| CPC G01N 33/24 (2013.01) [E21B 44/00 (2013.01); E21B 49/02 (2013.01); G01N 23/223 (2013.01); G01N 25/00 (2013.01); G01N 25/20 (2013.01); G01V 11/00 (2013.01); H01J 49/105 (2013.01); E21B 25/00 (2013.01); E21B 49/00 (2013.01); E21B 49/06 (2013.01); G01N 2223/076 (2013.01); G01N 2223/616 (2013.01)] | 14 Claims |
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1. A method, comprising:
obtaining at least one well log from a segment of a wellbore penetrating a subterranean region of interest;
obtaining a first plurality of core samples from the segment;
obtaining a second plurality of core samples from the segment;
for each core sample of the first plurality of core samples, determining a relative abundance of each of a set of inorganic materials, forming inorganic data;
for each given core sample of the second plurality of core samples:
determining, using pyrolysis, a first yield (S1), a second yield (S2), and a third yield (S3),
determining, a hydrogen index (HI), an oxygen index (OI), a production index (PI), a normalized S1 (Norm_S1), and a total organic content (TOC) value based on the S1, S2, and S3,
comparing the HI, OI, PI, and Norm S1 to a corresponding organic material data cut-off condition, and
discarding the given core sample in response to any of the HI, OI, PI, and Norm S1 not satisfying a corresponding organic material data cut-off condition;
determining a cross-checked total organic content (xc-TOC) matrix comprising the TOC value of each core sample of the second plurality of core samples that was not discarded;
identifying, based on the inorganic data, at least one sensitive element from the set of inorganic materials that correlates with the xc-TOC, wherein each of the at least one sensitive elements has either a corresponding high or low value that correlates to a high TOC value;
discarding, from the xc-TOC matrix, TOC values that, for each of the at least one sensitive elements, do not have a corresponding high or low sensitive element forming a validated total organic content (vTOC) matrix;
determining a data portion and a prediction portion of the segment, based on sample locations of the second plurality of core samples, wherein the data portion and the prediction portion are mutually exclusive and the prediction portion excludes the sample locations of the second plurality of core samples;
determining, in the data portion, depth ranges corresponding to source rock locations based on the TOC values of the vTOC;
determining a measured source rock thickness based on the depth ranges;
determining at least one cut-off value for each of the at least one well log based, at least in part, on the vTOC;
determining, in the prediction portion, zones of high TOC based on the at least one cut-off value for each of the at least one well log;
predicting a predicted source rock thickness by combining a thickness of each of the zones of high TOC;
determining a net source rock thickness of the segment from a sum of the predicted source rock thickness and the measured source rock thickness;
identifying a drilling target in the subterranean region of interest spanned by the segment based, at least in part, on the net source rock thickness; and
drilling another wellbore or another segment of the wellbore, using a drilling system, to intersect the drilling target.
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