Water-soluble shunting agent as well as preparation method and use method thereof

Abstract

The invention belongs to the technical field of oil exploitation, and particularly discloses a water-soluble shunting agent as well as a preparation method and a use method thereof. According to the prepared water-soluble shunting agent, hydrochloric acid and ammonium fluoride are added into water, the shunting agent, the chelating agent, the corrosion inhibitor and the anti-swelling shrinkage agent are added after uniform mixing, online shunting acid is obtained after uniform stirring, the shunting acid is injected into a well, temporary plugging particles are formed by the shunting agent in an acidic environment, the shunting agent can enter a high-permeability layer with small flow resistance more easily, and the water-soluble shunting agent can be used for well drilling. And shielding bridge plugging is formed on a high-permeability channel, so that acid liquor diversion and steering are realized, the acid liquor enters low-permeability, ultra-low-permeability and compact oil reservoir channels, effective plugging removal is performed on the acid liquor, and good diversion and guiding performance is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum extraction, and in particular relates to a water-soluble diverter and a preparation method and a use method thereof. Background Art

[0002] Acidizing can remove acid-soluble particles, cuttings and scale in the boreholes of the wellbore, dredge the perforated holes, and restore or improve the permeability of the oil layer in a large range near the wellbore, thereby achieving the purpose of increasing production and injection. It is one of the important measures to increase production and injection in sandstone oil and gas reservoirs. However, due to the heterogeneity of the reservoir, the acid is unevenly distributed between and within the layers of the sand body, and the acid is easy to enter the high-permeability channel, making it difficult to effectively unblock the low-permeability pores.

[0003] The current mainstream process technologies include: mechanical diversion technology, chemical microparticle diversion technology, foam diversion technology, thickened acid diversion technology, viscoelastic surfactant diversion technology, etc. Mechanical diversion technology is the most effective method for acid placement, but it has strict requirements on construction well conditions, high requirements on storage permeability, and high operating costs; foam diversion technology and viscoelastic surfactant diversion technology have high requirements on reservoir temperature, reservoir permeability, and porosity, respectively, and cause greater damage to the formation, are not easy to flow back, and are complex in construction and subject to certain restrictions; thickened acid diversion technology has problems such as high cost, complex construction, and difficulty in flow back. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a water-soluble diverter and a preparation method and a use method thereof, so as to solve the problem that acid liquid easily enters the hyperosmotic channel and is difficult to effectively unblock the hypoosmotic gap, and the existing diversion technology has high requirements on storage permeability and poor diversion guiding performance.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a water-soluble diverting agent, comprising:

[0007] Fatty acid diester, sodium fatty acid methyl ester sulfonate, sodium hexadecylbenzene sulfonate, water, dibutyl carbitol and sodium chloroacetate, the mass ratio of fatty acid diester, sodium fatty acid methyl ester sulfonate, sodium hexadecylbenzene sulfonate, water, dibutyl carbitol and sodium chloroacetate is (1-2): (1-1.5): (2-4): (1-1.5): (1-1.5): (1-1.5).

[0008] In a second aspect, the present invention provides a method for preparing a water-soluble diverting agent, comprising:

[0009] Stir fatty acid diester, sodium fatty acid methyl ester sulfonate, sodium hexadecylbenzene sulfonate and water until they are uniformly mixed, and then add them into a reaction kettle for reaction to obtain a mixed solution;

[0010] Dibutyl carbitol and sodium chloroacetate are added to the mixed solution for reflux reaction to obtain a splitting agent.

[0011] Furthermore, the stirring temperature of the fatty acid diester, sodium fatty acid methyl ester sulfonate, sodium hexadecylbenzene sulfonate and water is 60° C.-80° C., and the stirring time is greater than or equal to 10 min; and the reaction time of the reactor is 3 h-5 h.

[0012] Furthermore, the temperature when adding dibutyl carbitol and sodium chloroacetate to the mixed solution is 50° C.-60° C., and the reaction time of the reflux reaction is 1.5-2.5 h.

[0013] In a third aspect, the present invention provides a method for using a water-soluble diverting agent, comprising:

[0014] At room temperature, hydrochloric acid and ammonium fluoride are sequentially added to water, and stirred evenly to obtain a uniformly stirred mixed solution; a shunt agent, a chelating agent, a corrosion inhibitor and an anti-swelling agent prepared by any one of the above-mentioned methods for preparing a water-soluble shunt agent are sequentially added to the uniformly stirred mixed solution, and stirred evenly to obtain an online shunt acid for continuous injection into a water injection well, and the shunt acid is injected into the well.

[0015] Furthermore, the hydrochloric acid and ammonium fluoride are both commercially available chemically pure or industrially pure.

[0016] Furthermore, the mass percentage of the diverter agent to the online diverter acid is 4%-8%.

[0017] Furthermore, the chelating agent is an aqueous solution obtained by mixing citric acid monohydrate and nitrilotriacetic acid.

[0018] Furthermore, the corrosion inhibitor is an aqueous solution obtained by mixing triethanolamine, thiolamine, acetophenone and anhydrous ethanol.

[0019] Furthermore, the anti-swelling and shrinking agent is an ammonium chloride aqueous solution with a mass concentration of 45%-55%.

[0020] The present invention has at least the following beneficial effects:

[0021] 1. The water-soluble diverter prepared by the present invention is prepared by adding hydrochloric acid and ammonium fluoride into water, mixing them evenly, then adding the diverter, chelating agent, corrosion inhibitor and anti-swelling agent, stirring them evenly to obtain online diverting acid, injecting the diverting acid into the well, and the diverting agent forms temporary plugging particles in an acidic environment, which are easier to enter the high permeability layer with smaller flow resistance, forming a shielding bridge to block the high permeability channel, thereby realizing the diversion and redirection of the acid liquid, allowing the acid liquid to enter the low permeability, ultra-low permeability and dense oil reservoir channels, and effectively unblocking them with good diversion and guiding performance.

[0022] 2. The water-soluble diverter of the present invention has good compatibility with formation water / injection water and can be used for adjusting the water injection profile; the mixed diverter acid can effectively increase the water injection volume of the injection well, reduce the wellhead pressure of the injection well, increase the water injection volume of the injection well, improve the water absorption profile, and improve the circulation of the formation fluid.

[0023] 3. The preparation method of the water-soluble diverter of the present invention is simple and the reaction time is short, which can simplify the construction steps, shorten the construction time, reduce the intensity of on-site work, and achieve the purpose of reducing the pressure and increasing the injection of injection wells with uneven water absorption. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0025] Figure 1 The figure is a schematic diagram of the preparation method of the water-soluble diverting agent;

[0026] Figure 2 The figure is a schematic diagram of the method for using a water-soluble diverting agent. DETAILED DESCRIPTION

[0027] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0028] The following detailed description is an exemplary description, which is intended to provide further detailed description of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art to which the present invention belongs. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0029] A water-soluble diverting agent, comprising:

[0030] Fatty acid diester, sodium fatty acid methyl ester sulfonate, sodium hexadecylbenzene sulfonate, water, dibutyl carbitol and sodium chloroacetate, the mass ratio of fatty acid diester, sodium fatty acid methyl ester sulfonate, sodium hexadecylbenzene sulfonate, water, dibutyl carbitol and sodium chloroacetate is (1-2): (1-1.5): (2-4): (1-1.5): (1-1.5): (1-1.5).

[0031] A method for preparing a water-soluble diverting agent comprises:

[0032] Stir fatty acid diester, sodium fatty acid methyl ester sulfonate, sodium hexadecylbenzene sulfonate and water at 60°C-80°C for 10 minutes or more until uniformly mixed, add into a reaction kettle and react for 3h-5h to obtain a mixed solution;

[0033] At 50° C.-60° C., dibutyl carbitol and sodium chloroacetate are added to the mixed solution, and the mixture is refluxed for 1.5-2.5 hours to obtain a splitting agent.

[0034] A method for using a water-soluble diverting agent, comprising:

[0035] At room temperature, hydrochloric acid and ammonium fluoride are added to water in sequence, stirred evenly, to obtain a mixed solution that is stirred evenly; a shunt agent, a chelating agent, a corrosion inhibitor and an anti-swelling agent are added to the mixed solution that is stirred evenly, to obtain an online shunt acid that is continuously injected into the injection well, and the shunt acid is injected into the well.

[0036] The hydrochloric acid and ammonium fluoride used were both commercially available chemically pure or industrially pure;

[0037] The mass percentage of the diverting agent to the online diverting acid is 4%-8%.

[0038] The chelating agent is an aqueous solution obtained by mixing citric acid monohydrate and nitrilotriacetic acid.

[0039] The corrosion inhibitor is an aqueous solution obtained by mixing triethanolamine, thiolamine, acetophenone and anhydrous ethanol.

[0040] The anti-swelling and shrinking agent is an ammonium chloride aqueous solution with a mass concentration of 45%-55%.

[0041] Example 1

[0042] This embodiment 1 provides a water-soluble diverting agent, which is composed of the following substances in percentage by mass: 10% fatty acid diester, 10% sodium fatty acid methyl ester sulfonate, 40% sodium hexadecylbenzene sulfonate, 10% water, 15% dibutyl carbitol and 15% sodium chloroacetate.

[0043] The basic physical properties of the water-soluble diverter of this embodiment are shown in Table 1.

[0044] Table 1 Basic physical properties of water-soluble diverting agent in Example 1

[0045]

[0046]

[0047] Table 1 shows that the water-soluble diverter of this embodiment has a strong reservoir plugging ability and has good practical application value.

[0048] Example 2

[0049] The present embodiment provides a water-soluble diverter, which is composed of the following substances in percentage by mass: 15% fatty acid diester, 15% sodium fatty acid methyl ester sulfonate, 35% sodium hexadecylbenzene sulfonate, 15% water, 10% dibutyl carbitol and 10% sodium chloroacetate.

[0050] The basic physical properties of the water-soluble diverter of this embodiment are shown in Table 2.

[0051] Table 2 Basic physical properties of water-soluble diverting agent in Example 2

[0052]

[0053] Table 2 shows that the water-soluble diverter of this embodiment has a strong reservoir plugging ability and has good practical application value.

[0054] Application Example 1

[0055] The water-soluble diverter of Example 1 and Example 2 was uniformly mixed with hydrochloric acid, ammonium fluoride, diverter, chelating agent, corrosion inhibitor and anti-swelling agent, and then applied to a well blocked by inorganic scale and clay expansion migration, and the construction results of Example 1 are shown in Table 3, and the construction results of Example 2 are shown in Table 4. The specific mass ratio of the water-soluble diverter is 5%.

[0056] Table 3 Construction results of Example 1

[0057]

[0058]

[0059] Table 4 Construction results of Example 2

[0060]

[0061] It can be seen from Table 3 and Table 4 that the diverting acid after mixing the water-soluble diverting agents of Example 1 and Example 2 can effectively increase the water injection volume of the water injection well, reduce the wellhead pressure of the water injection well, increase the water injection volume of the water injection well, improve the water absorption profile, improve the formation fluid circulation condition, shorten the construction time, reduce the intensity of on-site work, and achieve the purpose of reducing pressure and increasing injection in injection wells with uneven water absorption. It has good practical application value.

[0062] Example 3

[0063] A method for preparing a water-soluble diverting agent comprises:

[0064] At 60° C., the fatty acid diester, sodium fatty acid methyl ester sulfonate, sodium hexadecylbenzene sulfonate and water were stirred for greater than or equal to 10 min until they were uniformly mixed, and then added into a reaction kettle for reaction for 3 h to obtain a mixed solution;

[0065] At 50° C., dibutyl carbitol and sodium chloroacetate were added to the mixed solution, and the mixture was refluxed for 1.5 h to obtain a splitting agent.

[0066] Example 4

[0067] A method for preparing a water-soluble diverting agent comprises:

[0068] At 80° C., the fatty acid diester, sodium fatty acid methyl ester sulfonate, sodium hexadecylbenzene sulfonate and water were stirred for greater than or equal to 10 min until they were uniformly mixed, and then added into a reaction kettle for reaction for 5 h to obtain a mixed solution;

[0069] At 60° C., dibutyl carbitol and sodium chloroacetate were added to the mixed solution, and the mixture was refluxed for 2.5 h to obtain a splitting agent.

[0070] Example 5

[0071] A method for preparing a water-soluble diverting agent comprises:

[0072] At 70° C., the fatty acid diester, sodium fatty acid methyl ester sulfonate, sodium hexadecylbenzene sulfonate and water were stirred for greater than or equal to 10 min until they were uniformly mixed, and then added into a reaction kettle for reaction for 4 h to obtain a mixed solution;

[0073] At 55° C., dibutyl carbitol and sodium chloroacetate were added to the mixed solution, and the mixture was refluxed for 2 h to obtain a splitting agent.

[0074] It is known from common technical knowledge that the present invention can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the above disclosed embodiments are only illustrative in all respects and are not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are included in the present invention.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A water-soluble diverting agent, characterized in that: include: Fatty acid diester, sodium fatty acid methyl ester sulfonate, sodium hexadecylbenzene sulfonate, water, dibutyl carbitol and sodium chloroacetate, the mass ratio of fatty acid diester, sodium fatty acid methyl ester sulfonate, sodium hexadecylbenzene sulfonate, water, dibutyl carbitol and sodium chloroacetate is (1-2): (1-1.5): (2-4): (1-1.5): (1-1.5): (1-1.5).

2. A method for preparing a water-soluble diverting agent, characterized in that: include: Stir fatty acid diester, sodium fatty acid methyl ester sulfonate, sodium hexadecylbenzene sulfonate and water until they are uniformly mixed, and then add them into a reaction kettle for reaction to obtain a mixed solution; Dibutyl carbitol and sodium chloroacetate are added to the mixed solution for reflux reaction to obtain a splitting agent.

3. The method for preparing a water-soluble diverting agent according to claim 2, characterized in that: The stirring temperature of the fatty acid diester, sodium fatty acid methyl ester sulfonate, sodium hexadecylbenzene sulfonate and water is 60° C.-80° C., and the stirring time is greater than or equal to 10 minutes; the reaction time of the reactor is 3h-5h.

4. The method for preparing a water-soluble diverting agent according to claim 2, characterized in that: The temperature when adding dibutyl carbitol and sodium chloroacetate to the mixed solution is 50° C.-60° C., and the reaction time of the reflux reaction is 1.5-2.5 hours.

5. A method for using a water-soluble diverting agent, characterized in that: include: At room temperature, hydrochloric acid and ammonium fluoride are sequentially added to water, and stirred evenly to obtain a uniformly stirred mixed solution; a shunt agent, a chelating agent, a corrosion inhibitor and an anti-swelling agent prepared by the preparation method of a water-soluble shunt agent according to any one of claims 2 to 4 are sequentially added to the uniformly stirred mixed solution, and stirred evenly to obtain an online shunt acid continuously injected into a water injection well, and the shunt acid is injected into the well.

6. The method for using a water-soluble diverting agent according to claim 5, characterized in that: The hydrochloric acid and ammonium fluoride are both commercially available chemically pure or industrially pure.

7. The method for using a water-soluble diverting agent according to claim 5, characterized in that: The mass percentage of the diverting agent to the online diverting acid is 4%-8%.

8. The method for using a water-soluble diverting agent according to claim 5, characterized in that: The chelating agent is an aqueous solution obtained by mixing citric acid monohydrate and nitrilotriacetic acid.

9. The method for using a water-soluble diverting agent according to claim 5, characterized in that: The corrosion inhibitor is an aqueous solution obtained by mixing triethanolamine, thiolamine, acetophenone and anhydrous ethanol.

10. The method for using a water-soluble diverting agent according to claim 5, characterized in that: The anti-swelling and shrinking agent is an ammonium chloride aqueous solution with a mass concentration of 45%-55%.

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