A rubber emulsion plugging agent, a preparation method and application thereof

Abstract

The application provides a rubber emulsion plugging agent, a preparation method and application thereof. Raw materials of the rubber emulsion plugging agent include rubber, white oil, a crosslinking agent, an emulsifier, a dispersant and water.

Description

TECHNICAL FIELD

[0001] The present application relates to a plugging agent. BACKGROUND

[0002] Tahe oilfield belongs to high-temperature and high-salinity fractured-vug reservoir. When developed, injected water and bottom water break through along the fractures rapidly, and the water cut of oil wells increases significantly, resulting in rapid reduction of oil production. Polymer gel profile control technology is an important means to control water and stabilize oil in fractured reservoirs. The anti-dilution performance of conventional polyacrylamide gel is poor, and it is easily hydrolyzed at high temperature, resulting in poor plugging effect. The bridging of granular plugging agent in large fracture channels of fractured-vug reservoirs is difficult, and it is difficult to achieve long-distance profile control. The use of non-water-soluble monomers to form polymer-based plugging agents in the formation environment can solve the problem of dilution by formation water, but the polymerization reaction is easily affected by underground temperature, pressure and sulfides, making it difficult to control accurately. Non-water-soluble, high-temperature and high-salt, cross-linkable and elastic polymer materials represented by rubber have broad application prospects in the field of oilfield water plugging and profile control agents.

[0003] A Chinese patent with patent number CN201711298206.7, "A water plugging and profile control agent and its preparation method", discloses a water plugging and profile control agent and its preparation method. Ethylene-propylene rubber is used as the basic resin raw material, and calcium carbonate and white oil are used as additives. After cross-linking and foaming reaction, a micro-foamed cross-linked ethylene-propylene rubber with uniform pore size is obtained, and the water plugging and profile control agent is obtained after granulation. It can be widely used in the secondary and tertiary exploitation of oilfields under different conditions. An authorized patent with patent number CN202210926906.0, "A water-swelling rubber composite material and its preparation method and application", discloses a water-swelling rubber composite material, which is prepared from rubber, superabsorbent resin, metal ion blocking agent, solid softening agent, colorant, anti-aging agent, accelerator, zinc oxide, reinforcing agent, plasticizer, vulcanizing agent, PEG and MDI, etc. The ultra-fine rubber swelling particles are used in the large channels or high-permeability strips in the deep formation of the oil reservoir as a water plugging and profile control agent for oil and water wells. An authorized patent with patent number CN201610424247.5, "A temperature-resistant and salt-resistant latex plugging agent and its preparation method", discloses a temperature-resistant and salt-resistant latex plugging agent, which is prepared from hydrophobic monomers, hydrophilic monomers, emulsifiers, buffers, molecular weight regulators, protective agents, initiators and deionized water, etc. After polymerization reaction, a rubbery microsphere plugging agent with a core / shell structure is formed, which has good plugging and fluid loss reduction effects, and is resistant to high pressure and high temperature. The mud cake formed is dense, thin and tough.

[0004] In the prior art, rubber is basically in the form of cross-linked particles as the main body of the plugging agent, which has the problem of near-well accumulation when injected and cannot reach the far end. Therefore, there is an urgent need to develop a polymer plugging agent that is easy to inject before gelation and has high strength after gelation, so as to achieve the effect of "easy to inject, easy to travel far, and easy to plug". SUMMARY

[0005] One of the present application provides a rubber emulsion plugging agent, which raw materials include rubber, white oil, crosslinking agent, emulsifier, dispersant and water.

[0006] In one embodiment, the rubber is at least one of natural rubber, cis-butyl rubber, butyl rubber and styrene-butadiene rubber.

[0007] In one embodiment, the kinematic viscosity of the white oil is 3 to 50 mm 2 / s.

[0008] In one embodiment, the white oil is at least one of 3# industrial white oil, 5# industrial white oil and 15# industrial white oil.

[0009] In one embodiment, the crosslinking agent is at least one of bis-dipentyl, cumene peroxide, di-tert-butyl peroxide, dicumyl peroxide, tert-butyl peroxybenzoate, sulfur and bis-tert-butyl peroxide isopropyl benzene.

[0010] In one embodiment, the emulsifier is at least one of Triton X100, Tween 80, sodium stearate, Span 80, Tween 60, Tween 65, Tween 85, Span 60, Peregine O-20 and sodium oleate.

[0011] In one embodiment, the dispersant is at least one of polyvinyl alcohol, gelatin and polyvinyl pyrrolidone.

[0012] In one embodiment, based on the total mass of the rubber emulsion plugging agent as 100%, the total mass of the rubber, white oil and crosslinking agent is 30% to 50%, the mass of the emulsifier is 1% to 2%, and the mass of the dispersant is 1% to 1.5%.

[0013] In one embodiment, based on the total mass of the rubber, oil and crosslinking agent as 100%, the content of the rubber is 5% to 7%, and the content of the crosslinking agent is 0.2% to 1%.

[0014] The second of the present application provides a method for preparing the rubber emulsion plugging agent as claimed in any one of the first of the present application, which comprises the following steps:

[0015] 1) mixing rubber, white oil and crosslinking agent to obtain a rubber solution;

[0016] 2) mixing the rubber solution with emulsifier, dispersant and water, emulsifying to obtain the rubber emulsion plugging agent.

[0017] In one specific embodiment, in step 1), the rubber and the oil are first mixed uniformly, and then the crosslinking agent is added and mixed uniformly to obtain the rubber emulsion.

[0018] In one specific embodiment, the viscosity of the rubber solution is 500 to 10000 mPa·s.

[0019] In one specific embodiment, in step 2), the emulsification is performed using a high-speed stirrer, an emulsifier or a homogenizer.

[0020] In one specific embodiment, in step 2), the rotation speed for emulsification is 1000 to 20000 r / min.

[0021] In one specific embodiment, in step 2), the rotation speed for emulsification is 10000 to 20000 r / min.

[0022] In one specific embodiment, in step 2), the emulsification time is 5 to 60 min.

[0023] In one specific embodiment, in step 2), the emulsification time is 10 to 20 min.

[0024] The application III provides an application of the rubber emulsion plugging agent according to any one of the application I or the method according to the application II in plugging fractures and / or watered channels in a fractured reservoir formation.

[0025] The application has the following advantages:

[0026] The rubber emulsion plugging agent provided by the application has good injectability due to low viscosity when used in water plugging and profile control operations. When injected into a high-temperature and high-salt formation, the rubber emulsion plugging agent gradually breaks emulsion and re-aggregates into a rubber solution oil phase. At this time, the rubber solution still has good flow performance, the crosslinking agent in the oil phase gradually decomposes to generate free radicals to initiate crosslinking of the rubber, and an oil-based gel plugging agent is formed. Due to the constraint of the decomposition rate (usually represented by half-life) of the crosslinking agent, the oil phase can delay gelation for 5 to 13 hours, and the gel strength can reach the rigid gel level of the visual code method.

[0027] The rubber emulsion plugging agent provided by the application has the following advantages compared with existing plugging agents:

[0028] 1) The rubber emulsion plugging agent provided by the application is a micro-liquid droplet formed by uncrosslinked rubber liquid before gelation, and has good flowability, better injectability and flowability than particulate plugging agents;

[0029] 2) The rubber emulsion plugging agent provided by the application is essentially an oil-based rubber crosslinking system, which has excellent water dilution resistance and salt resistance, and the gelation process and the gel after gelation are not affected by water and salt;

[0030] 3) The rubber emulsion plugging agent provided by the application can control the gelation time at 130 to 150 DEG C by the type and amount of crosslinking agent, and the gelation time can be delayed to 5 to 13 h, and the gelation strength reaches the I level of the visual code method, and the controllable performance is superior to the existing plugging agent system; after gelation, the plugging agent has excellent temperature resistance and can be stable at 130 to 150 DEG C for more than 2 months;

[0031] 4) The rubber emulsion plugging agent provided by the application uses the cheapest white oil in industry as a rubber solvent, reduces the amount of rubber, and further reduces the cost, and has a cost advantage in all non-aqueous plugging agent systems. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The gelation process of the plugging agent is shown.

[0033] Figure 2 The microscope observation results of the plugging agent of Example 1 are shown.

[0034] Figure 3 The microscope observation results of the plugging agent of Comparative Example 1 are shown. DETAILED DESCRIPTION

[0035] The application will be further described below in combination with examples, but the examples of the application are only exemplary descriptions, and the implementation manner does not constitute a limitation on the application in any case.

[0036] Example 1

[0037] The natural rubber is purchased from Shanghai Fuyou International Trade Co., Ltd., and the type is Yunxiangbiao No. 1 rubber.

[0038] The 3# industrial white oil is purchased from Mozhong Petroleum Chemical Co., Ltd. (Shanghai).

[0039] The double 25 is purchased from Shanghai Boer Chemical Reagent Co., Ltd.

[0040] The Triton X100 is purchased from Shanghai Jinpan Biological Technology Co., Ltd.

[0041] The polyvinyl alcohol (PVA) is purchased from Shanghai Maier Biochemical Technology Co., Ltd., and the type is 1799.

[0042] Preparation of the rubber solution:

[0043] 50 g of natural rubber and 948 g of 3# industrial white oil are put into a stirring kettle, and stirred until the rubber is dissolved, then 2 g of double 25 is added and stirred uniformly to obtain a natural rubber solution with a natural rubber mass concentration of 5%, and the viscosity at 25 DEG C is 900 mPa·s.

[0044] Preparation of rubber emulsion plugging agent

[0045] 500 g of natural rubber solution, 10 g of Triton X100, 10 g of PVA (model 1799) and 480 g of water were put into a homogenizing emulsifier and emulsified at a speed of 10000 r / min for 15 min to obtain a stable natural rubber emulsion plugging agent.

[0046] The viscosity of the plugging agent at 25°C was determined using a rotary viscometer (Shanghai Fangrui Instrument Co., Ltd., NDJ-8S), and the results are shown in Table 1.

[0047] Stability evaluation: The particle size of the emulsion of the plugging agent was tested by laser light scattering; the delamination was recorded after being placed at room temperature for 14 days, and the results are shown in Table 1; the morphology of the plugging agent was observed under a microscope, and the results are shown in Table 1. Figure 2 .

[0048] Gelation performance evaluation: The plugging agent was placed in an ampoule, sealed and placed in an aging oven at 130°C, and the demulsification and gelation times were recorded, and the gel strength was determined according to the visual code method, and the results are shown in Table 1.

[0049] Example 2

[0050] Butadiene rubber was purchased from Beijing Yanshan Petrochemical Co., Ltd., and the brand was BR9000.

[0051] 5# industrial white oil was purchased from Mochina Petrochemical (Shanghai) Co., Ltd.

[0052] Cumene hydroperoxide was purchased from Shanghai Bailingwei Chemical Technology Co., Ltd.

[0053] Tween 80 was purchased from Shanghai Bide Pharmaceutical Technology Co., Ltd.

[0054] Span 80 was purchased from Shanghai Bide Pharmaceutical Technology Co., Ltd.

[0055] Polyvinyl alcohol (PVA) was purchased from Shanghai Mayreer Biotech Co., Ltd., and the model was 2488.

[0056] Preparation of rubber solution:

[0057] 70 g of butadiene rubber (Yanshan BR9000) and 927 g of 5# industrial white oil were put into a stirred tank, stirred until the rubber was dissolved, then 3 g of cumene hydroperoxide was added and stirred uniformly to obtain a butadiene rubber solution with a butadiene rubber mass concentration of 7%, and the viscosity at 25°C was 1500 mPa·s.

[0058] Preparation of rubber emulsion plugging agent:

[0059] 400 g of cis-butadiene rubber solution, 10 g of Tween 80, 10 g of Span 80, 10 g of PVA (model 2488) and 570 g of water were put into a homogenizing emulsifier and emulsified at a speed of 15000 r / min for 10 min to obtain a stable cis-butadiene rubber emulsion plugging agent.

[0060] The viscosity of the plugging agent at 25°C was determined using a rotary viscometer (Shanghai Fangrui Instrument Co., Ltd., NDJ-8S), and the results are shown in Table 1.

[0061] Stability evaluation: The particle size of the emulsion of the plugging agent was tested by laser light scattering; the delamination was recorded after being placed at room temperature for 14 days, and the results are shown in Table 1; the morphology of the plugging agent was observed under a microscope.

[0062] Gelation performance evaluation: The plugging agent was placed in an ampoule, sealed and placed in an aging oven at 150°C, and the demulsification and gelation time were recorded, and the gelation strength was determined according to the visual code method, and the results are shown in Table 1.

[0063] Example 3

[0064] The butyl rubber was purchased from Beijing Yanshan Petrochemical Co., Ltd., and the brand was 1751.

[0065] 15# industrial white oil was purchased from Mochina Petrochemical (Shanghai) Co., Ltd.

[0066] Di-tert-butyl peroxide was purchased from Shanghai Bailingwei Chemical Technology Co., Ltd.

[0067] Sodium stearate was purchased from Jiangsu Anhui Chemical Technology Co., Ltd.

[0068] Gelatin was purchased from Shanghai Enna Ma Biological Technology Co., Ltd.

[0069] Preparation of rubber solution:

[0070] 60 g of butyl rubber and 930 g of 15# industrial white oil were put into a stirred tank, and after the rubber was dissolved, 10 g of di-tert-butyl peroxide was added and stirred uniformly to obtain a butyl rubber white oil solution with a concentration of 6%, and the viscosity at 25°C was 3500 mPa·s.

[0071] Preparation of rubber emulsion plugging agent:

[0072] 300 g of the above butyl rubber solution, 15 g of sodium stearate, 15 g of gelatin and 670 g of water were put into a homogenizing emulsifier and emulsified at a speed of 20000 r / min for 20 min to obtain a stable butyl rubber emulsion plugging agent.

[0073] The viscosity of the plugging agent at 25°C was determined using a rotary viscometer (Shanghai Fangrui Instrument Co., Ltd., NDJ-8S), and the results are shown in Table 1.

[0074] Stability evaluation: The particle size of the plugging agent was tested by laser light scattering; the delamination was recorded after 14 days at room temperature, and the results are shown in Table 1; the morphology of the plugging agent was observed by microscope.

[0075] Gelation performance evaluation: The plugging agent was placed in an ampoule, sealed, and then placed in an aging oven at 150℃, and the demulsification and gelation time were recorded, and the gel strength was determined according to the visual code method, and the results are shown in Table 1.

[0076] Comparative Example 1

[0077] The natural rubber was purchased from Shanghai Fuyou International Trade Co., Ltd., and the model was Yunxiangbiao No. 1 rubber.

[0078] 3#industrial white oil was purchased from Sinopec (Shanghai) Co., Ltd.

[0079] Dobell was purchased from Shanghai Boer Chemical Reagent Co., Ltd.

[0080] Sodium dodecyl benzene sulfonate was purchased from Shanghai Bide Pharmaceutical Technology Co., Ltd.

[0081] Polyvinyl alcohol was purchased from Shanghai Maier Biochemical Technology Co., Ltd., and the model was 1799. The emulsifier Triton X100 in Example 1 was replaced by sodium dodecyl benzene sulfonate, and the rest was unchanged.

[0082] Preparation of rubber solution:

[0083] 50g of natural rubber and 948g of 3#industrial white oil were put into a stirred tank, stirred until the rubber was dissolved, then 2g of Dobell was added and stirred uniformly to obtain a natural rubber solution with a natural rubber mass concentration of 5%, and the viscosity at 25℃ was 900mPa·s.

[0084] Preparation of rubber emulsion plugging agent:

[0085] 500g of natural rubber solution, 10g of sodium dodecyl benzene sulfonate, 10g of PVA (model 1799) and 480g of water were put into a homogenizing emulsifier and emulsified at a speed of 10000r / min for 15min to obtain a natural rubber emulsion plugging agent.

[0086] The viscosity of the plugging agent at 25℃ was determined using a rotational viscometer (Shanghai Fangrui Instrument Co., Ltd., NDJ-8S), and the results are shown in Table 1.

[0087] Stability evaluation: The particle size of the emulsion of the plugging agent was tested by laser light scattering; the delamination was recorded after 14 days at room temperature, and the results are shown in Table 1; the morphology of the plugging agent was observed by microscope, and the results are shown in Figure 3 .

[0088] Gelation performance evaluation: The emulsion was placed in an ampoule, sealed and placed in an aging oven at 130°C. The demulsification and gelation times were recorded, and the gelation strength was determined according to the visual code method. The results are shown in Table 1.

[0089] Comparative Example 2

[0090] The cis-butadiene rubber was purchased from Beijing Yanshan Petrochemical Co., Ltd., and the brand was BR9000.

[0091] The 5# industrial white oil was purchased from Mochina Petrochemical (Shanghai) Co., Ltd.

[0092] Tween 80 was purchased from Shanghai Bide Pharmaceutical Technology Co., Ltd.

[0093] Span 80 was purchased from Shanghai Bide Pharmaceutical Technology Co., Ltd.

[0094] Polyvinyl alcohol was purchased from Shanghai Maier Biochemical Technology Co., Ltd., and the model was 2488. The crosslinking agent cumene hydroperoxide in Example 2 was removed, and the rest remained unchanged.

[0095] Preparation of rubber solution:

[0096] 70 g of cis-butadiene rubber (Yanshan BR9000) and 930 g of 5# industrial white oil were put into a stirred tank, stirred until the rubber was dissolved, and uniformly stirred to obtain a cis-butadiene rubber white oil solution with a concentration of 7%, and the viscosity at 25°C was 1500 mPa·s.

[0097] Preparation of rubber emulsion plugging agent:

[0098] 400 g of the above cis-butadiene rubber solution, 10 g of Tween 80, 10 g of Span 80, 10 g of PVA (model 2488), and 570 g of water were put into a homogenizing emulsifier and emulsified at a speed of 15000 r / min for 10 min to obtain a stable cis-butadiene rubber emulsion plugging agent.

[0099] Stability evaluation: The particle size of the emulsion was tested by laser light scattering; the stratification was recorded after being placed at room temperature for 14 days, and the results are shown in Table 1; the morphology of the plugging agent was observed under a microscope.

[0100] Gelation performance evaluation: The emulsion was placed in an ampoule, sealed and placed in an aging oven at 150°C. The demulsification and gelation times were recorded, and the gelation strength was determined according to the visual code method. The results are shown in Table 1.

[0101] Table 1

[0102] Test item Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Viscosity of the plugging agent, mPa-s 320 210 95 280 335 Average particle size of the plugging agent, pm 1.35 0.98 1.05 3.21 1.34 Stability of the plugging agent over 14 days No delamination No delamination No delamination Delamination No delamination Breakup time of the plugging agent, h 0.2 a ]] 0.1 b ]] 0.1 b ]] 0.1 a ]] 0.1 a ]] Gel time of the plugging agent, h 5 a ]] 13 b ]] 7 b ]] 4 a ]] non-gelling a ]] Gel strength of the plugging agent (visual code) I H I I No gelation

[0103] While the application has been described with reference to particular embodiments thereof, it is to be understood that variations and modifications can be affected therein by those skilled in the art without departing from the true spirit and scope of the application. Further, it is to be understood that the application can be practiced by employing techniques and manipulations other than those described above without departing from the true spirit and scope of the application. All such variations and modifications are to be included within the scope of the following claims.

Claims

1. A rubber emulsion plugging agent, raw materials of which comprise rubber, white oil, crosslinking agent, emulsifier, dispersant and water; The rubber is at least one of natural rubber, cis-butadiene rubber, butyl rubber and styrene-butadiene rubber; The crosslinking agent is at least one of bis-dipentyl, cumene hydroperoxide, di-tert-butyl peroxide, dicumyl peroxide, tert-butyl peroxybenzoate, sulfur and bis-tert-butyl peroxyisopropylbenzene; The emulsifier is at least one of Triton X100, Tween 80, sodium stearate, Span 80, Tween 60, Tween 65, Tween 85, Span 60, PEGASUS O-20 and sodium oleate; The dispersant is at least one of polyvinyl alcohol, gelatin and polyvinylpyrrolidone; The total mass of the rubber, white oil and crosslinking agent is 30% to 50%, the mass of the emulsifier is 1% to 2%, and the mass of the dispersant is 1% to 1.5%, based on the total mass of the rubber emulsion plugging agent as 100%; The content of the rubber is 5% to 7%, and the content of the crosslinking agent is 0.2% to 1%, based on the total mass of the rubber, white oil and crosslinking agent as 100%.

2. The rubber emulsion plug agent of claim 1, wherein, The white oil has a kinematic viscosity of 3 to 50 mm 2 / s.

3. The rubber emulsion plug agent of claim 1, wherein, The white oil is at least one of 3# industrial white oil, 5# industrial white oil and 15# industrial white oil. 4.A method for preparing the rubber emulsion plugging agent according to any one of claims 1 to 3, comprising the following steps: 1) mixing rubber, white oil and crosslinking agent to obtain a rubber solution; 2) mixing the rubber solution with emulsifier, dispersant and water, and emulsifying to obtain the rubber emulsion plugging agent. 5.Use of the rubber emulsion plugging agent according to any one of claims 1 to 3 or prepared by the method of claim 4 in plugging fractures and / or water-flooded channels in a fractured-vug reservoir formation.

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