Mexicanos Exploración y Producción. He has been active at the Tampico office for more than 5 years. During the Bureau of Economic Geology–Petroleos Mexicanos joint research project on the offshore Laguna Madre–Tuxpan area, he was responsible for

Description: This multidisciplinary study evaluates the structural and hydrogeologic evolution of Cretaceous-age reservoirs in the Putumayo basin, Colombia. We focused on the Eastern Cordillera fold-thrust belt along the southern Garzón Massif. Many important hydrocarbon accumulations occurred regionally along the proximal foreland basin and frontal fold-thrust belt defining the eastern margin of the northern Andes. To understand why recent Putumayo basin and adjacent thrust belt exploration has resulted in a wide range of oil quality and limited economic discoveries, we reconstructed the structural evolution, timing of oil migration, and timing of groundwater infiltration by (1) assessing regional trends in formation water, oil, and reservoir properties; (2) quantifying the timing of hydrocarbon generation and migration relative to trap formation using (a) two-dimensional (2-D) and three-dimensional seismic data to define and constrain a restorable balanced cross section from the Upper Magdalena Valley to the Putumayo foreland and (b) coupled one-dimensional thermal basin modeling; (3) evaluating the potential roles of Mesozoic extensional faulting and Paleogene shortening in the generation and preservation of structural traps; and (4) assessing groundwater influx from the modern foothills into the reservoir using a 2-D numerical groundwater flow model. We suggest that four-way closure is limited in the study area, where most foreland-verging structures create three-way fault closures that do not effectively trap light hydrocarbons. In addition, east-dipping structures and a relatively large reservoir outcrop area provide water infiltration pathways. Groundwater modeling suggests reservoirs were water washed by 2–200 million pore volumes since Andean uplift. Finally, average reservoir temperatures are 〈80°C (〈176°F), which further facilitated biodegradation.

Description: The Miocene and Pliocene interval of the Veracruz Basin, southeast Mexico, experienced an evolving array of shortening, strike-slip, and volcanic forces in response to plate-scale interactions. The basin is divided into six structural domains that define regions of comparable timing and type of structural deformation, and the basin fill is separated into two long-term depositional phases, each of which can be tied to a waning and then waxing of major basin-bounding tectonic events. The first phase of deposition took place from the early to late Miocene and is tied to the waning effects of the Laramide orogeny. The Miocene basin inherited a tectonically steepened basin margin, across which deep canyons were carved and variably filled with mudstone and thin remnants of coarse sandstone and conglomerate. This zone of erosion and bypass grades into thick, sandstone-rich basin-floor fans. Later in phase I, subaqueous volcanoes, tied to distant plate subduction, developed offshore and formed a bathymetric barrier that prevented turbidity currents from entering the ancestral Gulf of Mexico. The volcanoes also served as immovable buttresses, around which intrabasinal thrust belts developed in response to regional shortening. The second depositional phase is tied to the onset of internal basin shortening and uplift of the north basin margin known as the trans-Mexican volcanic belt. This uplift caused a dramatic reconfiguration of the sediment-dispersal system, whereby large shelf clinoforms prograded from north to south across the basin. In contrast to the onlapping stacking pattern of phase I units, phase II units stack in a strongly offlapping pattern. Proven and postulated reservoir-trap combinations, ranging from four-way to three-way combination (stratigraphic), to pure stratigraphic traps are common. Four-way closures mapped from the two-dimensional and three-dimensional seismic data are large (P50: 5000 km2) and are covered with thick, lower Miocene fan sandstones. Traps that depend on a stratigraphic component are thinner and smaller in size (P50: 1000 km2), but more numerous than the four-way closures. Because many structures have experienced prolonged pulses of compression, top seal is considered an important geologic risk to the retention of substantial gas-column heights. David C. Jennette received a B.S degree from Allegheny College and an M.S. degree from the University of Cincinnati. He is currently a program director at the Bureau of Economic Geology, conducting a range of studies on siliciclastic basins, reservoirs, and outcrops. Previously, he was a senior research geologist at ExxonMobil's Upstream Research in their Deepwater Reservoirs Research Group. He maintains a research focus on multidisciplinary analyses of turbidite reservoir systems.Tim F. Wawrzyniec is a structural geologist specializing in kinematic analyses and geophysics. He earned his Ph.D. from the University of New Mexico in 1999 and joined the Bureau of Economic Geology in 2000. Tim is currently a senior research scientist at the University of New Mexico and continues to work with the Bureau of Economic Geology on several basin analysis projects. Khaled Fouad is a senior researcher responsible for seismic interpretation and visualization technology. Before joining the Bureau of Economic Geology in 1997, he worked over 14 years as a seismic interpreter with various major oil companies where he gained experience in the Gulf of Mexico, Maracaibo Basin, Vienna Basin, and Gulf of Suez basins. Khaled received his B.Sc. degree in 1982 from Alexandria University, Egypt, and a Diploma of Higher Studies in 1984. Dallas B. Dunlap is a geologist and database coordinator for the Bureau of Economic Geology. He received a B.S. degree from the University of Texas at Austin in 1997. He has worked on many international and domestic projects that focus on subsurface mapping, 3-D visualization, modeling, and data management. Javier J. Meneses-Rocha received a B.S. degree in geological engineering in 1976 and earned his M.A. degree and his Ph.D. in geology from the University of Texas at Austin in 1985 and 1991, respectively. Meneses-Rocha started with Pemex in an 1985 as field geologist and then worked on regional petroleum evaluation projects, planning, reserve evaluation, prospect evaluations, and structural and play analysis projects. He is now manager of Geological and Geophysical Integration and Interpretation for Pemex Exploración and Producción. He is the past president of the Asociación Mexicana de Geólogos Petroleros. Francisco is a geologist and petrophysicist presently developing prospects and interpreting drillwell data from northern Veracruz Basin. Rafael Munoz is a geophysical interpreter identifying prospects and drilling exploration wells in the northern Veracruz Basin. David Barrera received a geologist engineering degree from the Instituto Politecnico Nacional in 1982. He has worked in Pemex for 15 years conducting petroleum systems, play, and prospect analysis. He is currently the team leader of the southern Veracruz exploration project in the Activo Salina del Istmo. Carlos T. Williams-Rojas is a geologist working on stratigraphy, basin, and play analysis, and economic evaluation. He earned an M.S. degree from Universidad Nacional Autonoma de Mexico in 1995 and an M.S. degree from Colorado School of Mines in 2000. Carlos is currently a senior geologist working for Pemex in the Activo Salina del Istmo. Arturo Escamilla-Herrera is a geologist conducting seismic interpretation, basin, and play analysis, and formation evaluation. He earned a B.S. degree from Instituto Politecnico Nacional in 1985 and is candidate for an M.S. degree in the same institution. Arturo is currently a senior geologist working for Pemex in the Activo Salina del Istmo.

Description: The lower continental slope of Morocco's west coast consists of Triassic-age salt manifested in the form of diapirs, tongues, sheets, canopies, and toe thrusts. Active salt diapirism and regional tectonics greatly influence the morphology of the modern sea floor, forming a severely rugose expression with ongoing minibasin development and episodic submarine failure. Detailed mapping of a 1064-km2 (411-mi2) seismic survey acquired in the Safi Haute Mer area revealed that Jurassic to Holocene salt mobilization continually affected distribution of sediment, causing a range of depositional flow styles, from slumps to sheet slides and mass-transport complexes (MTCs). Large sediment waves (20 km [12 mi] long, 1.5-km [0.9-mi] wavelength) were also documented at the end of the Aptian. An east-west–trending structural anticline downdip of the salt activated during initiation of the Atlas uplift in the latest Cretaceous to earliest Tertiary and shaped much of the lower slope into the Tertiary with a persistent canyon system and slope channels. The largest of the debris flows is a Cretaceous-age MTC, a 500-m (1640-ft)-thick flow that spans an area of up to 20,000 km2 (7722 mi2). Composing the MTC are (1) chaotic, mounded seismic facies; (2) internal syndepositional thrusts; and (3) transported megablocks (3.3 km2 [1.3 mi2]) with preserved internal stratigraphy. The MTC originated from an upslope collapse of a narrow shelf during the earliest phases of the Alpine orogeny. Dallas B. Dunlap received his B.S. degree in geology from the University of Texas at Austin in 1996. That year he joined the Bureau of Economic Geology's (BEG) international projects group as a research scientist associate focused on reservoir characterization studies in Austria, Mexico, and Venezuela. In 2006, he moved to the BEG's Quantitative Clastics Laboratory studying various marine depositional systems. Lesli J. Wood is a senior research scientist and lecturer at the Bureau of Economic Geology, and the director of the Quantitative Clastics Laboratory Industrial Associates program. Her interests include seismic geomorphology, clastic depositional systems, and Martian sedimentology. She holds B.S. and M.S. degrees in geology from Arkansas Tech University and the University of Arkansas, respectively, and a Ph.D. in earth resources from Colorado State University. Chad Weisenburger is currently employed by EOG Resources in Tyler, Texas, as a geologist on the Haynesville Shale Team. He received his B.S. degree in geology from North Dakota State University in 2005. In 2007, he earned an M.S. degree in geology from the University of Texas, where he worked on salt tectonics, sedimentology, and stratigraphy of offshore Morocco. Haddou Jabour graduated from the Rabat School of Mines in 1980 with first class honors and worked at National Office of Hydrocarbons and Mining (ONHYM) until 1983. After receiving his M.S. degree in geology from the University of South Carolina in 1985, he rejoined ONHYM and is now a senior explorationist in charge of basin evaluation and promotion. His interests include petroleum system assessment and prospect evaluation.

Description: The lower continental rise of Morocco’s Atlantic Margin contains three varying morphologies of buried deepwater sediment waves. The 3D mapping of a [Formula: see text] seismic survey acquired in the Safi Haute Mer seismic block revealed numerous linear features that range from small, less than 17-m-thick Jurassic-age amplitude striations up to 110-m-thick migrating Cretaceous contourite sediment waves. Early proto-Atlantic deposition in Safi Haute Mer initiated in the Triassic, with syn- and postrift accumulation in basement half-grabens basinward of the modern Moroccan salt front. Sedimentation continued through the Mesozoic with deposition of turbidites, progradation of clinoforms, and culminating in multiple Late Cretaceous, regionally expansive, mass-transport deposits ([Formula: see text]). Tertiary stratigraphy consists of multiple thin, pelagic drapes and unconformities. The complex history of sedimentation and tectonics gave rise to three styles of sediment waves found within the study area: (1) type J1 — small and poorly imaged, Jurassic age, locally generated wave forms that have wavelengths of up to 12 km and crest-to-crest separations of less than 1 km with little or no vertical expression; (2) type K1 — early Aptian constructional sediment waves ([Formula: see text] thick) built by contour currents that traveled in and near a contourite moat at the base of a seafloor high produced by shallowly buried mobile salt; and (3) type K2 — latest Albian and earliest post-Albian sediment waves built by along-slope currents on a relatively stable slope, showing evidence of updip migration. The type K2 sediment wavefield exhibits wave heights of 40 m and crest-to-crest separations of 1 km, and it is continuous over the entire study area.