Patent ID: 11946360
Assignee: MAGNETIC VARIATION SERVICES, LLC
Field: Civil engineering (Other fields)
Classification: CPC E  G | IPC E  G

Claim 25:
26. A computer system, comprising:
a processor enabled to access memory media storing instructions executable by the processor for:
for a subject wellbore, selecting a starting measured depth of the subject wellbore, MDSW1, to begin a stratigraphic depth analysis, wherein the stratigraphic depth analysis is associated with a target measured depth for the subject wellbore, TMDsw, that is greater than the starting measured depth of the subject wellbore, MDSW1;
beginning with the starting measured depth of the subject wellbore, MDSW1, performing the stratigraphic depth analysis by identifying a plurality of sequences of stratigraphic vertical depths of the subject wellbore, SVDsw, along the subject wellbore and generating a heat map curve for the subject wellbore, the heat map curve indicative of a misfit between well log data of the subject wellbore and offset well log data indicative of stratigraphic vertical depth of at least one offset wellbore, SVDow, respectively, wherein the sequences are paths through the heat map curve;
ordering the plurality of sequences according to a stratigraphic vertical depth of the subject wellbore, SVDsw, for each sequence in the plurality of sequences, wherein the stratigraphic vertical depth of the subject wellbore, SVDsw, is determined with respect to the target measured depth for the subject wellbore, TMDsw;
grouping the plurality of sequences into sets of sequences, each set of sequences respectively having a similar value for the stratigraphic vertical depth of the subject wellbore, SVDsw;
calculating a likelihood using the starting measured depth of the subject wellbore, MDSW1, and the target measured depth for the subject wellbore, TMDsw, that the target measured depth for the subject wellbore, TMDsw, is equal to or within a tolerance of the stratigraphic vertical depth of the subject wellbore, SVDsw, respectively for each of the sets of sequences, wherein the likelihood is based on a sum of an inverse function of an equation describing the misfit between the starting measured depth of the subject wellbore, MDSW1, and the target measured depth for the subject wellbore, TMDsw; and
based on the likelihood calculated, adjusting a steering direction of the subject wellbore during drilling of the subject wellbore.