# Application of USCCD on Girth Weld Defect Detection of Oil Pipelines
## 4 Real Operational Run & Excavation Results and Analysis
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**GW**} & \multicolumn{2}{c}{**Feature Type**} & \multicolumn{2}{c}{**Orientation [o\({}^{\prime}\)/clock]**} & \multicolumn{2}{c}{**Depth**} & \multirow{2}{*}{**Length [mm]**} & \multirow{2}{*}{**Method**} \\ \cline{2-2} \cline{5-8}  & **Field** & **ILI** & **Field** & **ILI** & **Field** & **ILI** & **Field** & **ILI** & **Field** \\ \hline \multirow{8}{*}{7050} & Repair Welding & & 2:00-3:00 & 2:45 & \multirow{8}{*}{0.6} & \multirow{8}{*}{392} & \multirow{8}{*}{TOFD} \\  & Repair Welding & & 6:00-7:00 & & & 70 & & Visual \\  & Linear & External & & & & & & \\ \cline{1-1}  & Imperfection & Linear Indication & 2:00-5:00 & & 0.6 & & 392 & & TOFD \\  & (undercut) & & & & & & & & TOFD \\  & Inclusion & & 0:00-2:00 & & & & & & direct ultrasonic \\  & Inclusion & & 1:00-2:00 & & 12.4 & & & & wave pulse \\  & & & & & & & & reflection \\  & Lack of Fusion & & & & & & & & direct ultrasonic \\  & & & & & & & & & wave pulse \\  & & & & & & & & reflection \\ \hline \multirow{8}{*}{18540} & Repair Welding & & 5:00-7:00 & 6:25 & \multirow{8}{*}{0.8} & \multirow{8}{*}{186} & \multirow{8}{*}{TOFD} \\  & Linear & Linear Indication & & 7:00-8:00 & & & & & 186 & \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & imperfection & & & 11:00-12:00 & & 0.4 & & 135 & & TOFD \\ \hline \multirow{8}{*}{18560} & Repair Welding & & 4:00-5:00 & 3:25 & \multirow{8}{*}{0.4} & \multirow{8}{*}{1.4} & \multirow{8}{*}{510} & \multirow{8}{*}{TOFD} \\  & Linear & & & & & & & & \\ \cline{1-1}  & imperfection & & & & & & & & \\ \cline{1-1}  & Linear & & & & & & & & TOFD \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & imperfection & & & & & & & & \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & imperfection & & & & & & & & \\ \cline{1-1}  & & Linear Indication & & & & & & & \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & & Linear Indication & & & & & & & \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & & Linear Indication & & & & & & & \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & Linear & & & & & & & & \\ \cline{1-1}  & & Linear Indication & & & & & & & \\ \cline{1-1}  & Linear & & & &  
PPC carried out two further dig verifications on reported \"linear indications\" with NDE results shown in Table 7.  
The primary observations and learnings resulted from the comparison of dig verifications (NDE results) and UltraScan(tm) CCD data focused on distinguishing features between the internal and external surfaces as a result of the high number of external weld-related anomalies identified. For features on the external surface, the UltraScan(tm) CCD signals from the external features in the inspection data would not be distinguished from the signals received from the weld repairs as based on the rules derived from pull-throughs. Five areas were excavated for external linear indications and all were confirmed as weld repairs. Without a significant number of verified external cracks, no distinction can be made in the analysis of UltraScan(tm) CCD inspection data between weld repairs and linear indications or other weld defects (including but not limited to lack of fusion or metal loss of welding cap). For features on the internal surface, the characteristic of UltraScan(tm) CCD weld reflection signals in the inspection data was also different from the weld reflection signals obtained from pull-throughs. The weld reflections in the pipeline are very heterogeneous with large variations in signal amplitude and weld geometry.