System and method for automatically correlating geologic tops

A method for automatically correlating geologic tops using at least one processor, the method comprising:

• receiving a plurality of well logs including a first well log of a first well bore and at least a second well log of a second well bore, each well log for each well bore being a record of a plurality of geologic formations penetrated by the well bore along a depth of the well bore;
• constructing a graph of the plurality of well logs, the graph having a node at each well bore location for each well log and an edge between two nodes weighted based on a distance between the two well bores represented by the two nodes;
• determining, using the graph, at least one neighbor well log for each well log;
• placing the well logs including the at least one neighbor well log into a priority queue sorted by a quality measure indicating a similarity between a source well log pick and the at least one neighbor well log of a pair of well logs;
• traversing the priority queue until the queue is empty by retrieving a first element from the priority queue having a highest quality measure, determining a new pick by performing correlation on each neighbor of the first element using a slope constraint that minimizes data singularities during the correlation, assigning the new pick a pick quality value, adding the new pick to the priority queue and generating a candidate well pick, wherein adding the new pick to the priority queue comprises adding the new pick to the priority queue when a quality value of the pick exceeds a quality threshold that comprises a defined numeric value and when the candidate well pick is statistically tested against a depth-window tolerance about the source well log pick to identify the candidate well pick as a final well pick and the final well pick has more than two wellbore sources and the measured depths of the candidate well pick has a statistical variance less than the depth-window tolerance;
• and
• displaying the set of correlated geologic tops candidate well pick.

An apparatus, comprising:

• a computer system having at least one processor, memory and a plurality of lines of computer code that is configured to:
• receive a plurality of well logs including a first well log of a first well bore and at least a second well log of a second well bore, each well log for each well bore being a record of a plurality of geologic formations penetrated by the well bore along a depth of the well bore;
• construct a graph of the plurality of well logs, the graph having a node at each well bore location for each well log and an edge between two nodes weighted based on a distance between the two well bores represented by the two nodes;
• determine, using the graph, at least one neighbor well log for each well log;
• generate a priority queue that contains the plurality of well logs and at least one neighbor well log sorted by a quality measure indicating a similarity between the two well logs of the pair of well logs;
• select a pair of well logs from the priority queue having a highest quality measure, wherein the selected pair of well logs includes a source well log pick and at least one neighbor well log;
• perform an automatic correlation of the selected pair of well logs, the automatic correlation having a slope constraint;
• generate the quality measure for the pair of well logs;
• determine that the quality measure for the pair of well logs is more than a threshold to identify a candidate well pick, where the threshold comprises a defined numeric value;
• statistically test the candidate well pick log against a depth-window tolerance about the source well log pick to identify the candidate well pick as a final well pick, and the final well pick has more than two wellbore sources and the measured depths of the candidate well pick has a statistical variance less than the depth-window tolerance;
• and
• based on the determination that the quality measure for the pair of well logs is more than the threshold, displaying the set of correlated geologic tops candidate well pick.