CN114906855B - Preparation method of visual artificial rock core for displaying fingering phenomenon - Google Patents

Abstract

The invention discloses a preparation method of a visual artificial core for displaying a fingering phenomenon, which is implemented according to the following steps: step 1, preparing KH560 modified luminol; step 2, preparing gel; step 3, carrying out gel modification on the gel prepared in the step 2; and 4, curing and molding the gel prepared in the step 3 to form the artificial rock core. According to the invention, the visual artificial rock core with high simulation degree and simple process is obtained by introducing the substance with the chemiluminescence potential into the silicon dioxide gel and forming the pore throat structure of the porous structure simulation rock core by using the silicon dioxide gel in the curing and forming process. The chemiluminescence phenomenon of the rock core is that the alkaline fluid containing hydrogen peroxide contacts with the modified luminol on the surface of the rock core pore channel in the advancing process of the rock core in the pore space environment, and the chemiluminescence phenomenon is displayed under the action of the ferric citrate which is the silica gel body weight, so that the three-dimensional fingering phenomenon of the fluid is clearly displayed.

Description

Preparation method of visualized artificial core for demonstration of fingering phenomenon

technical field

The invention belongs to the technical field of oil and gas reservoir development, and relates to a method for preparing a visualized artificial rock core for displaying fingering phenomena.

Background technique

Viscous fingering is an interfacial instability phenomenon produced when a fluid with a lower viscosity displaces a fluid with a higher viscosity. Because the non-uniform advancement of the two-phase interface is like a "finger", it is called fingering. In the process of oil field development, it is necessary to inject other fluids to displace crude oil. The phenomenon of viscous fingering makes a large amount of crude oil remain in the ground because it has not been swept, resulting in a decline in displacement efficiency, which in turn leads to a decrease in oil recovery efficiency. Therefore, the study of viscous fingering by microscopic model simulation is of great significance for deepening the understanding of microscopic seepage mechanism of chemical flooding and improving the development effect of oil and gas fields.

At present, physical simulation experiments are often used to study chemical flooding theory and technology. Compared with field experiments, this model has the advantages of low cost, short time and repeatability. The selection of artificial cores in physical simulation experiments is very important, especially the selection of visualized artificial cores is helpful for the in-depth study of chemical flooding seepage flow theory. At present, the commonly used visualized artificial cores are mainly glass simulation cores. Glass simulation cores reflect the real pore structure by engraving channels on the glass model. However, the structural pore throat diameter of glass simulation cores is too large to reflect the real formation. The physical and chemical properties of the pore surface and the limited degree of visualization severely limit its application research. Therefore, it is urgent to develop a visual artificial core with high simulation degree, high visualization degree, simple preparation process and low price.

Contents of the invention

The purpose of the present invention is to provide a method for preparing a visualized artificial core for displaying the fingering phenomenon, which solves the problems of low fidelity and difficult manufacturing process of the visualized artificial core prepared in the prior art.

The technical solution adopted in the present invention is a method for preparing a visualized artificial rock core for displaying the fingering phenomenon, which is specifically implemented according to the following steps:

Step 1, preparing KH560 modified luminol;

Step 2, preparing the gel;

Step 3, modifying the gel prepared in step 2;

Step 4, curing and molding the gel prepared in step 3 to form an artificial rock core.

The present invention is also characterized in that,

Step 1 is specifically implemented according to the following steps: dissolve luminol in 0.001mol/L sodium hydroxide aqueous solution, and then add the ethanol solution of γ-glycidyl etheroxypropyl trimethoxysilane, wherein γ-glycidyl ether oxygen The molar ratio of propyltrimethoxysilane to luminol is 1:1.0-1.1, and the reaction is carried out at 25°C for 2 hours, and the solvent is distilled off under reduced pressure to obtain KH560 modified luminol.

Step 2 is specifically implemented according to the following steps: add tetraethyl orthosilicate, ethanol, and water into a flask equipped with a stirring device, mix well, and then add 0.5mol/L acetic acid aqueous solution dropwise, adjust the pH of the system to 2-3, and continue stirring After 60 minutes to obtain silicic acid sol, add ferric citrate to the silicic acid sol, stir evenly, add 0.01mol/L sodium hydroxide aqueous solution, adjust the pH of the system to 6-7, and stir for 30 minutes to obtain a gel.

Step 3 is specifically implemented according to the following steps: mix the KH560 modified luminol prepared in step 1 with trimethylchlorosilane/n-hexane, soak the gel in step 2 in trimethylchlorosilane/n-hexane and KH560 modified luminol/ethanol, sealed and placed in an oven at 20-40°C for 24-48 hours to obtain a hydrophobically modified silica gel carrying a luminescent substance. Pour the gel system containing the solvent to remove a large amount of solvent. A silica gel was obtained.

Step 4: Put the silica gel prepared in step 3 into a rock core mold, and then place it in a constant temperature oven to gradually dry. The silica gel is being dried and solidified to form the skeleton structure of the artificial rock core.

In step 1, any one of 3-amino-phthalohydrazide, N-(4-aminobutyl)-N-ethylisoluminol and 4-aminophthalohydrazide is used for luminol.

In step 2, the molar ratio of ethyl orthosilicate, ethanol, and water is 1:8:4.

In step 2, the amount of ferric citrate added accounts for 0.2 to 0.4 wt% of the amount of ethyl orthosilicate in the silicic acid sol;

In step 3, the amount of trimethylchlorosilane added accounts for 1-15% by weight of the amount of ethyl orthosilicate in the gel.

The added amount of KH560 modified luminol in the step 3 accounts for 0.2-0.5wt% of the tetraethyl orthosilicate in the gel.

The beneficial effects of the present invention are: the present invention is used for the preparation method of the visualized artificial rock core displaying the fingering phenomenon, through the improvement of the alkaline fluid containing hydrogen peroxide in the process of advancing in the void environment of the artificial rock core, contacting the surface of the core channel luminol, and under the action of ferric citrate in silica gel, it shows a chemiluminescence phenomenon, which can clearly show the three-dimensional fingering phenomenon of the fluid, and utilizes the chemiluminescence potential of the artificial core to realize the fluid in the void 3D visualization of the fingering phenomenon as the environment progresses. The surface layer of the artificial rock core proposed by the present invention is modified by different contents of trimethylchlorosilane, which can simulate the degree of wetting of the rock core under different conditions, and the artificial rock core of silica airgel with luminescence potential can be prepared According to the simulation, the three-dimensional shape of the water flooding front shows obvious fingering phenomenon according to the light, and then the injection and production of the oil reservoir are adjusted, and artificial cores with low price, simple manufacturing process and high degree of simulation can be prepared.

Detailed ways

The present invention will be described in detail below in combination with specific embodiments.

The method for preparing a visualized artificial core for displaying the fingering phenomenon of the present invention is specifically implemented according to the following steps:

Step 1, preparing KH560 modified luminol;

The specific process of step 1 is:

Dissolve luminol in 0.001mol/L sodium hydroxide aqueous solution, and then add the ethanol solution of γ-glycidyl etheroxypropyl trimethoxysilane, wherein γ-glycidyl etheroxypropyltrimethoxysilane and Luminol The molar ratio of minol is 1:1.0~1.1, the reaction is carried out at 25°C for 2h, and the solvent is distilled off under reduced pressure to obtain KH560 modified luminol.

Luminol adopts any one of 3-amino-phthalic hydrazide, N-(4-aminobutyl)-N-ethyl isoluminol, and 4-aminophthalic hydrazide.

KH560 modified luminol is through the reaction of γ-glycidyl etheroxypropyltrimethoxysilane (KH560) and luminol under the action of alkaline catalyst sodium hydroxide, wherein the molar ratio of KH560 to luminol is 1:( 1～1.1), the reaction temperature is 25°C, and KH560 modified luminol is obtained.

Step 2, preparing the gel;

Add tetraethyl orthosilicate, ethanol, and water into a flask equipped with a stirring device, mix well, and then add dropwise 0.5mol/L acetic acid aqueous solution to adjust the pH of the system to 2-3, and continue stirring for 60 minutes to obtain silicic acid sol. Add ferric citrate to the silicic acid sol, stir evenly, add 0.01mol/L sodium hydroxide aqueous solution, adjust the pH of the system to 6-7, and stir for 30 minutes to obtain a gel.

Wherein the molar ratio of tetraethyl orthosilicate, ethanol, water is 1:8:4, and the amount of ferric citrate accounts for 0.2～0.4wt% of the amount of tetraethyl orthosilicate in the silicic acid sol;

Step 3, modifying the gel prepared in step 2;

Mix the KH560 modified luminol/ethanol prepared in step 1 with trimethylchlorosilane/n-hexane, soak the gel in step 2 in trimethylchlorosilane/n-hexane and KH560 modified luminol/ethanol After being sealed, put it in an oven and react at 20-40°C for 24-48 hours to obtain a hydrophobically modified silica gel carrying a luminescent substance. Pour the gel system containing the solvent to remove a large amount of solvent to obtain a silica gel body.

Hydrophobic modified silica gel is formed by the reaction of trimethylchlorosilane and gel. The amount of trimethylchlorosilane determines the hydrophilicity and hydrophobicity of the artificial core. The introduction of modified luminol makes the silica gel have luminescence potential, and the addition of KH560 modified luminol accounts for 0.2-0.5wt of the amount of ethyl orthosilicate in the gel %.

Step 4, solidifying and molding the gel prepared in step 3 to form an artificial rock core;

Put the silica gel prepared in step 3 into a core mold, and then place it in a constant temperature oven to gradually dry, and the silica gel will form the skeleton structure of the artificial core during drying and curing.

The present invention prepares a visualized artificial rock core for displaying the fluid fingering phenomenon, introduces substances with chemiluminescent potential into the silica gel body, and utilizes the silica gel to form a porous structure simulated rock core during the solidification molding process. Pore-throat structure, to obtain a visualized artificial core with high simulation degree and simple process.

The invention prepares a visualized artificial rock core for displaying the fluid fingering phenomenon. The chemiluminescent phenomenon is that the alkaline fluid containing hydrogen peroxide is in the process of advancing in the core void environment, and contacts the modified luminol on the surface of the core channel, and Under the action of the ferric citrate of the silica gel, it shows a chemiluminescent phenomenon, which can clearly demonstrate the three-dimensional fingering phenomenon of the fluid.

Example 1

This embodiment is used to demonstrate the method for preparing a visualized artificial core of the fingering phenomenon, which is specifically implemented according to the following steps:

Step 1, prepare KH560 modified luminol, dissolve 3-amino-phthalic hydrazide in 0.001mol/L sodium hydroxide aqueous solution, add γ-glycidyl etheroxypropyl trimethoxysilane (KH560) The ethanol solution, wherein the molar ratio of KH560 and luminol is 1:1.0, was reacted at 25°C for 2h, and the solvent was distilled off under reduced pressure to obtain KH560 modified luminol.

Step 2, to prepare the gel, add ethyl orthosilicate, ethanol, and water into a flask equipped with a stirring device, wherein the molar ratio of ethyl orthosilicate, ethanol, and water is 1:8:4, mix well and drop Add 0.5mol/L acetic acid aqueous solution, adjust the pH of the system to 2, and continue to stir for 60 minutes to obtain silicic acid sol; add ferric citrate to the silicic acid sol and stir evenly, and the amount of ferric citrate accounts for 0.2% of the amount of ethyl orthosilicate wt%; and adding 0.01 mol/L aqueous sodium hydroxide solution to adjust the pH of the system to 6, and stirring for 30 minutes to obtain a gel.

Step 3, modify the gel prepared in step 2; soak the gel formed in step 2 in trimethylchlorosilane/n-hexane and KH560 modified luminol/ethanol, seal it and place it in an oven Reaction at 20°C for 24h, wherein the addition of trimethylchlorosilane and KH560 modified luminol accounted for 1wt% and 0.2wt% of the amount of ethyl orthosilicate, respectively, to obtain hydrophobically modified silica gel with luminescent substances glue. The gel system containing the solvent is poured to remove a large amount of solvent, and then the gel is gradually dried in a constant temperature oven to obtain a silica aerosol.

Step 4, curing and molding to form an artificial core:

Remove a large amount of solvent from the above-mentioned gel system containing solvent, put it into a core mold, and then gradually dry it in a constant temperature oven to obtain a visual artificial core for displaying the fingering phenomenon.

Example 2

This embodiment is used to demonstrate the method for preparing a visualized artificial core of the fingering phenomenon, which is specifically implemented according to the following steps:

Step 1, prepare KH560 modified luminol, dissolve 3-amino-phthalic hydrazide (luminol) in 0.001mol/L sodium hydroxide aqueous solution, add γ-glycidyl etheroxypropyl trimethoxy The ethanol solution of base silane (KH560), wherein the molar ratio of KH560 and luminol is 1:1.0, was reacted at 25°C for 2h, and the solvent was distilled off under reduced pressure to obtain KH560 modified luminol.

Step 2, to prepare the gel, add ethyl orthosilicate, ethanol, and water into a flask equipped with a stirring device, and mix them evenly, wherein the molar ratio of ethyl orthosilicate, ethanol, and water is 1:8:4 , add 0.5 mol/L aqueous acetic acid solution dropwise to the above system, adjust the pH of the system to 2, and continue to stir for 60 minutes to obtain silicic acid sol; add iron citrate to the above system and stir evenly, the amount of iron citrate added accounts for 0.3wt% of the amount of ethyl ester; and adding 0.01mol/L aqueous sodium hydroxide solution to adjust the pH of the system to 6, and stirring for 30min to obtain a gel.

Step 3, modify the gel prepared in step 2; soak the gel formed in step 2 in trimethylchlorosilane/n-hexane and KH560 modified luminol/ethanol, seal it and place it in an oven Reaction at 30°C for 48h, wherein the addition of trimethylchlorosilane and KH560 modified luminol accounted for 5wt% and 0.3wt% of the amount of ethyl orthosilicate, respectively, to obtain hydrophobically modified silica gel with luminescent substances glue. The gel system containing the solvent is poured to remove a large amount of solvent, and then the gel is gradually dried in a constant temperature oven to obtain a silica aerosol.

Step 4, curing and molding to form an artificial core:

Remove a large amount of solvent from the above-mentioned gel system containing solvent, put it into a core mold, and then gradually dry it in a constant temperature oven to obtain a visual artificial core for displaying the fingering phenomenon.

Example 3

This embodiment is used to demonstrate the method for preparing a visualized artificial core of the fingering phenomenon, which is specifically implemented according to the following steps:

Step 1, prepare KH560 modified luminol, dissolve 3-amino-phthalic hydrazide (luminol) in 0.001mol/L sodium hydroxide aqueous solution, add γ-glycidyl etheroxypropyl trimethoxy The ethanol solution of base silane (KH560), wherein the molar ratio of KH560 and luminol is 1:1.0, was reacted at 25°C for 2h, and the solvent was distilled off under reduced pressure to obtain KH560 modified luminol.

Step 2, to prepare the gel, add ethyl orthosilicate, ethanol, and water into a flask equipped with a stirring device, and mix them evenly, wherein the molar ratio of ethyl orthosilicate, ethanol, and water is 1:8:4 , add 0.5 mol/L aqueous acetic acid solution dropwise to the above system, adjust the pH of the system to 2, and continue to stir for 60 minutes to obtain silicic acid sol; add iron citrate to the above system and stir evenly, the amount of iron citrate added accounts for 0.4wt% of the amount of ethyl ester; and adding 0.01mol/L sodium hydroxide aqueous solution to adjust the pH of the system to 6, and stirring for 30min to obtain a gel.

Step 3, modify the gel prepared in step 2; soak the gel formed in step 2 in trimethylchlorosilane/n-hexane and KH560 modified luminol/ethanol, seal it and place it in an oven Reaction at 40°C for 48h, wherein the addition of trimethylchlorosilane and KH560 modified luminol accounted for 10wt% and 0.4wt% of the amount of ethyl orthosilicate, respectively, to obtain hydrophobically modified silica gel with luminescent substances. glue. The gel system containing the solvent is poured to remove a large amount of solvent, and then the gel is gradually dried in a constant temperature oven to obtain a silica aerosol.

Step 4, curing and molding to form an artificial core:

Remove a large amount of solvent from the above-mentioned gel system containing solvent, put it into a core mold, and then gradually dry it in a constant temperature oven to obtain a visual artificial core for displaying the fingering phenomenon.

Example 4

This embodiment is used to demonstrate the method for preparing a visualized artificial core of the fingering phenomenon, which is specifically implemented according to the following steps:

Step 1, prepare KH560 modified luminol, dissolve 3-amino-phthalic hydrazide (luminol) in 0.001mol/L sodium hydroxide aqueous solution, add γ-glycidyl etheroxypropyl trimethoxy The ethanol solution of base silane (KH560), wherein the molar ratio of KH560 and luminol is 1:1.0, was reacted at 25°C for 2h, and the solvent was distilled off under reduced pressure to obtain KH560 modified luminol.

Step 2, to prepare the gel, add ethyl orthosilicate, ethanol, and water into a flask equipped with a stirring device, and mix them evenly, wherein the molar ratio of ethyl orthosilicate, ethanol, and water is 1:8:4 , add 0.5 mol/L aqueous acetic acid solution dropwise to the above system, adjust the pH of the system to 3, continue to stir for 60 minutes, and obtain silicic acid sol; add ferric citrate to the above system and stir evenly, the amount of ferric citrate is 0.4wt% of the amount of ethyl ester; and adding 0.01mol/L aqueous sodium hydroxide solution to adjust the pH of the system to 7, and stirring for 30min to obtain a gel.

Step 3, modify the gel prepared in step 2; soak the gel formed in step 2 in trimethylchlorosilane/n-hexane and KH560 modified luminol/ethanol, seal it and place it in an oven Reaction at 40°C for 36h, wherein the addition of trimethylchlorosilane and KH560 modified luminol accounted for 15wt% and 0.5wt% of the amount of ethyl orthosilicate, respectively, to obtain hydrophobically modified silica gel with luminescent substances. glue. The gel system containing the solvent is poured to remove a large amount of solvent, and then the gel is gradually dried in a constant temperature oven to obtain a silica aerosol.

Step 4, curing and molding to form an artificial core:

Remove a large amount of solvent from the above-mentioned gel system containing solvent, put it into a core mold, and then gradually dry it in a constant temperature oven to obtain a visual artificial core for displaying the fingering phenomenon.

Example 5

This embodiment is used to demonstrate the method for preparing a visualized artificial core of the fingering phenomenon, which is specifically implemented according to the following steps:

Step 1, prepare KH560 modified luminol, dissolve 4-aminophthalhydrazide (luminol) in 0.001mol/L sodium hydroxide aqueous solution, add γ-glycidyl etheroxypropyl trimethoxy The ethanol solution of base silane (KH560), wherein the molar ratio of KH560 and luminol is 1:1.1, was reacted at 25°C for 2h, and the solvent was distilled off under reduced pressure to obtain KH560 modified luminol.

Step 2, to prepare the gel, add ethyl orthosilicate, ethanol, and water into a flask equipped with a stirring device, and mix them evenly, wherein the molar ratio of ethyl orthosilicate, ethanol, and water is 1:8:4 , add 0.5 mol/L aqueous acetic acid solution dropwise to the above system, adjust the pH of the system to 3, continue to stir for 60 minutes, and obtain silicic acid sol; add ferric citrate to the above system and stir evenly, the amount of ferric citrate is 0.2wt% of the amount of ethyl ester; and adding 0.01mol/L aqueous sodium hydroxide solution to adjust the pH of the system to 6, and stirring for 30min to obtain a gel.

Step 3, modify the gel prepared in step 2; soak the gel formed in step 2 in trimethylchlorosilane/n-hexane and KH560 modified luminol/ethanol, seal it and place it in an oven Reaction at 20°C for 24h, wherein the addition of trimethylchlorosilane and KH560 modified luminol accounted for 1wt% and 0.2wt% of the amount of ethyl orthosilicate, respectively, to obtain hydrophobically modified silica gel with luminescent substances glue. The gel system containing the solvent is poured to remove a large amount of solvent, and then the gel is gradually dried in a constant temperature oven to obtain a silica aerosol.

Step 4, curing and molding to form an artificial core:

Remove a large amount of solvent from the above-mentioned gel system containing solvent, put it into a core mold, and then gradually dry it in a constant temperature oven to obtain a visual artificial core for displaying the fingering phenomenon.

Example 6

This embodiment is used to demonstrate the method for preparing a visualized artificial core of the fingering phenomenon, which is specifically implemented according to the following steps:

Step 1, prepare KH560 modified luminol, dissolve N-(4-aminobutyl)-N-ethyl isoluminol (luminol) in 0.001mol/L sodium hydroxide aqueous solution, add γ - Ethanol solution of glycidyl etheroxypropyltrimethoxysilane (KH560), wherein the molar ratio of KH560 and luminol is 1:1.1, react at 25°C for 2h, and distill off the solvent under reduced pressure to obtain KH560 modified Luminol.

Step 2, to prepare the gel, add ethyl orthosilicate, ethanol, and water into a flask equipped with a stirring device, and mix them evenly, wherein the molar ratio of ethyl orthosilicate, ethanol, and water is 1:8:4 , add 0.5 mol/L aqueous acetic acid solution dropwise to the above system, adjust the pH of the system to 2, and continue to stir for 60 minutes to obtain silicic acid sol; add iron citrate to the above system and stir evenly, the amount of iron citrate added accounts for 0.4wt% of the amount of ethyl ester; and adding 0.01mol/L aqueous sodium hydroxide solution to adjust the pH of the system to 7, and stirring for 30min to obtain a gel.

Step 3, modify the gel prepared in step 2; soak the gel formed in step 2 in trimethylchlorosilane/n-hexane and KH560 modified luminol/ethanol, seal it and place it in an oven Reaction at 40°C for 48h, wherein the addition of trimethylchlorosilane and KH560 modified luminol accounted for 15wt% and 0.5wt% of the amount of ethyl orthosilicate, respectively, to obtain hydrophobically modified silica gel with luminescent substances. glue. The gel system containing the solvent is poured to remove a large amount of solvent, and then the gel is gradually dried in a constant temperature oven to obtain a silica aerosol.

Step 4, curing and molding to form an artificial core:

Remove a large amount of solvent from the above-mentioned gel system containing solvent, put it into a core mold, and then gradually dry it in a constant temperature oven to obtain a visual artificial core for displaying the fingering phenomenon.

The visualized artificial core prepared in the above examples 1-6 utilizes the chemiluminescence potential of the artificial core to realize the three-dimensional visual display of the fingering phenomenon of the fluid to be measured during the process of advancing in the void environment. When displaying the fingering phenomenon, under the action of ferric citrate, the modified luminol and the alkaline hydrogen peroxide fluid contact to produce a luminescent phenomenon. Wherein the pH value of the alkaline hydrogen peroxide system is 8-9, and the addition amount of 10% hydrogen peroxide accounts for 0.5-5.0 wt% of the fluid. The process of showing the fingering phenomenon is to inject the fluid to be tested containing alkaline hydrogen peroxide into the pore throat of the core after the prepared silica gel carrying the luminescent substance is dried and solidified, and the fluid fingering phenomenon can be realized. 3D visualization.

The invention is used for the preparation method of a visualized artificial rock core exhibiting the fingering phenomenon. The artificial rock core with chemiluminescent potential is a hydrophobically modified silica gel, and the surface of the silica gel carries modified Lu Minol chemiluminescent substance. The porous structure formed by the evaporation of water during the drying and solidification of the gel is similar to the pore throat structure in the rock core. The chemiluminescent phenomenon of the visualized artificial rock core is that the alkaline fluid containing hydrogen peroxide is in the process of advancing in the void environment of the artificial rock core, and it contacts the modified luminol on the core surface. glow phenomenon.

Claims (7)

1. The preparation method of the visual artificial core for displaying the fingering phenomenon is characterized by comprising the following steps:

step 1, preparing KH560 modified luminol;

the step 1 is specifically implemented according to the following steps: dissolving luminol in 0.001mol/L aqueous solution of sodium hydroxide, and adding ethanol solution of gamma-glycidoxypropyltrimethoxysilane, wherein the molar ratio of the gamma-glycidoxypropyltrimethoxysilane to the luminol is 1:1.0 to 1.1, reacting for 2 hours at the temperature of 25 ℃, and distilling under reduced pressure to remove the solvent to obtain KH560 modified luminol;

step 2, preparing gel;

the step 2 is specifically implemented according to the following steps: adding tetraethoxysilane, ethanol and water into a flask provided with a stirring device, uniformly mixing, then dropwise adding 0.5mol/L acetic acid aqueous solution, adjusting the pH of the system to 2 to 3, continuously stirring for 60min to obtain silicic acid sol, adding ferric citrate into the silicic acid sol, uniformly stirring, adding 0.01mol/L sodium hydroxide aqueous solution, adjusting the pH of the system to 6 to 7, and stirring for 30min to obtain gel;

step 3, carrying out gel modification on the gel prepared in the step 2;

the step 3 is specifically implemented according to the following steps: mixing the KH560 modified luminol prepared in the step 1 with trimethylchlorosilane/n-hexane, soaking the gel in the step 2 in the trimethylchlorosilane/n-hexane and the KH560 modified luminol/ethanol, sealing, placing in an oven, and reacting at 20-40 ℃ for 24-48h to obtain hydrophobic modified silica gel carrying luminescent substances, and pouring a gel system containing a solvent to remove a large amount of the solvent to obtain silica gel;

and 4, curing and molding the gel prepared in the step 3 to form the artificial rock core.

2. The method for preparing the artificial core for displaying the fingering phenomenon according to claim 1, wherein the silica gel prepared in step 3 is filled into a core mold, and then is placed in a constant temperature oven for gradual drying, and the silica gel is formed into a skeleton structure of the artificial core during drying, curing and molding.

3. The method for preparing a visual artificial core for displaying fingering phenomenon according to claim 1, wherein the luminol in step 1 is any one of 3-amino-benzenedicarboxhydrazide, N- (4-aminobutyl) -N-ethyl isoluminol, and 4-aminophthalic hydrazide.

4. The method for preparing a visual artificial core for displaying fingering phenomenon according to claim 1, wherein the molar ratio of ethyl orthosilicate, ethanol and water in the step 2 is 1.

5. The preparation method of the visual artificial core for displaying fingering phenomenon according to claim 1, wherein the addition amount of ferric citrate in the step 2 is 0.2-0.4 wt% of the amount of ethyl orthosilicate in the silicic acid sol.

6. The preparation method of the visual artificial rock core for displaying the fingering phenomenon in the claim 1, characterized in that the addition amount of the trimethylchlorosilane in the step 3 is 1-15wt% of the amount of the ethyl orthosilicate in the gel.

7. The preparation method of the visual artificial rock core for displaying the fingering phenomenon, according to the claim 1, is characterized in that the addition amount of the KH560 modified luminol in the step 3 is 0.2 to 0.5wt% of the amount of ethyl orthosilicate in the gel.