Method for modeling hydrocarbon degradation in an oil deposit

A method of modeling the progressive biodegradation of hydrocarbons trapped in an oil reservoir or trap studied, through action of a bacterial population in an aquifer, from data relative to the reservoir studied, concerning the form and the height of the reservoir, the physical characteristics of the porous medium, the thickness of the transition zone between the hydrocarbons and the water, the base of the transition zone containing only water and the top of the transition zone containing a residual amount of water, the composition of the hydrocarbons, the flow of electron acceptors entering the reservoir and data relative to the bacterial population in the aquifer, in order to determine the reservoir development conditions, characterised in that it comprises:

• discretizing the reservoir by means of a grid wherein the height of each grid cell is the thickness of the transition zone, and
• determining the variation, over the height of said reservoir, of the composition of hydrocarbons under the effect of biodegradation by iterative adjustment in each grid cell of the bacterial population to the amount of hydrocarbons available, to the pore space available, to the amount of electron acceptors present in the reservoir and to the degradation capacities of said population.