Abstract: The invention notably relates to a computer-implemented method for analyzing a hydrocarbon trap, for hydrocarbon production. The hydrocarbon trap has a top surface. The method comprises providing one or more geological meshes each representing the top surface. Each geological mesh has cells each representing a location on the top surface. The method further comprises for each geological mesh, determining one or more cells on the geological mesh. Each determined cell corresponds to a respective saddle of the trap.

Abstract: The invention notably relates to a computer-implemented method for analyzing a hydrocarbon trap, for hydrocarbon production. The hydrocarbon trap has a top surface. The method comprises providing one or more geological meshes each representing the top surface. Each geological mesh has cells each representing a location on the top surface. The method further comprises for each geological mesh, determining one or more cells on the geological mesh. Each determined cell corresponds to a respective saddle of the trap.

Abstract: This invention relates to a method for determining a location of karst caves in a geological model. The method comprising for each current point of a set of points of a closed space of the model, determining a distance value; receiving an average value; and for each current point of the set of points of the closed space, determining a presence of caves for the current point. The determination at the presence of caves depends at least on the received average value and on the distance value determined for the current point. A collapse procedure can also be implemented as described in the description.

Abstract: The present invention relates to a method for determining a lithology map. The method comprises receiving a geophysical attribute image comprising a plurality of points associated with geophysical attribute value, and receiving first information data representing a plurality of zones in the image, each point of the image being contained in a zone. For at least one point of the image, computing a uniform value associated with said point based on the geophysical attribute value and distributions values of the geophysical attribute values. The method further comprises receiving second information data representing geological probability value for a plurality of facies associated with the points of the image, and for at least one point of the image, determining a facies in the plurality facies based on the computed uniform value and the geological probabilities associated with said point.

Abstract: The present invention relates to a method for determining a truncation diagram for a pluri-Gaussin geological parameter estimation associated with a zone of a real subsoil. The method comprises receiving an auxiliary variable describing the zone, computing a normalized variable based on the auxiliary variable and determining a weighted probability map for the normalized variable, each point of the weighted probability map being in correspondence with a point, of the truncation diagram. Moreover for each point of the truncation diagram, the method further comprises determining an associated geological parameter based on the probability value of each point of the weighted probability map. The method is also used to adapt truncation diagram to global or local target, proportions of the facies model to built.

Abstract: The present invention relates to a method for determining a stacked model describing architectural elements from a plurality of architectural element. The method comprises selecting an architectural element, determining merged zone, the merged zone being function of the zone of the selected architectural element and zones of related architectural elements, determining a probabilistic zone, the probabilistic zone being a function of the merged zone, and determining a probabilistic superposition value associated with the determined probabilistic zone, the probabilistic superposition value being a function of the superposition value of the selected architectural element. The previous steps are repeated for each architectural element in the plurality of architectural elements. The method further comprises stacking every determined probabilistic zone in a stacked model according to the determined probabilistic superposition value associated therewith, and providing the stacked model.

Abstract: According to the invention, a training image denotes, for each cell of a first three-dimensional grid, a respective type of geological facies assigned to said cell. For each cell of a second three-dimensional grid, the morphology of which is matched to estimated geological horizons, the well data comprise a respective type of geological facies estimated for said cell. Two-dimensional patterns, each of which is defined along a respective geological horizon and includes, in a cell containing the intersection of a well with said geological horizon, the type of geological facies estimated for each cell, are defined. The instances of the identified two-dimensional patterns are counted in the training image so as to verify the ability of the training image to account for correlations between wells.

Abstract: The present invention relates to a method for determining a karstic region modified by karstification phenomena. This method comprises, from a geological model, determining a seed cell and a target cell in that model. If a distance between the seed cell and the target cell is above a given distance, it is possible to update the seed cell with a bifurcation cell based at least on the coordinates of the seed cell, the coordinates of the target cell, a distance distribution, an angular distribution, and to re-iterate the test. Based on that bifurcation cells, trajectory is computed and cells of that trajectory is updated with new cell characteristics.

Abstract: The invention relates to a method for estimating a set of variables associated with sites of an area, the method comprising the following steps: a) a set of observation data is supplied, b) a variable associated with a site of a first sub-area is estimated by krigeing, using the precision matrix of the first sub-area, c) a second adjacent sub-area is determined, d) a variable associated with a site of the second sub-area is estimated by krigeing, on the basis of the first sub-space, the second sub-space, and the precision matrix determined for the first sub-space.

Abstract: This invention relates to a method for determining a location of karst caves in a geological model. The method comprising for each current point of a set of points of a closed space of the model, determining a distance value; receiving an average value; and for each current point of the set of points of the closed space, determining a presence of caves for the current point. The determination at the presence of caves depends at least on the received average value and on the distance value determined for the current point. A collapse procedure can also be implemented as described in the description.

Abstract: The present invention relates to a method for determining a stacked model describing architectural elements from a plurality of architectural element. The method comprises selecting an architectural element, determining merged zone, the merged zone being function of the zone of the selected architectural element and zones of related architectural elements, determining a probabilistic zone, the probabilistic zone being a function of the merged zone, and determining a probabilistic superposition value associated with the determined probabilistic zone, the probabilistic superposition value being a function of the superposition value of the selected architectural element. The previous steps are repeated for each architectural element in the plurality of architectural elements. The method further comprises stacking every determined probabilistic zone in a stacked model according to the determined probabilistic superposition value associated therewith, and providing the stacked model.

Abstract: According to the invention, in order to initialize the use of a multipoint geostatistical technique (MPS), the method takes information, which was collected in wells drilled in the area of the subsoil to be modeled, into account. Particularly, the method takes inter-well connectivity data into account, which indicate one or more groups of cells of a reservoir grid that are located along a plurality of wells and between which hydrodynamic communications have been observed. For each of said groups, compatible thumbnail images are searched for in a training image used in the MPS technique. Said thumbnail images have, in the training image, facies that enable the flows between the cells of the group. The thumbnail images are applied onto the reservoir grid in order to initialize MPS simulation while ensuring that the inter-well connectivity constraints will be respected.

Abstract: The present invention relates to a method for determining a karstic region modified by karstification phenomena. This method comprises, from a geological model, determining a seed cell and a target cell in that model. If a distance between the seed cell and the target cell is above a given distance, it is possible to update the seed cell with a bifurcation cell based at least on the coordinates of the seed cell, the coordinates of the target cell, a distance distribution, an angular distribution, and to re-iterate the test. Based on that bifurcation cells, trajectory is computed and cells of that trajectory is updated with new cell characteristics.

Abstract: The present invention relates to a method for determining a truncation diagram for a pluri-Gaussin geological parameter estimation associated with a zone of a real subsoil. The method comprises receiving an auxiliary variable describing the zone, computing a normalized variable based on the auxiliary variable and determining a weighted probability map for the normalized variable, each point of the weighted probability map being in correspondence with a point, of the truncation diagram. Moreover for each point of the truncation diagram, the method further comprises determining an associated geological parameter based on the probability value of each point of the weighted probability map. The method is also used to adapt truncation diagram to global or local target, proportions of the facies model to built.

Abstract: The present invention relates to a method for determining a lithology map. The method comprises receiving a geophysical attribute image comprising a plurality of points associated with geophysical attribute value, and receiving first information data representing a plurality of zones in the image, each point of the image being contained in a zone. For at least one point of the image, computing a uniform value associated with said point based on the geophysical attribute value and distributions values of the geophysical attribute values. The method further comprises receiving second information data representing geological probability value for a plurality of facies associated with the points of the image, and for at least one point of the image, determining a facies in the plurality facies based on the computed uniform value and the geological probabilities associated with said point.

Abstract: According to the invention, a training image denotes, for each cell of a first three-dimensional grid, a respective type of geological facies assigned to said cell. For each cell of a second three-dimensional grid, the morphology of which is matched to estimated geological horizons, the well data comprise a respective type of geological facies estimated for said cell. Two-dimensional patterns, each of which is defined along a respective geological horizon and includes, in a cell containing the intersection of a well with said geological horizon, the type of geological facies estimated for each cell, are defined. The instances of the identified two-dimensional patterns are counted in the training image so as to verify the ability of the training image to account for correlations between wells.

Abstract: According to the invention, in order to initialize the use of a multipoint geostatistical technique (MPS), the method takes information, which was collected in wells drilled in the area of the subsoil to be modeled, into account. Particularly, the method takes inter-well connectivity data into account, which indicate one or more groups of cells of a reservoir grid that are located along a plurality of wells and between which hydrodynamic communications have been observed. For each of said groups, compatible thumbnail images are searched for in a training image used in the MPS technique. Said thumbnail images have, in the training image, facies that enable the flows between the cells of the group. The thumbnail images are applied onto the reservoir grid in order to initialize MPS simulation while ensuring that the inter-well connectivity constraints will be respected.

Abstract: The invention relates to a method for estimating a set of variables associated with sites of an area, the method comprising the following steps: a) a set of observation data is supplied, b) a variable associated with a site of a first sub-area is estimated by krigeing, using the precision matrix of the first sub-area, c) a second adjacent sub-area is determined, d) a variable associated with a site of the second sub-area is estimated by krigeing, on the basis of the first sub-space, the second sub-space, and the precision matrix determined for the first sub-space.

Abstract: A method of estimating lithologic properties of a geological zone represented by a grid, in which method facies are allocated to the nodes of the grid by sequential stochastic simulation. For a target node (x0) from a set of target nodes for scanning iteratively, and for each possible facies (ck0), a conditional probability (pk0/k1, . . . , kn) of observing said facies is estimated knowing that respective facies have already been allocated to other nodes in the neighborhood. A random draw weighted by these conditional probabilities is then performed. The estimation of the conditional probabilities makes use of univariate probabilities (pk0) and of bivariate probabilities (pk0,ki) of observing two facies at two respective nodes of the grid. Each bivariate probability used in estimating the conditional probability relates to the target node (x0) and to a node (xi) neighboring the target node.

Abstract: A method of estimating lithologic properties of a geological zone represented by a grid, in which method facies are allocated to the nodes of the grid by sequential stochastic simulation. For a target node (x0) from a set of target nodes for scanning iteratively, and for each possible facies (ck0), a conditional probability (pk0/k1, . . . , kn) of observing said facies is estimated knowing that respective facies have already been allocated to other nodes in the neighborhood. A random draw weighted by these conditional probabilities is then performed. The estimation of the conditional probabilities makes use of univariate probabilities (pk0) and of bivariate probabilities (pk0,ki) of observing two facies at two respective nodes of the grid. Each bivariate probability used in estimating the conditional probability relates to the target node (x0) and to a node (xi) neighboring the target node.