Patent ID: 8855987
Filing Date: 2014-10-07
Classification: G01V

Abstract:
1. A method of improving a geologic model of a subsurface region, comprising: (a) selecting one or more sets of parameter values, each parameter directly or indirectly representing a geologic property; (b) inputting each of the one or more sets of parameter values into a numerical model to produce a predicted outcome for each set of parameter values; (c) comparing the predicted outcome for each of the one or more sets of parameter values with observations of the subsurface region, the difference therebetween defined as a cost associated with each of the one or more sets of parameter values; (d) obtaining a gradient of the cost associated with each of the one or more sets of parameter values; (e) constructing a geometric approximation of a parameter space defined by one or more formations, each formation corresponding to one of the one or more sets of parameter values for which the cost and the gradient of the cost have been evaluated; (f) generating a response surface model based on the geometric approximation, the response surface model expressing the cost and the gradient of the cost associated with each formation; (g) when a finishing condition is not satisfied, selecting at least one additional set of parameter values based at least in part on the response surface model associated with previously selected sets of parameter values; (h) repeating parts (b), (c), (d), (e), (f) and (g) using successively selected additional sets of parameter values to update the geometric approximation and the response surface model until the finishing condition is satisfied; (i) outputting at least one of the sets of parameter values having a predetermined level of cost to a geologic model of the subsurface region; and (j) updating the geologic model, taking into account at least one of wherein each of the additional sets of parameter values are selected by: