Abstract Decline curve analysis is a graphical procedure used for analyzing declining production rates, and forecasting future performance of oil and gas wells. This is achieved by curve fitting the past production performance using the rate-time data and extrapolating it to predict future performance, with the primary aim of estimating reservoir remaining reserves and/or remaining productive life. The effective use of the forecast techniques: Empirical, Fetkovich, Locke & Sawyer, and Analytical Transient solutions for oil and gas wells/Reservoirs, using a production surveillance tool that manages multi-wells effectively in less time is discussed. The last three techniques-type-curves require good understanding of the reservoir model as well as the parameters controlling the well behaviour. To effectively use any of these techniques for forecasting future production, it is imperative to determine the dominant flow regime from the production data. This paper focuses on concepts that enable engineers determine the dominant flow regime from diagnostic plots generated from rate-time data and/or numerical iterative method. Once we are able to establish the dominant flow regime, we can now decide which of these techniques to be used. Finally, the concepts were applied to field rate-time data.