Abstract: Pressure derivative method at constant flow rate, Peres convolution and deconvolution methods are used to interpret pressure data in flow period. The result shows that reliable formation parameters can be obtained when flow period is long enough. Peres convolution and deconvolution methods are applicable to infinite acting radial flow, but can not be applied to analyze pressure data in early and late periods which are affected by wellbore storage and boundary. Pressure derivative method at constant flow rate has multi-solutions because the pres-sure derivative curve is not on the 0.5 horizontal line. Buildup period is longer than flow period, so the pressure derivative curve is more com-plete, reflecting flow regime of various models. A new method is proposed which use pseudo-steady time and pseudo-steady flow rate to sim-ulate flow period. According to these two parameters, typical curve match and non-linear regression methods are used to analyze the buildup period. Pressure buildup data from 10 wells are interpreted using the proposed method. The interpreted results are correlated with results of linear analysis methods (three kinds of pressure buildup methods) and average flow rate method. The results show that the new method is more accurate and reliable and makes identification of variable boundary conditions.

Key words: low permeability reservoir, oil well, formation pressure detection, interpretation, method