Espírito Santo Basin

Integrated Study of The Petroleum Systems

GEOCHEMICAL SOLUTIONS INTERNATIONAL INC. (GSI) is conducting a new geochemical study of oils in the Espírito Santo basin aimed at identifying and comparing the petroleum systems that have contributed to accumulations in this petroliferous basin. Forty-five crude oils from 31 wells will be analyzed using state-of-the-art oil fingerprinting techniques 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.

Oil geochemistry is a fundamental component of any regional exploration and production program. It can be used to determine the number of discrete sources in a basin and their respective stratigraphic and areal distribution, source age, lithology, depositional environment (marine, non-marine, lacustrine) and thermal maturity. Areas with overlapping petroleum systems can be identified in relation to possible oil mixing from two or more sources. Mapping source-related oil families is the first step toward understanding and predicting the lateral extent of oil fields and regional oil quality variations in different parts of the basin.

The extent of processes that act to modify the original composition of oils, such as biodegradation and oil mixing, can also be assessed. This is a fundamental issue in the Espírito Santo basin, because the effect of these processes is widespread and significantly degrades oil quality. Because oil quality can impact exploration economics at both the prospect and basin-wide scale, it is imperative to gain a firm understanding of the factors that govern it prior to acquiring acreage or drilling a well.

Deliverables for this study will consist of printed data volumes summarizing the analytical results in addition to an interpretative final report. The final report will contain a synthesis and interpretation of all information provided including oil-oil and oil-source rock correlations, thermal maturity, and oil quality. All geochemical data will also be provided in digital format in a database contained on CD, which will include a proprietary data browser to facilitate access.