ANAPPRES V2.0: a Computerized Expert System for Well-Test Analysis

Abstract

This paper presents ANAPPRES V2.0, the second version of a computerized expert system that interprets data of constant and variable-flowrate interference tests in which there are an arbitrary number of production wells and an arbitrary number of observation wells. From the analysis, the transmissivity (kh/y), storativity ($ch), and hydrologic boundaries (existence, type and location) are obtained. ANAPPRES successfully couples a mathematical model, an optimization technique and heuristic knowledge, an unusual combination rarely found in published expert systems. The main advantages of ANAPPRES as compared to standard methods, are: (1) it can analyze variable flowrate interference tests; (2) it can obtain 4 to 5 parameters (transmissivity, storativity, type of boundary, distance and angle to boundary) in one computer run; (3) it is considerably faster than a human expert in completion of the job and (4) allows analysis of well tests including an arbitrary number of observation wells and an arbitary number of production wells.