Thermal Evolution

The thermal model includes anisotropic conductive heat transfer and convective heat transport by migrating brine, oil, and gas in all three dimensions. The in-situ heat generation from radiogenic heat in the sediments is also included.

The thermal conductivity of the sediments is modeled from a volumetric geometric mean between solid rock, brine, oil, and gas. The thermal conductivity of the solid rock is modeled by a linear-hyperbolic temperature relation. In the multi-phase simulation the fluid thermal conductivity is tied to the heat capacity at constant volume, the average molecular speed, and the average mean collision free path calculated from the EoS. In the non multi-phase simulation the thermal conductivity of brine is modeled by a parabolic temperature relation, and the thermal conductivity of oil and gas is modeled by a linear temperature relation.

The upper thermal boundary is retrieved from a data base on plate tectonics and global paleo surface temperatures. Digital paleo geographic maps are used to reconstruct the plate trajectory and from this the paleo latitude of the basin. Tabulated values of global surface temperatures and latitude in paleo time are then used to get the paleo surface temperature of the basin.

The paleo surface temperature is also corrected for the temperature decrease in the water using average gradients for the upper, the middle, and the lower water depth zone (Brun, 1957).