January, 2000
HGS Meetings

Houston Geological Society presents:

"Legends in Wildcatting"

The HGS is pleased to present a panel discussion featuring living legends in wildcatting, to be held January 10th in honor of the Spindletop 99th Anniversary. Details:

Moderators: Byrd Larberg, Burlington International, and Charles Sternbach, Jordan Oil and Gas

Panelists for HGS' "Legends in Wildcatting" are:

George Mitchell, Mitchell Energy

George P. Mitchell is Chairman and CEO of Mitchell Energy & Development Corp. and its two principal operating subsidiaries.

During his career, Mr. Mitchell has been active in the drilling of approximately 8,000 wells, including more than 1,000 wildcats. He and his company have found upwards of 200 oil and 350 gas discoveries. He was the visionary behind the development of The Woodlands. He was personally instrumental in the founding of the Houston Advanced Research Center (HARC), a contract and grant research institution headquartered at The Woodlands' Research Forest, and is an active philanthropist.

Gene Van Dyke, President, Vanco Energy Company

Gene Van Dyke is president and owner of Vanco Energy Company, the largest license holder of deepwater acreage off West Africa with in excess of 20 million gross acres under lease in four countries. After 20 years of successful exploration on the Gulf Coast, this visionary moved to new international frontiers in 1972, first in the North Sea, and in 1992, into West Africa.

By 1996, and 46 years into his career, Gene decided to concentrate on deepwater exploration, this time looking for "elephants" offshore West Africa. He recognized that the time was right for deepwater exploration, both in terms of the potential reserves to be found as well as the fact that the emerging technology for drilling, development and production was in place. Using his talents as a deal maker, first honed in North Central Texas, he has signed contracts in Gabon, Morocco, Cote d'Ivoire and most recently Senegal.

Joe B. Foster, Chairman and Chief Executive Officer of Newfield Exploration Company

Newfield was founded by Foster in January, 1989, and is an independent oil producer, exploring for and acquiring oil and gas reserves primarily in the Gulf of Mexico. By 1998 Newfield had become the 10th leading operator of production in the Gulf of Mexico.

Previously, Foster was Chairman of Tenneco Oil Company and Executive Vice President and director of its parent, Tenneco Inc. He was with Tenneco for 31 years and also served as Chairman of the Tenneco Gas Pipeline Group.

John N. Seitz, President and Chief Operating Officer, Anadarko

Mr. Seitz began his career at Anadarko in 1977 as a Senior Exploration geologist and became Chief Geologist in 1982. In 1983, Mr. Seitz was appointed General Manager overseeing all exploration for the Company and was promoted to Vice President of Exploration and Production in 1989. He was named Senior Vice President of Exploration in 1995 and Executive Vice President of Exploration and Production in August of 1997. Mr. Seitz was appointed to his present position in April of this year.

In his capacity as president and COO, John Seitz is responsible for Anadarko's exploration and development drilling activities and production operations in the U.S. and overseas.

Marlan W. Downey, Bartell Professor of Geology & Chief Scientist-Sarkeys Energy Center, University of Oklahoma

Marlan worked for Shell Oil Company from 1957 to 1987. He spent four years in Shell's Research Center, responsible for making Shell's theoretical work in organic geochemistry useful in finding oil. In 1969, he became Shell's youngest Chief Geologist, and in 1973 became Shell's first Alaska Division Exploration Manager. In 1977 Marlan moved to Shell Oil's International Exploration & Production business and became Vice President of Shell, and then President of Shell Oil's newly-formed International subsidiary, Pecten International. At Pecten, Marlan's team increased reserves 325% and production 600% in a 7-year period. Marlan retired from Shell in 1987 after 30 years of service.

Marlan joined ARCO in 1990 as Senior Vice President of Exploration for ARCO International, becoming President of ARCO International, and then Senior Vice President and Executive Exploration Advisor to ARCO. His responsibilities were to oversee oil and gas exploration and development for ARCO in foreign countries.

Poster Session:

Pockmarks along the California margin--implications for fluid flow. S. S. Foland, N. M. Maher, J. W. Yun

Abstract

Pockmarks observed along the continental margin of California give new insight to processes of fluid flow. Pockmarks are circular to elongate depressions that occur on the seafloor and are associated with fluid expulsion. We document the presence of pockmarks from Pt. Conception northward to the Eel River Basin, offshore California. We find that pockmark size varies from giant (>250 m in diameter) to small (10m in diameter), and morphologies vary from conical to sediment-draped and infilled. Additionally, we observe that pockmarks may be randomly distributed, clustered, or occur along linear trends.

Offshore central California, pockmarks are imaged on the shelf and upper slope, including a 560 km2 pockmark field containing about 1,500 individual depressions between water depths 900 m to 1200 m. Pockmarks range from 130 m to 260 m in diameter and are 8-12 m deep. Pockmark densities range from 1.5/km2 in the north increasing to 6/km2 in the south. The southern extent of the pockmark field is unknown but almost certainly extends beyond the southern edge of the surveyed area.

A single field of pockmarks is identified in the northwestern portion of the offshore Point Arena Basin. Individual pockmarks are in excess of 200 m in diameter. The pockmarks occur in linear trends oriented north-northwest. The pockmark trends occur over subsurface faults identified from multichannel seismic reflection surveys. These subsurface faults cut Miocene-age reflectors.

In the offshore Eel River Basin, nearly 4,000 pockmarks 10-25 m in diameter occur on the upper continental slope in an area about 2100 km2. Over 80 percent of the pockmarks are located between 400 to 600 m water depths. These small pockmarks are in contrast to four giant (200 m diameter) pockmarks imaged near the headscarp of a submarine slide. The observed bimodal distribution of pockmark size suggests different fluid expulsion mechanisms.

HGS Environmental / Engineering Section Dinner Meeting

"TNRCC, Case Histories of TERP"

Abstract:

Mr. Carsten will use case studies to illustrate the technical and adminstrative requirements of the Voluntary Cleanup Program (VCP) and Innocent Owner Operator Program. The case studies will highlight various key technical issues that are critical to efficiently moving a site through the VCP. Topics addressed by the case studies will include natural attenuation for chlorinated solvents, sampling requirements based on default exposure areas, the burden of proof for innocent owner/operator demonstrations, and an update on Brownfield initiatives.

Biographical Sketch:

Jay Carsten is responsible for a team of project managers reviewing site investigation and remediation documents, including application of the Risk Reduction Rules, for facilities participating in the Voluntary Cleanup and Innocent Owner Operator Program. Prior to joining the Voluntary Cleanup Program, Mr. Carsten was a project manager in the TNRCC Corrective Action Program. Mr. Carsten has been with the Commission for seven years, and previously worked six years in environmental consulting in Houston implementing site investigation and remediation projects. Mr. Carsten holds a B.S. degree in Geology from Texas A&M University.

International Section Dinner Meeting

Focus on Sub-Andean petroleum systems: "Depositional environments of Upper Cretaceous source and reservoir rocks of western Venezuela"

Abstract:

The deposition of organic carbon-rich sediments of the Late Cretaceous La Luna and Navay formations resulted in the formation of a world-class petroleum system in western Venezuela. Over 33 billion barrels of oil have been produced from reservoirs charged by oil from this system, with remaining recoverable reserves of at least 22 billion barrels. Assuming 14% average recovery of original oil in place, as much as 370 billion barrels of oil may have been trapped in the Maracaibo and Barinas/Apure basins following generation and expulsion from the La Luna and Navay formations.

The deposition of oil-prone source rocks in northwestern Maracaibo began following drowning of the Albian-Cenomanian Maraca Formation carbonate platform. La Luna/Navay deposition continued in southeastern Maracaibo after drowning of the more southerly Guayacan Member carbonate platform (Capacho and Escandalosa formations) during the Late Cenomanian to Early Turonian. The Maraca Formation and other shallow water Cogollo Group carbonates are important reservoirs in the western, central (Lake Maracaibo), and southern parts of the Maracaibo Basin, with arguably the best example of this being the giant Mara-La Paz fields. Fracture-enhanced Cogollo Group reservoirs there have produced over 850 MMBO since 1923. New discoveries in the central Barinas/Apure Basin may yield a similar (aggregate) volume from slightly younger Escandalosa Formation sandstones and carbonates.

The conditions under which organic carbon-rich sediments accumulated reflect complex paleoclimatic and paleoceanographic variables, including bathymetric restriction and bottom water anoxia. Specifically, paleobathymetric barriers (Santa Marta and Santander massifs, Paraguana Block, and ancestral Mérida Andes) enhanced the development of anoxia by causing poor circulation and limited ventilation. Anoxia was also promoted by high evaporation and low precipitation rates (high salinity bottom water), and high levels of marine algal productivity (high organic matter flux).

Bottom water oxygen levels apparently increased from the Late Santonian through the end of the Cretaceous, due primarily to changes in local and global climate. Increased tectonic uplift and higher rainfall rates in eastern Colombia during the Campanian and Maastrichtian contributed to lower TOC levels, through delta progradation and siliciclastic dilution. Subsidence of the Paraguana paleobathymetric barrier facilitated exchange with better-oxygenated water from the Atlantic Ocean, thus ending source rock deposition in the Maracaibo Basin. The deposition of sealing Colón and Burgüita Formation shales overlying the La Luna/Navay source rocks completed the key components of the Cretaceous petroleum system.

The best areas for the future discovery of large oil fields sourced from and reservoired within Cretaceous rocks may occur along the Sierra Perijá Mountains of the western Maracaibo Basin, and along the central Mérida Andes Mountain front in the western Barinas/Apure Basin.

Biographical Sketch:

Bob Erlich received his Ph.D. in paleoceanography from the Vrije Universiteit of Amsterdam, The Netherlands, where he worked with Wolfgang Schlager. Bob earned his M.S. in sedimentology and stratigraphy at the University of North Carolina at Chapel Hill, and his B.S. in geology at the University of Miami, Florida. He began his career as a field geologist in Guatemala in 1975 following the early influences of Cesare Emiliani, Jerry Stipp, and Fred Nagle.

Bob has since worked in the field throughout Latin America, as well as in the People's Republic of China. He worked for 19 years in various exploration positions for Amoco Production Company, first in domestic exploration in New Orleans and later in the Worldwide Exploration Business Group in Houston. He joined Burlington Resources International in early 1999 as the Geological Advisor for Latin America, where he advises on exploration projects throughout the region.

Bob has published on numerous topics during his career, including the seismic stratigraphy of carbonate platforms, the petroleum geology of Eastern Venezuela, the Miocene carbonates of Trinidad, and the Late Cretaceous source rocks of Costa Rica and Western Venezuela. His current research interests are in Late Cretaceous source rocks, and carbonate stratigraphy.

Poster Session:

Poster One:

Fold and thrust belt along the western flank of the Eastern Cordillera of Colombia: style, kinematics and timing constraints derived from seismic data and detailed surface mapping

RESTREPO-PACE, Pedro A. (1), Fabio Colmenares (2), Camilo Higuera (2), Marcela Mayorga (2) and Jairo Leal (3) 1. Conoco Colombia Inc., 2. Geosearch Ltda., 3. Texaco Colombia

Further comments and questions could be directed to PEDRO.A RESTREPO-PACE@usa.conoco.com

The Middle Magdalena Valley (MMV) of Colombia is an asymmetric, intermontane depression bordered on the Central and Eastern Cordilleras. The basin here developed encompasses a Tertiary sedimentary wedge, which thickens to the east below the foldbelt exposed along the western flank of the Eastern Cordillera. The base of the wedge is defined by an easterly dipping regional unconformity depicting truncation of Pre-Tertiary strata below it and progressive onlap of Late-Eocene-Miocene sediments above it. This surface has acted as the main conduit for migration of oil from the kitchen areas located within the foldbelt to traps within the basin. More than 3.5 BBOE reserves have been discovered since the first discoveries in the early 1900's. These were sourced by the Upper Cretaceous La Luna Formation and reservoired in Eocene to Oligocene fluvial sandstones.

The foldbelt exposed along the eastern margin of the basin consists of a polydeformed west verging thrustbelt . Seismic data, synkinematic deposits and field relationships indicate that west verging compressive structures developed in Late Paleocene-Early Eocene time, Middle Miocene (?) and during the major Mio-Pliocene Andean orogenic phase. Structural inversion is evident in the hinterland portion of the foldbelt were Jurassic/basal Cretaceous rocks are exposed in the cores of northeasterly trending, north and south plunging anticlinoria. Within the middle portions of the foldbelt, the hinterland inversion structures deflect into thin-skinned structures detaching at Middle and Late Cretaceous levels, forming more classical fault bend and fault propagation geometries. The outer portions of the foldbelt exhibit a series on NS trending inversion related anticlines, which have yielded the majority of hydrocarbons in the basin e.g. Provincia, La Cira-Infantas, Opon fields.

In this poster we summarize the evidence for polyphase deformation at the western flank of the Eastern Cordillera of Colombia, along the eastern margin of Middle Magdalena Valle (MMV). The sequence of events and related evidence is outlined below:

Current resolution of Tertiary stratigraphy precludes better dating of deformational events. Poor correlations and simple structural models have resulted in erroneous burial history curves and HC maturation and migration models for the foldbelt area. Large exposures of oil saturated Upper Eocene sands within the mapped area may indicate that these formed part of early traps (Late Oligocene-Early Miocene?) breached during the later stages of deformation (Late Miocene-Pliocene).

Regionally, timing of the eastward propagation of deformation within the central and eastern Andean ranges argues for a crustal scale forward breaking sequence of thrusting: latest Campanian to Maastrichtian uplift of the Central Cordillera, Paleocene-E. Eocene thrusting in the MMV and along the western flank of the Eastern Cordillera and ultimately inversion and major uplift of the entire Eastern Cordillera in Late Miocene-Pliocene time. Kinematically, the driving element of deformation would have been the obliquely accreting western terranes of the Central and Western Cordilleras of Colombia, which transfer its easterly component of convergence through a basal crustal scale detachment as depicted by Dengo and Covey (1993), Cooper et al. (1995), Roeder and Chamberlain (1995) and this work. An easterly transported crustal scale wedge below the MMV would cause structuration along the western flank of the Eastern Cordillera as a series of backthrusts.

References

Poster Two:

Campanian-Miocene tectonostratigraphy, depocenter evolution and basin development of Colombia and western Venezuela

By Tomas Villamil

The position of the central axis of deposition over Colombian and Venezuelan continental crust has varied markedly through time. The axis migrated from west to east from Late Cretaceous to Oligocene but at times, secondary drainage divides were established by local uplift events. In Oligocene times with initial inversion of the Eastern Cordillera the central axis of deposition was divided into two main axes, the proto Magdalena and the proto Orinoco systems. The west to east migration of the central axis of deposition had a tectonic origin and it happened in combination with tectonically driven changes in accommodation space. Depocenter evolution can be divided as follows.

  1. The axis of Campanian and Early Maastrichtian depocenter was located few km east of the present position of the Central Cordillera of Colombia; it migrated east with gradual uplift of the Central Cordillera.
  2. The central axis of Late Maastrichtian deposition is positioned approximately over the present day western foothills of the Eastern Cordillera, possibly crosses the Eastern Cordillera over the Santander massif and continues into the Maracaibo Lake. In Cretaceous-Tertiary boundary times parts of the eastern margin of the Eastern Cordillera were uplifted by an initial phase of inversion of deeply rooted Jurassic and early Cretaceous normal faults.
  3. In Paleocene times the central axis of deposition was located along the spine of the Eastern Cordillera and extended into the Maracaibo basin.
  4. In latest Paleocene times the central axis of deposition shifted to eastern regions of the Eastern Cordillera and accommodation space decreased.
  5. The Early Eocene central axis of deposition was located along the present-day eastern foothills of the Eastern Cordillera; accommodation space continued to decrease and the regional Middle Eocene unconformity began to develop. In Middle Eocene times a regional unconformity developed, marking the climax of the pre-Andean Orogeny. Deposition during these times was dominant in the Maracaibo basin area where large amounts of sediment derived from vast exposed areas accumulated.
  6. The Late Eocene central axis of deposition was confined to the present position of the Llanos foothills. Late Eocene deposition reflects a regional increase in accommodation space. In Oligocene times the initial uplift of the Eastern Cordillera divided the main depocenter into two central axes. Accommodation space diminished in uplifted regions but continued to increase in the depocenters allowing sporadic marine ingressions into the present position of the Llanos foothills. As uplift of the Eastern Cordillera continued, the eastern depocenter axis (proto Orinoco) migrated east and the western depocenter axis (proto Magdalena) migrated west. This process continued through the rest of the Cenozoic.

Implications of this model for hydrocarbon exploration will be discussed through the presentation.

Poster Three:

"Hidden Structures in the Upper Magdalena Valley: New Exploratory Frontier"

by German Rodriguez, Andres Fuenzalida and René Robertson A. from, Sipetrol, Sucursal Colombia (Bogotá) office.

Emerging Technologies Section Dinner Meeting

"High resolution sequence stratigraphy on a geologic workstation: hunting for sub-seismic resolution features in mature basins"

Reservations: Tickets Make or cancel reservations by January 18. You MUST include a name and a contact telephone number for every person for whom you are reserving or canceling a place. HGS members are requested to provide their HGS member number. Note: Some people have experienced a problem with this email reservation system. If you do not receive a reply email confirmation from the HGS office, please call the HGS office (713) 785-6402) to verify your email reservation was received.

Abstract:

Sequence stratigraphy, pioneered in the 1950s and revitalized with the seismic tool in the 1980s, represents a powerful approach to the interpretation of geologic systems. By applying the discipline of careful time-line correlations and unconformity recognition it becomes possible to identify genetically related packages of rock that are most appropriate for subsurface mapping.

Sequence stratigraphy and time-stratigraphic correlations require tracing time lines from either outcrop, well log, or seismic data.Continuous outcrop and seismic data offer opportunities to trace time lines and observe stratigraphic discordance directly. Well-log data require the careful correlation of "marker events" in the log character, interpreted as time lines, over broad areas of the basin in order to reconstruct the time-stratigraphic basin-fill geometries of the subsurface.

Well-log correlation and sequence stratigraphic methodology are enhanced through the use of computer workstations capable of working with large numbers of well logs. By harnessing the power of well-designed software and inexpensive raster well-log images, geologists have the capability to correlate very detailed regional correlation frameworks established on the basis of log character.

Examples of high-resolution sequence stratigraphy are offered from the Almond, Lewis and Fox Hills formations of the eastern Green River Basin, where hundreds of well logs were correlated with as many as 50 correlations per five-hundred foot interval. The results delineate subtle unconformities, faults and basin-fill geometries that are below the resolution of seismic in the area. Techniques for overcoming computer screen size limitations and for simulating paper-based log correlation techniques on a geologic workstation are illustrated in a live software demonstration.

While much of what is possible on the computer workstation is possible using paper well-logs, the sheer volume of well logs and the inefficiencies of paper-based methodologies prohibit stratigraphic studies of this detail by most workers. By leveraging the power of the computer, low-cost raster images and the established methodologies of sequence stratigraphy, the industry has an opportunity to revisit mature basins to explore the resolution of geologic features on a sub-seismic scale. Such features may be the basis for a new wave of discoveries in old basins.

Biographical Sketch:

William C. Ross began his career with Shell Development Company in 1979. As a senior research geologist, he worked in seismic and sequence stratigraphy, basin analysis and stratigraphic modeling until 1984, at which time he joined Marathon's Geological research center in Littleton, Colorado, working with field to basin-scale stratigraphic studies, stratigraphic modeling and training. In 1995, Ross founded Interpretive Imaging. He is currently Vice President of Integrated Solutions for A2D Technologies/Interpretive Imaging.

North American Exploration Section Dinner Meeting

"Permeability trends in distributary-mouth bar sandstones: a key to reducing risk in deltaic reservoirs"

Author: by R. S. Tye, and J. J. Hickey, ARCO, Plano, Texas

Date: Monday, January 24, 2000

Place: Westchase Hilton, 9999 Westheimer

Time: 5:30 Social 6:30 Dinner

Cost:

Reservations: Tickets Make or cancel reservations by January 21. You MUST include a name and a contact telephone number for every person for whom you are reserving or canceling a place. HGS members are requested to provide their HGS member number. Note: Some people have experienced a problem with this email reservation system. If you do not receive a reply email confirmation from the HGS office, please call the HGS office (713) 785-6402) to verify your email reservation was received.

Abstract:

Biographical Sketch:

HGS Lunch Meeting

"Petroleum exploration and stratigraphy of the Lower Cretaceous James Limestone (Aptian) and Andrew Formation (Albian): Main Pass, Viosca Knoll, and Mobile areas, northeastern Gulf of Mexico."

Abstract:

Hydrocarbon exploration of Lower Cretaceous carbonates on the Outer Continental Shelf began in 1968, targeting the Andrew Formation and James Limestone. Seven fields were discovered in this carbonate trend: the Andrew Formation's Main Pass 253 and Main Pass 221 (relinquished), and the James Limestone's Mobile 991, Viosca Knoll 69, Viosca Knoll Block 114, Viosca Knoll 252, and Viosca Knoll 256 (terminated). In 1986 Tenneco's Viosca Knoll Block 117 well no. 1 initially encountered James Limestone gas during drilling to a deeper Jurassic target. Lower Cretaceous hydrocarbon potential remains in relatively unexplored regions of the the Southern Platform in the Desoto Canyon-Florida Middle Ground Areas, Tampa Basin, Sarasota Arch, and in the South Florida Basin adjacent to the Lower Cretaceous shelf-edge-reef-trend.

Stratigraphically positioned between the Dantzler and Paluxy formations, the Andrew Formation is composed of an upper Washita and two Fredericksburg age carbonate platforms separated by shelf mudstones. The James Limestone, comprising upper and lower members, dominate thin shale members of the Pearsall Formation. Six facies compose the Lower Cretaceous carbonates where grainstone detritus zones, adjacent to reef/patch reef boundstones, were redistributed by wave action over the interior platform. Shelf lagoonal micrites, deposited nearest the paleoshoreline, occur in the central and eastern portions of the Mobile and northern Viosca Knoll Areas. Shelf-edge-reef boundstones interfinger with oolitic grainstones on the shelf and fore reef mudstones off the shelf.

Biographical Sketch:

Andrew J. Petty has worked twenty years for the Minerals Management Service in New Orleans, Louisiana in the Rate Control Section and as Corpus Christi District Geologist. He is currently in the Basin Analysis unit where he has authored several papers on biostratigraphy in the Eastern Gulf of Mexico. Andy holds a B.S. from Stephen F. Austin State University in 1973 and an M.S. from the University of Texas at El Paso, 1975.

SPE-GCS General Lunch Meeting : Global Issues Shaping Oil & Gas Company Shareholder Returns

Description:

The topic of "Global Issues Shaping Oil & Gas Company Shareholder Returns" will include:

Biographical Sketch:

Bill Marko is a Principal of Navigant Consulting with 20 years experience in the energy business, Bill has worked in technical, operational, and commercial areas. His career includes assignments in offshore project construction, reservoir and operations engineering, and producing operations. His commercial and business experience includes acquisitions, trades, and sales, business development, and corporate M&A. Bill's experience includes most of the major oil and gas basins of the world, economic modeling, acquisition and sales analysis, alternative business models, and portfolio management techniques.