Testing device and testing method for gas permeability of compacted sandstone

Abstract

The invention belongs to the field of the evaluation of reservoir rock physical properties, and particularly relates to a testing device for the gas permeability of compacted sandstone. The testing device comprises a high pressure gas cylinder, a buffer container, a core holding unit, a back-pressure valve, a confining pressure pump and a return pressure pump, wherein the high pressure gas cylinder is provided with a reducing valve, the buffer container is connected with the reducing valve through a first pipeline, and the buffer container is connected with a vacuum pump through a second pipeline; the inlet of the core holding unit is connected with the buffer container through an inlet pipeline, the outlet of the core holding unit is connected with the inlet of the return pressure pump through an outlet pipeline, and the return pressure valve is communicated with atmosphere; a pressurization connector of the return pressure valve is connected with the return pressure pump through a third pipeline, and a confining pressure connector of the core holding device is connected with the confining pressure pump through a fourth pipeline. The testing device for the gas permeability of the compacted sandstone provided by the invention is simple to operate, a theory is likely to be deduced, the klinkenberg permeability and a slip factor can be obtained at the same time by a testing pressure depression curve only; furthermore, compared with a steady-state method, the testing device is accurate in result and takes short time.

Description

technical field [0001] The invention belongs to the field of reservoir rock physical property evaluation, and in particular relates to a tight sandstone gas permeability test device and a test method. Background technique [0002] Rock permeability is an important parameter and index for reservoir physical property research, formation damage evaluation, and oil and gas reservoir development plan design. The methods of indoor permeability measurement are divided into steady-state method and unsteady-state method. The seepage medium includes gas (N 2 , air, H e ) and liquids (such as kerosene and formation fluids). The measurement of rock permeability by liquid will be affected by many factors, such as the expansion of clay in rock when it encounters water, the adsorption of liquid on the surface of rock pores, etc., which will affect the accuracy of permeability measurement. Therefore, gas is often used to measure the permeability of rocks. However, tight sandstone cores...

AI Technical Summary

Problems solved by technology

However, the principle of this method is complicated, and the slippage effect of the gas is still not considered, so the measured value is too high

Images