Thesis (M.Eng.)--Chulalongkorn University, 2006

The objective of this work is to build a simple technique to analyze production data of oil wells producing from commingled reservoirs, in order to estimate the amount of movable oil in place. When a well producing in pseudo-steady-state period, rate normalization enables early estimation of ultimate recovery on both single and multi-layer reservoirs. Contribution of layers with different productivity can be qualitatively recognized. For oil and gas reservoirs, when combined with dynamic material balance chart, the rate normalization technique serves as a diagnostic tool to help reservoir practitioners evaluate and manage well performance more effectively. Combination of the two plots (rate normalization and flowing material balance) visually allows for the forecast of producible reserve after all boundaries have been felt. Rate normalization graph is a plot between normalized rate and cumulative production. Surface production data are necessary for constructing the graph.