Method for determining parameters of earth formations surrounding a well bore
AssigneeHalliburton Energy Services, Inc.
InventorLi Gao
Life of this patent
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Abstract
A method for determining a formation profile surrounding a well bore includes receiving field log data for the formation and generating a Jacobian matrix responsive to the provided field log data. A quasi-Newton update is used to update the Jacobian matrix for each necessary iteration until a generated formation profile converges with the received field log data.
Claims11
A method for determining a formation profile surrounding a well bore, comprising the steps of:
- (a) receiving field log data for a formation surrounding the well bore;
- (b) generating a Jacobian matrix responsive to the field log data;
- (c) solving for a new formation conductivity profile using the Jacobian matrix;
- (d) calculating a new log response using the new formation conductivity profile;
- (e) determining if the log response converges with the received field log data;
- (f) performing a quasi-Newton update of the Jacobian matrix and repeating step (c) and (e) if the log response does not converge with the received field log data;
- and
- (g) outputting the formation profile based upon the log response if the log response converges with the received field log data.
A method for determining a formation profile surrounding a well bore, comprising the steps of:
- (a) receiving field log data for a formation surrounding the well bore;
- (b) determining an initial vector from the field log data, said initial vector being a conductivity or resistivity vector;
- (c) generating the Jacobian matrix using a sliding window and the initial vector;
- (d) solving for a formation conductivity vector using the Jacobian matrix with maximum flatness constraint;
- (e) calculating a log response using the new formation conductivity vector;
- (f) determining if the log response converges with the received field log data;
- (g) performing a quasi-Newton update of the Jacobian matrix and repeating step (d) and (f) if the log response does not converge with the received field log data;
- and
- (h) outputting the formation profile based upon the log response if the log response converges with the received field log data.
A method for determining a formation profile surrounding a well bore, comprising the steps of:
- (a) receiving field log data for a formation surrounding the well bore;
- (b) determining an initial vector from the field log data, said initial vector being a conductivity or resistivity vector;
- (c) generating the Jacobian matrix using a sliding window and the initial vector;
- (d) generating the Jacobian Matrix using a sliding window and the initial vector said step further comprising the steps of:
- determining an single column vector of the Jacobian matrix using a three-bed formation;
- and
- sliding the single column vector across the formation to populate the Jacobian matrix;
- (e) solving for a formation conductivity vector using the Jacobian matrix with maximum flatness constraint;
- (f) calculating a log response using the new formation conductivity vector;
- (g) determining if the log response converges with the received field log data;
- (h) comparing the determined log response to the received field log data to determine if the log response converges with the received field log data;
- (i) performing a quasi-Newton update of the Jacobian matrix and repeating step (e) and (f) if the log response does not converge with the received field log data;
- and
- (j) outputting the formation profile based upon the log response if the log response converges with the received field log data.
Dependencies are inferred from the claim text.