Deep Petroleum Systems Of The Northern Gulf Of Mexico Shelf
GEOCHEMICAL SOLUTIONS INTERNATIONAL, INC. (GSI) and BASELINE/DGSI INC. are offering a non-exclusive, multi-client study of the deep petroleum systems of the Gulf of Mexico (GOM) Shelf. The GOM Shelf is a mature hydrocarbon province that has yielded 10 billion barrels of oil and 140 TCF of gas, largely from Plio-Pleistocene and Miocene reservoirs. Recent royalty incentives have generated a renewed interest in deep exploration on the GOM Shelf. The high drilling and completion costs of a deep well make an understanding of the operative petroleum systems a key aspect of charge risking for prospective targets.
The principal hydrocarbon sources on the GOM Shelf vary from Upper Jurassic carbonates to Lower Cretaceous carbonates and shales to Lower Tertiary shales. Their g is based largely on geochemical analysis of biological markers in oils. However, many shelf oils have a complex migration and charge history involving a variable combination of gas washing, biodegradation, phase separation and mixing with re-migrated or late-mature condensate. In some cases, the sources that resulted in an accumulation, in particular the origin of the lighter hydrocarbons, may not be reflected entirely by biomarkers, which are more representative of the C15+ oil phase. For example, a reservoir fluid consisting of early, biodegraded oil and late-mature or re-migrated gas condensate would exhibit primary biomarker characteristics of the oil source.
The proposed study will focus on a re-assessment of GOM shelf petroleum systems based on analysis of over 120 key oils. In addition to routine geochemical parameters (i.e. biomarkers), several novel approaches to source correlation and thermal maturity assessment will be employed including the use of diamondoids. Diamondoids are source-specific hydrocarbons of exceptional thermal stability. Their semi-volatile nature makes them particularly useful for detecting late gas and gas condensate charge in mixed oils, which would go unrecognized by conventional methods. Regional distributions of these high maturity products in shallow reservoirs may also identify areas with better deep hydrocarbon prospectivity. Diamondoid-based source and maturity indications will be compared with those indicated by heavier hydrocarbons to evaluate whether an accumulation has multiple origins.
Deliverables include printed analytical data volumes and an interpretative final report containing regional maps of principal oil families, lateral and vertical variations in thermal maturity, and assessment of post-generative alteration. All geochemical data and data products will be provided in digital format on CD in a relational database. In addition, primary and reduced data will be distributed as geospatial-referenced formats to facility import into internal map-based applications.
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