Insights from Basin Modeling on Dynamics of Hydrocarbon Systems and Distribution of Material Plays

Nourse, Rod¹, Robin Hamilton¹, John Stainforth², Larry Garmezy³ (1) Shell International, Houston, TX (2) Shell Deepwater Services, Houston, (3) Shell International, Houston, Albania

Detailed, basin-wide, petroleum system models provide valuable insights into the extent and controls on hydrocarbon plays. This can be demonstrated from a variety of settings from rifts, passive margins through to foreland basins. The models permit rapid scenario testing to facilitate identification of the key play-making parameters. These considerations focus attention on the charge rate, tank size and leakage rate controlling factors in a play and suggest the basis for a simple classification of petroleum plays.

Factors affecting rate of hydrocarbon charge include source rock richness, temperature history and charge capture area, all of which can be measured, estimated or modeled. Rate of hydrocarbon leakage from traps may occur via multiple parallel methods and with rates that change through time due to constantly evolving regimes of hydrocarbon column length, overburden, temperature/pressure and permeability. Leakage rate phenomena are therefore consistently more difficult to analyze than charge rate phenomena.

A further important control is the pore volume of the array of hydrocarbon traps into which charge from a given capture area can be distributed – these “tank volumes” have a direct effect on the spillage of hydrocarbons from full traps and on many of the key leakage parameters and so affect, amongst others, column lengths, hydrocarbon phase and oil/gas properties.