In naturally fractured reservoirs, the transition zone observed on semi-log plots of pressure data versus time exhibits slope characteristics that are often ignored by the analyst. This study shows that analysis of this segment can lead to the quantification of matrix heterogeneity and fracture intensity. A pressure transient model is developed to substantiate this concept. It is found that the transition zone slope characteristics cover a spectrum embracing, as special cases, double porosity and triple porosity response corresponding to both pseudo-steady state and unsteady state inter-porosity flow.

Keywords:
matrix layer, porosity, fractured reservoir, correlation, transition zone, eqn, upstream oil & gas, spe 16341, society of petroleum engineers, storativity
Subjects:
Formation Evaluation & Management, Unconventional and Complex Reservoirs, Pressure transient analysis, Drillstem/well testing, Naturally-fractured reservoirs
Copyright 1987, Society of Petroleum Engineers
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