| dc.description.abstract | This study mainly focuses on the detection and characterization of micro-annuli at the interface of cement and casing, usually caused by changes in pressure, temperature, or volume change of zonal isolation material. For the purposes of this study, leakage channel measurements of two pipes and the Infrared Thermography technique are analyzed to understand the size and shape of this gap.
To analyze the potential flow through the fluid migration leakage path, the assumption of “more than half full pipe flow” was used to estimate the flow rates for different channel heights using the Darcy-Weisbach and the Manning’s equations. For the Manning’s equation, initially a cast-iron channel surface was assumed and then a corrugated metal channel surface to assess the effect of friction losses.
The study shows that using the infrared thermography method has potential to characterize the leakage paths in sandwich casing sections. From the experiments, an anomaly was observed in a section of the investigated set-up (section C6), and after evaluation it was identified that the channel along this section was not uniform, and that the micro-annulus was not homogeneous. Investigating another section of the set-up (section A2), it did not show a visible anomaly or irregularity, and after analysis, it was concluded that the channel along this section was uniform, and that the micro-annulus was homogeneous.
The study also shows that the estimated leakage rates in section A2 using the Manning’s equation for a corrugated metal channel surface are more accurate because of the uniformity of the channel, which is consistent with the results obtained using the infrared thermography cameras. | en_US |
