The Search for a 'Definitive' Tectonic Model for the Gulf of Mexico Basin—Innovative Solutions from Potential Field Data

John M. Jacques, Simon E. Williams, and J. Derek Fairhead
Getech, Leeds, United Kingdom

Despite the Gulf of Mexico Basin attracting enormous amounts of investment, involving some of the most advanced exploration and drilling techniques seen anywhere in the world, there is still great uncertainty in the basin's tectonic evolution. By far the most important and controversial is how did the basin open during the Mesozoic and what were the mechanistic crustal processes operating. What floors the central Gulf of Mexico Basin – is it oceanic or highly attenuated continental crust? How and when was it created? How thick is it and how far does it extend? Where are the basement highs and lows, and how thick are its sediments? All these unresolved questions have a direct influence on our understanding of the most elementary elements of the basin's petroleum systems.

To address some of these questions, we have combined gravity and magnetic data with a variety of complimentary datasets (seismic and well). Qualitative techniques include the interpretation of gravity to define basin geometry and depth-to-basement, and magnetics to define the spatial extent and depth of basement structures. Quantitative techniques include: gravity/magnetic data enhancements, modelling and inversion techniques; spatial derivatives; 2-D gravity/magnetic profile modelling; 2-D and 3-D forward gravity/magnetic modelling, constrained by seismic, well data and inversion modelling techniques (Spectral Methods, Euler and Local Wavenumber Methods); Pseudolithology mapping; and continental-scale plate tectonic modelling of the gravity/magnetic data to test alternative models.

The resultant structural/geological framework has been used to create a regional ‘palaeotectonic-template' for predicting the contemporary distribution of play elements (source, reservoir and seal).

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005