Temperature modelling

Palaeo-temperature regime is considered important for many reasons. The temperature distribution of a sedimentary basin controls the generation, expulsion and migration of hydrocarbons, it governs the rate of diagenetic reactions, such as the transition from opal to quartz, and it controls the viscosity of the oil and in fact also the basin subsidence.

For a successful reconstruction of the palaeo-temperature in a sedimentary basin, it is imperative that the thermal properties of the rocks are known in detail. One of the most important parameters for determining the temperature regime of an offshore sedimentary basin is the thermal conductivity of sedimentary rocks.

Thermal conductivity of sedimentary rocks

The thermal conductivity is thus a parameter of utmost importance for petroleum exploration. Because the temperature is a function of the thermal conductivity, it is important for prediction of reservoir quality and for prediction of hydrocarbon maturity. However, basin modeling systems often ignore the impact of the thermal conductivity. The thermal conductivity is often given as a default value, e.g. for shales. But the thermal conductivity of shales can vary significantly from an area to another. Thus improving the prediction of the thermal conductivity will lead to considerable improvements in the accuracy of basin modeling, and prospect identification.

For details: Fjeldskaar, W., Christie, O. H. J., Midttømme, K., Virnovsky, G., Jensen, N. B., Lohne, A.,  Eide, G. I. and Balling, N., 2009. On the determination of thermal conductivity of sedimentary rocks and the significance for basin temperature history. Accepted for publication in Petroleum Geoscience.