No. Registros Solicitud 1 5614 colombia

IS - ISSN: 0149-1423

CO - CODEN: AABUD2

AN - ACCESSION NUMBER: 1996-072114

UD - UPDATE CODE: 199622

Registro 4656 de 5614 - GeoRef Disc 4: 1993-1996

TI - TITLE: The petroleum geology of the sub-Andean basins.

AU - AUTHORS: Mathalone-Jeremy-M-P

AF - AUTHOR AFFILIATION: PetroSantander, Houston, TX, United States

BK - BOOK TITLE: In: AAPG international conference and exhibition; abstracts.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: AAPG Bulletin. 80; 8, Pages 1313. 1996.

PB - PUBLISHER: American Association of Petroleum Geologists. Tulsa, OK, United States. 1996.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1996

CN - CONFERENCE INFORMATION: AAPG international conference and exhibition. Caracas, Venezuela. Sept. 8-11, 1996.

LA - LANGUAGE: English

AB - ABSTRACT: The sub-Andean trend of basins spans the entire length of South America from Venezuela in the north to Argentina in the south. All the basins produce hydrocarbons with the exception of the Argentinian Bolsones complex and the Peruvian Madro do Dios which is prospective but virtually unexplored. There have been some 119 billion barrels of oil and 190 TCF of gas discovered to date, comprising 93% of the continent's oil reserves. The basins lie immediately east of the Andes mountain range and are mainly asymmetric Upper Tertiary, westerly dipping foreland basins that overlie a series of earlier Tertiary, Mesozoic and Paleozoic depocentres. All the basins have been compressively deformed as recently as the Upper Miocene, by the eastwards growth of the Andean Cordillera. Giant oil and gas fields sourced from shales of varying age, have been found along the whole trend of basins, with a predominance of gas in the south. The rich marine Upper Cretaceous La Luna and equivalent shales of Venezuela, Colombia and Ecuador have been responsible for generating 86% of the hydrocarbons discovered to date in the sub-Andean basins. Proven sources include Devonian, Carboniferous, Permian and Triassic shales in the central area, comprising Peru, Bolivia and northern Argentina. In southern Argentina, oils have been sourced from Uppermost Jurassic and Lower Cretaceous marine and lacustrine shales. Over 7,500 wildcat wells have been drilled in basins along the trend, with a 15% success rate. Many of the basins are very lightly explored, with considerable potential for future discoveries.

DE - DESCRIPTORS: Andes-; Argentina-; basins-; Bolivia-; Carboniferous-; Cenozoic-; clastic-rocks; compression-tectonics; Cretaceous-; Devonian-; drilling-; foreland-basins; future-; genesis-; giant-fields; La-Luna-Formation; marine-environment; Mesozoic-; natural-gas; oil-and-gas-fields; Paleozoic-; Permian-; Peru-; petroleum-; petroleum-exploration; possibilities-; production-; reserves-; sedimentary-rocks; shale-; source-rocks; South-America; tectonics-; Tertiary-; Triassic-; Upper-Cretaceous; upper-Tertiary; wells-

CC - CATEGORY CODES: 29A-Economic-geology,-geology-of-energy-sources

DT - DOCUMENT TYPE: Abstract; Serial; Conference-Document

BL - BIB LEVEL: Analytic

RF - REFERENCE SOURCE: GeoRef, Copyright 2000, American Geological Institute. Reference includes data supplied by American Association of Petroleum Geologists, Tulsa, OK, United States

IS - ISSN: 0149-1423

CO - CODEN: AABUD2

AN - ACCESSION NUMBER: 1996-072117

UD - UPDATE CODE: 199622

Registro 4657 de 5614 - GeoRef Disc 4: 1993-1996

TI - TITLE: Petroleum system of the Cano Limon Field, Llanos Basin, Colombia.

AU - AUTHORS: Molina-Jorge

AF - AUTHOR AFFILIATION: Occidental de Colombia, Bogota, Colombia

BK - BOOK TITLE: In: AAPG international conference and exhibition; abstracts.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: AAPG Bulletin. 80; 8, Pages 1315. 1996.

PB - PUBLISHER: American Association of Petroleum Geologists. Tulsa, OK, United States. 1996.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1996

CN - CONFERENCE INFORMATION: AAPG international conference and exhibition. Caracas, Venezuela. Sept. 8-11, 1996.

LA - LANGUAGE: English

AB - ABSTRACT: The Chipaque-Lower Carbonera Petroleum System of the northernmost Llanos Basin of Colombia, covers 11,100 km (super 2) and includes two major oil fields: Cano Limon in Colombia, and Guafita in Venezuela, jointly with three more relatively small fields in Colombia: Redondo, Cano Rondon, and Jiba. Ultimate recoverable reserves are in the order of 1.4 BBO. The sedimentary section penetrated in the Northern Llanos has been informally subdivided into four Cretaceous formations: K3, K2B, K2A, and Lower K1 deposited during the Albian-Senonian, and into four Tertiary formations: Lower Carbonera, Upper Carbonera, Leon, and Guayabo deposited during the Late Eocene to Pliocene time. The main reservoir is the Lower Carbonera Formation, which contains 81% of the total reserves. The Cretaceous K2A and Lower K1 reservoirs contain 6% and 8%, respectively of the reserves. Minor reserves are accumulated in the discontinuous sandstones of the Oligocene Upper Carbonera Formation Geochemical analyses of the Cano Limon/Guafita oils indicate that these are aromatic intermediate to paraffinic-naphthenic, non degradated, genetically related to a common marine-derived type of kerogen. These oils were generated by a mature, marine clastic source rock with a small contribution of continental organic matter. The geochemistry of the hydrocarbon suggest a genetic relationship with the shales of the Chipaque formation, basinward equivalent of the K2 Formation, which presents kerogen type II organic matter and has been recognized as a good source rock. The petroleum system is hypothetical because a definite oil-source rock correlation is lacking. The development of the petroleum system is directly related to the history of movement of the Santa Maria, La Yuca, Cano Limon, and Matanegra wrench faults. It has been determined that these faults of pre-Cretaceous rifting origin, created the Santa Maria Graben of which the Espino Graben is the continuation in Venezuela. Thermal maturation modelling indicates that the hydrocarbons could have been generated from a pod of active Chipaque source rocks, located along the Santa Maria Graben. Geochemical migration indicators of the Cano Limon oils imply an original upward migration of the oil along the faults and subsequent short lateral migration of the hydrocarbons into the different reservoirs. Indicated oil migration is from the southwest. The same migration indicators suggest an orderly filling of the different Cano Limon structures and reservoirs from the oil generating area. Oil generation and migration took place during Eocene/Oligocene times. The major trapping folds had been formed by that time and were filled prior to the regional tilting that started during Leon time. Subsequent re-migration of part of the oil was caused by this regional tilting and resulted in different oil property trends for different areas, as well as different zones.

DE - DESCRIPTORS: aliphatic-hydrocarbons; alkanes-; aromatic-hydrocarbons; Cano-Limon-Fault; Cano-Limon-Field; Cano-Rondon-Field; Carbonera-Formation; Cenozoic-; Chipaque-Formation; clastic-rocks; Colombia-; Cretaceous-; Espino-Graben; faults-; genesis-; geochemistry-; Guafita-Field; Guayabo-Formation; hydrocarbons-; Jiba-Field; kerogen-; La-Yuca-Fault; Leon-Formation; Llanos-; Matanegra-Fault; maturity-; Mesozoic-; migration-; oil-and-gas-fields; organic-compounds; organic-materials; paraffins-; petroleum-; petroleum-accumulation; properties-; Redondo-Field; reserves-; reservoir-rocks; sandstone-; Santa-Maria-Fault; Santa-Maria-Graben; sedimentary-rocks; shale-; South-America; Tertiary-; tilt-; Venezuela-; wrench-faults

CC - CATEGORY CODES: 29A-Economic-geology,-geology-of-energy-sources

DT - DOCUMENT TYPE: Abstract; Serial; Conference-Document

BL - BIB LEVEL: Analytic

RF - REFERENCE SOURCE: GeoRef, Copyright 2000, American Geological Institute. Reference includes data supplied by American Association of Petroleum Geologists, Tulsa, OK, United States

IS - ISSN: 0149-1423

CO - CODEN: AABUD2

AN - ACCESSION NUMBER: 1996-072124

UD - UPDATE CODE: 199622

Registro 4658 de 5614 - GeoRef Disc 4: 1993-1996

TI - TITLE: Petroleum systems of the middle Magdalena Valley, Colombia.

AU - AUTHORS: Mora-Cesar; Cordoba-Fabio; Luna-Octavio; Sarmiento-Luis-Fernando; Rangel-Antonio; Giraldo-Blanca-Nubia; Bartels-Hans-M; Reyes-Juan-Pablo; Magoon-Leslie-B

AF - AUTHOR AFFILIATION: Ecopetrol, Santafe de Bogota, Colombia

BK - BOOK TITLE: In: AAPG international conference and exhibition; abstracts.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: AAPG Bulletin. 80; 8, Pages 1316. 1996.

PB - PUBLISHER: American Association of Petroleum Geologists. Tulsa, OK, United States. 1996.

RP - RESEARCH PROGRAM: USGSOP (Non-USGS publications with USGS authors)

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1996

CN - CONFERENCE INFORMATION: AAPG international conference and exhibition. Caracas, Venezuela. Sept. 8-11, 1996.

LA - LANGUAGE: English

AB - ABSTRACT: The petroleum systems of the Middle Magdalena Valley include 29 oil fields and numerous oil seeps with recoverable reserves of 3 billion barrels of oil. Based on API gravity, sulfur content, pristane/phytane index, carbon isotopic ratios of the saturated and aromatic hydrocarbon fractions, and biomarkers, at least two oil families occur within this province. Each oil family covers a different area. Based on stratigraphic occurrence, one oil family originated from the Tablazo Formation of Aptian age while the other oil family originated from the La Luna Formation of Cenomanian to Santonian age. Both of these rock units have high organic carbon contents and hydrogen indices indicative of petroleum source rocks. The primary reservoir rocks are the Tertiary sandstones of the La Paz, Esmeraldas, Mugrosa, and Colorado Formations. The La Cira Shale, a regional seal rock, is the uppermost part the Colorado Formation. Secondary reservoirs are limestones of the Tablazo, Rosablanca, and La Luna formations, and sandstones of the Lisama and Umir Formations. An Eocene unconformity separates the primary reservoir rocks above from the secondary reservoir rocks and active source rocks below. This unconformity places the primary reservoir rocks in angular discordance with the underlying active source rock Intervals, forming the main plumbing system for migrating petroleum. Traps are related to pre-Andean and Andean folding and faulting. Overburden rocks are Cretaceous marine, Paleocene transitional, and Eocene-Pleistocene nonmarine sedimentary rocks. Thermal data and modeling indicates that the thermal history of the source rock intervals was sufficient to generate hydrocarbons during late Tertiary time.

DE - DESCRIPTORS: aliphatic-hydrocarbons; alkanes-; Aptian-; aromatic-hydrocarbons; biomarkers-; C-13-C-12; carbon-; Cenozoic-; Colombia-; Colorado-Formation; Cretaceous-; Esmeraldas-Formation; faults-; folds-; genesis-; hydrocarbons-; hydrogen-; isotope-ratios; isotopes-; La-Cira-Shale; La-Luna-Formation; La-Paz-Formation; Lisama-Formation; Lower-Cretaceous; Magdalena-Valley; marine-environment; Mesozoic-; migration-; Mugrosa-Formation; oil-and-gas-fields; oil-seeps; organic-carbon; organic-compounds; organic-materials; overburden-; petroleum-; phytane-; pristane-; reserves-; reservoir-rocks; Rosablanca-Formation; saturated-hydrocarbons; sedimentary-rocks; source-rocks; South-America; stable-isotopes; stratigraphic-traps; Tablazo-Formation; Tertiary-; thermal-history; traps-; Umir-Formation; unconformities-; Upper-Cretaceous

CC - CATEGORY CODES: 29A-Economic-geology,-geology-of-energy-sources

DT - DOCUMENT TYPE: Abstract; Serial; Conference-Document

BL - BIB LEVEL: Analytic

RF - REFERENCE SOURCE: GeoRef, Copyright 2000, American Geological Institute. Reference includes data supplied by American Association of Petroleum Geologists, Tulsa, OK, United States

IS - ISSN: 0149-1423

CO - CODEN: AABUD2

AN - ACCESSION NUMBER: 1996-072126

UD - UPDATE CODE: 199622

Registro 4659 de 5614 - GeoRef Disc 4: 1993-1996

TI - TITLE: Seismic and gravity analysis, upper Cauca Basin, Colombia.

AU - AUTHORS: Noel-James-A; Baldwin-Thomas

AF - AUTHOR AFFILIATION: Trinity Gas, USA, United States

BK - BOOK TITLE: In: AAPG international conference and exhibition; abstracts.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: AAPG Bulletin. 80; 8, Pages 1318. 1996.

PB - PUBLISHER: American Association of Petroleum Geologists. Tulsa, OK, United States. 1996.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1996

CN - CONFERENCE INFORMATION: AAPG international conference and exhibition. Caracas, Venezuela. Sept. 8-11, 1996.

LA - LANGUAGE: English

AB - ABSTRACT: The Upper Cauca Basin is the southern portion of the Cauca Basin in western Colombia. It is bounded on the west by the Cordillera Occidental and the Cauca Fault, and on the east by the Cordillera Central and the Romeral Fault. The study area represents 370,000 acres. The basin is a rift valley between the two faults. The rift was probably caused by the westward movement of the South American Plate against the eastward movement of the Caribbean Plate. The gravity survey was completed in 1964 by United Geophysical for Intercol. The seismic work was done by Western Geophysical in 1979 and 1981 for ECOPETROL. Intercol drilled Candelaria in 1965, which penetrated over 3700 feet of Tertiary sandstone, shale, and coal, and bottomed in 400 feet of igneous rock. There are five gravity anomalies of interest: two on the west side, the Vijes and Cali, and three on the east side, the Manulita, Palmira, and Candeleria anomalies. Together the first two are 25 kilometers long, bounded on the west by the Cauca Fault and on the east by the Candeleria Fault, and separated by a transverse fault. The last three are bounded on the west by the Palmira-Buga fault and on the east by the Romeral Fault. Cross faults separate the three and shift the trends. Seismic lines/sections confirm the gravity interpretations. The anomalies are defined and the many faults are obvious. The sections show events arching over the anomalies and pinching out along the flanks and over the crests. The sedimentary section thins over the anomalies and increases to more than twice the thickness in the center of the basin. The seismic sections show that the anomalies are not intrusions but uplifted basement blocks.

DE - DESCRIPTORS: Andes-; basement-tectonics; block-structures; Candelaria-Fault; Caribbean-Plate; Caribbean-region; Cauca-Basin; Cauca-Fault; Central-Cordillera; Colombia-; Eastern-Cordillera; faults-; geophysical-methods; geophysical-surveys; gravity-anomalies; gravity-methods; plate-tectonics; rift-zones; Romeral-Fault; seismic-methods; South-America; South-American-Plate; surveys-; systems-; tectonics-; thickness-; uplifts-; western-Colombia

CC - CATEGORY CODES: 20-Applied-geophysics

DT - DOCUMENT TYPE: Abstract; Serial; Conference-Document

BL - BIB LEVEL: Analytic

RF - REFERENCE SOURCE: GeoRef, Copyright 2000, American Geological Institute. Reference includes data supplied by American Association of Petroleum Geologists, Tulsa, OK, United States

IS - ISSN: 0149-1423

CO - CODEN: AABUD2

AN - ACCESSION NUMBER: 1996-072136

UD - UPDATE CODE: 199622

Registro 4660 de 5614 - GeoRef Disc 4: 1993-1996

TI - TITLE: Mesozoic and Cenozoic plate tectonic setting of the foldbelts of northwestern South America.

AU - AUTHORS: Norton-I-O; Goodman-E-D; Green-A-R

AF - AUTHOR AFFILIATION: Exxon Exploration Company, Houston, TX, United States

BK - BOOK TITLE: In: AAPG international conference and exhibition; abstracts.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: AAPG Bulletin. 80; 8, Pages 1319. 1996.

PB - PUBLISHER: American Association of Petroleum Geologists. Tulsa, OK, United States. 1996.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1996

CN - CONFERENCE INFORMATION: AAPG international conference and exhibition. Caracas, Venezuela. Sept. 8-11, 1996.

LA - LANGUAGE: English

AB - ABSTRACT: Mesozoic tectonic evolution of northern South America was dominated by Jurassic rifting of North America, the Mexico-Mayan blocks and possibly Chortis. Grabens on South America formed in this rift event trend northeast-southwest, following basement grain established during Paleozoic continental collision between North and South America. In Cretaceous time, a passive margin facing the proto-Caribbean formed on South America. Carbonate and clastic sediments forming a wide passive margin wedge prograded over the South American continental margin. Arrival of the Caribbean Plate in Late Cretaceous time only affected the northern margin of South America; the Pacific margin remained tectonically inactive until Oligo-Miocene time. At this time, a plate reorganization in the Pacific resulted in reactivation of the Pacific margin of Ecuador and Colombia. Jurassic grabens were reactivated as strike slip fault zones which moved the Bonaire Block several hundred kilometers to the northeast. Near the end of Miocene time, another Pacific plate reorganization resulted in a change from strike slip to east-west compression along South America. This caused final uplift of the Andes mountain ranges. The influence of these tectonic events on sediment deposition and hydrocarbon play parameters will be discussed in this paper.

DE - DESCRIPTORS: Andes-; basement-tectonics; Bonaire-Block; Caribbean-Plate; Caribbean-region; Cenozoic-; Central-America; Chortis-Block; Colombia-; compression-tectonics; continental-margin; deposition-; Ecuador-; evolution-; faults-; fold-belts; grabens-; Maya-Block; Mesozoic-; Mexico-Block; northwestern-South-America; passive-margins; petroleum-; plate-tectonics; progradation-; reactivation-; rift-zones; South-America; systems-; tectonics-; uplifts-

CC - CATEGORY CODES: 18-Solid-earth-geophysics

DT - DOCUMENT TYPE: Abstract; Serial; Conference-Document

BL - BIB LEVEL: Analytic

RF - REFERENCE SOURCE: GeoRef, Copyright 2000, American Geological Institute. Reference includes data supplied by American Association of Petroleum Geologists, Tulsa, OK, United States

IS - ISSN: 0149-1423

CO - CODEN: AABUD2

AN - ACCESSION NUMBER: 1996-072138

UD - UPDATE CODE: 199622

Registro 4661 de 5614 - GeoRef Disc 4: 1993-1996

TI - TITLE: Upgrading and integrating field work data with templates, remote sensing, and associated technologies.

AU - AUTHORS: Perez-Gildardo; Ellis-James-M

AF - AUTHOR AFFILIATION: Chevron Overseas Petroleum, San Ramon, CA, United States

BK - BOOK TITLE: In: AAPG international conference and exhibition; abstracts.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: AAPG Bulletin. 80; 8, Pages 1323. 1996.

PB - PUBLISHER: American Association of Petroleum Geologists. Tulsa, OK, United States. 1996.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1996

CN - CONFERENCE INFORMATION: AAPG international conference and exhibition. Caracas, Venezuela. Sept. 8-11, 1996.

LA - LANGUAGE: English

AB - ABSTRACT: Remote sensing is a basic tool for interpreting geology, generating basemaps, and planning field programs. However, field work for major projects is becoming more dependent upon contractors who have a variety of training, experience, and methodology. A digitally supported template was developed that minimizes contactor gaps in data collected, inconsistent methodology and terminology, and out-of-context observations. The system utilizes off-the-shelf PC software and portable hardware. Some field data can be customized to easily correlate with well logs utilizing computer-aided drafting (CAD) technology. Satellite imagery for supporting field operations is selected and processed to maximize geological and environmental information. The enhanced image is georeferenced to a specific latitude/longitude and/or UTM Northing/Easting map projection, utilizing ground control points determined with Global Positioning System (GPS). The geologic interpretation of georeferenced images and field work in the Rio Blanco license of Colombia resulted in 1) an improved geologic map with better definition of source-reservoir rock from the hangingwall to the footwall of the main thrust and 2) better surface controlled balanced cross-sections that led to play definition and to improve seismic planning/field parameters design for refining seismic acquisition. Geographical Information System (GIS) technology is being evaluated as an integration tool data to make complex tables of field data, CAD basemaps, interpretation maps, and images more useful to Earth Scientists. The GIS enables users to: 1. examine their field data, maps, and images in a PC-based environment, 2. better understand spatial relationships between field observations, images and geologic maps, 3. interactively query field data while viewing associated images and maps, and 4. ultimately improve database usage, database quality, and geological interpretations.

DE - DESCRIPTORS: CAD-; Colombia-; computer-programs; data-acquisition; data-bases; data-processing; faults-; field-studies; foot-wall; geophysical-methods; geophysical-surveys; Global-Positioning-System; hanging-wall; imagery-; interpretation-; petroleum-; petroleum-exploration; planning-; remote-sensing; reservoir-rocks; satellite-methods; seismic-methods; source-rocks; South-America; surveys-; technology-; thrust-faults; well-logs

CC - CATEGORY CODES: 29A-Economic-geology,-geology-of-energy-sources; 20-Applied-geophysics

DT - DOCUMENT TYPE: Abstract; Serial; Conference-Document

BL - BIB LEVEL: Analytic

RF - REFERENCE SOURCE: GeoRef, Copyright 2000, American Geological Institute. Reference includes data supplied by American Association of Petroleum Geologists, Tulsa, OK, United States

IS - ISSN: 0149-1423

CO - CODEN: AABUD2

AN - ACCESSION NUMBER: 1996-072155

UD - UPDATE CODE: 199622

Registro 4662 de 5614 - GeoRef Disc 4: 1993-1996

TI - TITLE: The evolution of the Piedemonte Llanero petroleum system, Cordillera Oriental, Colombia; 2, Reservoir petrography & petroleum geochemistry.

AU - AUTHORS: Piggott-Neil; Vear-Alwyn; Warren-Edward-A; Graham-Rod; Howe-Spencer; O-Leary-John; Pulham-Andrew-J

AF - AUTHOR AFFILIATION: BP Exploration, London, United Kingdom

BK - BOOK TITLE: In: AAPG international conference and exhibition; abstracts.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: AAPG Bulletin. 80; 8, Pages 1324. 1996.

PB - PUBLISHER: American Association of Petroleum Geologists. Tulsa, OK, United States. 1996.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1996

CN - CONFERENCE INFORMATION: AAPG international conference and exhibition. Caracas, Venezuela. Sept. 8-11, 1996.

LA - LANGUAGE: English

AB - ABSTRACT: Detailed quantification of cements and rock texture, fluid inclusion microthermometry, thermal maturity data, oil-source rock correlations and structural restorations have been integrated to reveal the porosity and hydrocarbon charge evolution of reservoirs in the Piedemonte Llanero thrustbelt of Colombia. Active exploration of deeply buried structures in different thrust sheets of the Piedemonte Llanero has encountered quartz arenites of widely varying average porosities (4-15%). Porosity has been reduced by mechanical compaction and quartz cementation during burial, and by pressure solution during structural deformation. The relative importance and timing of these processes varies between thrust sheets controlling the observed porosity variation. Thermal maturity data indicate that all thrust sheets have been deeply buried and uplifted in several stages of compression. Detailed structural restorations indicate significant differences in the burial histories of individual thrust sheets. Oil-source rock correlations suggest two major hydrocarbon components in the thrustbelt: a Late Cretaceous oil-prone source and a Tertiary oil- and gas-prone source. Initial generation charged early structures leading to partial inhibition of quartz cementation. For most structures quartz cementation predated major hydrocarbon migration. Average quartz cementation temperature is uniform within a structure, but varies between thrust sheets. These variations appear to reflect differences in burial depths during quartz cementation rather than variations in timing. Integration of all data reveals a complex but predictable evolution of porosity and hydrocarbon charge in both space and time which is being applied to current exploration in the Piedemonte Llanero and is relevant to thrustbelt exploration elsewhere.