Non-steady state detection device and non-steady state detection method for permeability of low-permeability rock

Abstract

The invention discloses a non-steady state detection device and a non-steady state detection method for permeability of low-permeability rock. The detection device comprises a rock core holder for holding a rock core sample, wherein the side wall of the holder is connected to an annular pressure pump; the holder is provided with an inlet pipeline and an outlet pipeline; an inlet buffering container is arranged in the inlet pipeline; an outlet buffering container is arranged in the outlet pipeline; a check loop is connected to the holder in parallel; a check cylinder is arranged in the check loop. Due to the adoption of the non-steady state detection device for the permeability of the low-permeability rock, the permeability of the low-permeability rock core can be detected quickly and accurately; the permeability of the low-permeability rock core sample can be detected through two non-steady state detection methods; the device is simple to operate, accurate to test and capable of adjusting the volume of the inlet and outlet buffering containers according to a porosity of the rock core so as to ensure the detection precision of the permeability.

Description

technical field [0001] The invention relates to a device and method for measuring the permeability of low-permeability rocks such as tight sandstone, coal rock, mudstone, and shale in laboratories in the fields of petroleum, geology, and mining, and particularly relates to an unsteady-state measurement of the permeability of low-permeability rocks Devices and methods. Background technique [0002] At present, a series of progress has been made in the exploration and development of tight sandstone gas, shale gas, coalbed methane and other low-permeability gas reservoirs, and permeability has become one of the key parameters for evaluating low-permeability reservoirs. The existing laboratory core permeability measurement adopts the steady-state method. The basic principle is based on Darcy's law (the permeability test of rocks with a permeability greater than 0.1mD is mainly based on Darcy's law), measuring the fluid flow through the core under a certain pressure. Permeabilit...

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Problems solved by technology

However, when using such a measuring device and method to measure low-permeability core samples (permeability <0.1mD), because the rock has low porosity and poor connectivity between pores, fluids often cannot pass through, and it is difficult to obtain a stable flow rate in a short time. Difficult measurement, long time-consuming, low accuracy

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