Neuquen Basin

Petroleum Geochemistry of Crude Oils and Source Rocks from The Neuquen Basin, Argentina

GEOCHEMICAL SOLUTIONS INTERNATIONAL and URIEN & ASSOCIATES have conducted an evaluation of the petroleum systems active in the Neuquen Basin of Argentina. This study was designed to provide an understanding of the origin of liquid and gaseous hydrocarbons in order to assist exploration efforts in the less developed regions. It has been accomplished by the geochemical analysis of 160 crude oil samples representing the major stratigraphic horizons. Outcrop and cuttings samples representing the principal source horizons have also been analyzed.

Each crude oil sample has been characterized through the use of a detailed analytical program including API Gravity, weight percent sulfur, oil composition (% saturate and aromatic hydrocarbons and polar compounds), stable carbon isotopes (whole oils, saturates and aromatics), whole oil gas chromatography (GC), and quantitative biomarker analysis of saturate and aromatic fractions by gas chromatography/mass spectrometry (GC/MS). Selected samples have been analyzed by GC/MS/MS. Results have been used to develop an understanding of how generative petroleum systems, maturity, and biodegradation affect oil quantity and quality in the Neuquen Basin. This information together with available source rock data has been used to 1) Determine the number of distinct oil families and determine the age and paleoenvironment of the associated source rocks, 2) Map the stratigraphic and geographic distribution of the oil families and distinguish areas where oil mixing has occurred, 3) Assess oil quality with respect to alteration by bacteria or by water washing, 4) Identify distinct kitchen areas and estimate migration directions by comparing oil family distributions with the location of known source rocks, and 5) Utilize the geographic, stratigraphic and structural distribution of the oil families to identify, map, and rank petroleum systems.

Oil analyses have been performed at the state-of-the-art laboratory at CEGEQ in Rio de Janeiro and oil families determined through the use of multivariate statistical analyses of the available data. Detailed age- and source-facies biomarker analyses have been performed using GC/MS/MS on selected samples from each oil family. Diamonoid analyses have also been conducted on selected samples. The analytical data and the final interpretive report are complete and ready for immediate delivery. Data products also include maps showing the distribution of oil families, interpreted source rock kitchens, and inferred migration pathways and associated petroleum systems.

This project is complete and available for immediate delivery.