Device and method for measuring rock diffusion coefficient based on automatic injection of micro-pressure difference

Abstract

The invention provides a device and a method for detecting the rock diffusion coefficient based on micro-differential pressure automatic injection. The device comprises a natural gas source, a nitrogen source, a first multiplication supercharger, a second multiplication supercharger, a differential pressure sensor, a confining pressure tracing pump, a boosting injection pump, a first displacement transmitter, a second displacement transmitter and a core clamp, wherein one end of the first multiplication supercharger is connected with the natural gas source and connected with a first diffusion chamber, and the other end of the first multiplication supercharger is connected with the boosting injection pump; one end of the second multiplication supercharger is connected with the nitrogen source and connected with a second diffusion chamber, and the other end of the second multiplication supercharger is connected with the boosting injection pump; and the confining pressure tracing pump is connected with the core clamp between the first diffusion chamber and a second diffusion chamber. According to the embodiment of the invention, the problem of inaccurate measurement result caused by existence of the pressure difference between two diffusion chambers can be solved, the whole process of diffusion injection can be operated automatically, errors caused by manual operation can be reduced, and the measurement result accuracy can be effectively improved.

Description

technical field [0001] The invention relates to the technical field of oil and gas exploration, in particular to a device and method for measuring the diffusion coefficient of rocks based on micro-pressure automatic injection. Background technique [0002] Diffusion refers to a physical process in which gas molecules migrate freely from high-concentration areas through various media to low-concentration areas to reach equilibrium under the action of concentration gradients of hydrocarbon gases. Diffusion is one of the important mechanisms of oil and gas migration. It plays an important role in the migration, accumulation, accumulation, Both preservation and destruction play a vital role. [0003] For the accumulated gas reservoirs, in addition to the sealing ability of the caprock itself and the influence of faults, the ability of the caprock rocks to diffuse hydrocarbons is the most important factor affecting the later transformation and destruction of the gas reservoir; h...

AI Technical Summary

Problems solved by technology

[0006] At present, when measuring the diffusion coefficient of hydrocarbons in rocks, the laboratory generally adopts the method of manual pressurized gas injection, that is, by manually controlling the speed and flow of gas intake, the gas injection pressure in the diffusion chamber reaches the pressure required for the experiment. However, manual operation Inevitably there will be errors, making the pressures of the two diffusion chambers unbalanced or inconsistent

Since the diffusion coefficient is generally a small value, the existence of the pressure difference between the two sides of the diffusion chamber will inevitably cause the gases on both sides to not diffuse each other but to permeate to the other side under the action of pressure, making the final result inaccurate. This phenomenon is especially evident under the experimental conditions of high temperature and high pressure.

[0007] For the above problems, no effective solution has been proposed

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