QUANTITATIVE MODELING OF PETROLEUM SYSTEMS AND BASIN PROCESSES: PAST, PRESENT, AND FUTURE

Basin modelling has loosely been defined as the numerical modelling of any process that takes place in a basin. Petroleum basin modelling was originally developed and used by oil companies to quantitatively understand the generation, migration, and accumulation of hydrocarbons in basins to better predict the location, type, and amount of oil and gas. More recently, basin models have become more widely available and they are now being used to study a variety of physical, chemical, and thermal processes affecting basins.

On the surface, basin modelling seems like an impossible task. Models must account for one or more fluids including: water, brine, oil, and different gases. These fluids can be driven by a variety of different driving forces such as: topography, compaction, lateral tectonic loading, buoyancy (both convection and compositionally driven), and possibly by osmosis. Each of these processes can take place over lengthy time scales, cover vast areas and great depths, involve significant temperature variations, and occur in every possible geologic setting. Combinations of the above driving forces can occur sequentially or simultaneously. Finally, the present day conditions in a basin are only one snapshot of the basin’s history. Some basins are dominated by remnants of processes that do not even exist today (e.g., erosion and glaciation).

Remarkable progress has been made in the past 25 years towards the integrated goal of basin modelling. Advances in understanding of the constituent processes and in computer power (speed and memory) have led to the availability of one, two, and three-dimensional models that incorporate deforming rock frameworks, multiphase fluid flow, heat transport, and sophisticated models of hydrocarbon generation. Cutting edge models are attempting to incorporate fully-coupled reactive solute transport, “full physics” hydrocarbon migration, salt tectonics, different tectonic regimes (e.g. faulting, thrusting, glacial loading, etc.), better geothermometers and geobarometers , and many other useful features.

The future for petroleum basin modelling is bright. Lack of calibration data and ever-present limits on computer speed, memory, and storage, appear to be some of the few remaining barriers to wider application of this extremely useful technology.