Abstract: A process for stochastic simulation of ancient riverbeds or ancient geological structures includes the following stages: (a) parameterize the geological reference horizon by linking to it a two-dimensional parametric system of paleogeographic coordinates; (b) construct a modeling function, the isovalue curves of which are approximately parallel to the general direction of the ancient riverbed to be simulated; (c) use the absolute value of the modeling function of the general direction of the ancient riverbed to be located in order to define a topographic function of the pseudo-valley; (d) transform the topographic function of the pseudo-valley by using a transfer function to determine the thicknesses, dimensions and characteristics of the ancient riverbed to be located and/or the ancient geological structures associated with this ancient riverbed.

Abstract: The invention concerns a method for extracting a geological horizon and related properties of a seismic representation, comprising a step (100) which consists in digital modeling with continuous local seismic traces, calculating the optimal offset and defining a conditional neighbourhood of a reference central continuous local seismic trace; a step (101) which consists in defining a two-dimensional matrix whereof the line and column indices correspond to the coordinates of the geophones; a third step (102) which consists in selecting a seed point; a fourth step (103) which consists in determining the point vertically closest to the seed point and a fifth step (104) which consists in assigning to the point P(p,q,t) the value P(p,q,t+hij,pq,k), where hij,pq,k is optimal offset of the neighbouring point P(i,j,k), so as to estimate the related properties of the conditional neighbourhood thereby filling the two-dimensional extraction matrix of step (101).

Abstract: A method for locally determining a profile of geological horizons includes a step (100) which consists in digital modeling with continuous local seismic traces, calculating an optimal offset and defining a conditional neighborhood of a reference central continuous local seismic trace; a step (101) which consists in defining residuals relative to the reference central continuous local seismic trace; a third step (102) which consists in minimizing the set of residuals on the conditional neighborhood and a fourth step (103) which consists in determining parametric coefficients corresponding to the minimization of the set of residuals on the conditional neighborhood carried out at step (102).

Abstract: The invention concerns a method for smoothing a subsurface property in a geological structure represented by seismic measurements comprising a step (100) which consists in digital modelling by continuous local seismic traces, calculating an optimal offset and defining a conditional neighbourhood of a reference central continuous local seismic trace; a step (101) which consists in selecting the property to be smoothed on a conditional neighbourhood; a third step (102) which consists in substituting properties of the conditional neighbourhood with offset properties; and a fourth step (103) which consists in selecting an average of the properties offset on the conditional neighbourhood at step (102).

Abstract: A method for three-dimensional modelling of a geological volume, which consists in defining cells adapted to the critical surfaces of the geological volume to be modelled; defining an assembly of polyhedral macrocells (M) adapted to the geometry (1) of the geological layers of the volume to be modelled; parametering the geological space to match the observed geological domain and a parametric domain by associating with a point belonging to the geological domain an image point located in the parametric domain; then defining a virtural subdivision of the polyhedral macrocells (M) into hexahedral microcells (m) whereof the geometry is obtained by subdividing the geometry of each macrocell (M).

Abstract: A process for stochastic simulation of ancient riverbeds or ancient geological structures includes the following stages: (a) parameterize the geological reference horizon by linking to it a two-dimensional parametric system of paleogeographic coordinates; (b) construct a modeling function, the isovalue curves of which are approximately parallel to the general direction of the ancient riverbed to be simulated; (c) use the absolute value of the modeling function of the general direction of the ancient riverbed to be located in order to define a topographic function of the pseudo-valley; (d) transform the topographic function of the pseudo-valley by using a transfer function to determine the thicknesses, dimensions and characteristics of the ancient riverbed to be located and/or the ancient geological structures associated with this ancient riverbed.