Permeability testing device without confining pressure and using method thereof

Abstract

The invention relates to a confining pressure-free permeability test device and a using method thereof, and the problems that an existing permeability test device is complex in structure, inconvenient to operate and low in accuracy and reliability are solved. According to the technical scheme, the permeability test device comprises a cylindrical holder, the upper end and the lower end of the holder are connected with a top cover and a bottom cover in a threaded or clamped mode respectively, a glue layer used for sealing and gluing a sample is arranged on the inner surface of the cylindrical holder, and through holes are formed in the center point of the top cover and the center point of the bottom cover. The confining pressure-free permeability test device is simple in structure, easy to operate, high in accuracy and reliability, long in service life, economic and practical.

Description

technical field [0001] The invention relates to a permeability testing device and a using method thereof, in particular to a non-confined pressure permeability testing device suitable for rock gas and liquid permeability testing and concrete anti-seepage performance testing and a using method thereof. Background technique [0002] Rock permeability is a parameter that characterizes permeability and measures its ability to pass through fluid media. In the exploration and production of oil and gas resources, reservoir rock permeability is a necessary indicator for productivity evaluation and development plan formulation. In order to obtain the permeability of the rock formation (concrete), a common method is to drill core samples at the engineering site, and then process the rock samples to a specified size (usually a cylinder with a diameter of 50 mm and a height of 100 mm). Then experiment indoors. [0003] The current steady flow technique based on Darcy's law is commonly ...

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Problems solved by technology

[0006] The existing permeability testing device, such as the permeability testing device in the patent CN 103776745, first adjusts the confining pressure with a hand-operated confining pressure pump, injects methane gas through the test gas kettle to give the core an initial pressure and keeps it stable, and then opens the valve The pressure is balanced, and the permeability is calculated by the change of the measured pressure. The structure of the device is simple, but the measurement accuracy is low, and it is not suitable for the permeability test of low-permeability materials, and the scope of use is limited.

In order to improve the measurement accuracy, when testing the permeability testing device disclosed in the patent CN102435537, a confining pressure of 0.5MPa higher than the upstream pressure is first added to the core, and it is realized by increasing the upstream pressure of the core and improving the measurement accuracy of the gas flow The measurement of core gas permeability and equivalent liquid permeability can reduce the experimental error, but the device uses a high-pressure gas source to increase the upstream pressure and improve the flow measurement accuracy. The system is relatively complicated, with high requirements for instruments and high cost

Another example is the permeability test device disclosed in the patent CN 103743661, which is suitable for the permeability test of rocks with different permeability levels through the arrangement of two cavities with different volumes, through the obvious degree of the change of the air pressure inside, to improve the data accuracy and test The use range of various permeability rocks, but the device is more complicated and the cost is higher

[0007] It can be seen that all the existing permeability test devices must apply confining pressure before the test without exception. However, the application of confining pressure changes the internal pore structure of the sample, changes the true state of the sample, and the measured results deviate from the real state. value

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