Core permeability experimental testing method and device under condition of stratum pressure

Abstract

The invention provides a core permeability experimental testing method and a device under a condition of stratum pressure. The method comprises the steps of: installing a core sample in a core holder and applying confining pressure to the core holder through a high-pressure injection pump; adjusting a back pressure controller and setting pressure to an initial back pressure value; filling air into pores of the core sample, and after the pressure of the pores of the core sample is balanced, stopping filling air and cutting off an air source; and testing the permeability of the core sample and recording the permeability testing result. The experiment not only simulates pressure which is applied by an overlying rock stratum to the core sample in a stratum, but also simulates original stratum pressure applied by fluid in bypass pores to the core sample in the stratum. Therefore, the actual physical condition of the core sample in the stratum is fully simulated, and the permeability of the core sample which is tested based on the experimental testing method and the device is enabled to be more scientific and more accurate.

Description

technical field [0001] The invention relates to an oil-gas field development rock core experiment analysis technology, in particular to a rock core permeability test method and a device thereof under formation pressure conditions. Background technique [0002] Reservoir core permeability is a key parameter for gas reservoir resource potential analysis, gas well productivity evaluation, and development technical plan formulation. Tight sandstone reservoirs have complex pore-throat structure characteristics and low reservoir permeability. It is difficult to obtain original reservoirs by conventional experimental testing methods. In the development process, the reservoir permeability changes due to the decrease of pore pressure, that is, the reservoir shows a certain stress sensitivity, but the experimental testing and analysis techniques for studying this change law are still lacking. [0003] At present, there are many instruments for rock stress-sensitivity testing, complete...

AI Technical Summary

Problems solved by technology

In these methods, almost only the overburden pressure is considered, and the original formation pressure of the fluid in the core pores is not considered, let alone the stress recovery experiment on the core

And there is no actual simulation of formation pressure, overlying rock pressure, temperature and other conditions for testing, so the obtained test value cannot truly represent the permeability under the original reservoir conditions

Moreover, there is no real experimental test method and device for the change law of reservoir permeability during the development process, and the characteristics of reservoir permeability change during the development process are still in theoretical speculation and conjecture.

Therefore, it is not possible to scientifically test the formation condition core permeability by existing experimental methods

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