CPC E21B 47/04 (2013.01) [E21B 7/04 (2013.01); E21B 44/00 (2013.01); G01B 21/18 (2013.01); G05B 13/04 (2013.01); G05B 13/041 (2013.01); E21B 2200/20 (2020.05)] | 31 Claims |
1. A computer system, comprising:
a processor enabled to access memory media storing instructions executable by the processor for:
for a subject wellbore, generating a misfit curve between stratigraphic vertical depth of an offset wellbore, SVDow and a measured depth of the subject wellbore, MDsw;
based on the misfit curve, calculating a plurality of likelihoods that respective target measured depths for the subject wellbore, TMDsw, are equal to or within a tolerance of respective stratigraphic vertical depths of the subject wellbore, SVDsw, respectively corresponding to a plurality of interpretations of stratigraphic vertical depth of the subject wellbore, SVDsw based on a subject well log for the subject wellbore and an offset well log respectively for at least one offset wellbore, wherein the interpretations are paths through the misfit curve;
assigning, to the subject wellbore, a likelihood calculated using a starting measured depth of the subject wellbore, MDsw1, and the target measured depth for the subject wellbore, TMDsw, from the plurality of likelihoods that a target measured depth for the subject wellbore, TMDsw, is equal to or within a tolerance of a stratigraphic vertical depth of the subject wellbore, SVDsw, associated with the target measured depth for the subject wellbore, TMDsw; and
based on the misfit curve and the assigned likelihood, adjusting at least one drilling parameter during drilling of the subject wellbore.
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