Abstract: A method for modelling geomechanical effects in the subsurface by conditioning geomechanical model parameters to time-lapse observations. The model is driven by displacement boundary conditions derived from observed time-lapse travel time shift and time strain. The displacements at the boundaries of the model are extracted from time-lapse data, converted from travel time shift to depth shift and lateral shifts if necessary, and applied as displacement increments on the initial geomechanical model. Subsequently, increments of stresses and strains are calculated by the geomechanical simulator, and time-lapse related parameters in the interior of the model are compared with the time-lapse observations. This enables a comprehensive study of mismatch between simulations and observations that can be used to update material properties, faults, fractures and the rock strain-velocity change relationship (R factor).

Abstract: A method for modelling geomechanical effects in the subsurface by conditioning geomechanical model parameters to time-lapse observations. The model is driven by displacement boundary conditions derived from observed time-lapse travel time shift and time strain. The displacements at the boundaries of the model are extracted from time-lapse data, converted from travel time shift to depth shift and lateral shifts if necessary, and applied as displacement increments on the initial geomechanical model. Subsequently, increments of stresses and strains are calculated by the geomechanical simulator, and time-lapse related parameters in the interior of the model are compared with the time-lapse observations. This enables a comprehensive study of mismatch between simulations and observations that can be used to update material properties, faults, fractures and the rock strain-velocity change relationship (R factor).

Abstract: A method of determining a search expression describing a feature of interest in a set of data points distributed throughout a geological object is provided. Each data point contains a value for a geological attribute at that point. The search expression has a plurality of entries. The method including the steps of: (i) displaying the geological object using display codings corresponding to value subranges for the geological attribute such that all data points which have values for the geological attribute falling within a given value subrange are displayed with the same coding; (ii) selecting a plurality of data points of the feature of interest; and (iii) allocating value characters to entries of the search expression, the value characters corresponding to the value subranges for the geological attribute of the selected data points.

Abstract: A computer-implemented method of determining a search expression describing a feature of interest in a set of data points distributed throughout a geological object is provided. Each data point contains a value for a geological attribute at that point. The search expression has a plurality of entries. The method including the steps of: (i) displaying the geological object using display codings corresponding to value subranges for the geological attribute such that all data points which have values for the geological attribute falling within a given value subrange are displayed with the same coding; (ii) selecting a plurality of data points of the feature of interest; and (iii) allocating value characters to entries of the search expression, the value characters corresponding to the value subranges for the geological attribute of the selected data points.