Abstract
We show that a pressure pulse originating in a well is correlated to a pulse observed at a distant well with a characteristic time. The correlation time is directly related to the diffusion time scale arising out of the pressure diffusion equation. The relationship is affected by the source-observer or observer-observer distance but the correction is small for large distances. In practice, further corrections have to be included for finite width pulses. For these pulses, we present a practical scheme for continuous permeability monitoring.
Wellbore storage also has a strong influence on the correlation time-scales. We show a simple forward calculation that removes this effect and allows a direct estimation of reservoir scale permeability. The techniques developed in this paper are simpler to practice than conventional interference testing, and do not require the same level of periodicity or uniformity of pulses.
