Introduction
Fetkovich introduced “decline type curve“ analysis (we often refer to traditional decline as Decline Curve Analysis). The method focused mostly on liquid cases, and also showed youd could simultaneously estimate reservoir properties from production data. A precursor to modern FMB and Rate Transient Analysis (RTA)with transient and depletion stems, Fetkovich overlaid data to estimate reservoir properties.
Blasingame [2019] once described it as a composite of analytical and empirical (Arps) solutions. A Discussion on the Fetkovich plot is shown below:
Carter introduced the “Carter Decline Type Curve“ as a correction of Fetkovich for gas flow properties (the correction was done numerically). Similar to Fetkovich the method used the overlay of data on Transient and Depletion Stems.
References:
T. A. Blasingame, Petroleum Engineering 648, Pressures Transient Testing. Lecture 18 - Fetkovich Method for Production Analysis. 2019.