The formation of gas in nature can occur through the thermal cracking as well as through bacterial degradation of organic matter preserved in sediments. At shallower depths, where temperatures are low, bacterial gas is of major importance while thermal gas becomes dominant with increasing burial and thermal stress. However thermal gas has also been found at maturities which are conventionally thought to be too low to drive thermal gas formation (Ro = 0.31%).
From a technical standpoint, we have developed extended kinetic models to predict the hydrocarbon generation window at low maturity levels, especially in cases where macromolecule structure is heterogeneous (Dieckmann, 2005).
From a genetic point of view, we are determining what types of organic matter have the potential to generate high GOR petroleums at low maturity. Thermal cracking as well as condensation and aromatisation reactions are under review using PhaseKinetics modelling and a mass balance approach.