Rock porosity and permeability are two vital parameters to evaluate the oil & gas reservoir and calculate the reserves. Normally they are tested in normal temperature and atmosphere pressure. But it does not represent the true characteristics of reservoir property. Theory suggests that
temperature and pressure of environmental factors has a great influence on the determination of rock porosity and permeability. Therefore, to develop the special equipment has important significance to the precise calculation of reservoir parameters and make development plan reasonably.
1. Methods the principles
A measurement of porosity under high-temperature and high-pressure is a kind of gas method measurement using nitrogen as measuring medium. The principle is based on Boyle's law, that is, under the already set initial pressure with a known volume of standards body, make the gas to the core chamber for isothermal expansion under atmospheric pressure, gas diffusion into core porosity, using the change of pressure and the known volume to calculate the effective pore volume of sample and particle size with gas equation, the rock porosity can calculated.
Using nitrogen gas as the standard testing medium. When nitrogen under certain pressure through the tested samples, differential pressure △Pc set up on both ends of the sample.Measuring gas flow accurately with the mass flow-meter, combining other parameters, you will calculate the core permeability with Darcy law.
2. Main performance
Range of measurement:0.001×10-3μm2~8000×10-3μm2;
Range of measurement:≤50%
Pressure : Axial pressure 0~70MPa
Circling pressure 0~70MPa