AVERAGE RESERVOIR PRESSURE DETERMINATION FROM DRAWDOWN TESTS BY THE TDS TECHNIQUE.

The average reservoir pressure plays an important role in all phases of reservoir appraisal. Although buildup pressure tests are meant to be used for the estimation of this parameter, drawdown tests can also be used by a mathematical combination with material balance. Therefore, in this study, the TDS Technique is applied to drawdown tests for the development of expressions to obtain the average reservoir pressure for vertical wells in homogeneous and heterogeneous systems, and fractured wells in homogeneous formations, as well. Applications to three simulated and one field cases were successfully compared to those from material balance providing absolute derivation errors lower than 3%. [ABSTRACT FROM AUTHOR]