Using gas geochemistry to delineate structural compartments and assess petroleum reservoir-filling directions: A Venezuelan case study

Here we examined the light hydrocarbon and nitrogen content and isotopic signatures of eleven gaseous samples in order to evaluate lateral intra-reservoir continuity in a Venezuelan reservoir in the central area of Lake Maracaibo Basin. At least three single compartments, located in the northern-cen...

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Detalhes bibliográficos
Autores: Márquez Martínez, Gonzalo, Escobar, Marcos, Lorenzo García, Erica, Gallego, Jose Ramón, Tocco, R.
Tipo de documento: artigo
Data de publicação:2013
País:España
Recursos:Universidad de Huelva (UHU)
Repositório:Arias Montano. Repositorio Institucional de la Universidad de Huelva
Idioma:inglês
OAI Identifier:oai:ariasmontano.uhu.es:10272/24906
Acesso em linha:https://hdl.handle.net/10272/24906
Access Level:Acceso aberto
Palavra-chave:Isotope Geochemistry
Reservoir compartment
hydrocarbon gas composition
Nitrogen
C1-C4 alkanes
2506.12 Geología del Petróleo
2503.07 Geoquímica Orgánica
Descrição
Resumo:Here we examined the light hydrocarbon and nitrogen content and isotopic signatures of eleven gaseous samples in order to evaluate lateral intra-reservoir continuity in a Venezuelan reservoir in the central area of Lake Maracaibo Basin. At least three single compartments, located in the northern-central and southern parts of the reservoir, are revealed by nitrogen concentrations showing clear step-like compositional breaks. The occurrence of step-breaks was also supported by the isotopic signature of individual hydrocarbon compounds in the range of C1 to C4 alkanes. Samples presented only slight differences in N2 and hydrocarbon gas compositions within the central and northern parts of the reservoir, and therefore it was not possible to infer structural barriers in coherence with the geological section. Some oil bulk parameters corroborate gradual changes that provide additional information on the reservoir-filling history, thus suggesting that the lateral physical-chemical equilibrium of fluids was not reached in this reservoir.