Patent ID: 6711529
Filing Date: 2004-03-23
Classification: E21B,G01V

Abstract:
A method for determining at least one optimal trajectory starting from a predetermined point so as to reach a target situated in a medium and comprising a centre and a peripheral boundary, said target forming a centred volume, the position of each of whose points is known with geometrical uncertainties, said method consisting of:(a) defining for the centred volume a gain which takes a first value at the centre of the said centred volume, a second value lower than said first value at each of the points of the peripheral boundary, intermediate values at each of the other points of the said centred volume and a zero value outside the centred volume; (b) calculating at least 30 instances of the positions of the centred volume as a function of the geometrical uncertainties which affect it; (c) summing at each point of the medium the values taken by the gain for the various positions of the centred volume so as to obtain an aggregate gain at each point; (d) defining a volume of interest, site of the points with positive aggregate gains in the medium; (e) defining curvilinear trajectories which pass through the volume of interest from at least one entry point of the volume of interest to at least one exit point of the said volume of interest; (f) integrating the aggregate gain along each of the said curvilinear trajectories in such a way as to obtain a profit associated with each trajectory; and (g) retaining all the trajectories whose profit is greater than a threshold, said retained trajectories being the optima trajectories.