Microcosmic experimental device and experimental method for studying damage of fracturing fluid to crack-matrix system

Abstract

The invention provides a microcosmic experimental device and an experimental method for researching damage of fracturing fluid of a crack-matrix system, and designs a microfluidic model for simulating the crack-matrix system according to the characteristics of a real hydraulic fracturing reservoir. A microscopic experiment device and an experiment method which are used for researching damage and retention mechanisms of fracturing fluid to a crack-matrix system are constructed by taking the device as a core, and the device is provided with an image real-time acquisition system and a data quantitative analysis system at the same time. The damage mechanism of the fracturing fluid to a crack-matrix system is understood essentially, so that guidance is provided for control of hydraulic fracturing fluid damage and screening of low-damage fracturing fluid.

Description

technical field [0001] The invention belongs to the technical field of reservoir physics simulation, and in particular relates to a microscopic experimental device and an experimental method for studying the damage of fracturing fluid to a fracture-matrix system. Background technique [0002] With the development of economic construction, my country's demand for traditional fossil energy has grown rapidly. What followed is the rapid rise of my country's energy dependence on foreign countries, and energy security is facing severe challenges. At the same time, the development of old oil and gas fields on land has mostly entered the late stage of high water cut. Therefore, unconventional oil and gas reservoirs with increasing annual proven reserves have become an important growth point of oil and gas production in China. However, the inherent geological characteristics of unconventional oil and gas reservoirs, such as small pore throat radius and poor connectivity, make it di...

AI Technical Summary

Problems solved by technology

(2) The microporous medium network model device makes a model of the simulated reservoir matrix by etching the two-dimensional pattern of the matrix casting sheet on the glass sheet, and then injects fracturing fluid into it. The flow behavior in it is used to study its damage characteristics, and this type of model device is usually used to study the interaction between different displacement agents and crude oil, and there are few precedents of using a microscopic porous media network model device to study fracturing fluid damage.

[0006] All three technologies have their own disadvantages and limitations

(1) The core used in the core physical simulation device can only simulate the reservoir matrix, but cannot simulate the characteristics of the fracture-matrix system formed after hydraulic fracturing, and the intrusion and retention process of the fracturing fluid in the core cannot be simulated during the experiment. From visual observation, fracturing fluid damage can only be reflected through indirect parameters such as permeability and residual resistance coefficient.

(2) Although the microporous media model can visualize the flow behavior of fracturing fluid, because its geometric structure is derived from matrix rock casting thin slices, it cannot well reflect the characteristics of the fracture-matrix system, and the randomness of the geometric shape It also makes the repeatability of microporous media model experiments poor, and it is difficult to draw regular conclusions

Finally, (3) In order to reduce the difficulty of modeling and improve the calculation speed, the numerical simulation method usually adopts a large number of approximate processing and ideal condition assumptions, which makes the authenticity and credibility of the whole process decrease.

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