Method for determining relationship between pressure and flow in micron capillary channel

Abstract

The invention provides a method for determining the relationship between pressure and flow in a micron capillary channel. According to the method in the invention, control on the pressure or the flowspeed in a gas-liquid two-phase flow process in a micron capillary is realized by utilization of a dynamic test device; a method for obtaining a phase interface and phase interface displacement is provided; obtaining of the phase interface shape under the states of low capillary number and low bond number is realized for the first time; phase interface shape calculation and speed calculation basedon an image processing method are adopted for the first time; therefore, the data processing efficiency and the measurement precision are greatly increased; due to determination on the speed, the contact angle and the displacement of the phase interface, the relationship between the pressure and the test liquid flow in the micron capillary channel can be determined; therefore, a control system directly controls and adjusts pressure change according to the flow; an experimental process and a speed control algorithm of a movable base are simplified; the actual operation flexibility is improved;and requirements of all kinds of working conditions can be satisfied.

Description

technical field [0001] The invention relates to the field of enhanced petroleum exploitation, in particular to a method for determining the relationship between pressure and flow in a micron capillary channel after obtaining the displacement, contact angle and velocity of the gas-liquid dynamic displacement phase interface by using a dynamic measuring device equipped with a micron capillary channel. Background technique [0002] The mechanism of two-phase displacement in a single micron-scale capillary is the basis of two-phase displacement in porous media in natural environments. Two-phase displacement in porous media occurs in many industrial or natural processes, such as water in tight oil reservoirs. Gas drive, solution gas drive, water drive and other processes, the above-mentioned industrial processes are characterized by weak viscous force (the range of capillary number is 10 -10 <Ca<10 -5 ), weak gravity (Bond number Bo is less than 10 -4 ). The key factor a...

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Problems solved by technology

[0007] But adopt above-mentioned two kinds of schemes all can't measure capillary number 10 -10 -5 and Bond number Bo-4 Dynamic contact angle under working conditions

[0008] In addition, in order to observe the contact angle, it is necessary to use a high-magnification microscope to obtain a magnified image, which means that the observation field of view is small

However, the dynamic displacement process means that the phase interface will move a certain distance, so high-magnification microscopes cannot observe the movement process of the phase interface

If a low magnification microscope is used to observe, the change of the position of the phase interface can be observed, but the phase interface cannot be observed, so the contact angle cannot be directly measured

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