A profile control composition and a method of making the same

Abstract

This invention provides a profile control composition and its preparation method. The profile control composition comprises epoxy resin, emulsifier, curing agent, and water, and is a water-in-epoxy resin 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. The profile control composition uses high-salinity formation water (200,000 mg / L to 300,000 mg / L) as the aqueous phase, establishing a stable water-in-epoxy resin emulsion while simultaneously enabling the reinjection of produced water from high-salinity oilfields. After curing at 130°C for 12 hours, the profile control composition exhibits high strength and achieves good sealing effects, making it suitable for widespread application as a profile control and water shut-off agent in carbonate fractured-vuggy reservoirs.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of oil and gas field development, and particularly relates to a profile control composition and a preparation method thereof. BACKGROUND

[0002] Due to the fact that fractures are relatively developed in carbonate fracture-cave type reservoirs, water is prone to channel into fractures during development, causing problems such as ineffective water flooding of well groups or excessively high water content of oil wells. Therefore, profile control and water plugging operations are required for such well groups / single wells. Profile control and water plugging mainly block high permeability layers to improve the sweep efficiency of injected water, so as to improve the recovery rate. As an important technical means for improving water flooding development effect and realizing stable production of reservoirs, profile control and water plugging has been successfully applied in high water cut oilfields at home and abroad.

[0003] Fresh water resources are scarce in western China, and most oilfields are high-salinity oilfields. The produced formation water has very high salinity (salinity can reach 200000 mg / L to 300000 mg / L). If the produced formation water is not reinjected, corresponding water treatment processes and equipment need to be matched, which increases the cost of oilfield development. Therefore, if the produced formation water can be applied to the construction of oilfield profile control and water plugging system, the operation cost can be effectively saved. Existing profile control and water plugging agents can be mainly divided into the following types: gel type profile control and water plugging agent, particle type profile control and water plugging agent, precipitation type profile control and water plugging agent, foam type profile control and water plugging agent, and resin type profile control and water plugging agent. However, 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, for example:

[0004] (1) The gel time of the gel type profile control and water plugging agent is too fast, which easily causes plugging in the near wellbore zone. The stability of the gel is poor under high temperature and high salinity. Moreover, the water-based gel system entering the oil layer during operation is prone to cause damage;

[0005] (2) The particle type profile control and water plugging agent is mainly composed of inorganic solid particles such as cement and fly ash and other organic particles, and is 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 the water phase permeability are adjusted to block high permeability layers and water layers, so as to adjust the water absorption profile and block water. However, this is a non-selective plugging agent, and the stability of this particle type plugging agent is poor and it is prone to caking and damaging the reservoir, and is only suitable for near wellbore zone plugging;

[0006] (3) The precipitation type profile control and water plugging agent has limited depth of entry in porous media and is not suitable for deep treatment;

[0007] (4) The stability of the foam type profile control and water plugging agent is poor and the effective period is short due to the influence of high temperature and high salinity of the reservoir.

[0008] Compared with the other four profile control and water plugging agents, the resin profile control composition is a very potential profile control and water plugging system. However, the high viscosity of the resin seriously limits its application as a profile control composition. How to prepare the emulsified epoxy resin by using the high salinity brine produced from the formation is the key to solve the problems of high cost of treatment of the formation water and difficulty in injection of the epoxy resin. SUMMARY

[0009] The present application aims to provide a profile control composition and a preparation method thereof. The profile control composition is an epoxy resin-in-water emulsion prepared by using high salinity formation water, epoxy resin, emulsifier and curing agent. The profile control composition is stable under high salinity, has low viscosity, is easy to inject and has high plugging strength. The profile control composition can achieve high plugging strength and solve the problems of high cost of treatment of high salinity formation water and difficulty in injection of the epoxy resin in the prior art.

[0010] The present application provides a profile control composition comprising epoxy resin, emulsifier, 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 one embodiment of the present application, the profile control composition comprises 40wt% to 50wt% epoxy resin, 2.5wt% to 5wt% emulsifier, 2.5wt% to 5wt% curing agent and the balance of water, based on 100% by mass of the profile control composition.

[0014] According to one embodiment of the present application, 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 one embodiment of the present application, the epoxy resin is bisphenol A type epoxy resin.

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

[0019] According to one embodiment of the present application, 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 m-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 one specific embodiment of the present application, the salinity of the water is 200000 mg / L to 300000 mg / L.

[0025] Preferably, the salinity of the water is 220000 mg / L.

[0026] According to one specific embodiment of the present application, the curing condition of the profile control composition is heating at 110℃ to 130℃ for no less than 12h.

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

[0028] The thiourea and m-phenylenediamine are reacted to obtain the thiourea modified m-phenylenediamine.

[0029] According to one specific embodiment of the present application, the thiourea and m-phenylenediamine are mixed and heated from room temperature to melting, and then the reaction is performed;

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

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

[0032] The temperature of the reaction is 140℃; and / or the time length is 3h;

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

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

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

[0036] The second aspect of the present application provides a method for preparing the profile control composition as described in the first aspect of the present application, which comprises the following steps:

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

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

[0039] According to one specific embodiment of the present application, in step a, the mixture is first heated to 40-60℃, and then step b is carried out under stirring;

[0040] Preferably, the temperature of the mixture after heating is 50-60℃.

[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 application or the profile control composition prepared by the method according to the second aspect of the present application has the application in profile control and water plugging in carbonate fracture-cave type reservoirs, especially as a profile control agent for carbonate fracture-cave type reservoirs.

[0043] The present application has the following advantages:

[0044] In view of the problems of high cost of treatment of high salinity formation water and difficulty in injection of epoxy resin in the prior art, the present application 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. 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 salinity of 200000-300000 mg / L as the water phase, and through formula design, a stable emulsified epoxy resin system is established. The profile control composition is liquid before curing, which not only solves the problems of high viscosity and poor injectability of epoxy resin, but also utilizes the high salinity formation water produced by oilfields, solves the problem of treatment of high salinity formation water, and saves the cost of oilfield development. Moreover, the profile control composition has high strength after curing, and can achieve good plugging effect. After the profile control composition provided by the present application is prepared and injected into a metal pipe, it is heated in an oven at 130℃ for 12 h to complete system modification and curing, and then water is injected into the metal pipe. The breakthrough pressure difference of the injected water is 7.2-10.2 MPa, and the plugging effect on the metal pipe is good. It is shown that the profile control composition provided by the present application can achieve high plugging strength, can achieve good plugging effect, and can be applied as a profile control agent in profile control and water plugging operations in carbonate fracture-cave type reservoirs. DETAILED DESCRIPTION

[0045] The present application will be further described below in conjunction with examples, but the examples of the present application are only exemplary descriptions, and the examples do not constitute a limitation on the present application in any case.

[0046] Preparation of thiourea-modified m-phenylenediamine

[0047] Example 1

[0048] 1) Take 15.2 g of thiourea and 64.8 g of m-phenylenediamine, add them to a three-necked flask equipped with a reflux condenser, and slowly stir them from room temperature to the complete melting of the thiourea and m-phenylenediamine;

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

[0050] Preparation of the profile control composition

[0051] Example 2

[0052] 1) Mix 50 g of epoxy resin E44, 5 g of emulsifier (including octylphenol polyoxyethylene ether 50 and castor oil polyoxyethylene ether 90 at a mass ratio of 1:4) and 5 g of curing agent (including thiourea-modified m-phenylenediamine and imidazoline oleate at a mass ratio of 4:1), and stir until the emulsifier and curing agent are completely dissolved in the epoxy resin to obtain a mixture;

[0053] 2) Heat the mixture to 50°C, and stir the mixture at a speed of 1000 r / min while injecting 60 g of formation water with a mineralization degree of 220000 mg / L into the mixture at a constant speed by using a syringe pump to obtain the profile control composition, an epoxy resin-in-water emulsion.

[0054] Example 3

[0055] 1) Mix 40 g of epoxy resin E44, 2.5 g of emulsifier (including octylphenol polyoxyethylene ether 50 and castor oil polyoxyethylene ether 90 at a mass ratio of 1:2) and 2.5 g of curing agent (including thiourea-modified m-phenylenediamine and imidazoline oleate at a mass ratio of 1:1), and stir until the emulsifier and curing agent are completely dissolved in the epoxy resin to obtain a mixture;

[0056] 2) Heat the mixture to 60°C, and stir the mixture at a speed of 1000 r / min while injecting 55 g of formation water with a mineralization degree of 200000 mg / L into the mixture at a constant speed by using a syringe pump to obtain the profile control composition, an epoxy resin-in-water emulsion.

[0057] Example 4

[0058] 1) Mix 50 g of epoxy resin E44, 5 g of emulsifier (including octylphenol polyoxyethylene ether 50 and castor oil polyoxyethylene ether 90 at a mass ratio of 1:3) and 5 g of curing agent (including thiourea-modified m-phenylenediamine and imidazoline oleate at a mass ratio of 2:1), and stir until the emulsifier and curing agent are completely dissolved in the epoxy resin to obtain a mixture;

[0059] 2) heating the mixture to 60℃, stirring the mixture at a speed of 1000 r / min, and injecting 40 g of formation water with a salinity of 300 000 mg / L into the mixture at a constant speed by using a syringe pump to obtain a profile control composition, an epoxy resin-in-water emulsion.

[0060] Example 5

[0061] 1) mixing 50 g of epoxy resin E51, 3 g of emulsifier (including octylphenol polyoxyethylene ether 50 and castor oil polyoxyethylene ether 90 at a mass ratio of 1:4) and 3 g of curing agent (including thiourea modified m-phenylenediamine and imidazoline oleate at a mass ratio of 4:1) to obtain a mixture, stirring until the emulsifier and the curing agent are completely dissolved in the epoxy resin;

[0062] 2) heating the mixture to 50℃, stirring the mixture at a speed of 1000 r / min, and injecting 44 g of formation water with a salinity of 220 000 mg / L into the mixture at a constant speed by using a syringe pump to obtain a profile control composition, an epoxy resin-in-water emulsion.

[0063] Comparative Example 1

[0064] 1) mixing 50 g of epoxy resin E44, 5 g of emulsifier (Span-80) and 5 g of curing agent (including thiourea modified m-phenylenediamine and imidazoline oleate at a mass ratio of 4:1) to obtain a mixture, stirring until the emulsifier and the curing agent are completely dissolved in the epoxy resin;

[0065] 2) heating the mixture to 50℃, stirring the mixture at a speed of 1000 r / min, and injecting 60 g of formation water with a salinity of 220 000 mg / L into the mixture at a constant speed by using a syringe pump to obtain a profile control composition, an epoxy resin-in-water emulsion.

[0066] Comparative Example 2

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

[0068] 2) heating the mixture to 50℃, stirring the mixture at a speed of 1000 r / min, and injecting 60 g of formation water with a salinity of 220 000 mg / L into the mixture at a constant speed by using a syringe pump to obtain a profile control composition, an epoxy resin-in-water emulsion.

[0069] Comparative Example 3

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

[0071] 2) Heat the mixture to 50°C, stir the mixture at a speed of 1000 r / min, and at the same time, inject 60 g of formation water with a mineralization of 220000 mg / L into the mixture at a constant speed using a syringe pump to obtain a profile control composition, an epoxy resin-in-water emulsion.

[0072] Experimental evaluation

[0073] 1. Profile control composition plugging strength determination

[0074] First, the profile control compositions prepared in Examples 2 to 5 and Comparative Examples 1 to 3 are cured in metal pipes, then water is injected into the metal pipes, and the pressure difference at the breakthrough of the injected water is determined, which represents the plugging strength of the profile control composition after the profile control composition prepared in Examples 2 to 5 and Comparative Examples 1 to 3 is cured in the metal pipe.

[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, then inject them into 7 metal pipes with equal height and inner diameter of 3 mm at a flow rate of 0.5 mL / min using a laminar flow pump;

[0077] ii. Seal the two ends of the metal pipes containing the profile control composition, place them in an oven at 130°C for 12 h to allow the profile control composition to undergo system modification and complete curing;

[0078] iii. Inject water into the 7 metal pipes containing the profile control compositions prepared in Examples 2 to 5 and Comparative Examples 1 to 3 at a flow rate of 0.5 mL / min using a laminar flow pump, and determine the pressure difference at the breakthrough of the injected water.

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

[0080] Table 1. Breakthrough pressure difference of injected water

[0081] No. Injection water breakthrough differential pressure / 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] As can be seen from Table 1, the pressure difference at the breakthrough of the injected water after the profile control compositions prepared in Examples 2 to 5 are cured in the metal pipes is 9 MPa, 7.2 MPa, 10.2 MPa and 8.6 MPa, respectively. This shows that the profile control compositions prepared in Examples 2 to 5 achieve effective plugging in the metal pipes after curing, and have high plugging strength.

[0083] As can be seen from Comparative Example 2 and Comparative Example 1, the water breakthrough pressure difference of the system using octylphenol polyoxyethylene ether 50 and castor oil polyoxyethylene ether 90 with a mass ratio of 1:4 as emulsifiers (Example 2) is 3.6 times that of the system using Span 80 as emulsifiers (Comparative Example 1); as can be seen from Comparative Example 2 and Comparative Example 2, the water breakthrough pressure difference of the system using thiourea modified m-phenylenediamine and imidazoline oleate with a mass ratio of 4:1 as curing agents (Example 2) is 2.6 times that of the system using diethylene triamine as curing agents (Comparative Example 2); the plugging effect of Comparative Example 3 is the worst, as can be seen from Comparative Example 2 and Comparative Example 3, the water breakthrough pressure difference of the system using octylphenol polyoxyethylene ether 50 and castor oil polyoxyethylene ether 90 with a mass ratio of 1:4 as emulsifiers and thiourea modified m-phenylenediamine and imidazoline oleate with a mass ratio of 4:1 as curing agents (Example 2) is 5 times that of the system using Span 80 as emulsifiers and diethylene triamine as curing agents. The inventors believe that the water breakthrough pressure difference is too low due to the lack of emulsion stability and low curing strength of the systems prepared in Comparative Examples 1 to 3. It can be known from the above analysis that the use of emulsifiers outside the scope of the application and / or curing agents outside the scope of the application will affect the stability of the emulsion or the curing strength, and ultimately affect the water breakthrough pressure difference.

[0084] In addition, the formation water used in the preparation of the profile control composition in Examples 2 to 5 has a salinity of 200000 mg / L to 300000 mg / L, which is a stable emulsion before curing, and can be injected into a metal pipe with an inner diameter of only 3 mm, proving that the profile control composition prepared in Examples 2 to 5 has good fluidity before curing, overcoming the problem of injection difficulty caused by poor fluidity of epoxy resin; at the same time, the profile control composition prepared in Examples 2 to 5 also utilizes the high salinity formation water produced by the oilfield, realizes the reinjection of high salinity oilfield produced water, saves the additional treatment process of high salinity oilfield produced water, saves the cost of oilfield development, and simplifies the process flow.

[0085] Although the present application has been described with reference to specific embodiments, it is understood by those skilled in the art that various changes can be made without departing from the true spirit and scope of the present application. In addition, various changes can be made to the subject matter, spirit and scope of the present application to adapt to specific circumstances, materials, material compositions and methods. All these changes are included in the scope of the claims of the present application.

Claims

1. A profile control composition, comprising an epoxy resin, an emulsifier, a curing agent and water; the emulsifier is a mixture of an alkylphenol polyoxyethylene ether and a castor oil polyoxyethylene ether; the curing agent is a mixture of a modified aromatic polyamine and an oil-soluble imidazoline; the modified aromatic polyamine is thiourea-modified m-phenylenediamine; the oil-soluble imidazoline is oleic acid imidazoline; the mass ratio of the alkylphenol polyoxyethylene ether and the castor oil polyoxyethylene ether is 1: (1-4) ; the mass ratio of the modified aromatic polyamine and the oil-soluble imidazoline is (1-4) :

1.

2. The profile control composition of claim 1, wherein, The profile control composition comprises 40-50 wt% of the epoxy resin, 2.5-5 wt% of the emulsifier, 2.5-5 wt% of the curing agent and the balance of water, based on 100% by mass of the profile control composition.

3. The profile control composition of claim 1, wherein, The epoxy resin is a bisphenol A type epoxy resin.

4. The profile control composition of claim 3, wherein, The average epoxy value of the bisphenol A type epoxy resin is 0.44-0.51 eq / 100 g.

5. The profile control composition of any one of claims 1 to 4, wherein, 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 epoxy resin is selected from epoxy resin E44 and / or epoxy resin E51.

6. The profile control composition of any one of claims 1 to 4, wherein, The water has a salinity of 200000-300000 mg / L. 7.A method for preparing the profile control composition according to any one of claims 1-6, comprising the following steps: a. mixing the epoxy resin, the emulsifier and the curing agent to obtain a mixture; b. mixing the mixture and water to obtain the profile control composition.

8. The method of claim 7, wherein, In step a, the mixture is first heated to 40-60℃, and then step b is carried out under stirring.

9. The method of claim 8, wherein, The stirring speed is not less than 1000 r / min. 10.Use of the profile control composition according to any one of claims 1-6 or prepared by the method according to any one of claims 7-9 as a profile control agent in profile control and water plugging in carbonate fracture-cave type reservoirs.