Magnetic flux leakage (MFL) intelligent pigs are the most common tools used for pipeline inspection. But, the MFL inspection results are subject to various sources of uncertainties which must be quantified and accounted for in the integrity assessment of the inspected pipeline. A series of pull-through tests (PTT) of seven MFL tools from four service providers was performed on a 12-inch diameter pipe containing preexisting internal corrosion defects of various length, width, and depth, and located in a variety of circumferential and longitudinal positions. The results of these tests are used to quantify the detectability statistics and the sizing uncertainties of the different tools for future use in developing calibrated probabilistic models for reliability based inspection, quantitative risk assessment and life extension studies for pipelines.
Seismic structural health monitoring allows for the continuous evaluation of engineering structures by monitoring changes in the structural response that can potentially localize associated damage that has occurred. For the first time in Colombia, a permanent and continuous monitoring network has been deployed in a 14-story ecofriendly steel-frame building combined with a reinforced concrete structure in downtown Bogota. The six three-component ETNA-2 accelerometers recorded continuously for 225 days between July 2019 and February 2020. We use deconvolution-based seismic interferometry to calculate the impulse response function (IRF) using earthquake and ambient-vibration data and a stretching technique to estimate velocity variations before and after the Ml 6.0 Mesetas earthquake and its aftershock sequence. A consistent and probably permanent velocity variation (2% reduction) is detected for the building using ambient-vibration data. In contrast, a 10% velocity reduction is observed just after the mainshock using earthquake-based IRFs showing a quick recovery to about 2%. A combination of both earthquake-based and ambient-vibration-based deconvolution interferometry provides a more complete picture of the state of health of engineering structures.
Along the past decades the prolific Talara Basin, located at the northwest part of the Peruvian coast, has been intensively studied based mainly on the huge amount of onshore wells on the area. Beside this, contributions come up from 3D seismic. These contributions are stratigraphic and/or structural analysis, which provide suggestions about reservoir communication, fault movement and optimize well positioning. The reservoir characterization methodology applied on this work used 3D PSDM seismic data. The first step aimed to better understand deep reservoir levels (Lower Eocene and Paleozoic), that are less sampled by wells than upper levels (e.g., Middle Eocene). The second step focused on Middle Eocene reservoirs, sampled by tens of wells with a good geological correlation. From well data and geological interpretation, it is well known that Lower Eocene reservoirs are high energy fluvial systemsthis depositional pattern appeared with a distinct seismofacies in the entire seismic cube. Seismic data and well logs showed that Lower Eocene presents more fractures and faults than Middle Eocene. However, the relation between directions and fracture classification as open, semi-open or closed fractures was not conclusive. The seismic facies found at Middle Eocene show sin-depositional differential tectonics movements that could have caused compartmentalization. At this level, seismic facies are very clear, with strong and parallel reflectors, indicating the presence of amalgamated lobes (probably derived from erosion of an eastern ridge located). Identified seismic anomalies were mainly related to structural highs, associated to hydrocarbon saturated reservoirs. An understanding of stress field behavior along geological time is very important to achieve a better trapping model and hydrocarbon migration routes. In this work, the high number of structures observed provided the tools to set up an event chronology. According to the stress history, N70W normal faults acted as migration routes probably during Miocene. Considering the last compressive reactivations (occurred between Upper Eocene and Oligocene) these previously migration routes could be changed to sealing faults.
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