This paper presents a transient pressure analysis method for analyzing the rate decline of a constant pressure well producing in an infinite doubieporosity reservdr, without wellbore skin. This analysis method may be used to interpret well test rate data, and to compute the rate behavior of an infinitely acting reservoir that is being produced at constant pressure. The development of the pseudo steady state bg-log type curve is presented along with a hypothetical example of Its use. This type curve dlOW8 the estimation of the two controlling parameters in double-porosity systems: A and o. The first perameter, A, describes the Interporosity flow, and the second parameter, o describes the relative fracture storatlvlty. This paper considers the estimation of these two parameters. The estimations of permeabillties and storativities have been described in the past, hence, are not considered. In a double-porosity system, with pseudo steady state Interporosity flow, the initial infinite acting rate decline, representing only the fracture system, is folbwed by a constant rate flow period. The length of this constant rate flow period is controlled by the parameter 0. The beginning of this period is controlled by the interporosity flow parameter, A. Following this constant rate period, the rate resumes an Infinite homogeneous decline, representing the total 8ystem. fractures and matrix. The parameters A and w may be estimated from a log-log match of rate data to the type curve. A comparison between rate responses of two translent flowing matrices and the pseudo steady state matrix Is presented. Transient Interporosity flow ellows the matrix to Increase the well flowrate in the early and transition portions of the flow. The final decline, representing the total system, is identical to the decline with a pseudo steady state matrix.

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