阅读说明：本技术 一种体积压裂用暂堵材料及其制备方法和应用 (Temporary plugging material for volume fracturing and preparation method and application thereof ) 是由 王萌 李向东 张腾 董凯 补成中 熊小林 刘俊辰 于 2020-04-28 设计创作，主要内容包括：本发明公开了一种体积压裂用暂堵材料及其制备方法和应用。该体积压裂用暂堵材料的制备方法包括如下步骤：1)在CO气体气氛中,使CO与环氧丙基酯类化合物在有机钯化合物的催化下进行共聚反应,得到产物A；2)将产物A和非质子有机溶剂混合,得到混合溶液；3)将混合溶液和沉淀剂混合,得到产物B；产物B经过滤和除杂得到所述体积压裂用暂堵材料。本发明还提供了一种体积压裂用暂堵材料及其在油气井压裂暂堵中的应用。本发明制得的体积压裂暂堵材料耐受温度高,暂堵强度强,暂堵时间长,5％盐酸溶解率高。(The invention discloses a temporary plugging material for volume fracturing and a preparation method and application thereof. The preparation method of the temporary plugging material for volume fracturing comprises the following steps: 1) in the atmosphere of CO gas, CO and a glycidyl ester compound are subjected to copolymerization reaction under the catalysis of an organic palladium compound to obtain a product A; 2) mixing the product A with an aprotic organic solvent to obtain a mixed solution; 3) mixing the mixed solution with a precipitator to obtain a product B; and filtering and removing impurities from the product B to obtain the temporary plugging material for volume fracturing. The invention also provides a temporary plugging material for volume fracturing and application thereof in fracturing temporary plugging of an oil-gas well. The volume fracturing temporary plugging material prepared by the invention has high temperature resistance, strong temporary plugging strength, long temporary plugging time and high dissolution rate of 5% hydrochloric acid.)

1. A preparation method of a temporary plugging material for volume fracturing is characterized by comprising the following steps:

1) in the atmosphere of CO gas, CO and a glycidyl ester compound are subjected to copolymerization reaction under the catalysis of an organic palladium compound to obtain a product A;

2) mixing the product A with an aprotic organic solvent to obtain a mixed solution;

3) mixing the mixed solution with a precipitator to obtain a product B; and filtering and removing impurities from the product B to obtain the temporary plugging material for volume fracturing.

2. The method for preparing a temporary plugging material for volume fracturing according to claim 1, wherein the glycidyl ester compound in step 1) comprises glycidyl methyl formate and/or glycidyl ethyl formate.

3. The method for preparing a temporary plugging material for volume fracturing according to claim 1, wherein said organopalladium compound in step 1) comprises bis (dibenzylideneacetone) palladium.

4. The preparation method of the temporary plugging material for volume fracturing as claimed in claim 1, wherein the mass ratio of the glycidyl ester compound to the organic palladium compound in the step 1) is 50-200: 0.3-1.2.

5. The method for preparing a temporary plugging material for volume fracturing according to claim 1, wherein the conditions of the reaction in step 1) comprise: the reaction temperature is 60-200 ℃, the reaction pressure is 5-30 MPa, and the reaction time is 12-36 h.

6. The method for preparing a temporary plugging material for volume fracturing according to claim 1, wherein the aprotic organic solvent in step 2) comprises one or more of chloroform, dichloromethane and tetrahydrofuran.

7. The preparation method of the temporary plugging material for volume fracturing as claimed in claim 1, wherein the volume-to-mass ratio of the aprotic organic solvent to the product A in step 2) is 20-200 mL: 40-200 g.

8. The method for preparing a temporary plugging material for volume fracturing according to claim 1, wherein the precipitant comprises ethanol at a temperature of-10 ℃ to 10 ℃ in step 3).

9. The preparation method of the temporary plugging material for volume fracturing as claimed in claim 1, wherein the volume ratio of the precipitant in step 3) to the aprotic organic solvent in step 2) is 100-400: 20 to 200 parts.

10. The preparation method of the temporary plugging material for volume fracturing as claimed in claim 1, wherein the condition of removing impurities in step 3) is to remove impurities under vacuum degree of-30 Kpa to-90 Kpa.

11. A volume fracturing plugging material prepared by the preparation method of the plugging material according to any one of claims 1 to 10.

12. The application of the temporary plugging material for volume fracturing of claim 11 or the temporary plugging material for volume fracturing prepared by the preparation method of the temporary plugging material for volume fracturing of any one of claims 1 to 10 in fracturing temporary plugging of oil and gas wells.

Technical Field

The invention relates to the technical field of oil extraction engineering. More particularly, relates to a temporary plugging material for volume fracturing and a preparation method and application thereof.

Background

When fracturing and acidizing are carried out on a long well section oil and gas reservoir, the general transformation effect is not ideal enough, and the problems of high risk, high cost and the like exist in the layered and segmented transformation of mechanical tools. In the face of such a situation, a temporary plugging material is generally used. A temporary plugging material is a substance that can temporarily reduce the permeability of a formation or temporarily plug a highly permeable hydrocarbon reservoir. After being mixed with the traditional fracturing and acidizing working fluid, the mixture is injected into a well, and a compact temporary plugging zone of an oil-gas layer can be quickly formed under the action of pressure difference. The blockage can be automatically removed after a certain time.

The plugging agent material meets two major technical requirements according to the application requirements: the first type is high in bearing strength, adjustable in bearing capacity and amplitude time and other requirements; the second type is that the fracturing acidizing working fluid has solubility, which is beneficial to post-fracturing production operation. The first technical requirement requires that the molecular weight of the temporary plugging material is increased, but the molecular weight is too large, so that the temporary plugging material is difficult to dissolve, high in viscosity and difficult to flowback; the second technical requirement requires that the molecular weight of the temporary plugging material is reduced, but the reduction of the molecular weight is easy to cause the reduction of the strength of the temporary plugging material. It can be seen that the two major technical requirements are a pair of spears.

In the paper of "research and evaluation of water-soluble temporary plugging agent HD" published in volume 19, 2 of "environmental protection of oil and gas field", it is mentioned that the temporary plugging agent is prepared from inorganic salts, organic acids (mixture of organic acid and organic acid salt, high softening point, and small change of solubility with temperature) and other additives (including water-soluble high molecular polymer polyacrylamide, surfactant lauric acid monoester, cross-linking agent and solid particles). The temporary plugging agent has good water solubility and can be used for high-water-content oil wells, but the temporary plugging agent cannot be dissolved in acid and does not react with the acid, so that the purpose of dissolving after acid fracturing is difficult to achieve for carbonate oil and gas reservoirs, and secondary damage to reservoirs is easily caused. In patent application No. CN200410009408.1, a water-soluble volume fracturing temporary plugging material is disclosed, which consists of three components of bone glue, sulfonated asphalt and guanidine gum; patent application No. CN1101010.6 discloses a water-soluble temporary plugging material, which is composed of bone glue, sesbania powder (or hydroxymethyl starch) and sulfonated asphalt. The two temporary plugging materials have the problem that the temporary plugging materials can not be dissolved and can not be automatically unplugged after the acid fracturing of the carbonate oil-gas reservoir.

The patent with the application number of CN201110330609.1 provides a volume fracturing temporary plugging material which is prepared by combining resin, ozokerite, calcium carbonate, magnesium carbonate, potassium chloride and ammonium chloride, is suitable for formation temperature of 100 ℃, has the plugging rate of 96 percent, the acid dissolution rate of more than 98 percent and the plugging strength of more than 50MPa, and can meet the requirement of acid fracturing temporary plugging in long well sections of carbonate reservoirs. Patent application No. CN201410076638.3 discloses a viscosity-changing temporary plugging fluid, which consists of 1-5% of water-soluble polyvinyl alcohol, 1-3% of dimethyl bisacrylamide, 0.005-0.02% of N' N-methylene bisacrylamide, 0.005-0.2 of azo initiator, 0.1-0.5 of organic boron crosslinking agent, 0.5-5% of ammonium persulfate capsule and the balance of water, but applicable conditions such as applicable formation temperature, bearable pressure and the like are not published. In recent years, with the advancement of exploration and development to the deep field, the formation temperature is higher and higher, the formation pressure is higher and higher, and the volume fracturing temporary plugging material suitable for the formation temperature of more than 150 ℃ and the pressure bearing pressure of more than 60MPa is not reported.

In order to solve the problems, the invention provides a temporary plugging material for volume fracturing and a preparation method and application thereof.

Disclosure of Invention

The invention aims to provide a temporary plugging material for volume fracturing and a preparation method and application thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of a temporary plugging material for volume fracturing comprises the following steps:

1) in the atmosphere of CO gas, CO and a glycidyl ester compound are subjected to copolymerization reaction under the catalysis of an organic palladium compound to obtain a product A;

2) mixing the product A with an aprotic organic solvent to obtain a mixed solution;

3) mixing the mixed solution with a precipitator to obtain a product B; and filtering and removing impurities from the product B to obtain the temporary plugging material for volume fracturing.

In the invention, the epoxypropyl ester compound and CO are reactants, and the epoxypropyl ester compound and the CO are subjected to ring-opening copolymerization under the catalysis of the organic palladium compound.

Preferably, the glycidyl ester compound in step 1) comprises glycidyl methyl formate and/or glycidyl ethyl formate.

Preferably, the organopalladium compound in step 1) comprises bis (dibenzylideneacetone) palladium.

Preferably, the mass ratio of the glycidyl ester compound to the organic palladium compound in the step 1) is 50-200: 0.3-1.2.

Preferably, the conditions of the reaction in step 1) include: the reaction temperature is 60-200 ℃, the reaction pressure is 5-30 MPa, and the reaction time is 12-36 h.

Preferably, the aprotic organic solvent in step 2) comprises one or more of chloroform, dichloromethane and tetrahydrofuran.

Preferably, the volume mass ratio of the aprotic organic solvent to the product A in the step 2) is 20-200 mL: 40-200 g.

Preferably, the precipitant in step 3) comprises ethanol at a temperature of-10 ℃ to 10 ℃.

Preferably, the volume ratio of the precipitant in the step 3) to the aprotic organic solvent in the step 2) is 100-400: 20 to 200 parts.

Preferably, the impurity removal condition in the step 3) is to remove the unreacted epoxy propyl ester compounds by removing the impurity under the vacuum degree of-30 Kpa to-90 Kpa.

Preferably, the step 3) of obtaining the temporary plugging material for volume fracturing further comprises the step of crushing and sieving the temporary plugging material for volume fracturing, or performing compression molding.

Preferably, the temporary plugging material for volume fracturing is a spherical material with 5-200 meshes.

Preferably, step 1) and step 2) are carried out in a stainless steel tank reactor.

Preferably, in the step 1), before the reaction of the glycidyl ester compound, a step of performing CO gas replacement on air in the stainless steel tank reactor is further included.

Preferably, the ratio of the volume of the stainless steel tank reactor to the volume of the CO gas is 1-5: 100-450.

As another aspect of the invention, the invention also provides a temporary plugging material for volume fracturing, which is prepared by the preparation method of the temporary plugging material for volume fracturing.

The invention also provides an application of the temporary plugging material for volume fracturing prepared by the preparation method of the temporary plugging material for volume fracturing in fracturing temporary plugging of an oil and gas well.

The invention has the following beneficial effects:

the volume fracturing temporary plugging material prepared by the invention has high temperature resistance, strong temporary plugging strength, long temporary plugging time and high dissolution rate of 5% hydrochloric acid.

Detailed Description

In order to more clearly illustrate the invention, the invention is further described below in connection with preferred embodiments. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and is not to be taken as limiting the scope of the invention.

Example 1

The embodiment provides a preparation method of a volume fracturing temporary plugging material, which comprises the following specific steps:

1) the method comprises the following steps of (1) completely replacing air in a stainless steel tank type reactor with the volume of 2.2L with CO gas, adding 102.0g of epoxypropylmethyl formate and 575mg of bis (dibenzylideneacetone) palladium into the stainless steel tank type reactor, then introducing 224L of CO gas, heating to 125 ℃, enabling the pressure in the stainless steel tank type reactor to be 15.1MPa, carrying out ring-opening copolymerization on CO and epoxypropylmethyl formate for 24 hours, cooling to room temperature to obtain 86.7g of a product A, and releasing unreacted CO gas from the stainless steel tank type reactor and carrying out combustion treatment;

2) adding 100mL of trichloromethane into a stainless steel tank type reactor and stirring to obtain a mixed solution;

3) pouring the mixed solution obtained in the step 2) into 200mL of ethanol cooled to 0 ℃, forming a white precipitate in the ethanol, filtering the white precipitate, and removing unreacted epoxypropylmethyl formate under the vacuum degree of-75 Kpa to obtain the volume fracturing temporary plugging material; and crushing and sieving the volume fracturing temporary plugging material to obtain particles of 5-200 meshes.

Example 2

The embodiment provides a preparation method of a volume fracturing temporary plugging material, which comprises the following specific steps:

1) the method comprises the following steps of (1) replacing all air in a stainless steel tank reactor with the volume of 1L with CO gas, adding 50g of methyl epoxypropylformate and 300mg of bis (dibenzylideneacetone) palladium into the stainless steel tank reactor, then introducing 102 liters of CO gas, heating to 135 ℃, controlling the pressure in the stainless steel tank reactor to be 15.5MPa, carrying out ring-opening copolymerization on CO and methyl epoxypropylformate for 24 hours, cooling to room temperature to obtain 42.5g of a product A, and releasing unreacted CO gas from the stainless steel tank reactor and carrying out combustion treatment;

2) adding 60mL of trichloromethane into a stainless steel tank type reactor and stirring to obtain a mixed solution;

3) pouring the mixed solution obtained in the step 2) into 100mL of ethanol cooled to 0 ℃, forming a white precipitate in the ethanol, filtering the white precipitate, and removing unreacted epoxypropylmethyl formate under the vacuum degree of-80 Kpa to obtain the volume fracturing temporary plugging material; and crushing and sieving the volume fracturing temporary plugging material to obtain particles of 20-200 meshes.

Example 3

The embodiment provides a preparation method of a volume fracturing temporary plugging material, which comprises the following specific steps:

1) replacing all air in a stainless steel tank reactor with the volume of 4.5L with CO gas, adding 220g of epoxypropylmethyl formate and 1.0g of bis (dibenzylideneacetone) palladium into the stainless steel tank reactor, then introducing 450 liters of CO gas, heating to 120 ℃, wherein the pressure in the stainless steel tank reactor is 15.1MPa, performing ring-opening copolymerization on CO and epoxypropylmethyl formate for 20 hours, cooling to room temperature to obtain 191.5g of a product A, and releasing unreacted CO gas from the stainless steel tank reactor and performing combustion treatment;

2) adding 200mL of trichloromethane into a stainless steel tank type reactor and stirring to obtain a mixed solution;

3) pouring the mixed solution obtained in the step 2) into 300mL of ethanol cooled to 0 ℃, forming a white precipitate in the ethanol, filtering the white precipitate, and removing unreacted epoxypropylmethyl formate under-70 Kpa vacuum degree to obtain the volume fracturing temporary plugging material; and crushing and sieving the volume fracturing temporary plugging material to obtain particles of 10-40 meshes.

Example 4

The embodiment provides a preparation method of a volume fracturing temporary plugging material, which comprises the following specific steps:

1) the method comprises the following steps of (1) completely replacing air in a stainless steel tank reactor with the volume of 4.5L with CO gas, adding 200g of epoxypropylethyl formate and 0.12g of bis (dibenzylideneacetone) palladium into the stainless steel tank reactor, then introducing 435L of CO gas, heating to 120 ℃, wherein the pressure in the stainless steel tank reactor is 14.8MPa, carrying out ring-opening copolymerization on CO and epoxypropylethyl formate for 20 hours, cooling to room temperature to obtain 160.0g of a product A, and releasing unreacted CO gas from the stainless steel tank reactor and carrying out combustion treatment;

2) adding 200mL of trichloromethane into a stainless steel tank type reactor and stirring to obtain a mixed solution;

3) pouring the mixed solution obtained in the step 2) into 300mL of deionized water cooled to 0 ℃, forming a white precipitate in the deionized water, filtering the white precipitate, and removing unreacted epoxypropylethyl formate under the vacuum degree of-69 Kpa to obtain the volume fracturing temporary plugging material; and crushing and sieving the volume fracturing temporary plugging material to obtain particles of 10-40 meshes.

Example 5

The embodiment provides a preparation method of a volume fracturing temporary plugging material, which comprises the following specific steps:

1) the method comprises the following steps of (1) completely replacing air in a stainless steel tank reactor with the volume of 4.5L with CO gas, adding 200g of epoxypropylethyl formate and 1.2g of bis (dibenzylideneacetone) palladium into the stainless steel tank reactor, then introducing 400L of CO gas, heating to 120 ℃, wherein the pressure in the stainless steel tank reactor is 13.9MPa, carrying out ring-opening copolymerization reaction on CO and epoxypropylethyl formate for 20 hours, cooling to room temperature to obtain 168.5g of a product A, and releasing unreacted CO gas from the stainless steel tank reactor and carrying out combustion treatment;

2) adding 210mL of dichloromethane into a stainless steel tank type reactor and stirring to obtain a mixed solution;

3) pouring the mixed solution obtained in the step 2) into 310mL of deionized water cooled to 0 ℃, forming a white precipitate in the deionized water, filtering the white precipitate, and removing unreacted epoxypropylmethyl formate under the vacuum degree of-72 Kpa to obtain the volume fracturing temporary plugging material; and crushing and sieving the volume fracturing temporary plugging material to obtain particles of 10-40 meshes.

Comparative example 1

The comparative example provides a preparation method of a volume fracturing temporary plugging material, which comprises the following specific steps:

1) the method comprises the following steps of (1) completely replacing air in a stainless steel tank reactor with the volume of 4.5L with CO gas, adding 200g of epoxypropylethyl formate and 0.09g of bis (dibenzylideneacetone) palladium into the stainless steel tank reactor, then introducing 435L of CO gas, heating to 120 ℃, wherein the pressure in the stainless steel tank reactor is 14.8MPa, carrying out ring-opening copolymerization on CO and cycloepoxypropylethyl formate for 20 hours, cooling to room temperature to obtain 156.8g of a product A, and releasing unreacted CO gas from the stainless steel tank reactor and carrying out combustion treatment;

2) adding 200mL of trichloromethane into a stainless steel tank type reactor and stirring to obtain a mixed solution;

3) pouring the mixed solution obtained in the step 2) into 300mL of deionized water cooled to 0 ℃, forming a white precipitate in the deionized water, filtering the white precipitate, and removing unreacted epoxypropylethyl formate under the vacuum degree of-69 Kpa to obtain the volume fracturing temporary plugging material; and crushing and sieving the volume fracturing temporary plugging material to obtain particles of 10-40 meshes.

Test example 1

The performance of the volume fracturing temporary plugging material is tested by the test example, which comprises the following steps:

the tests of the tolerance temperature, the temporary plugging strength and the temporary plugging time adopt self-made temporary plugging materials for evaluation, the temporary plugging materials are annular filling containers with the inner diameter of one inch and the outer diameter of 1.2 inches, the length of the annular filling containers is 2 inches, a stainless steel net with the aperture of 200 meshes is welded at one end of the annular filling containers, which is welded with the stainless steel net, is connected with a cylindrical artificial Core (the diameter of 1.2 inches and the length of 3 inches), and then the annular filling containers are put into a Core flow system (model AFS-870) produced by Core Lab company. The temporary plugging experiment is carried out in a mobile experimental device for the temporary plugging experiment, and the specific process is as follows:

and filling the temporary plugging particles in the annular container, connecting a high-permeability artificial rock core after flowing, putting the artificial rock core into a rock core holder, and testing in a flowing experimental device for temporary plugging experiments. The temperature of the core holder was raised to the experimental temperature and the pump was started to inject 5% hydrochloric acid. The particle temporary plugging agent of the temporary plugging material is subjected to vitrification conversion at the experimental temperature to form temporary plugging, and the injection pressure can be increased rapidly. And (4) stabilizing the injection pressure at the experimental pressure, maintaining the experimental temperature, and observing and recording the tolerance temperature, the temporary plugging strength and the temporary plugging time.

And (3) placing 10g of temporary plugging agent and 200mL of residual acid in an autoclave, placing the autoclave in an oven heated to the experimental temperature for degradation, filtering after a period of time, drying, and weighing to obtain the mass Wd of the residual temporary plugging agent. The dissolution rate of the temporary plugging material in 5% hydrochloric acid and the time required for dissolution were recorded, and the degradation rate was calculated by the following formula: the degradation rate was (10-Wd)/10 × 100%.

The volume fracturing temporary plugging materials prepared in example 1, example 2, and examples 3, 4, 5 and comparative example 1 were subjected to performance tests by the method of the present test example, and the performance effects are shown in table 1.

TABLE 1 Effect of the embodiment

Therefore, compared with the conventional method in the field, the volume fracturing temporary plugging material provided by the invention has the tolerance temperature of more than 165 ℃, the temporary plugging strength of more than 63MPa, the temporary plugging time of more than 12h and the 5% hydrochloric acid dissolution rate of more than 98%.

It should be understood that the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention, and it will be obvious to those skilled in the art that other variations or modifications may be made on the basis of the above description, and all embodiments may not be exhaustive, and all obvious variations or modifications may be included within the scope of the present invention.