COMPLEXITIES IN THE ANALYSIS OF PRESSURE-TRANSIENT RESPONSE IN FAULTED NATURALLY FRACTURED RESERVOIRS

Pressure-transient modeling for bulk testing of naturally fractured sy stems requires consideration of the effect of no-flow barriers on the pressure response. This study shows that, depending on the distance to the fault and under certain reservoir conditions, the presence of a l inear barrier can affect the duration and the nature of the transition interval and estimation of interporosity parameters and reservoir tra nsmissivities. Typical semilog plots for naturally fractured reservoir s (NFR's) may not be observed unless the fault is at a large distance away from the test well. In most cases, a double reflection is predict ed-i.e., fracture response and the total system response. A correlatio n is developed to estimate the distance to the fault from the early fa ult reflection data. A critical wellbore storage constant can also be identified above which the detection of the fault becomes impractical.