Method for exploiting a geological reservoir from a reservoir model conditioned by calculating an analytic law of the conditional distribution of uncertain parameters of the model

The method involves providing a reservoir model (EMRi) matched to data measured in a reservoir e.g. oil reservoir. An initial set of reservoir models is stochastically generated from laws of probability of a set of parameters and an analytical law is determined. An objective function (OF) that measures deviation between acquired dynamic data (DD) and simulated dynamic data is determined. An optimum exploitation scheme (SE) is determined for the reservoir by simulating the exploitation of the reservoir with a matched reservoir model. The reservoir is exploited (EX) by implementing the scheme. The laws may be uniform law or Gaussian law. An independent claim is also included for a computer program product comprising instructions for performing a method for exploiting a geological reservoir from a reservoir model.