--> Abstract: Application Of Sandstone Diagenetic Modeling To Reservoir Quality Assesment Of The Misoa Formation, Bachaquero Field, Maracaibo Basin, Venezuela, by R. Perez, S. Ghosh, J-Y. Chatellier, and R. Lander; #90928 (1999).

Datapages, Inc.Print this page

PEREZ, RENEE1, SANTOSH GHOSH2, JEAN-YVES CHATELLIER1, and ROBERT LANDER3
1PDVSA-Intevep, Los Teques, Venezuela
2PDVSA-Exploracion Venezuela
3Gelogica, Stavanger, Norway

Abstract: Application of Sandstone Diagenetic Modeling to Reservoir Quality Assesment of the Misoa Formation, Bachaquero Field, Maracaibo Basin, Venezuela

The Bachaquero field is one of the largest Maracaibo Basin oil fields, produces from Miocene sandstones. The largely unexplored Eocene Misoa Formation was the subject of study to establish the potential reservoir quality and hydrocarbon potential. Numerical models of sandstone compaction and cementation were used toghether with basin models in our assessment.

Sedimentologic studies of cores indicate that the upper Misoa Formation is composed of shallow marine and tidal influenced deltaic deposits. Petrographic analysis indicated that the quartz arenites of the upper Misoa Formation are the most porous and hence, the greatest prospectivity. Quartz cement and compaction are the dominant controls on reservoir quality. Fluid inclusion homogenization temperatures from quartz overgrowths ranges from 110°C to 115°C. Numerical simulation of quartz precipitation shows an excellent match with the microthermometry and observed quartz cement from high resolution cathodoluminescence analysis. Model results indicate slow rate of quartz precipitation in the Misoa during the first period of oil expulsion from the underlying La Luna source rock, indicating good reservoir quality during the initial charge. Gas shows and thermal modeling indicate that high temperatures associated with deeper burial during the Miocene, resulted in cracking of oil to gas within Misoa Formation reservoirs.

Modeling indicates that the Misoa Formation has gas potential in quartz cemented, low porosity sandstones within the study area. Kinetic modeling of reservoir evolution provides needed constraint for the petroleum geological models and was the basis for recognition of reservoir potential of Misoa Formation as a new gas play within the area.

AAPG Search and Discovery Article #90928©1999 AAPG Annual Convention, San Antonio, Texas