INTEGRATED USE OF HYDRODYNAMIC, GEOCHEMICAL, AND GEOTHERMAL DATA FOR BASIN-SCALE IDENTIFICATION OF HYDROCARBON GENERATION, MIGRATION PATHS AND MAJOR ACCUMULATIONS, WITH EXAMPLES FROM THE ALBERTA, WILLISTON AND LLANOS BASINS

摘要

Hydrocarbon exploration leads to a collection of stratigraphic, lithologic, rock-properties, hydrody-namic, geothermal, hydrochemical and geochemical data. These data are unevenly distributed, of variable quality, and usually are analyzed separately. Culling erroneous data, deriving additional information, and integration of all the data is conducive to a comprehensive analysis of basin evolution and processes. This provides a basis for the conceptual, large-scale understanding of hydrocarbon generation, migration and accumulation in a basin, which, in turn, could be used as a tool for better-targeted, local-scale exploration and discovery of hydrocarbons.The approach is exemplified for the mature Alberta and Williston basins in Canada and U.S., and the developing Llanos basin in Colombia. Hydrocarbon migration and accumulations in the Alberta basin, including huge tar sands deposits, and in the Williston basin, were controlled by stratigraphy and structure, and by several flow systems driven by different mechanisms. Low rock permeability led to incomplete flushing of the original formation waters, and a conduction-dominated geothermal regime. The Llanos basin is characterized by high rock-permeability, being probably flushed of the original formation waters. The geothermal regime is controlled by both conduction and convection. Hydrocarbons migrated updip and have been flushed out of the basin unless caught in stratigraphic, structural or hydrodynamic traps.