Harmonic pulse testing for well performance monitoring

Harmonic testing was developed as a form of well testing that can be applied during ongoing production or injection operations, as a pulsed signal is superimposed on the background pressure trend. Thus no interruption of well and reservoir production is needed before and during the test. If the pulsed pressure and rate signal analysis is performed in the frequency domain, strong similarity exists between the derivative of the harmonic response function versus the harmonic period and the pressure derivative versus time, typical of conventional well testing. Thus the interpretation of harmonic well tests becomes very straightforward. In this paper, we present the analytical models for the most commonly encountered well and reservoir scenarios and we validate the model for horizontal wells against real data of a harmonic test performed on a gas storage well in Italy.