An Acid Stress Simulation Method Considering the Dynamic Process of Mucosal Acid

Abstract

The invention discloses an acid pressure simulation method considering the dynamic process of mucovisic acid. The relationship between the viscosity of mucovisic acid and shear rate, temperature, calcium ion concentration, pH value and surfactant concentration is respectively measured, and a mucoviscic constitutive equation is established. ; Simulate the flow and reaction process of viscous acid in the fracture system, and obtain the pressure profile in the fracture system; take the pressure profile in the fracture system as the inner boundary condition, and the ground pressure as the outer boundary condition, simulate the calculation of the variation of viscous acid in the matrix the reaction process; simulate the viscosity change of the acid solution in the matrix system, and calculate the fluid loss velocity; bring the obtained fluid loss velocity into the pressure profile of the fracture system in the step. The invention is used to solve the problem that the acid pressure simulation technology in the prior art does not consider the dynamic filtration process of mucoacid, resulting in a low coincidence rate between the simulated seam length of the mucoacid acid pressure and the actual situation, and realizes that the simulation can be obtained considering the viscous acid. The purpose of acid fracturing fracture morphology after acid dynamic drop rate.

Description

technical field [0001] The invention relates to the field of fracturing, in particular to an acid fracturing simulation method considering the dynamic process of viscous acid. Background technique [0002] Mucic acid is a variable-viscosity acid first synthesized by Schlumberger in 1997. It is used in the fracturing fluid for oil and gas stimulation through hydraulic fracturing and acidification. A large number of foreign oil fields have been restored. Successful use of production capacity, new oil fields to increase recoverable reserves. The initial viscosity of the existing mucoacid is 170 -1 It can be about 30mpa·s under the shear rate of 100 ℃. With the reaction between the acid liquid and the formation matrix, the pH value increases. When the pH value rises to about 2, the viscosity of the acid liquid system rises sharply and can reach 1000mpa·s. Then, as the acid-rock reaction continues, when the pH value reaches about 4, another chemical reaction is stimulated to re...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a kind of acid fracturing simulation method considering the dynamic process of viscous acid, to solve the acid fracturing simulation technology in the prior art that does not consider the dynamic filtration process of viscous acid, resulting in the length of the simulated seam length of viscous acid fracturing In order to achieve the purpose of simulating the shape of acid fracturing fractures after considering the dynamic drop rate of viscous acid due to the fact that the rate of agreement with the actual situation is not high

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