Monitoring Fluid-Fluid Interface by Well Test Analysis

This project involves the monitoring of fluid-fluid interface by well test analysis in the presence of wellbore storage and skin effects. The study therefore is on the interpretation of well tests data obtained for both short and long duration well tests. The term ¿short-duration¿ is used herein to indicate either drawdown or build-up tests run for a period of time insufficient to reach the usual straight-line portion of a well test. The analytical solution is presented to the problem of flow of slightly compressible fluid in a limited, composite reservoir with radial symmetry which is produced by a well at the centre. The system is composed of two zones of different permeability in concentric series. The solution to this problem is useful in the fundamental study of the behavior of reservoirs having low permeability ¿rim¿ and in the pressure transient behavior of some wells having horizontal fracture or a large fractured area such as would be created by a nuclear explosion.