Patent ID: 11952881
Assignee: NORALIS LIMITED
Field: Civil engineering (Other fields)
Classification: CPC E | IPC E

Claim 9:
10. The method for drilling, according to claim 9, further comprising the steps of:
Step M2: moving said drill bit to a location (K+S+said first segment length+said second segment length) in the borehole according to the second level adjusted error correction of Step L1, said bit location being at said location (K+S+said first segment length+said second segment length), said downhole location being at said (K+S) location,
Step N2: measuring with said surface location sensor at said surface location for said bit location at said location (K+S+said first segment length+said second segment length) so as to determine a location (K+S+said first segment length+said second segment length) surface sensor measurement;
Step O2: measuring with said downhole sensor at said downhole location for said bit location at said location (K+said first segment length+said second segment length) so as to determine a location (K+S) downhole sensor measurement; and
Step P2: applying another third level adjusted Kalman filter to said location (K+S+said first segment length+said second segment length) surface sensor measurement and said location (K+S) downhole sensor measurement, so as to generate another third level adjusted projection of said borehole end for steering said drill bit,
wherein said another third level adjusted Kalman filter is comprised of a third level adjusted error correction based on said initial location (K) surface sensor measurement, said location (K+said first segment length) surface sensor measurement, said location (K+S) surface sensor measurement, said location (K+S+said first segment length) surface sensor measurement, said location (K+S+said first segment length+said second segment length) surface sensor measurement, said location (K−S) downhole sensor measurement, said location (K) downhole sensor measurement, said location (K+said first segment length) downhole sensor measurement, and said location (K+S) downhole sensor measurement.