Coupled Ocean-Atmosphere Global Paleo-Climate Modeling for Source Rock Prediction in Frontier Basins

Daniel R. Burggraf¹, James P. Harris², John Suter¹, Nick Stronach², Bradley J. Huizinga¹, Rob Crossley², Paul J. Markwick³, Frank Richards², Samir Ghazi¹, Tim Hudson², Paul Valdes⁴, and Roger Proctor^5
1 ConocoPhillips, Houston, TX
² Fugro-Robertson Ltd, Llandudno, United Kingdom
³ Getech, Leeds, United Kingdom
⁴ University of Bristol, Bristol, United Kingdom
⁵ Proudman Oceanographic Laboratory, Liverpool, United Kingdom

Frontier exploration programs have historically relied on direct measurement of some aspect of source rock presence(surface geochemistry, basin margin outcrop sampling, etc.) but lacked objective source rock prediction methodologies. Such a process-based quantitative predictive methodology has been developed, using robust global reconstructions of paleogeography, paleotopography and paleobathymetry, coupled with state-of-the-art Earth System modeling.

For each of five Mesozoic or Cenozoic time slices representing known source rock intervals developed during either icehouse or hothouse conditions, critical maps providing boundary conditions for the numerical modeling were prepared. Predictive masks derived from spatial analysis of organic-matter enrichment and dilution processes interpreted from the modeling results, successfully predict the likelihood of source rock development at the basin level for more than 80 percent of the known source rock occurrences in the time slices evaluated.

While earlier industry investigations of paleoclimate control on source rock development have been made, several new elements critical to the present study are the availability of 1) extensive global databases to control depositional settings integral to the development of reliable paleogeography, and environment; 2) state-of-the-art coupled ocean-atmosphere GCMs (general circulation models) to simulate paleoclimate (HadCM3), and a barotropic numerical model for simulating paleotidal forcing; 3) fast and relatively inexpensive computing allowing appropriate cycle-time for obtaining modeling results; 4) robust and flexible GIS (geographic information system) applications for building and viewing input, analyzing output through spatial processing, and displaying final results. Fugro-Robertson Ltd developed the methodology as a proprietary study for ConocoPhillips.