Over the entire life cycle of a well there is a concentrated focus on well integrity, specifically through leak detection. Hydrophones mounted on a downhole chassis enable the extraction and transmission of acoustic-signal data used to detect potential leaks in wellbores. By suitably processing the acoustic signals, the location, phase, and rate of the leak flow can be estimated using models based on theory and empirical data. The model presented in this paper proposes a direct relation between flow rate and acoustic amplitude by combining their dependence on fluid properties and environmental parameters, such as pressure and temperature. Experiments were conducted for various leak scenarios for a wide range of differential pressures to obtain acoustic amplitudes. The proposed model was calibrated in two steps: (1) A numerical wave-propagation model was used to convert the acoustic amplitude for the leak geometry used in experiment to an equivalent in free space, and (2) partial experimental data were used to obtain coefficients for the proposed model. The model was validated by comparing its flow-rate predictions with the rest of the experimental data. Statistics for the accuracy and success rate of the predictions of the proposed model are provided.
ASJC Scopus subject areas
- Geotechnical Engineering and Engineering Geology