US 12,435,616 B2
System and method for bond log analysis
Laslo Olah, Richardson, TX (US); Kirk Lane Harris, Lafayette, LA (US); and Gergely Sebestyen, Budapest (HU)
Assigned to Texas Institute of Science, Inc., Richardson, TX (US)
Filed by Texas Institute of Science, Inc., Richardson, TX (US)
Filed on Jun. 25, 2024, as Appl. No. 18/753,233.
Application 18/753,233 is a continuation in part of application No. 18/538,168, filed on Dec. 13, 2023, abandoned.
Claims priority of provisional application 63/589,204, filed on Oct. 10, 2023.
Prior Publication US 2025/0116184 A1, Apr. 10, 2025
Int. Cl. G06F 17/40 (2006.01); E21B 47/005 (2012.01)
CPC E21B 47/005 (2020.05) [G06F 17/40 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A computer-program product for bond-log analysis, embodied on a non-transitory computer-readable medium, comprising program instructions executable by a processor of a computer system to:
receive, from a digital log file, a single Cement Bond Log (CBL) of a wellbore casing that includes Variable Density Log (VDL) data and at least one Secondary Data Track (SDT) recorded concurrently with the VDL data;
for each of a plurality of discrete depths represented in the VDL data, perform an initial VDL-only assessment that classifies the depth as clear or possible discontinuity present;
tag every depth classified as having a possible discontinuity;
initiate a rolling investigation that sequentially analyzes depths immediately above and below each tagged depth until two consecutive clear depths are found in each direction;
for every depth examined during the rolling investigation, analyze at least one SDT in conjunction with the VDL data;
dynamically update the depth queue during the rolling investigation when subsequent SDT analyses change a depth's status from clear to imperfect, or vice versa;
for each tagged or updated depth, analyze the corresponding SDT data together with the VDL data to:
determine a probable cause of the possible discontinuity, and
re-classify the depth as clear or confirm the possible discontinuity;
compare and group the depths whose discontinuities are confirmed according to their vertical positions in the CBL to delineate one or more imperfect intervals;
rank the intervals by severity before generating a report; and
generate the report that synthesizes results from the VDL and SDT analyses and summarizes cement integrity of the wellbore casing.