Method for extracting hydrocarbons present in a sedimentary basin, said sedimentary basin having undergone a plurality of geological events defining a sequence of states of said basin, said sequence of states comprising the state of said basin at the current time and at least one state of said basin at a prior geological time, by means of a computer-executed numerical basin simulation, said numerical basin simulation simulating at least migration of said hydrocarbons in said basin according to at least two mechanisms of migration, said mechanisms of migration being induced by hydrodynamics and/or by capillary forces and/or by buoyancy, characterized in that said method comprises determining a mechanism of migration of said hydrocarbons that is preponderant in said sedimentary basin through implementation, by data-processing means, of at least the following steps: A. physical quantities relating to said basin are measured by means of sensors, and a meshed representation representative of said basin is constructed for said state of said basin at said current time; B. based on said meshed representation of said basin for said state of said basin at said current time, a meshed representation of said basin is constructed for each of said states of said basin at said prior geological times; C. by means of said numerical basin simulation and of said meshed representations of each of said states, for each of said states and in each of said mesh cells of said meshed representation of said state, said contribution of each of said mechanisms of migration of said hydrocarbons is determined, in said mesh cell, for said state, D. at least one preponderant mechanism of migration of said hydrocarbons is deduced therefrom for at least one set of mesh cells of at least one meshed representation of said basin for at least one of said states; and in that, based at least on said preponderant mechanism of migration of said hydrocarbons, the following step is carried out: E. an extraction scheme is determined for said basin, the scheme comprising a pattern of at least one injection well and/or of at least one production well, and said hydrocarbons are extracted from said basin at least by drilling said wells in said pattern and equipping them with extraction equipment. A. physical quantities relating to said basin are measured by means of sensors, and a meshed representation representative of said basin is constructed for said state of said basin at said current time; B. based on said meshed representation of said basin for said state of said basin at said current time, a meshed representation of said basin is constructed for each of said states of said basin at said prior geological times; C. by means of said numerical basin simulation and of said meshed representations of each of said states, for each of said states and in each of said mesh cells of said meshed representation of said state, said contribution of each of said mechanisms of migration of said hydrocarbons is determined, in said mesh cell, for said state, D. at least one preponderant mechanism of migration of said hydrocarbons is deduced therefrom for at least one set of mesh cells of at least one meshed representation of said basin for at least one of said states; and in that, based at least on said preponderant mechanism of migration of said hydrocarbons, the following step is carried out: E. an extraction scheme is determined for said basin, the scheme comprising a pattern of at least one injection well and/or of at least one production well, and said hydrocarbons are extracted from said basin at least by drilling said wells in said pattern and equipping them with extraction equipment.