Damage Assessment for Refinement Towers in Oil Installations using 3D Laser Scanning Technique

Abstract

Terrestrial Laser Scanning (TLS) can be used to detect damage and analyze volumetric changes in large structural test specimens. Compared to traditional imaging and surface analysis methods, the primary reason for using 3D scanning is the difficulty of attaching targets to towers of varying heights, as well as the fact that some towers are covered with insulating materials that obscure key landmarks. In addition, the large number of incoming and outgoing pipes and stairs attached to the towers further complicates traditional assessment methods. This research focuses on assessing the damage to the three refining towers at the Baiji Refinery facility. Scanning was performed using a 3D laser scanner with HDR color imaging, capturing data from thirteen stations positioned around the towers. The data were exported for registration and processing to create as-built drawings that provide a visual inspection of the deviations for each tower, the second tower (V6) exhibited the maximum inclination compared to the others. The point cloud data were converted to solid geometry for further analysis. The analysis revealed that V3 tower has a regularly increasing slope in a linear pattern. V6 tower shows a gradual slope in the first seven courses at a constant rate and in a fixed direction, followed by a more drastic change from the middle of the tower to the top. The V8 tower exhibits a gradual increase in tilt from the base, which stabilizes from the middle to the top. Based on these results, which are consistent with the visual analysis and compared to the international standard for tilt value, tower V6 must be taken out of service. The other towers can be rehabilitated with periodic monitoring to ensure stability before being returned to service at the refinery.