Organic silicon modified furan resin sand consolidation agent main agent as well as preparation method and application thereof

Abstract

The invention relates to the technical field of sand consolidation agents, in particular to an organic silicon modified furan resin sand consolidation agent main agent and a preparation method and application thereof. The preparation method of the organic silicon modified furan resin sand consolidation agent main agent comprises the following steps: furfuryl alcohol reacts under the catalytic action of an acid catalyst to generate polyfurfuryl alcohol; the preparation method comprises the following steps: reacting polyfurfuryl alcohol, organosiloxane and water in a weak acid environment with the pH value of 4-6 to generate a main agent of the organic silicon modified furan resin sand consolidation agent; a large number of siloxane structures exist at the tail end of the main agent of the sand consolidation agent, the purpose of controlling the curing strength is achieved by controlling the number of siloxane, and therefore the siloxane structures show the slow-control curing performance; under the acidic condition, active silicon hydroxyl groups are formed after hydrolysis, can be in contact with polar groups on the surfaces of sand grains and are easy to generate condensation reaction to generate a stable covalent bond structure, and meanwhile, the silicon hydroxyl groups can also be subjected to condensation reaction to realize cross-linking among main agent molecules of the sand consolidation agent, so that a stable spatial network structure is generated.

Description

Technical Field

[0001] The present application relates to the technical field of sand consolidating agents, and in particular to a main agent of an organosilicon-modified furan resin sand consolidating agent and a preparation method and application thereof. Background Art

[0002] Oilfield water injection development technology is a technical means to increase formation pressure by injecting water into the oilfield to promote crude oil production. It is widely used in oilfield development. With the increasing frequency of oilfield water injection development, the sand production in oil wells has become increasingly serious. Sand production refers to the hydraulic scouring generated during water injection, in which fine silt gradually moves from the formation to the near-wellbore area and the wellbore of the oil wellbore under the action of hydraulic force, causing sand accumulation in the wellbore. Sand production can easily cause the permeability of the near-wellbore area of ​​the oil well to decrease and even cause the wellhead of the oil well to be blocked, resulting in difficulties in oil production and a decrease in recovery rate.

[0003] At present, conventional sand control measures use epoxy resin or phenolic resin and sand particles mixed on the ground to prepare coated sand with a certain permeability, which is then injected into the oil well in reverse to occupy part of the wellbore space and block the sand particles near the well from flowing into the wellbore, thereby alleviating the serious problem of sand production in the wellbore. However, after the sand film formed by the mixture of sand consolidating agent and fine sand is injected into the oil well, it can only prevent the sand particles from transferring into the wellbore, but cannot prevent the migration of sand particles near the wellbore, reduce the problems such as the decrease in permeability caused by the migration of sand particles, increase the thickness of the deposits near the wellbore of the oil well, especially in the wellbore, and easily cause wellhead blockage. Summary of the invention

[0004] The purpose of the present application is to provide a main agent of an organosilicon-modified furan resin sand-fixing agent and a preparation method and application thereof in order to address the shortcomings of using epoxy resin or phenolic resin and other sand-fixing agents for underground sand fixation.

[0005] The first aspect of the present application provides a main agent of an organosilicon-modified furan resin sand consolidating agent having the following structural formula:

[0006]

[0007] Wherein, m=5-10, n=1-5;

[0008] When R1 is CH3, R2 is CH2CH3;

[0009] When R1 is OCH3, R2 is CH3;

[0010] When R1 is OCH2CH3, R2 is CH2CH3.

[0011] The second aspect of the present application provides a method for preparing a main agent of an organosilicon-modified furan resin sand consolidating agent, the preparation method comprising the following steps:

[0012] Furan methanol reacts under the catalysis of an acidic catalyst to produce polyfurfuryl alcohol;

[0013] In a weakly acidic environment of pH=4-6, the polyfurfuryl alcohol, organosiloxane and water react to generate an organosilicon-modified furan resin sand consolidating agent main agent, wherein the organosiloxane is methyl orthosilicate, ethyl orthosilicate or polymethyltrioxyethylsiloxane.

[0014] In some embodiments, the acidic catalyst is hydrochloric acid, and the added mass of the acidic catalyst is 1% to 5% of the mass of the furan methanol used;

[0015] The reaction temperature of the furan methanol under the catalysis of the acidic catalyst is 50° C. to 70° C., and the reaction time is 2 h to 5 h.

[0016] In some embodiments, the added mass of the water is 1% to 5% of the sum of the mass of the furan carbinol and the organosiloxane, and the molar ratio of the furan carbinol to the organosiloxane is 1:2 to 6;

[0017] The reaction temperature of the polyfurfuryl alcohol, organosiloxane and water is 50° C. to 70° C., and the reaction time is 2 h to 4 h.

[0018] The third aspect of the present application provides an application of a main agent of an organosilicon-modified furan resin sand consolidating agent, the application comprising:

[0019] Diluting the main agent of the organosilicon-modified furan resin sand-fixing agent with a solvent to form a sand-fixing agent solution;

[0020] adding acid and water to the sand-fixing agent solution and mixing them evenly to form a sand-fixing agent emulsion;

[0021] The sand-fixing agent emulsion is injected into the oil production well, and the well is kept shut for at least 24 hours.

[0022] In some embodiments, the acid is one of citric acid, aminosulfonic acid, p-toluenesulfonic acid and oxalic acid, the added amount of the acid is 2%-4% of the mass of the sand fixation agent solution, and the mass ratio of the water to the sand fixation agent solution is 1:3-4.

[0023] In some embodiments, the solvent is a methanol solution or an ethanol solution, and the mass ratio of the main agent of the organosilicon-modified furan resin sand-consolidating agent to the solvent is 1:0.5-1.5.

[0024] Beneficial effects of the present application: The present application uses polyfurfuryl alcohol formed by the polycondensation of furan methanol as a rigid group, and then further connects silicon segments to the polyfurfuryl alcohol segments through a polycondensation reaction to prepare a main agent of an organosilicon-modified furan resin sand-fixing agent.

[0025] During the application stage, the main agent of the organosilicon-modified furan resin sand-fixing agent is diluted with a solvent to form a sand-fixing agent solution, acid and water are added to the sand-fixing agent solution and mixed evenly to form a sand-fixing agent emulsion, and the sand-fixing agent emulsion is injected into the oil well, and the well is kept shut for at least 24 hours.

[0026] It should be noted that under the temperature of the underground formation and acidic conditions, the main agent of the organosilicon-modified furan resin sand consolidating agent will undergo the following changes to achieve the consolidation of sand particles: Since a large amount of siloxane structure is introduced into the tail end of the main agent of the organosilicon-modified furan resin sand consolidating agent, the purpose of controlling the curing strength is achieved by controlling the amount of siloxane in the synthesis stage, so the siloxane structure exhibits the performance of slow-controlled curing;

[0027] Furthermore, under the acidic conditions of the underground formation, the main agent of the organosilicon-modified furan resin sand-fixing agent can be hydrolyzed to form active silanol groups, which can contact with the polar groups (Si-OH) on the surface of the sand particles and easily undergo condensation reactions to generate a stable covalent bond structure, thereby achieving an effective connection between the sand-fixing agent and the sand particles; at the same time, the silanol groups can also undergo condensation reactions to achieve intermolecular cross-linking of the main agent of the organosilicon-modified furan resin sand-fixing agent, thereby generating a stable spatial network structure;

[0028] Furthermore, under the acidic conditions of the underground formation, the conjugated double bonds of the furfuryl alcohol chain segments in the main agent of the organosilicon-modified furan resin sand consolidating agent will also undergo polymerization reaction to form a random saturated bond structure, which can enhance the curing strength of the system after sand consolidation.

[0029] Moreover, the reaction between the silanol groups in the above-mentioned organosilicon-modified furan resin sand-fixing agent main agent and the surface of the sand particles, the polycondensation reaction between the silanol groups, and the polymerization reaction between the conjugated double bonds of the furfuryl alcohol segments are all carried out in an acidic environment with water, so the organosilicon-modified furan resin sand-fixing agent main agent of the present application can achieve the effect of in-situ curing of the sand particles underwater. Moreover, water exists in the curing environment as a continuous medium, and the resin curing process is a process of adsorption on the surface of the sand particles and polycondensation, so the water exists in the gaps between the sand particles, which can ensure that the cured system formed after curing also exhibits good permeability.

[0030] In summary, the present application provides a main agent of an organosilicon-modified furan resin sand-consolidating agent, which utilizes the temperature of the formation itself to carry out a series of reactions, can consolidate sand particles in a water environment, and can also ensure that the sand particle consolidated body has high compressive strength and good permeability. It has the characteristics of high sand-consolidating strength, strong adaptability, and appropriate permeability after sand consolidation. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0032] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0033] Herein, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0034] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0035] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0036] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples are conventional commercial products unless otherwise specified, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage, "part" means weight part, and ratio means weight.

[0037] The organosilicon-modified furan resin sand-fixing agent main agent provided by the present application and its preparation method and application are further described below in conjunction with specific embodiments.

[0038] The present application provides a main agent of an organosilicon-modified furan resin sand-fixing agent, which can realize underwater sand fixation and has the following structural formula:

[0039]

[0040] Wherein, m=5-10, n=1-5;

[0041] When R1 is CH3, R2 is CH2CH3;

[0042] When R1 is OCH3, R2 is CH3;

[0043] When R1 is OCH2CH3, R2 is CH2CH3.

[0044] In some embodiments, a method for preparing a main agent of an organosilicon-modified furan resin sand consolidating agent comprises the following steps:

[0045] Furan methanol undergoes polycondensation under the catalysis of an acidic catalyst to generate polyfurfuryl alcohol, which can be expressed by the reaction equation:

[0046]

[0047] Among them, m=5~10.

[0048] The polyfurfuryl alcohol, organosiloxane and water react to generate the organosilicon-modified furan resin sand consolidating agent main agent, wherein the organosiloxane is methyl orthosilicate, ethyl orthosilicate or polymethyltrioxyethylsiloxane, which is expressed by the reaction equation:

[0049]

[0050] Wherein, m=5-100, n=1-5;

[0051] When R1 is CH3, R2 is CH2CH3;

[0052] When R1 is OCH3, R2 is CH3;

[0053] When R1 is OCH2CH3, R2 is CH2CH3.

[0054] In some embodiments, the acidic catalyst is hydrochloric acid, the added mass of the acidic catalyst is 1% to 5% of the mass of the furan methanol used, the reaction temperature during the polycondensation reaction is 50° C. to 70° C., and the reaction time is 2 h to 5 h.

[0055] In some embodiments, the added mass of the water is 1% to 5% of the sum of the mass of the furan carbinol and the organosiloxane, and the molar ratio of the furan carbinol to the organosiloxane is 1:2 to 6;

[0056] The reaction temperature of the polyfurfuryl alcohol, organosiloxane and water is 50°C to 70°C, and the reaction time is 2h to 4h. Under this reaction condition, after the reaction is completed, the product is stable and static without stratification, and is a reddish brown viscous liquid. However, when the reaction time exceeds 4h and the reaction temperature exceeds 70°C, Si-OR will be completely hydrolyzed into Si-OH, causing a sharp increase in the number of Si-OH, and then triggering Si-OH and Si-OH, Si-OH and hydroxyl groups in polyfurfuryl alcohol to undergo condensation reactions, and finally implode to generate extremely viscous and non-uniform polymers or even hard block polymers. This polymer has poor solubility and is difficult to operate, and because the implosion consumes a large number of active functional groups, the sand consolidation effect of the sand consolidating agent underwater is poor.

[0057] The present application also provides an application of an organosilicon-modified furan resin sand-fixing agent main agent, comprising: diluting the organosilicon-modified furan resin sand-fixing agent main agent with a solvent to form a sand-fixing agent solution, adding acid and water to the sand-fixing agent solution and mixing them evenly to form a sand-fixing agent emulsion, injecting the sand-fixing agent emulsion into an oil production well, and keeping the well shut for at least 24 hours.

[0058] In some embodiments, the amount of the acid added is 2%-4% of the mass of the sand-fixing agent, and the mass ratio of the water to the sand-fixing agent solution is 1:3-4.

[0059] The solvent is a methanol solution or an ethanol solution, and the mass ratio of the main agent of the organosilicon-modified furan resin sand-consolidating agent to the solvent is 1:0.5-1.5.

[0060] The main agent of the organosilicon-modified furan resin sand-fixing agent and the preparation method thereof are illustrated in conjunction with the following specific examples.

[0061] Example 1

[0062] The reactant furan methanol (98 g, 1 mol) was added to a small glass reactor, and the first step of polycondensation reaction was carried out under the catalytic action of hydrochloric acid, wherein the amount of hydrochloric acid added was 0.2%, the temperature in the reactor was 40°C, and the reaction time was 1 h; the reaction solution was then adjusted to weak acidity (pH = 4), and polymethyltrioxyethylsiloxane (Jinan Xingfeilong Chemical Co., Ltd., 534 g, 1 mol) and 6.32 g of water were added under normal pressure to carry out the second step of reaction, and the reaction was carried out at 50°C for 2 h. After standing without stratification, the obtained product was a reddish brown viscous liquid, namely the main agent of the organosilicon-modified furan resin sand-fixing agent.

[0063] Example 2

[0064] Add the reactant furan methanol (49g, 0.5mol) into a small glass reactor, and carry out the first step of polycondensation reaction under the catalytic action of hydrochloric acid, wherein the amount of hydrochloric acid added is 0.3%, wherein the temperature in the reactor is 60°C, and the reaction time is 3h; then adjust the above reaction solution to weak acidity (pH=5), add ethyl orthosilicate (208g, 1mol) and 5.14g water under normal pressure to carry out the second step of etherification reaction, wherein the mass ratio of polyfurfuryl alcohol to organosiloxane is 1:4, the amount of water added is 2% of the sum of the mass of furan methanol and the organosiloxane, react at 60°C for 0.5h, and stand still without stratification. The obtained product is a reddish brown viscous liquid silicon-modified furan resin sand consolidating agent main agent.

[0065] Example 3

[0066] Add the reactant furan methanol (98g, 1mol) into a small glass reactor, and carry out the first step of polycondensation reaction under the catalytic action of hydrochloric acid, wherein the amount of hydrochloric acid added is 1%, wherein the temperature in the reactor is 60°C, and the reaction time is 2h; then adjust the above reaction solution to weak acidity (pH=6), add polymethyl trioxyethyl siloxane (427.2g, 0.8mol) and 10.5g water under normal pressure to carry out the second step of etherification reaction, wherein the mass ratio of polyfurfuryl alcohol to organosiloxane is 1:4.24, the amount of water added is 2% of the total mass, react at 60°C for 1h, and stand still without stratification. The obtained product is a reddish brown viscous liquid, namely the main agent of the organosilicon-modified furan resin sand consolidating agent.

[0067] Example 4

[0068] Add the reactant furan methanol (98g, 1mol) into a small glass reactor, and carry out the first step of polycondensation reaction under the catalytic action of hydrochloric acid, wherein the amount of hydrochloric acid added is 2%, wherein the temperature in the reactor is 40°C, and the reaction time is 4h; then adjust the above reaction liquid to weak acidity (pH=5), add methyl orthosilicate (228g, 1.5mol) and 8.2g water under normal pressure to carry out the second step of etherification reaction, wherein the mass ratio of polyfurfuryl alcohol to organosiloxane is 1:3.18, the amount of water added is 2% of the total mass, react at 60°C for 2h, and stand for no stratification. The obtained product is a reddish brown viscous liquid, namely the main agent of organosilicon modified furan resin sand consolidating agent.

[0069] Performance Testing

[0070] Sand consolidation performance test of underwater sand consolidation using organosilicon-modified furan resin sand consolidation agent as main agent

[0071] First, the organosilicon-modified furan resin sand-fixing agent provided in the above embodiments is diluted with an alcohol solvent to form a low-viscosity sand-fixing agent solution, for example: the mass ratio of the organosilicon-modified furan resin sand-fixing agent to the solvent is 1:0.5-1.5. Methanol is selected and mixed with the organosilicon-modified furan resin sand-fixing agent to form a sand-fixing agent solution with a concentration of 50%.

[0072] Then, the sand consolidating agent solution, acid and water are fully mixed to form a sand consolidating agent emulsion according to the mass ratio of the sand consolidating agent solution, acid and water being 100:2-3:300-400. The acid is one of citric acid, aminosulfonic acid, p-toluenesulfonic acid and oxalic acid.

[0073] Next, add a sand sample with a sand particle diameter of 0.4 to 0.8 mm into the mold, pour the aforementioned sand-fixing agent emulsion into the mold, and put it into an insulation box at 60°C to 80°C. The mold is a glass tube with a specification of 250 mm in length and 30 mm in diameter.

[0074] After 24h to 48h, the consolidated sand samples are taken out for performance testing, mainly testing the strength and permeability of the consolidated sand samples. The instrument used to test the strength of the consolidated sand samples is a universal tensile machine, and the instrument used to test the permeability of the consolidated sand samples is a STY-2 permeability tester.

[0075] In this application, a consolidated sand sample is prepared according to the above requirements: 25g of the main agent of the sand consolidating agent prepared in each embodiment is taken, and mixed evenly with 25g of methanol to form a sand consolidating agent solution, and then 1g of citric acid and 150g of water are poured into the sand consolidating agent solution to form a sand consolidating agent emulsion, and then the sand consolidating agent emulsion is poured into a glass tube containing 200g of sand sample, and finally kept warm at 60°C for 24h, and the glass tube is broken to obtain a consolidated sand sample, and the strength and permeability performance of the consolidated sand sample corresponding to each embodiment are tested. This application also sets a comparative example: epoxy resin (25g, Zhilun New Materials Technology Co., Ltd.), curing agent (15g, polyamide resin, Guangzhou Rich Technology Co., Ltd.) and sand (200g) are mixed and poured into a film mold, and after being kept warm at 60°C for 24h, the comparative example consolidated sand sample is tested for curing strength and permeability. The results of each performance test are shown in Table 1.

[0076] Table 1 Performance test results

[0077]

[0078] From the test results in Table 1, it can be seen that the main agent of the organosilicon-modified furan resin sand consolidating agent prepared in each embodiment of the present application can achieve underwater sand consolidation, and the strength and permeability of the consolidated sand samples prepared therefrom meet the industry's performance requirements for underground sand consolidation, especially underground and underwater sand consolidation.

[0079] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A main agent of an organosilicon-modified furan resin sand-fixing agent, characterized in that: Has the following structural formula: Wherein, m=5-10, n=1-5; When R1 is CH3, R2 is CH2CH3; When R1 is OCH3, R2 is CH3; When R1 is OCH2CH3, R2 is CH2CH3.

2. A method for preparing a main agent of an organosilicon-modified furan resin sand-fixing agent, characterized in that: The preparation method comprises the following steps: Furan methanol reacts under the catalysis of an acidic catalyst to produce polyfurfuryl alcohol; In a weakly acidic environment of pH=4-6, the polyfurfuryl alcohol, organosiloxane and water react to generate a main agent of an organosilicon-modified furan resin sand consolidating agent; Wherein, the organosiloxane is methyl orthosilicate, ethyl orthosilicate or polymethyltrioxyethylsiloxane.

3. The method for preparing a main agent of an organosilicon-modified furan resin sand-fixing agent according to claim 2, characterized in that: The acidic catalyst is hydrochloric acid, and the added mass of the acidic catalyst is 1% to 5% of the mass of the furan methanol used; The reaction temperature of the furan methanol under the catalysis of the acidic catalyst is 50° C. to 70° C., and the reaction time is 2 h to 5 h.

4. The method for preparing a main agent of an organosilicon-modified furan resin sand-fixing agent according to claim 2, characterized in that: The added mass of the water is 1% to 5% of the sum of the mass of the furan carbinol and the organosiloxane, and the molar ratio of the furan carbinol to the organosiloxane is 1:2 to 6; The reaction temperature of the polyfurfuryl alcohol, organosiloxane and water is 50° C. to 70° C., and the reaction time is 2 h to 4 h.

5. An application of a main agent of an organosilicon-modified furan resin sand-fixing agent, characterized in that: The applications include: Diluting the main agent of the organosilicon-modified furan resin sand-fixing agent with a solvent to form a sand-fixing agent solution; adding acid and water to the sand-fixing agent solution and mixing them evenly to form a sand-fixing agent emulsion; The sand-fixing agent emulsion is injected into the oil production well, and the well is kept shut for at least 24 hours.

6. The use of a main agent of an organosilicon-modified furan resin sand-fixing agent according to claim 5, characterized in that: The acid is one of citric acid, aminosulfonic acid, p-toluenesulfonic acid and oxalic acid. The amount of the acid added is 2%-4% of the mass of the sand-fixing agent solution. The mass ratio of the water to the sand-fixing agent solution is 1:3-4.

7. The use of a main agent of an organosilicon-modified furan resin sand-fixing agent according to claim 5, characterized in that: The solvent is a methanol solution or an ethanol solution, and the mass ratio of the main agent of the organosilicon-modified furan resin sand-consolidating agent to the solvent is 1:0.5-1.5.

Images