Abstract: Saturation pressures were derived for various types of reservoir with low saturation reservoir pressure differences, using the pressure buildup curves, which not only makes up for such pitfalls as limited samples far PVT analysis and strict sampling condition, but also extends the application range of pressure buildup curve. This method is successful for use in Huoshaoshan and Beisantai oilfield in East Junggar oil area.

Key words: Saturation reservoir pressure difference, Pressure buildup curve, Saturation pressure, East Junggar oil area