Improve Reserves Estimation Using Interporosity Skin in Naturally Fractured Reservoirs

Abstract

An alternative method, named to as direct synthesis, is proposed for interpreting pressure transient tests in naturally fractured reservoirs. This new method offers consistent results from pressure tests with or without all reservoir flow regimes observed during the test period. Direct synthesis utilizes the characteristic intersection points and slopes of various straight lines from a log-log plot of reservoir or well parameters for improve reserves estimation.
The direct synthesis method (Tiab, 1989) offers the following advantages: (1) consistent results from using the exact, analytical equations to calculate reservoir parameters; (2) independent verification is frequently possible, (3) useful information is obtained when not all flow regimes are observed, as a direct result of the additional characteristic values developed by the method, and (4) determination of flow rate and cumulative production when It is shown that in deep and super deep wells the Temperature they are compared with a original volume it is generated the recuperation factor.
Application of this technique is presented for single-well pressure tests in a naturally fractured reservoir with transient interporosity flow with skin. Both the effect of wellbore storage and skin are included in the analysis. New analytical and empirical expressions were developed as a result of this work. These expressions are an integral part of the technique and provide the desired accuracy and versatility.
Several field examples are given to clarify the technique and also illustrate the consistency acquired by the method. When possible, a comparative analysis with other methods is included.