CN110982502B

CN110982502B - Temperature-resistant salt-resistant gel foam containing phosphonic acid structure and preparation method and application thereof

Info

Publication number: CN110982502B
Application number: CN201911310718.XA
Authority: CN
Inventors: 王彦玲; 兰金城; 蒋保洋; 孟令韬; 许宁
Original assignee: China University of Petroleum East China
Current assignee: China University of Petroleum East China
Priority date: 2019-12-18
Filing date: 2019-12-18
Publication date: 2022-02-01
Anticipated expiration: 2039-12-18
Also published as: CN110982502A

Abstract

The invention relates to a temperature-resistant salt-resistant jelly foam containing a phosphonic acid structure, and a preparation method and application thereof. The temperature-resistant salt-resistant gel foam is prepared by introducing carbon dioxide gas into liquid gel; the liquid-phase gel comprises the following components in percentage by mass: 0.3 to 0.9 percent of temperature-resistant and salt-resistant polymer, 0.2 to 0.9 percent of phenol or benzenediol, 0.2 to 0.9 percent of aldehyde compound, 0.2 to 0.8 percent of foaming agent, 0.3 to 0.6 percent of organic matter containing phosphonic acid structure, 0.3 to 0.7 percent of auxiliary agent and the balance of water; the method is used for selectively blocking water under the condition of high-temperature and high-salt formation.

Description

Temperature-resistant salt-resistant gel foam containing phosphonic acid structure and preparation method and application thereof

Technical Field

The invention relates to a temperature-resistant salt-tolerant jelly foam containing a phosphonic acid structure, and a preparation method and application thereof, belongs to the technical field of oilfield chemistry, and is particularly suitable for selective water shutoff of a high-temperature and high-salinity oil reservoir.

Background

The high-temperature and high-salinity oil and gas fields in China are widely distributed and rich in resources, have great exploitation value, but have great difficulty in development. The reason is that the high-temperature and high-salinity stratum characteristics limit the application of a plurality of production increasing measures.

In terms of selective water shutoff measures, partially Hydrolyzed Polyacrylamide (HPAM) is the most important polymer main agent in the water shutoff agent. However, due to the high temperature and high mineralization environment, the electrical property of the carboxyl group of the HPAM is easily shielded by small molecular salt, the molecular chain of the polymer is curled, the viscosity of the polymer is reduced, and the hydrolysis speed of the HPAM is increased due to the increase of the temperature. HPAM can be subjected to thermal degradation, shear degradation and oxidative degradation in a high-temperature and high-salinity oil reservoir, so that the viscosity is reduced rapidly, and a plurality of defects are exposed in practical application, thereby limiting the application of the HPAM in a water plugging technology. The temperature resistance and salt tolerance of the polyacrylamide polymer are improved, and the requirements of the water plugging technology on the temperature resistance and salt tolerance of the polymer can be met under the condition of not increasing the injection amount of the water plugging agent.

Chinese patent CN104342095B discloses a self-generating expandable foam gel and a preparation method and application thereof, wherein the self-generating expandable foam gel comprises 0.4-0.6 wt% of polyacrylamide and a cross-linking agent Na in water₂Cr₂O₇0.4-0.6 wt% and Na₂SO₃0.5-0.7 wt% of heat generating agent NH₄Cl 1mol/L and NaNO₂1 mol/L; adjusting pH of the solution to 6.5-7 with hydrochloric acid, and forming foam gel at 20-50 deg.C. The foam gel has the best performance when the pH value is 6.5-7, and the gel forming time is controllable within 20-90 h.

Chinese patent document CN105461860A discloses a preparation method of a temperature-resistant salt-tolerant biopolymer gel profile control agent, which comprises the following steps: dissolving macromolecular biogel in distilled water to prepare 0.05-5% of solution, adding monomer acrylamide accounting for 5-15% of the mass fraction of a reaction system, monomer 2-acrylamide-2-methylpropanesulfonic acid accounting for 0.1-5% of the mass fraction of the reaction system and a cross-linking agent accounting for 0.01-1% of the mass fraction of the reaction system into the solution, introducing nitrogen to isolate air, adding an initiator accounting for 0.05-1% of the mass fraction of the reaction system, and reacting at a constant temperature of 40-100 ℃ to prepare the profile control agent.

At present, gel foam is basically suitable for low-temperature low-salinity oil reservoirs because a common polyacrylamide phenolic gel system does not have good temperature resistance and salt tolerance, and is easy to dehydrate and degrade under the conditions of high temperature and high salinity of a stratum, so that the aim of selectively plugging water cannot be fulfilled.

Therefore, the development of a plugging agent of a foamed gel with good selective water plugging effect under the conditions of high temperature and high salt formation and the capability of ensuring that the plugging agent has small dehydration degree under the long-term high temperature condition is still one of the problems to be solved in the field.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a temperature-resistant salt-tolerant carbon dioxide gel foam liquid phase gel containing a phosphonic acid structure and a preparation method thereof; the method is used for a carbon dioxide gel foam system.

The invention also provides carbon dioxide gel foam for selectively blocking water under the condition of high-temperature and high-salinity stratum.

The invention also provides application of the carbon dioxide gel foam.

The technical scheme of the invention is as follows:

a temperature-resistant salt-tolerant carbon dioxide gel foam liquid phase gel is prepared by the following components in percentage by mass through a cross-linking reaction:

0.3 to 0.9 percent of temperature-resistant and salt-resistant polymer, 0.2 to 0.9 percent of phenol or benzenediol, 0.2 to 0.9 percent of aldehyde compound, 0.2 to 0.8 percent of foaming agent, 0.3 to 0.6 percent of organic matter containing phosphonic acid structure, 0.3 to 0.7 percent of auxiliary agent and the balance of water;

wherein the organic matter containing phosphonic acid structure is one or more of aminomethylphosphonic acid, phenylphosphonic acid and hexylphosphonic acid;

the temperature-resistant salt-resistant polymer is as follows: in a solvent and in the presence of an initiator, carrying out polymerization reaction on acrylamide or an acrylamide derivative, a salt-resistant monomer, 2-acrylamide-2-methylpropanesulfonic acid and N-vinyl pyrrolidone to obtain the compound; the salt-tolerant monomer is isooctyl acrylate or N-vinyl amide.

According to the preferable selection of the invention, the temperature-resistant and salt-tolerant carbon dioxide gel foam liquid phase gel comprises the following components in percentage by mass:

0.5 to 0.7 percent of temperature-resistant and salt-resistant polymer, 0.3 to 0.6 percent of phenol or benzenediol, 0.3 to 0.6 percent of aldehyde compound, 0.2 to 0.8 percent of foaming agent, 0.4 to 0.5 percent of organic matter containing phosphonic acid structure, 0.3 to 0.4 percent of auxiliary agent and the balance of water.

Preferably, according to the present invention, the hydroquinone is catechol, resorcinol or hydroquinone.

The aldehyde compound is formaldehyde, paraformaldehyde or hexamethylenetetramine.

The auxiliary agent is sodium sulfite, thiourea, potassium sulfite or sodium thiosulfate.

The foaming agent is a nonionic surfactant and is one or more of octyl phenol polyoxyethylene ether, nonyl phenol polyoxyethylene ether, lauryl alcohol and fatty acid polyoxyethylene ester.

According to the invention, in the synthesis process of the temperature-resistant salt-tolerant polymer, acetone is preferably used as a solvent; the initiator is selected from Benzoyl Peroxide (BPO), azodiisopropylimidazoline hydrochloride (AIBI), and persulfuric acid clock (KPS) or beta-dimethylamino-propanenitrile (DMAPN).

The temperature-resistant salt-tolerant carbon dioxide gel foam liquid phase gel is prepared by the following method, and comprises the following steps:

(1) proportionally placing acrylamide or acrylamide derivatives, salt-tolerant monomers, 2-acrylamide-2-methylpropanesulfonic acid and N-vinyl pyrrolidone into a reactor together with a solvent, introducing nitrogen to remove oxygen, and then stirring and heating;

the molar ratio of the acrylamide or acrylamide derivative, the salt-tolerant monomer, the 2-acrylamide-2-methylpropanesulfonic acid and the N-vinyl pyrrolidone is 1: (2.0-5.0): (1.0-2.0): (1.0-2.5);

(2) raising the temperature to the reaction temperature, adding an initiator, and carrying out polymerization reaction;

(3) and repeatedly soaking the obtained polymer crude product by using absolute ethyl alcohol to remove unreacted salt-tolerant monomers and initiators, and then drying to obtain the temperature-resistant salt-tolerant polymer.

According to the present invention, it is preferable that step (1) includes any one or more of the following conditions:

a1, wherein the molar ratio of the acrylamide derivative, the salt-tolerant monomer, the 2-acrylamide-2-methylpropanesulfonic acid and the N-vinyl pyrrolidone is 1: (3.0-4.0): (1.0-1.5): (1.0-1.5).

a2, wherein the heating temperature is 50-60 ℃;

a3, the solvent is acetone; the dosage of the solvent is the dissolving amount; acrylamide derivatives, salt-resistant monomers, 2-acrylamide-2-methylpropanesulfonic acid monomers and N-vinyl pyrrolidone are preferably completely dissolved.

According to the present invention, it is preferable that step (2) includes any one or more of the following conditions:

b1, wherein the initiator is selected from Benzoyl Peroxide (BPO), azodiisopropyl imidazoline hydrochloride (AIBI) and potassium persulfate (KPS) or beta-dimethyl amino acrylonitrile (DMAPN);

b2, wherein the reaction temperature is 65-75 ℃.

b3, the reaction time is 2-12 h, and the reaction time is further optimized to be 3-8 h.

b4, wherein the molar ratio of the acrylamide derivative to the initiator is 1: (0.02-0.05); further preferably, the molar ratio of the acrylamide derivative to the initiator is 1: (0.03-0.04).

According to the present invention, it is preferable that step (3) includes any one or more of the following conditions:

c1, wherein the volume ratio of the absolute ethyl alcohol to the crude product is 100: (1-5);

c2, wherein the drying temperature is 50-60 ℃.

And C4, drying for 12-24 h.

In the step (3), the repeated soaking of the obtained polymer crude product with absolute ethyl alcohol refers to soaking with absolute ethyl alcohol, separating, soaking again, and separating, and the operation is carried out for a plurality of times. Preferably 2-4 times.

The carbon dioxide gel foam for selectively blocking water under the condition of high-temperature and high-salt stratum is prepared by introducing carbon dioxide gas into the liquid gel. Preferably, the gas-liquid volume ratio of the carbon dioxide to the liquid gel is 40-50: 1 to 2.

The carbon dioxide gel foam is applied to selective water shutoff under the condition of high-temperature and high-salt formation. Preferably, the high temperature is 80-160 ℃.

The invention has the technical characteristics that: on one hand, the temperature-resistant monomer (N-vinyl pyrrolidone) introduced into the acrylamide or the derivative thereof can enhance the crosslinking strength of the crosslinked polymer, so that the crosslinked polymer can still well hold water molecules under the high-temperature condition; on the other hand, the introduced salt-tolerant monomer (isooctyl acrylate or N-vinyl amide) can well inhibit the hydrolysis of sodium ions, magnesium ions, calcium ions and the like after the polymer is gelatinized, thereby enhancing the salt-tolerant performance of the polymer. And the introduced phosphonic acid structure can further enhance the crosslinking density of the polymer, thereby further enhancing the temperature resistance of the polymer. Finally, the invention leads carbon dioxide gas into the obtained liquid gel to form gel foam, and the gel foam has the characteristic of reducing the seepage capability of water flow without influencing the seepage capability of oil flow, thereby achieving the purpose of selectively blocking water.

The invention has the following excellent effects:

1. the raw materials required by the invention are easy to purchase and have lower price, and the preparation process is simple and convenient. The construction process is simple, the initial viscosity of the system is low, and the system is easy to pump to the stratum.

2. The carbon dioxide gel foam provided by the invention has strong salt tolerance, and can still maintain good water plugging selectivity under the condition of a high-salinity stratum.

3. The carbon dioxide gel foam disclosed by the invention is strong in temperature resistance and can resist the high temperature of 80-160 ℃.

4. The temperature-resistant salt-tolerant polymer can still maintain a very low dehydration rate after being placed for a long time under a high-temperature condition after being reacted by the cross-linking agent. The polymer plugging agent can also be applied to the aspects of acidification, fracturing, profile control and the like.

5. The carbon dioxide gel foam has strong water plugging selectivity, the foaming agent is easy to dissolve in oil, no foam is formed, an oil flow channel is not blocked, the flowing of the oil is hardly influenced, the foam formed in a water phase is stable, a water flow channel is blocked, and the seepage capability of water is obviously reduced. The foaming agent is a surfactant, so that the oil-water interfacial tension can be reduced, the oil washing efficiency is improved, and the crude oil recovery rate is improved.

Drawings

FIG. 1 is a structural characterization infrared spectrum of the temperature and salt resistant polymer prepared in example 1;

FIG. 2 is a polymer gel solution (without adding a foaming agent) in example 1;

FIG. 3 is a photograph of the temperature and salt resistant carbon dioxide gel foam of example 1.

Detailed Description

The present invention is further illustrated by, but not limited to, the following examples.

Example 1

A preparation method of temperature-resistant salt-tolerant carbon dioxide gel foam for water shutoff in oil fields comprises the following steps:

1) 5.0g of N, N-dimethylacrylamide, 36.85g of isooctyl acrylate (salt-tolerant monomer), 10.4g of 2-acrylamide-2-methylpropanesulfonic acid monomer, 5.56g of N-vinylpyrrolidone and 200mL of acetone solvent were weighed into a four-neck flask placed in a constant-temperature water bath, then nitrogen was introduced into the four-neck flask for 10min to remove oxygen, and then the flask was heated under magnetic stirring at a heating temperature of 50 ℃.

When the temperature is raised to 70 ℃ and the reaction temperature is reached, 0.36g of Benzoyl Peroxide (BPO) initiator is added, the initiator is dissolved in 20mL of acetone solution and then slowly dripped through a constant pressure dropping funnel, the reaction is continued for 6 hours at the temperature to obtain a temperature-resistant salt-tolerant polymer, and the obtained polymer crude product is repeatedly soaked in absolute ethyl alcohol to remove unreacted hydrophobic monomer (isooctyl acrylate), initiator and the like. And drying the purified product in an oven at 50 ℃ for 24h to obtain the temperature-resistant salt-tolerant polymer. The structure infrared spectrum of the obtained polymer is shown in figure 1.

2) Weighing the following components in percentage by mass:

0.5 percent of temperature-resistant salt-tolerant polymer, 0.4 percent of resorcinol, 0.4 percent of hexamethylenetetramine, 0.4 percent of phenylphosphonic acid, 0.3 percent of sodium sulfite, 0.4 percent of octyl phenol polyoxyethylene ether (foaming agent) and the balance of water. Fully mixing the components, and then putting the mixture into a primary gel solution for 4 hours at the temperature of 20 ℃;

3) adding the mixture into the primary gel solution according to the gas-liquid ratio of 40: 1 (volume ratio), then putting the mixture into an environment at 90 ℃ for 48 hours, and finally preparing the temperature-resistant and salt-resistant carbon dioxide foamed gel.

Example 2

As shown in example 1, except that the mass percentages of the components in step 2) are changed to the following proportions:

0.6 percent of temperature-resistant salt-tolerant polymer, 0.5 percent of resorcinol, 0.5 percent of hexamethylenetetramine, 0.5 percent of octyl phenol polyoxyethylene ether, 0.5 percent of phenylphosphonic acid and 0.4 percent of sodium sulfite. The balance being water.

Example 3

As shown in example 1, except that the phenol in step 2) was changed to catechol.

Example 4

As shown in example 1, except that the phenol in step 2) was changed to phenol.

Example 5

As shown in example 1, except that the aldehyde in step 2) was changed to paraformaldehyde.

Example 6

As shown in example 1, except that the auxiliary in step 2) was changed to thiourea.

Example 7

As shown in example 1, except that the foaming agent in step 2) was changed to polyoxyethylene fatty acid ester.

Example 8

As shown in example 1, except that the phenylphosphonic acid in step 2) is exchanged for hexylphosphonic acid.

The comparative example comprises the following components in percentage by mass:

0.5% of N, N-dimethylacrylamide, 0.4% of resorcinol, 0.4% of hexamethylenetetramine, 0.4% of octylphenol polyoxyethylene ether, 0.4% of phenylphosphonic acid and 0.3% of sodium sulfite. The balance being water. The components are fully mixed and then are put into an environment with the temperature of 20 ℃ for 4 hours to obtain a primary gel solution.

Adding the mixture into the primary gel solution according to the gas-liquid ratio of 40: 1, introducing carbon dioxide gas, and then putting the mixture into an environment with the temperature of 90 ℃ for 48 hours to finally prepare the carbon dioxide foamed gel.

Examples product performance evaluation:

the polymer gels of the different examples were evaluated for their thermal stability (the dehydration rate was calculated as the ratio of the mass of water removed from the polymer gel to the total mass of the polymer gel) by laboratory experiments, the results of which are shown in Table 1.

TABLE 1 thermal stability of the different examples

As can be seen from the above table, after the temperature-resistant and salt-resistant monomer is introduced, the dehydration rate is greatly reduced, and the best effect is the embodiment 2.

Through the indoor experiment: evaluating the foam system by WARING method, placing the foam solution into a Blender, and introducing CO₂To replace other dissolved gases in the liquid, and then introducing CO while introducing₂Stirring for 3 minutes (rotation speed 10000r/min), pouring out the foam into a 1000mL measuring cylinder, placing the measuring cylinder in an oven at the required temperature, and recording the foaming volume and the liquid separation volume at different times, so as to obtain the foaming volume, the foaming rate and the liquid separation half-life period of the system. The foaming and foam stabilizing properties of the different examples were evaluated and the results are given in table 2.

TABLE 2 foaming and foam stabilizing Properties of the different examples

From the above table, the most effective is example 3, in terms of the combination of lather volume and half life.

The different examples were evaluated for gelling stability under hypersalinity conditions by laboratory experiments. The specific embodiment is that the prepared gel polymer is prepared by deionized water and 250000mg/L sodium chloride solution respectively, and the change of gel strength is observed. The results are shown in Table 3.

TABLE 3 evaluation results of salt tolerance characteristics of various examples

Product numbering	Is prepared by deionized water	Is prepared from brine
			Example 1	G	G
Example 2	H	H
			Example 3	H	G
Example 4	E	E
			Example 5	F	F
Example 6	G	G
			Example 7	G	G
Example 8	G	G
			Comparative example	G	D

Note: D. e, F, G, H is the gel strength rating specified using the GSC strength code method proposed by Sydansk, with higher alphabetical ordering indicating greater gel strength.

From the above table, the mineralization degree has almost no influence on the gel strength of the polymer gel, but the strength of the comparative example is obviously reduced, which indicates that the salt resistance of the polymer without the salt-resistant monomer is poor.

The product of example 4 is taken and subjected to indoor experiments to evaluate the selective water plugging effect of the prepared temperature-resistant and salt-tolerant carbon dioxide foam gel, the evaluation result is shown in table 4, and the core breakthrough pressure result is shown in table 5 (refer to SY/T6424-2014 composite displacement system performance test method).

TABLE 4 evaluation of plugging Rate Properties of plugging Agents

Table 5 core breakthrough pressure results

As can be seen from Table 3, the plugging rate of the polymer plugging agent to the saturated water phase core is more than 90%, and the plugging rate to the saturated oil phase core is less than 17%, which indicates that the polymer plugging agent has good water plugging selectivity; as can be seen from Table 4, the polymer plugging agent has a high breakthrough pressure for the saturated water phase and a low breakthrough pressure for the saturated oil phase core.

Claims

1. A temperature-resistant salt-tolerant carbon dioxide gel foam liquid phase gel is prepared by the following components in percentage by mass through a cross-linking reaction:

0.3 to 0.9 percent of temperature-resistant and salt-tolerant polymer, 0.2 to 0.9 percent of phenol or benzenediol, 0.2 to 0.9 percent of formaldehyde, paraformaldehyde or hexamethylenetetramine, 0.2 to 0.8 percent of foaming agent, 0.3 to 0.6 percent of organic matter containing phosphonic acid structure, 0.3 to 0.7 percent of auxiliary agent and the balance of water;

2. The temperature-resistant salt-tolerant carbon dioxide gel foam liquid phase gel of claim 1, which is characterized by comprising the following components in percentage by mass: 0.5 to 0.7 percent of temperature-resistant and salt-tolerant polymer, 0.3 to 0.6 percent of phenol or benzenediol, 0.3 to 0.6 percent of formaldehyde, paraformaldehyde or hexamethylenetetramine, 0.2 to 0.8 percent of foaming agent, 0.4 to 0.5 percent of organic matter containing phosphonic acid structure, 0.3 to 0.4 percent of auxiliary agent and the balance of water.

3. The temperature and salt tolerant carbon dioxide gel foam liquid phase gel of claim 1, wherein the hydroquinone is catechol, resorcinol, or hydroquinone.

4. The temperature and salt resistant carbon dioxide gel foam liquid phase gel of claim 1, wherein the auxiliary agent is sodium sulfite, thiourea, potassium sulfite or sodium thiosulfate.

5. The temperature and salt resistant carbon dioxide gel foam liquid phase gel of claim 1, wherein the foaming agent is a nonionic surfactant selected from one or more of polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether, lauryl alcohol and polyoxyethylene fatty acid ester.

6. The temperature and salt resistant carbon dioxide gel foam liquid gel of claim 1, wherein the temperature and salt resistant polymer is prepared by a method comprising:

7. The temperature and salt resistant carbon dioxide gel foam liquid phase gel of claim 6, wherein step (1) comprises any one or more of the following conditions:

a1, wherein the molar ratio of the acrylamide derivative, the salt-tolerant monomer, the 2-acrylamide-2-methylpropanesulfonic acid and the N-vinyl pyrrolidone is 1: (3.0-4.0): (1.0-1.5): (1.0-1.5);

a2, wherein the heating temperature is 50-60 ℃;

a3, wherein the solvent is acetone.

8. The temperature and salt resistant carbon dioxide gel foam liquid phase gel of claim 6, wherein step (2) comprises any one or more of the following conditions:

b1, wherein the initiator is selected from Benzoyl Peroxide (BPO), azodiisopropyl imidazoline hydrochloride (AIBI) and potassium persulfate (KPS) or beta-dimethyl amino propionitrile (DMAPN);

b2, wherein the reaction temperature is 65-75 ℃;

b3, wherein the reaction time is 2-12 h;

b4, wherein the molar ratio of the acrylamide derivative to the initiator is 1: (0.02-0.05).

9. The temperature-resistant salt-tolerant carbon dioxide gel foam liquid phase gel of claim 6, wherein in the step (2), the reaction time is 3-8 h.

10. The temperature and salt resistant carbon dioxide gel foam liquid phase gel of claim 6, wherein in step (2), the molar ratio of the acrylamide derivative to the initiator is 1: (0.03-0.04).

11. The temperature and salt resistant carbon dioxide gel foam liquid phase gel of claim 6, wherein step (3) comprises any one or more of the following conditions:

c2, wherein the drying temperature is 50-60 ℃;

c3, wherein the drying time is 12-24 h.

12. A temperature and salt resistant carbon dioxide gel foam prepared by introducing carbon dioxide gas into the liquid phase gel of any one of claims 1-11.

13. The temperature-resistant salt-tolerant carbon dioxide jelly foam according to claim 12, wherein the gas-liquid volume ratio of the carbon dioxide to the liquid gel is 40-50: 1 to 2.

14. The use of the temperature and salt tolerant carbon dioxide gel foam of claim 12 for selective water shutoff at high temperature and high salt formation conditions.

15. The use of the temperature and salt tolerant carbon dioxide gel foam of claim 14, wherein the elevated temperature is 80-160 ℃.