The standard methods available for determination of reservoir pressure from pressure build-up observations rely on the assumption of a flow geometry in the reservoir. A method of calculating reservoir pressure which does not require a specified reservoir flow pattern has been devised. This method is based entirely on the principle of superposition and develops the use of a single pressure drawdown curve for each well the well characteristic curve. Methods for constructing this curve are describes and its use in determining reservoir pressure from pressure build-up data is illustrated by the analysis of a transient pressure survey. The method has the advantage of requiring only a short shut-in period.
p(t) - the remanent pressure drawdown at time t, psi
G(t) - the characteristic remanent pressure drawdown functions psi/1000 bpd.
Pe - the reservoir pressure at the time of the pbu Pe - the reservoir pressure at the time of the pbu survey, psi.
