Permanent downhole gauges (PDGs) provide vast amounts of pressure-transient and rate data which may be interpreted with improved pressure-transient-analysis (PTA) approaches to gain more knowledge about reservoir dynamics. Permanent pressure and rate measurements allow for analysis of time-lapse pressure transients and comparative interpretation of flowing and shut-in periods. The approaches used provided the basis for an improved methodology of interpreting permanent pressure measurements, where the scope of the standard PTA application may be extended to integrate new data sources.
A Methodology of PDG Interpretation Focusing on Both Flowing and Shut-In Periods
Practical Remarks on Comparison of Pressure Transients and Choosing a Model. Comparison of different pressure transients is usually carried out on the basis of plotting all the transients and derivatives on the same log-log plot. In practice, a difference between time-lapse shut-in pressure transients does not necessarily indicate change in well reservoir parameters because such a comparison is usually carried out for rate-normalized data with a chosen reference transient.
