An oilfield is a volumetric undersaturated reservoir. Volumetric calculations indicate the reservoir contains 270.6 MMSTB of oil initially in place. The initial reservoir pressure is 3685 psi. The following additional data are available:

Swi=24% cw=3.6210-6psi-1 cf=4.9510-6psi-1 Bw=1.0 bbl/STB pb=1500psi

The field production and PVT data are summarized below:

Calculate the OOIP by using the MBE and compare with the volumetric estimate of N.