On the vertical and lateral distribution of hydrocarbon migration velocities during secondary migration

Abstract Recent improvements in the techniques for modelling the flow of oil and gas through carrier systems allow us to compute the column heights of migrating oil and gas stringers. The calculations are performed throughout the history of the basin and suggest that secondary migration occurs at low saturation, and very often with velocities in excess of 100 km/Ma. The migrating hydrocarbon stringer columns are modelled to be very thin, i.e. in the centimetre range, over large areas. This paper discusses the lateral and vertical distribution of the above properties in order to elucidate and quantify the extreme focusing that hydrocarbons can experience during secondary migration. A result of these very efficient migration mechanisms is that we can successfully explore for hydrocarbons, even in traps that require lateral migration distances in excess of 1000 km from source to trap.