Patent ID: 6442487
Filing Date: 2002-08-27
Classification: G01V

Abstract:
A method for assessing reliability of a predicted value of a specified geological or geophysical parameter at a designated location, the predicted value obtained from a prediction model constructed from N training data attribute vectors and N associated observed values of the specified parameter; each training data attribute vector including one or more seismic attributes obtained from seismic data traces located at or near a well, each associated observed value of the specified parameter obtained from well log or core data from the well, the method comprising the steps of:determining a predicted value of the specified parameter for each of the N training data attribute vectors, from the training data attribute vectors and the prediction model; determining a residual for each of the N training data attribute vectors, the residual being the difference between the associated observed value of the specified parameter for the training data attribute vector and the predicted value of the specified parameter for the training data attribute vector; determining an attribute vector for the designated location; determining the predicted value of the specified parameter at the designated location, from the attribute vector for the designated location and the prediction model; determining N basic probability distributions from the N training data attribute vectors, the N associated observed values, the N residuals, and the predicted value of the specified parameter at the designated location; determining N basic probability assignments for each of three hypotheses that the predicted value of the specified parameter at the designated location is reliable, unreliable, and unpredictable, respectably, from the N basic probability distributions; and determining a reliability value, an unreliability value, and an unpredictability value for the predicted value of the specified parameter at the designated location as combinations of the N basic probability assignments for each of the hypotheses that the predicted value of the specified parameter at the designated location is reliable, unreliable, and unpredictable, respectively.