This paper will present the findings from crack detection monitoring on the 777 full-scale aircraft during fatigue testing. Crack detection is a critical component of any comprehensive aircraft structural health-monitoring system. Health monitoring offers the promise of substantially reduced inspection and maintenance costs for military aircraft. To date, most testing has been performed in the laboratory on relatively small coupons and subcomponents. A persistent concern with broadband acoustic emission methods has been their ability to measure crack signals in the presence of noise. There is little broadband acoustic emission test data to provide any indication of the possible difficulties in monitoring a full-scale structure. This paper will present test data, results and discussion from broadband acoustic emission monitoring of the 777 Full-Scale Fatigue Test.
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AbstractReservoir connectivity is a key uncertainty when considering field appraisal and development options. Reducing this uncertainty can provide significant benefits in optimising the field development plan. Through the application of new wireless telemetry technology (Expro CaTS TM ), a fully abandoned subsea appraisal well has been cost effectively converted into a valuable reservoir monitoring asset.Clair Ridge appraisal well 206/8-13Y was drilled in 2006 and located some 8km from the existing Clair production platform. The well was the first step in an appraisal programme designed to confirm the next stage of development of the Clair Field. Reservoir connectivity and the risk of compartmentalisation are key uncertainties for development of the Clair reservoir (ref.1).On completion of testing operations, the well would typically have been permanently abandoned and of no further value for reservoir monitoring purposes. By installing a battery powered, wireless pressure monitoring system in the well at the time of final abandonment, it was possible to monitor for any fluctuations in the reservoir pressure in the Clair Ridge resulting from production / injection events on the Clair platform. This newly emerging wireless telemetry technology transmits data from the reservoir to the seabed using the well casing as the communication path and advantageously, the signal is not attenuated by the presence of cement or bridge plugs in the wellbore. The reservoir pressure and temperature data that is transmitted up the casing, is collected and stored by a CaTS subsea receiver located on the seabed. The stored data can be recovered, on demand, by a supply vessel located overhead using well established through seawater acoustic communications.The use of a wireless gauge enabled a downhole well abandonment to be performed. The traditional method for
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