Geochemical Solutions International (GSI) has expanded its 2015 geochemical study of oils from the basins along the Equatorial Margin of Brazil. The original study, designed to identify and compare the petroleum systems that have contributed to accumulations in Foz do Amazonas, Pará Maranhão, Barreirinhas, Ceará and Potiguar, included nearly 250 crude oils representing the major fields and producing horizons. Fifteen new oils mainly from discovery wells in deepwater Ceará and Potiguar have been analyzed using state-of-the-art oil fingerprinting techniques (see Northeast Brazil Oil study prospectus). These data were used to evaluate the major factors governing oil quality and quantity including: (1) source facies, (2) thermal maturity, (3) distance of migration from source to trap, (4) extent and timing of biodegradation, and (5) degree of oil mixing.
We have also conducted a geochemical characterization of potential source rock samples from the Foz do Amazonas, Pará Maranhão, Ceará, and Marajo basins located along the equatorial margin of Brazil. Samples included in this study represent rift, transition, drift, and passive margin sections. This study was designed to evaluate the organic richness, hydrocarbon-generating potential, oil proneness, and thermal maturity level of all potential source rock intervals in each of the four basins in order to assist exploration efforts in the less developed regions. This was accomplished by the detailed geochemical analysis of approximately one hundred and fifty (150) well cuttings and/or core samples. These samples were selected based on total organic carbon (TOC) data from more than 8,500 samples representing more than 180,000 m of section from more than 80 wells.
Crude oil and source rock analyses were performed at BRI-DGSI laboratories in Houston. The analytical data and the associated interpretative report are available for immediate delivery.
Results of the study are presented in both analytical and interpretive formats to ensure that all findings are accessible to explorationists and research personnel. All geochemical data will be provided in digital format in a database contained on CD that includes a proprietary data browser to facilitate access. A synthesis and interpretation of all information is presented in a series of comprehensive final reports including oil-oil and oil-source rock correlations, oil quality, hydrocarbon source potential, oil proneness, and thermal maturity.