Device and method for researching rock physical property parameter change under action of acid fluid

Abstract

The invention discloses a device and a method for researching rock physical property parameter change under the action of an acid fluid. The method comprises the steps of wrapping a cylindrical test sample and a porous gasket by using a sealing material; putting into a reaction kettle; vacuumizing a system; saturating water to the system after being vacuumized; preparing the acid fluid according to demands and sampling and analyzing; keeping a system pipeline at constant temperature; exerting confining pressure and backpressure to the reaction kettle; exerting porous pressure; and measuring permeation coefficients and displacement pressure of the material in real time. The device is excellent in antiseptic property; due to a liquid preparation relay device, the difficulty of preparing a large-capacity acid fluid under high pressure condition is solved, and the contact area of the acid fluid with the device is reduced as much as possible; and a sealing structure of a rock core end part is in a mode that a bandage is adopted to be tightly tied and sealed with a side surface sealing material at a sharp ring of an end part gasket, so that the device is simple and economic, and at the same time, anti-corrosion and sealing are realized.

Description

technical field [0001] The present invention relates to the field of research on the interaction between rock-like porous media materials and external fluids, more specifically to a device for studying changes in rock physical parameters under the action of acidic fluids, and also to a method for studying changes in rock physical parameters under the action of acidic fluids. It is suitable for the interaction between rock-like porous media materials and foreign fluids, such as the influence of long-term chemical reactions between sandstone and injected carbon dioxide and hydrogen sulfide aqueous solutions on the evolution of physical parameters such as sandstone permeability coefficient and displacement pressure. Background technique [0002] With the demand and development of deep development and safety evaluation projects of industrial projects such as enhanced coalbed methane recovery (ECBM), shale gas recovery, enhanced crude oil recovery (EOR), and deep geothermal recove...

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Problems solved by technology

The influence of the interaction between external fluid and rock on reservoir sandstone, specifically, the change of seepage characteristics may be due to the deterioration of formation injectability caused by the decrease of rock permeability coefficient near the injection well, which has a greater impact on the flow and migration of injected fluid in the formation. The influence is great; the evolution of rock displacement pressure may cause the displacement pressure at the interface between the reservoir and the caprock to be gradually lower than the formation pressure and the injected fluid (such as supercritical CO 2 ) buoyancy cannot prevent the fluid from infiltrating and penetrating the caprock, and the reservoir gradually loses the residual gas isolation ability; the long-term chemical reaction affects the mechanical properties of the rock, and the formation pressure also increases due to the continuous injection of fluid, which may lead to local failure and damage of the rock Or the integrity of the formation is unstable, and even induces an earthquake

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