Profile control composition and preparation method thereof

Abstract

The invention provides a profile control composition and a preparation method thereof. The profile control composition comprises epoxy resin, an emulsifier, a curing agent and water and is an epoxy resin-in-water emulsion, the emulsifier is a mixture of alkylphenol polyoxyethylene ether and castor oil polyoxyethylene ether, and the curing agent is a mixture of modified aromatic polyamine and oil-soluble imidazoline. According to the profile control composition, 200 thousand mg / L to 300 thousand mg / L of hypersalinity formation water is used as a water phase, and reinjection of hypersalinity oilfield produced water is achieved while an epoxy resin-in-water emulsion with good stability is established. After being heated at 130 DEG C for 12 hours and cured, the profile control composition has high strength, achieves a good plugging effect, and is suitable for being used as a profile control and water plugging agent to be popularized and applied in profile control and water plugging operation of the fractured-vuggy carbonate reservoirs.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas field development, and in particular relates to a profile control composition and a preparation method thereof. Background Art

[0002] Since fractures in carbonate fracture-cave reservoirs are relatively developed, water can easily penetrate along the fractures during the development process, resulting in ineffective water drive in the well group or excessive water content in the oil well. Therefore, it is necessary to perform profile control and water plugging operations on such well groups / single wells. Profile control and water plugging mainly achieve the purpose of improving the recovery rate by plugging the high permeability layer and increasing the sweep coefficient of the injected water. As an important technical means to improve the effect of water drive development and achieve stable production of oil reservoirs, it has been successfully applied in high-water-content oil fields at home and abroad.

[0003] There is a shortage of fresh water resources in western my country, and most of the oil fields are high-salt oil fields. The mineralization of the produced formation water is very high (the mineralization can reach 200,000 mg / L to 300,000 mg / L). If the formation water produced by this high-water-content oil well is not reinjected, it is necessary to match the corresponding water treatment process and equipment, which increases the cost of oil field development. Therefore, if the produced formation water can be applied to the construction of the oil field profile control and water plugging system, the operating cost can be effectively saved. The existing profile control and water plugging agents can be mainly divided into gel-type profile control and water plugging agents, particle-type profile control and water plugging agents, precipitation-type profile control and water plugging agents, foam-type profile control and water plugging agents and resin-type profile control and water plugging agents, but these existing gel-type profile control and water plugging agents, particle-type profile control and water plugging agents, precipitation-type profile control and water plugging agents, and foam-type profile control and water plugging agents all have various problems, such as:

[0004] (1) The gelling time of the profile control and water plugging agent is too fast, which can easily cause blockage in the near-wellbore area. The gel stability is poor under high temperature and high salinity conditions, and the water-based gel system can easily enter the oil layer and cause damage during the operation process.

[0005] (2) Granular profile control and water plugging agents are mainly composed of inorganic solid particles such as cement and fly ash and other organic particles. They are injected into the formation in the form of a suspension. Through the bridging of organic particles and the filling of inorganic particles, the water absorption profile and water phase permeability are adjusted to plug the high permeability layer and the water-producing layer, so as to achieve the purpose of adjusting the water absorption profile and plugging water. However, this is a non-selective plugging agent, and this granular plugging agent has poor stability and is easy to agglomerate and damage the reservoir. It is only suitable for plugging near the wellbore area.

[0006] (3) The penetration depth of precipitation-based profile control and water plugging agents in porous media is limited and is not suitable for deep treatment;

[0007] (4) Foam-based profile control and water plugging agents are affected by the high temperature and high salt content of the reservoir, resulting in poor system stability and a short effective period.

[0008] Compared with the other four types of profile control and water plugging, resin profile control compositions are a type of profile control and water plugging system with great potential. However, the high viscosity of the resin severely limits its application as a profile control composition. How to use the high-mineralization brine produced from the formation to prepare emulsified epoxy resin is the key to solving the problems of high formation water treatment costs and difficulties in epoxy resin injection. Summary of the invention

[0009] The purpose of the present invention is to provide a profile control composition and a preparation method thereof. The profile control composition is a water-in-epoxy resin emulsion prepared with high-mineralization formation water, epoxy resin, emulsifier, and curing agent. The composition is stable under high mineralization, has low viscosity, is easy to inject, and has high plugging strength. It can not only achieve a higher plugging strength, but also solve the problems of high cost of high-mineralization formation water treatment and difficulty in epoxy resin injection in the prior art.

[0010] The first aspect of the present invention provides a profile control composition, which includes an epoxy resin, an emulsifier, a curing agent and water;

[0011] The emulsifier is a mixture of alkylphenol polyoxyethylene ether and castor oil polyoxyethylene ether;

[0012] The curing agent is a mixture of modified aromatic polyamine and oil-soluble imidazoline.

[0013] According to a specific embodiment of the present invention, the mass of the profile control composition is calculated as 100%, and the profile control composition includes 40wt% to 50wt% epoxy resin, 2.5wt% to 5wt% emulsifier, 2.5wt% to 5wt% curing agent and the balance water.

[0014] According to a specific embodiment of the present invention, the mass ratio of the alkylphenol polyoxyethylene ether to the castor oil polyoxyethylene ether is 1:(1 to 4); and / or

[0015] The mass ratio of the modified aromatic polyamine to the oil-soluble imidazoline is (1 to 4):1;

[0016] Preferably, the mass ratio of the alkylphenol polyoxyethylene ether to the castor oil polyoxyethylene ether is 1:(2 to 4).

[0017] According to a specific embodiment of the present invention, the epoxy resin is bisphenol A epoxy resin;

[0018] Preferably, the average epoxy value of the bisphenol A epoxy resin is 0.44 eq / 100 g to 0.51 eq / 100 g.

[0019] According to a specific embodiment of the present invention, the alkylphenol polyoxyethylene ether is octylphenol polyoxyethylene ether 50; and / or

[0020] The castor oil polyoxyethylene ether is castor oil polyoxyethylene ether 90; and / or

[0021] The modified aromatic polyamine is thiourea-modified meta-phenylenediamine; and / or

[0022] The oil-soluble imidazoline is oleic acid imidazoline; and / or

[0023] The epoxy resin is selected from epoxy resin E44 and / or epoxy resin E51.

[0024] According to a specific embodiment of the present invention, the mineralization of the water is 200000 mg / L to 300000 mg / L;

[0025] Preferably, the mineralization of the water is 220,000 mg / L.

[0026] According to a specific embodiment of the present invention, the curing condition of the profile control composition is heating at 110° C. to 130° C. for not less than 12 hours.

[0027] According to a specific embodiment of the present invention, the thiourea-modified m-phenylenediamine is prepared by the following method:

[0028] The thiourea-modified meta-phenylenediamine is obtained by reacting thiourea with meta-phenylenediamine.

[0029] According to a specific embodiment of the present invention, the thiourea and m-phenylenediamine are mixed and heated from room temperature until they are melted, and then the reaction is carried out;

[0030] Preferably, the molar ratio of thiourea to m-phenylenediamine is 1:3;

[0031] Preferably, the reaction is a reflux reaction; and / or

[0032] The reaction temperature is 140°C; and / or the reaction time is 3 hours;

[0033] Preferably, the reaction is carried out under stirring; and / or

[0034] The stirring speed is 3000r / min.

[0035] The thiourea-modified meta-phenylenediamine prepared by the present invention can be directly used for preparing the profile control composition without purification.

[0036] The second aspect of the present invention provides a method for preparing the profile control composition according to the first aspect of the present invention, comprising the following steps:

[0037] a. mixing the epoxy resin, emulsifier and curing agent to obtain a mixture;

[0038] b. mixing the mixture with water to obtain the profile control composition.

[0039] According to a specific embodiment of the present invention, in step a, the mixture is first heated to 40° C. to 60° C., and then step b is performed under stirring;

[0040] Preferably, the temperature of the mixture after being heated is 50°C to 60°C;

[0041] Preferably, the stirring speed is not less than 1000 r / min.

[0042] The profile control composition according to the first aspect of the present invention or the profile control composition prepared by the method according to the second aspect of the present invention is used in profile control and water plugging of carbonate fracture-vuggy oil reservoirs, especially as a profile control agent for carbonate fracture-vuggy oil reservoirs.

[0043] Beneficial effects of the present invention:

[0044] In view of the high cost of treating high-mineralized formation water and the difficulty of injecting epoxy resin in the prior art, the present invention provides a profile control composition and a preparation method thereof. The profile control composition comprises epoxy resin, emulsifier, curing agent and water, and is a water-in-epoxy resin emulsion, wherein the emulsifier is a mixture of alkylphenol polyoxyethylene ether and castor oil polyoxyethylene ether, and the curing agent is a mixture of modified aromatic polyamine and oil-soluble imidazoline. The profile control composition can use water with a mineralization of 200000 mg / L to 300000 mg / L as the aqueous phase, and through formula design, establish an emulsified epoxy resin system with good stability. It is liquid before curing, which not only solves the problems of high viscosity and poor injectability of epoxy resin, but also uses the high mineralization formation water produced by the oil field, solves the treatment problem of high mineralization formation water, and saves the cost of oil field development; and the profile control composition has a high strength after curing, and can achieve a good plugging effect: the plugging control composition provided by the present invention is prepared and injected into the metal pipe, and it is heated in an oven at 130°C for 12 hours to transform the system, complete the curing, and then water is injected into the metal pipe. The breakthrough pressure difference of the injected water is measured to be 7.2MPa to 10.2MPa, and the plugging effect on the metal pipe is good. It is explained that the profile control composition provided by the present invention can achieve a high plugging strength, can achieve a good plugging effect, and can be promoted and applied as a profile control agent in the profile control and water plugging operation of carbonate fracture-cavity oil reservoirs. DETAILED DESCRIPTION

[0045] The present invention will be further described below in conjunction with examples, but the examples of the present invention are only exemplary descriptions, and the implementation manner does not constitute a limitation of the present invention under any circumstances.

[0046] Preparation of thiourea-modified m-phenylenediamine

[0047] Example 1

[0048] 1) Take 15.2g thiourea and 64.8g m-phenylenediamine, add them into a three-necked flask equipped with a reflux condenser, raise the temperature from room temperature and stir slowly until the thiourea and m-phenylenediamine are completely melted;

[0049] 2) Increase the stirring speed to 3000 r / min, raise the temperature to 140°C, and react for 3 hours to obtain thiourea-modified meta-phenylenediamine.

[0050] Preparation of profile control composition

[0051] Example 2

[0052] 1) 50 g of epoxy resin E44, 5 g of emulsifier (including octylphenol polyoxyethylene ether 50 and castor oil polyoxyethylene ether 90 in a mass ratio of 1:4) and 5 g of curing agent (including thiourea-modified metaphenylenediamine and oleic acid imidazoline in a mass ratio of 4:1) were mixed and stirred until the emulsifier and the curing agent were completely dissolved in the epoxy resin to obtain a mixture;

[0053] 2) The mixture is heated to 50° C., stirred at a speed of 1000 r / min, and 60 g of formation water with a mineralization degree of 220,000 mg / L is uniformly injected into the mixture by a syringe pump to obtain a profile control composition, which is a water-in-epoxy resin emulsion.

[0054] Example 3

[0055] 1) 40 g of epoxy resin E44, 2.5 g of emulsifier (including octylphenol polyoxyethylene ether 50 and castor oil polyoxyethylene ether 90 in a mass ratio of 1:2) and 2.5 g of curing agent (including thiourea-modified metaphenylenediamine and oleic acid imidazoline in a mass ratio of 1:1) were mixed and stirred until the emulsifier and the curing agent were completely dissolved in the epoxy resin to obtain a mixture;

[0056] 2) The mixture is heated to 60° C., stirred at a speed of 1000 r / min, and 55 g of formation water with a mineralization degree of 200,000 mg / L is uniformly injected into the mixture by a syringe pump to obtain a profile control composition, which is a water-in-epoxy resin emulsion.

[0057] Example 4

[0058] 1) 50 g of epoxy resin E44, 5 g of emulsifier (including octylphenol polyoxyethylene ether 50 and castor oil polyoxyethylene ether 90 in a mass ratio of 1:3) and 5 g of curing agent (including thiourea-modified metaphenylenediamine and oleic acid imidazoline in a mass ratio of 2:1) were mixed and stirred until the emulsifier and the curing agent were completely dissolved in the epoxy resin to obtain a mixture;

[0059] 2) The mixture is heated to 60° C., stirred at a speed of 1000 r / min, and 40 g of formation water with a mineralization degree of 300,000 mg / L is uniformly injected into the mixture by a syringe pump to obtain a profile control composition, which is a water-in-epoxy resin emulsion.

[0060] Example 5

[0061] 1) 50 g of epoxy resin E51, 3 g of emulsifier (including octylphenol polyoxyethylene ether 50 and castor oil polyoxyethylene ether 90 in a mass ratio of 1:4) and 3 g of curing agent (including thiourea-modified metaphenylenediamine and oleic acid imidazoline in a mass ratio of 4:1) were mixed and stirred until the emulsifier and the curing agent were completely dissolved in the epoxy resin to obtain a mixture;

[0062] 2) The mixture was heated to 50° C., the mixture was stirred at a speed of 1000 r / min, and 44 g of formation water with a mineralization degree of 220,000 mg / L was uniformly injected into the mixture by a syringe pump to obtain a profile control composition, which is a water-in-epoxy resin emulsion.

[0063] Comparative Example 1

[0064] 1) 50 g of epoxy resin E44, 5 g of emulsifier (Span-80) and 5 g of curing agent (comprising thiourea-modified m-phenylenediamine and oleic acid imidazoline in a mass ratio of 4:1) were mixed and stirred until the emulsifier and curing agent were completely dissolved in the epoxy resin to obtain a mixture;

[0065] 2) The mixture is heated to 50° C., stirred at a speed of 1000 r / min, and 60 g of formation water with a mineralization degree of 220,000 mg / L is uniformly injected into the mixture by a syringe pump to obtain a profile control composition, which is a water-in-epoxy resin emulsion.

[0066] Comparative Example 2

[0067] 1) 50 g of epoxy resin E44, 5 g of emulsifier (including octylphenol polyoxyethylene ether 50 and castor oil polyoxyethylene ether 90 in a mass ratio of 1:4) and 5 g of curing agent (diethylenetriamine) were mixed and stirred until the emulsifier and the curing agent were completely dissolved in the epoxy resin to obtain a mixture;

[0068] 2) The mixture is heated to 50° C., stirred at a speed of 1000 r / min, and 60 g of formation water with a mineralization degree of 220,000 mg / L is uniformly injected into the mixture by a syringe pump to obtain a profile control composition, which is a water-in-epoxy resin emulsion.

[0069] Comparative Example 3

[0070] 1) Mix 50 g of epoxy resin E44, 5 g of emulsifier (Span-80) and 5 g of curing agent (diethylenetriamine), and stir until the emulsifier and curing agent are completely dissolved in the epoxy resin to obtain a mixture;

[0071] 2) The mixture is heated to 50° C., stirred at a speed of 1000 r / min, and 60 g of formation water with a mineralization degree of 220,000 mg / L is uniformly injected into the mixture by a syringe pump to obtain a profile control composition, which is a water-in-epoxy resin emulsion.

[0072] Experimental evaluation

[0073] 1. Determination of plugging strength of profile control composition

[0074] First, the profile controlling compositions prepared in Examples 2 to 5 and Comparative Examples 1 to 3 were solidified in a metal tube, and then water was injected into the metal tube to measure the pressure difference when the injected water broke through. The pressure difference when water was injected into the profile controlling compositions prepared in Examples 2 to 5 and Comparative Examples 1 to 3 after they were solidified in the metal tube represented the plugging strength of the profile controlling compositions.

[0075] The specific steps are as follows:

[0076] i. Take equal amounts of the profile control compositions prepared in Examples 2 to 5 and Comparative Examples 1 to 3, and inject them into seven metal tubes of equal height and inner diameter of 3 mm respectively at a flow rate of 0.5 mL / min using a horizontal flow pump;

[0077] ii. Seal both ends of the metal tube injected with the profile control composition, place it in an oven at 130° C. and heat it for 12 hours to make the profile control composition therein undergo system transformation and complete solidification;

[0078] iii. Using a horizontal flow pump, water was injected into 7 metal tubes having the profile control compositions prepared in Examples 2 to 5 and Comparative Examples 1 to 3 solidified therein at a flow rate of 0.5 mL / min, and the pressure difference when the injected water broke through was measured.

[0079] The specific results are shown in Table 1.

[0080] Table 1. Injection water breakthrough pressure difference

[0081] Serial number Injection water breakthrough pressure difference / MPa Example 2 9 Example 3 7.2 Example 4 10.2 Example 5 8.6 Comparative Example 1 2.5 Comparative Example 2 3.4 Comparative Example 3 1.8

[0082] It can be seen from Table 1 that after the profile control compositions prepared in Examples 2 to 5 were solidified in the metal pipe, the pressure differences when the injected water broke through were 9 MPa, 7.2 MPa, 10.2 MPa and 8.6 MPa, respectively. This indicates that the profile control compositions prepared in Examples 2 to 5 were effectively plugged in the metal pipe after being solidified, and had high plugging strength.

[0083] Comparing Example 2 with Comparative Example 1, it can be seen that the system using octylphenol polyoxyethylene ether 50 and castor oil polyoxyethylene ether 90 in a mass ratio of 1:4 as emulsifiers (Example 2) has a water injection breakthrough pressure difference of 3.6 times that of the system using Span80 as an emulsifier (Comparative Example 1); Comparing Example 2 with Comparative Example 2, it can be seen that the system using thiourea modified metaphenylenediamine and oleic acid imidazoline in a mass ratio of 4:1 as curing agents (Example 2) has a water injection breakthrough pressure difference of 1.6 times that of the system using diethyl ether as an emulsifier (Example 1). The plugging effect of Example 3 is the worst. By comparing Example 2 and Example 3, it can be seen that the water injection breakthrough pressure difference of the system (Example 2) using octylphenol polyoxyethylene ether 50 and castor oil polyoxyethylene ether 90 with a mass ratio of 1:4 as emulsifiers and thiourea-modified metaphenylenediamine and oleic acid imidazoline with a mass ratio of 4:1 as curing agents is 5 times that of the system using Span80 as an emulsifier and diethylenetriamine as a curing agent. The inventor believes that the water injection breakthrough pressure difference may be too low due to the insufficient emulsion stability and low curing strength of the systems prepared in Examples 1 to 3. Combined with the above analysis, it can be seen that the use of emulsifiers outside the scope of the present invention and / or curing agents outside the scope of the present invention will affect the stability of the emulsion or the curing strength, and ultimately affect the water injection breakthrough pressure difference.

[0084] In addition, the formation water mineralization degree used in preparing the profile control composition in Examples 2 to 5 is 200,000 mg / L to 300,000 mg / L. It is in a stable emulsion before solidification and can be injected into a metal pipe with an inner diameter of only 3 mm, which proves that the profile control composition prepared in Examples 2 to 5 has good fluidity before solidification, overcoming the injection difficulty problem caused by the poor fluidity of epoxy resin; at the same time, the profile control composition prepared in Examples 2 to 5 also utilizes the high-mineralization formation water produced by the oil field, realizes the reinjection of high-mineralization oilfield produced water, eliminates the additional treatment process of high-mineralization oilfield produced water, saves the cost of oilfield development, and simplifies the process flow.

[0085] Although the present invention has been described with reference to specific embodiments, it will be appreciated by those skilled in the art that various changes may be made without departing from the true spirit and scope of the present invention. In addition, the subject matter, spirit and scope of the present invention may be varied to accommodate specific situations, materials, material combinations and methods. All of these changes are included within the scope of the claims of the present invention.

Claims

1. A profile control composition comprising an epoxy resin, an emulsifier, a curing agent and water; The emulsifier is a mixture of alkylphenol polyoxyethylene ether and castor oil polyoxyethylene ether; The curing agent is a mixture of modified aromatic polyamine and oil-soluble imidazoline.

2. The profile control composition according to claim 1, characterized in that: The mass of the profile control composition is calculated as 100%, and the profile control composition includes 40 wt % to 50 wt % of epoxy resin, 2.5 wt % to 5 wt % of emulsifier, 2.5 wt % to 5 wt % of curing agent and the balance of water.

3. The profile control composition according to claim 1 or 2, characterized in that: The mass ratio of the alkylphenol polyoxyethylene ether to the castor oil polyoxyethylene ether is 1:(1 to 4); and / or The mass ratio of the modified aromatic polyamine to the oil-soluble imidazoline is (1 to 4):

1.

4. The profile control composition according to any one of claims 1 to 3, characterized in that: The epoxy resin is bisphenol A epoxy resin; Preferably, the average epoxy value of the bisphenol A epoxy resin is 0.44 eq / 100 g to 0.51 eq / 100 g.

5. The profile controlling composition according to any one of claims 1 to 4, characterized in that: The alkylphenol polyoxyethylene ether is octylphenol polyoxyethylene ether 50; and / or The castor oil polyoxyethylene ether is castor oil polyoxyethylene ether 90; and / or The modified aromatic polyamine is thiourea-modified meta-phenylenediamine; and / or The oil-soluble imidazoline is oleic acid imidazoline; and / or The epoxy resin is selected from epoxy resin E44 and / or epoxy resin E51.

6. The profile controlling composition according to any one of claims 1 to 5, characterized in that: The mineralization of the water is 200,000 mg / L to 300,000 mg / L.

7. A method for preparing the profile control composition according to any one of claims 1 to 6, comprising the following steps: a. mixing the epoxy resin, emulsifier and curing agent to obtain a mixture; b. mixing the mixture with water to obtain the profile control composition.

8. The method according to claim 7, characterized in that In step a, the mixture is first heated to 40° C. to 60° C., and then step b is performed under stirring.

9. The method according to claim 8, characterized in that The stirring speed is not less than 1000 r / min.

10. Use of the profile control composition according to any one of claims 1 to 6 or the profile control composition prepared by the method according to any one of claims 7 to 9 in profile control and water plugging in carbonate fracture-vuggy oil reservoirs, especially as a profile control agent for carbonate fracture-vuggy oil reservoirs.