Abstract: In terms of the infinite homogeneity reservoirs, the automatic analysis of well test data and unique results are the goal of well testing. This paper proposes an algorithms of total optimization based on the method of the orthogonal experiment to estimate directly wellbore and reservoir parameters in single layered, boundless reservoirs from the possible bound of the unknown parameters. The algorithm does not depend on the initial guess of unkown reservoir parameters, such as permeability, accumulation factors and skin factors, and there is no need of the discussion of different analytic properties for model′s solution. The case given demonstrates the effectiveness of the algorithm. This paper focuses on the study of the well testing in an infinite homogeneous reservoir. It can be popularized to other well test analysis of reservoirs, such as natural fractured reservoirs and combined reservoirs. The method can be applied to estimate more unknown parameters of the reservoirs, such as boundary distance of the bounded reservoirs and crossflow factor of layered reservoirs.

Key words: method of the orthogonal experiment, automatic matching, well test analysis, reservoir parameter, parameter estimation, effective wellbore radius