No. Registros Solicitud 1 5614 colombia

AN - ACCESSION NUMBER: 2002-035019

UD - UPDATE CODE: 200212

Registro 574 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Facies & petrophysical 3D modeling, upscale and numerical simulation, reserve implications and recommendations according to production maturity; reservoir characterization of Apiay Field, Llanos Basin, Colombia.

AU - AUTHORS: Nieto-Jorge-E; Salgado-Alejandro

AF - AUTHOR AFFILIATION: Ecopetrol-Columbia, Bogota, Colombia

BK - BOOK TITLE: In: American Association of Petroleum Geologists 2000 annual meeting.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: Annual Meeting Expanded Abstracts - American Association of Petroleum Geologists. 2000; Pages 107. 2000.

PB - PUBLISHER: American Association of Petroleum Geologists and Society of Economic Paleontologists and Mineralogists (AAPG). Tulsa, OK, United States. 2000.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 2000

CN - CONFERENCE INFORMATION: American Association of Petroleum Geologists 2000 annual meeting. New Orleans, LA, United States. Apr. 16-19, 2000.

LA - LANGUAGE: English

AB - ABSTRACT: During the active development of the Apiay Field, many numerical simulations have been attempted to adjust and predict the future production behavior. Through time, it has been noticed that it is progressively more difficult to predict production in this field due to the initial conception of the geological model. As production advances, the presence of barriers tends to be notorious and create substantial implications in the general drainage patterns. Production forecasts from models without detailed perception of heterogeneities are optimistic because of different rock types being grouped into the same grid cell. This first study attempting to subdivide the formerly considered homogenous reservoir started with the recognition of six distinctive lithotypes as a product of the differentiation of thirteen sedimentary facies. In this way, basal cemented and very fine-grained sandstones, and abandoned channel successions conform the main non-permeable facies to model in the fluvial "massive" reservoir. These lithotypes create vertical and lateral restrictions to flow that have been clearly noticed in the current state of production, sometimes restricting water entrance or producing water fingering. The detailed rock type characterization, the effective determination of petrophysical properties along with a right calibration of capillary pressure and relative permeability curves, and the optimum simulation grid considering the internal heterogeneities within the reservoir, have produced a better understanding of production and a more reliable set of predictions in a more heterogeneous reservoir, with uneven saturation profiles through time, all of which has been reflected in different approaches to maximize reserves economically attractive.

DE - DESCRIPTORS: Apiay-Field; calibration-; capillary-pressure; characterization-; clastic-rocks; Colombia-; depositional-environment; development-; drainage-; fluvial-environment; heterogeneity-; lithofacies-; lithotypes-; Llanos-; models-; numerical-analysis; oil-and-gas-fields; optimization-; petroleum-engineering; production-; reserves-; reservoir-properties; sandstone-; sedimentary-rocks; simulation-; South-America; three-dimensional-models

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 2002, American Geological Institute. Reference includes data supplied by American Association of Petroleum Geologists, Tulsa, OK, United States

IS - ISSN: 0094-0038

CO - CODEN: APGAB2

AN - ACCESSION NUMBER: 2002-034621

UD - UPDATE CODE: 200212

Registro 575 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Geochemical characterization of oils in the Colombian basins with commercial production.

AU - AUTHORS: Mora-Cesar; Vaz-dos-Santos-Eugenio

AF - AUTHOR AFFILIATION: Ecopetrol, Bogota, Colombia

BK - BOOK TITLE: In: American Association of Petroleum Geologists 2000 annual meeting.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: Annual Meeting Expanded Abstracts - American Association of Petroleum Geologists. 2000; Pages 101. 2000.

PB - PUBLISHER: American Association of Petroleum Geologists and Society of Economic Paleontologists and Mineralogists (AAPG). Tulsa, OK, United States. 2000.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 2000

CN - CONFERENCE INFORMATION: American Association of Petroleum Geologists 2000 annual meeting. New Orleans, LA, United States. Apr. 16-19, 2000.

LA - LANGUAGE: English

AB - ABSTRACT: Based on geochemical information of 300 oil samples from the Colombian basins with commercial production (Putumayo, Upper Magdalena, Middle Magdalena and Lower Magdalena Valley, Catatumbo and Llanos) an evaluation about oil quality, age and depositional environment of the source rocks as well as level of biodegradation and thermal evolution was made. The quality of the Colombian oils varies largely with API Gravities between 5 degrees and 55 degrees , low concentrations of sulfur, vanadium and nickel and a percentage of saturates hydrocarbon with up to 40% in most cases. In relation to the depositional environments and age of the source rocks, it is concluded that Cretaceous organic facies are predominant and these are deposited in three main environments: marine anoxic with carbonatic influence, marine siliciclastic anoxic to suboxic and marine deltaic suboxic. Only in the Lower Magdalena Valley and Llanos Foothills, oils from Tertiary source rocks, deposited in marine deltaic environments were identified. Oils with higher levels of thermal maturity, corresponding to a late generation phase, are located in the Catatumbo basin. Lower Magdalena Valley and Llanos foothills, while oils with lower maturity level, corresponding to an early generation, are located in the Upper Magdalena Valley. Strong biodegradation processes have left their print in many oils affecting their quality. The most biodegraded oils are located in fields like Rubiales and Castilla, in the Llanos Basin, Teca and Cocorna in the Middle Magdalena Valley and Dina in the Upper Magdalena Valley. Biodegradation processes have been working all along the trap filling history, mixing intensively biodegraded oils with "fresh" hydrocarbons, improving in many cases the oil quality in the reservoirs, but difficulting the geochemical and geological interpretation.

DE - DESCRIPTORS: anaerobic-environment; biodegradation-; Castilla-Field; Catatumbo-Basin; Cenozoic-; characterization-; Cocorna-Field; Colombia-; deltaic-environment; depositional-environment; Dina-Field; genesis-; geochemistry-; hydrocarbons-; interpretation-; lithofacies-; Llanos-; Lower-Magdalena-Valley; marine-environment; metals-; Middle-Magdalena-Basin; mixing-; nickel-; oil-and-gas-fields; organic-compounds; petroleum-; Putumayo-Basin; Rubiales-Field; samples-; saturated-hydrocarbons; source-rocks; South-America; sulfur-; Teca-Field; Tertiary-; thermal-history; thermal-maturity; traps-; Upper-Magdalena-Basin; vanadium-; variations-

CC - CATEGORY CODES: 29A-Economic-geology,-geology-of-energy-sources; 02C-Geochemistry-of-rocks,-soils,-and-sediments

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

BL - BIB LEVEL: Analytic

RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. Reference includes data supplied by American Association of Petroleum Geologists, Tulsa, OK, United States

IS - ISSN: 0094-0038

CO - CODEN: APGAB2

AN - ACCESSION NUMBER: 2002-034591

UD - UPDATE CODE: 200212

Registro 576 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: The oil and gas frontiers for exploration in South America.

AU - AUTHORS: Mello-Marcio-Rocha

AF - AUTHOR AFFILIATION: Universidade Rio de Janeiro, Rio de Janeiro, Brazil

BK - BOOK TITLE: In: American Association of Petroleum Geologists 2000 annual meeting.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: Annual Meeting Expanded Abstracts - American Association of Petroleum Geologists. 2000; Pages 97. 2000.

PB - PUBLISHER: American Association of Petroleum Geologists and Society of Economic Paleontologists and Mineralogists (AAPG). Tulsa, OK, United States. 2000.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 2000

CN - CONFERENCE INFORMATION: American Association of Petroleum Geologists 2000 annual meeting. New Orleans, LA, United States. Apr. 16-19, 2000.

LA - LANGUAGE: English

AB - ABSTRACT: As a result of the giant oil discoveries in the Brazilian and Subandean sedimentary basins over the past few years, major oil companies have started to explore new petroleum systems in South America. The end of national oil monopolies has intensified interest in exploration, as oil companies recognize that these basins represent some of the best frontiers for the appropriation of large oil reserves. A detailed geochemical and biological marker investigation of he most important oil provinces in South American highlights the similarities and differences between the petroleum habitats of major Paleozoic and Mezosoic/Cenozoic sedimentary basins. The study included 200 oil samples from reservoirs ranging in age from Devonian to Miocene, and 100 selected source rocks of the same ages. This approach allowed correlation between the oils and source rocks, in order to determine the factors that control their composition and provenance (e.g. paleoenvironments of deposition and age the source rocks, thermal evolution, biodegradation stage and geographic distribution). The results indicate that most of the hydrocarbons discovered to date were generated from source rocks deposited in seven main types of hypoxic-anoxic lacustrine to marine paleoenvironments, ranging in age from Frasnian to Miocene. These are: lacustrine freshwater, lacustrine brackish-saline water, marine siliciclastic, marine carbonate, marine anoxic with predominance of calcareous mudstone lithology, and marine deltaic with predominance of either siliciclastic or carbonate rocks. Based on the oil types detected, the most promising frontiers for exploration are offshore Venezuela, targeting marine carbonate Upper Cretaceous oils, and offshore deep water Brazil, onshore Venezuela, and Colombia targeting marine deltaic oils.

DE - DESCRIPTORS: anaerobic-environment; Andes-; basins-; biodegradation-; biomarkers-; brackish-water-environment; Brazil-; Colombia-; deep-water-environment; deposition-; depositional-environment; fresh-water-environment; geochemistry-; lacustrine-environment; marine-environment; natural-gas; offshore-; paleoenvironment-; petroleum-; petroleum-exploration; provenance-; sedimentary-basins; source-rocks; South-America; spatial-distribution; thermal-history; Venezuela-

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 2002, American Geological Institute. Reference includes data supplied by American Association of Petroleum Geologists, Tulsa, OK, United States

IS - ISSN: 0094-0038

CO - CODEN: APGAB2

AN - ACCESSION NUMBER: 2002-034574

UD - UPDATE CODE: 200212

Registro 577 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Fractured reservoirs in calcareous rocks of the Middle Magdalena Basin, Colombia.

AU - AUTHORS: Linares-Roberto

AF - AUTHOR AFFILIATION: Ecopetrol, Bucaramanga, Colombia

BK - BOOK TITLE: In: American Association of Petroleum Geologists 2000 annual meeting.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: Annual Meeting Expanded Abstracts - American Association of Petroleum Geologists. 2000; Pages 86. 2000.

PB - PUBLISHER: American Association of Petroleum Geologists and Society of Economic Paleontologists and Mineralogists (AAPG). Tulsa, OK, United States. 2000.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 2000

CN - CONFERENCE INFORMATION: American Association of Petroleum Geologists 2000 annual meeting. New Orleans, LA, United States. Apr. 16-19, 2000.

LA - LANGUAGE: English

AB - ABSTRACT: The Middle Magdalena Basin of Colombia has been explored since the beginning of this century. The most important reservoirs are La Paz Fm. (Eocene), Mugrosa Fm. (Oligocene) and Colorado Fm. (Oligocene). The hydrocarbon potential of the Cretaceous rocks has also been identified by some wells in La Luna, Rosablanca and Cimarrona Formations. Those wells tested the hydrocarbon potential that remains untouched in the basin for calcareous rocks. The goal of this study is to identify the fracture framework of the calcareous rocks that will simplify exploitation of fractured reservoirs in the basin. This work integrates outcrop data, radar images, aerial photographs, seismic and well information. The Cretaceous sediments have been deformed into a variety of map-scale structures in a compressional structural setting, thus providing a series of natural experiments for observing the formation, distribution, and behavior of fractures in these carbonate units. The structural position plays a great role in the overall fracture character and density in the folded and faulted Cretaceous carbonates of the Middle Magdalena Basin. Two northeast-striking fracture sets dominate the Rosablanca Formation, a longitudinal and a conjugate set; the latter is more important because it improves the porosity and permeability of the reservoirs. These sets are interpreted as formed during Miocene event of deformation of the Eastern Cordillera. In this way a new insight is given for reducing the exploratory risk of the new prospects interpreted in the basin.

DE - DESCRIPTORS: aerial-photography; Andes-; calcareous-composition; carbonate-rocks; Cenozoic-; Cimarrona-Formation; Colombia-; Colorado-Formation; compression-tectonics; Cretaceous-; deformation-; Eastern-Cordillera; Eocene-; exploitation-; faults-; folds-; geophysical-methods; geophysical-surveys; history-; imagery-; La-Luna-Formation; La-Paz-Formation; Mesozoic-; Middle-Magdalena-Basin; Mugrosa-Formation; naturally-fractured-reservoirs; oil-wells; Oligocene-; outcrops-; Paleogene-; permeability-; petroleum-; petroleum-exploration; porosity-; radar-methods; remote-sensing; reservoir-rocks; Rosablanca-Formation; sedimentary-rocks; seismic-methods; South-America; strike-; surveys-; tectonics-; Tertiary-; testing-; 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 2002, American Geological Institute. Reference includes data supplied by American Association of Petroleum Geologists, Tulsa, OK, United States

IS - ISSN: 0094-0038

CO - CODEN: APGAB2

AN - ACCESSION NUMBER: 2002-034522

UD - UPDATE CODE: 200212

Registro 578 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: New opportunities for oil accumulation in the upper Magdalena Valley, Colombia, South America.

AU - AUTHORS: Kairuz-E-C; Cordoba-F; Ferreira-P; Solano-O

AF - AUTHOR AFFILIATION: Ecopetrol, Santa Fe de Bogota, Colombia

BK - BOOK TITLE: In: American Association of Petroleum Geologists 2000 annual meeting.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: Annual Meeting Expanded Abstracts - American Association of Petroleum Geologists. 2000; Pages 76. 2000.

PB - PUBLISHER: American Association of Petroleum Geologists and Society of Economic Paleontologists and Mineralogists (AAPG). Tulsa, OK, United States. 2000.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 2000

CN - CONFERENCE INFORMATION: American Association of Petroleum Geologists 2000 annual meeting. New Orleans, LA, United States. Apr. 16-19, 2000.

LA - LANGUAGE: English

AB - ABSTRACT: The Upper Magdalena Basin is one of the most prolific and active oil basins in Colombia. Two hundred five exploratory wells have been drilled in this basin, with 36 oil fields discovered. Proved reserves amount to 631 MBO and 123 GPCG. Structural and geochemical regional studies have shown a large variety of structural and stratigraphic potential oil traps that have not been drilled. On the other hand, a large amount of generated hydrocarbons, not discovered yet, have been estimated. Most of the discovered oil fields corresponds to accumulations in structural traps located in the hanging wall of structures associated with thrust systems and good clastic cretaceous reservoirs. A few fields are associated to stratigraphic traps in tertiary units. Regional structural review allowed us to identify a remaining high exploration potential in subthrust structural traps, as well as in stratigraphic traps in the tertiary sequence. Fractures in the calcareous cretaceous sequence constitute a new exploratory target which has been proven successfully. A mass balance calculation on new geochemical data along with identification of generation pods, have shown that there are a high amount of generated hydrocarbons still undiscovered. The combination of the above mentioned factors: structures not drilled and estimated undiscovered hydrocarbons reinforce the high exploratory potential of the Upper Magdalena Basin. Additionally the availability of oil infrastructure in the basin makes more attractive the exploration activity.

DE - DESCRIPTORS: Cenozoic-; clastic-rocks; Colombia-; faults-; genesis-; geochemistry-; Magdalena-Valley; oil-wells; petroleum-; petroleum-accumulation; petroleum-exploration; reserves-; reservoir-rocks; sedimentary-rocks; South-America; stratigraphic-traps; structural-traps; Tertiary-; thrust-faults; traps-; Upper-Magdalena-Basin

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 2002, American Geological Institute. Reference includes data supplied by American Association of Petroleum Geologists, Tulsa, OK, United States

IS - ISSN: 0094-0038

CO - CODEN: APGAB2

AN - ACCESSION NUMBER: 2002-034474

UD - UPDATE CODE: 200212

Registro 579 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Obertriassische Ammoniten der unteren Saldana-Formation (Chicala-Schichten) bei Payande, Provinz Tolima, Kolumbien

Translated Title: Upper Triassic Ammonites from the lower Saldana Formation (Chicala Beds) near Payande Tolima, Colombia.

AU - AUTHORS: Prinz-Grimm-Peter; Mojica-Jairo

AF - AUTHOR AFFILIATION: Universidad Nacional de Colombia, Bogota, Colombia

BK - BOOK TITLE: In: Herrn Prof. Dr. rer. nat. habil. Otto Franz Geyer zu seinem 75. Geburtstag gewidmet

Translated Title: In honor of Dr. Otto Franz Geyer on his 75th birthday.

BA - BOOK AUTHORS: Krautter-Manfred (editor); Seyfried-Hartmut (editor)

SO - SOURCE: Profil. 16; Pages 21-33. 1999.

PB - PUBLISHER: Institut fuer Geologie und Palontologie Universitaet Stuttgart. Stuttgart, Federal Republic of Germany. 1999.

CP - COUNTRY OF PUBLICATION: Federal-Republic-of-Germany

PY - PUBLICATION YEAR: 1999

LA - LANGUAGE: German

LS - LANGUAGE OF SUMMARY: Spanish

DE - DESCRIPTORS: Ammonites-; Ammonoidea-; biogeography-; biostratigraphy-; Cephalopoda-; Chicala-Beds; clastic-rocks; Colombia-; igneous-rocks; Invertebrata-; Magdalena-Valley; Mesozoic-; Mollusca-; Payande-Tolima-Colombia; pyroclastics-; Saldana-Formation; sandstone-; sedimentary-rocks; siltstone-; South-America; Tetrabranchiata-; Triassic-; Upper-Triassic; volcanic-rocks

CC - CATEGORY CODES: 12-Stratigraphy

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

IL - ILLUSTRATION: Refs: 26; sects., strat. col., geol. sketch maps.

RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. Reference includes data from Geoline, Bundesanstalt fur Geowissenschaften und Rohstoffe, Hanover, Germany

IS - ISSN: 0941-0414

AN - ACCESSION NUMBER: 2002-033943

UD - UPDATE CODE: 200212

Registro 580 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: 30 Jahre im Leben eines karibischen Korallenriffes

Translated Title: Thirty years in the life of a Caribbean coral reef.

AU - AUTHORS: Geister-Joern

AF - AUTHOR AFFILIATION: University of Bern, Bern, Switzerland

BK - BOOK TITLE: In: Herrn Prof. Dr. rer. nat. habil. Otto Franz Geyer zu seinem 75. Geburtstag gewidmet

Translated Title: In honor of Dr. Otto Franz Geyer on his 75th birthday.

BA - BOOK AUTHORS: Krautter-Manfred (editor); Seyfried-Hartmut (editor)

SO - SOURCE: Profil. 16; Pages 1-11. 1999.

PB - PUBLISHER: Institut fuer Geologie und Palontologie Universitaet Stuttgart. Stuttgart, Federal Republic of Germany. 1999.

CP - COUNTRY OF PUBLICATION: Federal-Republic-of-Germany

PY - PUBLICATION YEAR: 1999

LA - LANGUAGE: German

LS - LANGUAGE OF SUMMARY: English

DE - DESCRIPTORS: Anthozoa-; Atlantic-Ocean; Caribbean-Sea; Cenozoic-; Coelenterata-; Colombia-; Holocene-; Invertebrata-; modern-; North-Atlantic; pollution-; protection-; Quaternary-; reef-builders; reefs-; San-Andres-Island; South-America

CC - CATEGORY CODES: 10-Invertebrate-paleontology

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

IL - ILLUSTRATION: Refs: 8; illus. incl. geol. sketch map.

RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. Reference includes data from Geoline, Bundesanstalt fur Geowissenschaften und Rohstoffe, Hanover, Germany

IS - ISSN: 0941-0414

AN - ACCESSION NUMBER: 2002-033942

UD - UPDATE CODE: 200212

Registro 581 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Seabed piston coring; a cost-effective means of assessing petroleum charge, offshore Colombia.

AU - AUTHORS: Deckelman-James-A; Huizinga-Bradley-J

AF - AUTHOR AFFILIATION: ARCO Latin America, Plano, TX, United States

BK - BOOK TITLE: In: American Association of Petroleum Geologists 2000 annual meeting.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: Annual Meeting Expanded Abstracts - American Association of Petroleum Geologists. 2000; Pages 37. 2000.

PB - PUBLISHER: American Association of Petroleum Geologists and Society of Economic Paleontologists and Mineralogists (AAPG). Tulsa, OK, United States. 2000.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 2000

CN - CONFERENCE INFORMATION: American Association of Petroleum Geologists 2000 annual meeting. New Orleans, LA, United States. Apr. 16-19, 2000.

LA - LANGUAGE: English

AB - ABSTRACT: In 1998, ARCO and Amoco carried out a Seabed Piston Coring Program in the Los Galeones/La Fragata Contract Areas, offshore Lower Magdalena Basin, Colombia. The purpose of the program was to determine if a working liquid petroleum system was present in these areas and, if so, to determine if the petroleum was generated by Cretaceous, Tertiary, or a combination of both sources. Sediment soluble extracts from 76 cores were analysed using total scanning fluorescence (TSF), C15+ gas chromatographic, GC-MS, and headspace-gas data. These data indicated that 12 cores contained thermogenic gas and/or gas condensate, four cores contained strong shows of oil, and 16 cores contained weak shows of oil. The oils or condensates were moderately to highly biodegraded and, in most cases, seepage of gas, oil and condensate was associated with mud diapirs or faults. Cores containing gas and gas condensate were concentrated in the northern part of the survey area; cores containing oil were concentrated in the southern part of the survey area. Biomarker data indicate that Tertiary strata solely or dominantly sourced the oil in these cores. Cumulative expulsion modeling based on geochemical data from the adjacent onshore area indicates that Tertiary source rocks are likely to generate gas and minor amounts of oil, whereas Cretaceous source rocks are more oil-prone and generate substantially less gas. This is consistent with production from onshore fields in that those fields with known Tertiary (Oligo-Miocene) sources produce gas and gas condensate with subordinate amounts of oil. If the Tertiary sequence is the dominant source of petroleum in the offshore domain and if onshore-to-offshore source facies variation is minimal, oil will be present, but in quantities that are volumetrically insignificant with respect to gas, in the offshore Lower Magdalena Basin.