Which logs are used together to identify a breakout?

• A. Caliper logs and Image logs
• B. Gamma ray logs and Density logs
• C. Resistivity logs and Sonic logs
• D. Neutron logs and Porosity logs

Answer: (A)

Breakouts are borehole-wall enlargements caused by in-situ stresses that lead to fractures around the hole. To identify them, you need tools that reveal both the hole’s shape and the wall features. Caliper logs trace the borehole diameter along depth, highlighting spots where the hole widens. Image logs provide a direct, high-resolution view of the borehole wall, showing the actual breakout patches and their orientation. When you see localized diameter increases in the caliper data that correspond to elongated wall disturbances on the image log, you can confidently identify breakouts and determine their orientation, which is tied to the minimum horizontal stress direction. Other logs—gamma ray, density, resistivity, and sonic—focus on lithology or rock properties rather than wall defects, so they don’t directly indicate breakouts.