Rubber emulsion blocking agent as well as preparation method and application thereof

Abstract

The invention provides a rubber emulsion blocking agent as well as a preparation method and application thereof. The rubber emulsion plugging agent is prepared from the following raw materials: rubber, white oil, a cross-linking agent, an emulsifying agent, a dispersing agent and water.

Description

Technical Field

[0001] The invention relates to a plugging agent. Background Art

[0002] The Tahe Oilfield is a high-temperature, ultra-high-salt rock fracture-cave reservoir. During development, injected water and bottom water quickly break through along the fractures, and the water content of the oil wells increases significantly, resulting in a rapid decrease in oil production. Polymer gel profile control technology is an important means of controlling water and stabilizing oil in fractured reservoirs. Conventional polyacrylamide gels have poor anti-dilution performance, are easily hydrolyzed at high temperatures, and have poor plugging effects; granular plugging agents are difficult to bridge in large fracture channels in fracture-cave reservoirs, making it difficult to achieve long-distance plugging. Using non-water-soluble monomers to polymerize in the formation environment to form polymer-based plugging agents can solve the problem of being diluted by formation water, but the polymerization reaction is easily affected by underground temperature, pressure and sulfides, making it difficult to accurately control. Non-water-soluble, high-temperature and high-salt resistant, 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] The Chinese patent "A water plugging and profile control agent and its preparation method" with patent number CN201711298206.7 discloses a water plugging and profile control agent and its preparation method, which uses EPDM as the basic resin raw material, calcium carbonate and white oil as additives, and obtains micro-foamed cross-linked EPDM rubber with uniform pore size after cross-linking and foaming reaction. After granulation, the water plugging and profile control agent is obtained, which can be widely used in secondary and tertiary exploitation of oil fields under different conditions. The authorized patent "A water-swelling rubber composite material and its preparation method and application" with patent number CN202210926906.0 discloses a water-swelling rubber composite material, which is prepared from rubber, super absorbent resin, metal ion sealant, solid softener, colorant, anti-aging agent, accelerator, zinc oxide, reinforcing agent, plasticizer, vulcanizer, PEG and MDI, etc. The ultra-fine rubber expansion particles are used as oil and water well profile control and water plugging in large pores or high permeability strips in deep formations of oil reservoirs. The 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 formed from raw materials such as hydrophobic monomers, hydrophilic monomers, emulsifiers, buffers, molecular weight regulators, protective agents, initiators and deionized water through polymerization reaction to form a core / shell structured rubber microsphere plugging agent, which has good plugging and water 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 accumulates near the well when injected and cannot reach the far end. Therefore, it is urgent to develop a polymer plugging agent that is easy to inject before gelling and has high strength after gelling, so as to achieve the effect of "injecting in, traveling far, and blocking". Summary of the invention

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

[0006] In a specific embodiment, the rubber is at least one of natural rubber, butadiene 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 a specific embodiment, the white oil is at least one of 3# industrial white oil, 5# industrial white oil and 15# industrial white oil.

[0009] In a specific embodiment, the cross-linking agent is at least one of dipentadiene, cumene hydroperoxide, di-tert-butyl peroxide, diisopropylbenzene peroxide, tert-butyl perbenzoate, sulfur and di-tert-butyl peroxide isopropylbenzene.

[0010] In a specific embodiment, the emulsifier is at least one of Triton X100, Tween 80, sodium stearate, Span80, Tween 60, Tween 65, Tween 85, Span 60, Peregal O-20 and sodium oleate.

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

[0012] In a specific embodiment, taking the total mass of the rubber latex plugging agent as 100%, the total mass of the rubber, white oil and cross-linking 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 a specific embodiment, based on the total mass of the rubber, the oil and the cross-linking agent as 100%, the content of the rubber is 5% to 7%, and the content of the cross-linking agent is 0.2% to 1%.

[0014] The second aspect of the present invention provides a method for preparing the rubber latex plugging agent as described in any one of the claims 1 to 5, comprising the following steps:

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

[0016] 2) The rubber solution is mixed with an emulsifier, a dispersant and water, and emulsified to obtain the rubber latex plugging agent.

[0017] In a specific embodiment, in step 1), the rubber and the oil are firstly mixed uniformly, and then a cross-linking agent is added and mixed uniformly to obtain the rubber latex.

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

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

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

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

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

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

[0024] The third invention provides the use of the rubber latex plugging agent prepared according to any one of the first invention or the method described in the second invention in plugging formation cracks and / or water-flooded channels in rock fracture-cavity oil reservoirs.

[0025] Beneficial effects of the present invention:

[0026] The rubber emulsion plugging agent provided by the present invention has good injectability due to its low viscosity during water plugging and profile control operations. When injected into underground high-temperature and high-salt strata, it gradually breaks the emulsion and re-aggregates into a rubber solution oil phase. At this time, the rubber solution still has good flow properties, and the cross-linking agent in the oil phase gradually decomposes to generate free radicals to trigger the cross-linking of the rubber, forming an oily gel plugging agent. Constrained by the decomposition rate of the cross-linking agent (usually expressed as a half-life), the oil phase can be delayed to 5 to 13 hours to gel, and the gel strength can reach the rigid gel level of the visual code method.

[0027] The rubber latex plugging agent provided by the present invention has the following advantages compared with the existing plugging agents:

[0028] 1) The rubber latex plugging agent provided by the present invention is a micro-droplet formed by uncross-linked rubber liquid before gelation, and has good fluidity. Compared with the granular plugging agent, it has better injectability and fluidity;

[0029] 2) The rubber latex plugging agent provided by the present invention is essentially an oil-based rubber cross-linking system, which has excellent water dilution resistance and salt resistance, and the gelling process and the gel after gelling are not affected by water and salt;

[0030] 3) The gelling time of the rubber latex plugging agent provided by the present invention at 130 to 150°C can be adjusted by the type and amount of the cross-linking agent, and the gelling time can be delayed to 5 to 13 hours. The gelling strength reaches the I level of the visual code method. This adjustable performance is better than the existing plugging agent system; after gelling, it has excellent temperature resistance and can be stable at 130 to 150°C for more than 2 months;

[0031] 4) The rubber latex plugging agent provided by the present invention uses the cheapest white oil in industry as the rubber solvent, which reduces the amount of rubber used and thus reduces the cost, and has a cost advantage among all non-aqueous plugging agent systems. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0035] 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 methods do not constitute limitations of the present invention under any circumstances.

[0036] Example 1

[0037] The natural rubber was purchased from Shanghai Fuyou International Trading Co., Ltd., and the model was Yunxiang standard rubber.

[0038] 3# industrial white oil was purchased from Morocco-China Petrochemical (Shanghai) Co., Ltd.

[0039] Double 25 was purchased from Shanghai Boer Chemical Reagent Co., Ltd.

[0040] Triton X100 was purchased from Shanghai Jinpan Biotechnology Co., Ltd.

[0041] Polyvinyl alcohol (PVA) was purchased from Shanghai Myrrel Biochemical Technology Co., Ltd., model 1799.

[0042] Preparation of rubber solution:

[0043] 50g of natural rubber and 948g of 3# industrial white oil were put into a stirring kettle and stirred until the rubber was dissolved. Then, 2g of dichloroethylene was added and stirred evenly to obtain a natural rubber solution with a natural rubber mass concentration of 5% and a viscosity of 900mPa·s at 25°C.

[0044] Preparation of rubber latex plugging agent:

[0045] 500g of natural rubber solution, 10g of Triton X100, 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 stable natural rubber emulsion plugging agent.

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

[0047] Stability evaluation: Laser light scattering was used to test the particle size of the plugging agent emulsion; the emulsion was placed at room temperature for 14 days and the stratification was recorded. The results are shown in Table 1; the morphology of the plugging agent was observed under a microscope. The results are shown in Table 1. Figure 2 .

[0048] Evaluation of gelling performance: The plugging agent was placed in an ampoule bottle, sealed and placed in an aging box at 130°C. The demulsification and gelling time were recorded. The gelling strength was determined by the visual code method. The results are shown in Table 1.

[0049] Example 2

[0050] Butadiene rubber was purchased from Beijing Yanshan Petrochemical Co., Ltd. with a brand name of BR9000.

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

[0052] Cumene hydroperoxide was purchased from Shanghai J&K 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 Myrrel Biochemical Technology Co., Ltd., model 2488.

[0056] Preparation of rubber solution:

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

[0058] Preparation of rubber latex plugging agent:

[0059] 400 g of butyl 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 butyl rubber emulsion plugging agent.

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

[0061] Stability evaluation: Laser light scattering was used to test the particle size of the plugging agent emulsion; the emulsion was placed at room temperature for 14 days and the stratification was recorded. The results are shown in Table 1; the morphology of the plugging agent was observed under a microscope.

[0062] Evaluation of gelling performance: The plugging agent was placed in an ampoule bottle, sealed and placed in an aging box at 150°C. The demulsification and gelling time were recorded. The gelling strength was determined by the visual code method. The results are shown in Table 1.

[0063] Example 3

[0064] Butyl rubber was purchased from Beijing Yanshan Petrochemical Co., Ltd., brand 1751.

[0065] 15# industrial white oil was purchased from Morocco-China 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 Anhuai Chemical Technology Co., Ltd.

[0068] Gelatin was purchased from Shanghai Ennama Biotechnology Co., Ltd.

[0069] Preparation of rubber solution:

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

[0071] Preparation of rubber latex 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 homogenizer and emulsified at a speed of 20,000 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 measured using a rotational viscometer (Shanghai Fangrui Instrument Co., Ltd., NDJ-8S). The results are shown in Table 1.

[0074] Stability evaluation: Laser light scattering was used to test the particle size of the plugging agent. The plugging agent was placed at room temperature for 14 days and the stratification was recorded. The results are shown in Table 1. The morphology of the plugging agent was observed under a microscope.

[0075] Evaluation of gelling performance: The plugging agent was placed in an ampoule bottle, sealed and placed in an aging box at 150°C. The demulsification and gelling time were recorded. The gelling strength was determined by the visual code method. The results are shown in Table 1.

[0076] Comparative Example 1

[0077] The natural rubber was purchased from Shanghai Fuyou International Trading Co., Ltd., and the model was Yunxiang standard rubber.

[0078] 3# industrial white oil was purchased from Morocco-China Petrochemical (Shanghai) Co., Ltd.

[0079] Double 25 was purchased from Shanghai Boer Chemical Reagent Co., Ltd.

[0080] Sodium dodecylbenzenesulfonate was purchased from Shanghai Bidex Pharmaceutical Technology Co., Ltd.

[0081] Polyvinyl alcohol was purchased from Shanghai Myrel Biochemical Technology Co., Ltd., model 1799. The emulsifier Triton X100 in Example 1 was replaced with sodium dodecylbenzene sulfonate, and the rest remained unchanged.

[0082] Preparation of rubber solution:

[0083] 50g of natural rubber and 948g of 3# industrial white oil were put into a stirring kettle and stirred until the rubber was dissolved. Then, 2g of dichloroethylene was added and stirred evenly to obtain a natural rubber solution with a natural rubber mass concentration of 5% and a viscosity of 900mPa·s at 25°C.

[0084] Preparation of rubber latex plugging agent:

[0085] 500g of natural rubber solution, 10g of sodium dodecylbenzene 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 °C was measured using a rotational viscometer (Shanghai Fangrui Instrument Co., Ltd., NDJ-8S). The results are shown in Table 1.

[0087] Stability evaluation: Laser light scattering was used to test the particle size of the plugging agent emulsion; the emulsion was placed at room temperature for 14 days and the stratification was recorded. The results are shown in Table 1; the morphology of the plugging agent was observed under a microscope. The results are shown in Table 1. Figure 3 .

[0088] Evaluation of gelling performance: The emulsion was placed in an ampoule bottle, sealed and placed in an aging box at 130°C. The demulsification and gelling time were recorded. The gelling strength was determined by the visual code method. The results are shown in Table 1.

[0089] Comparative Example 2

[0090] Butadiene rubber was purchased from Beijing Yanshan Petrochemical Co., Ltd. with a brand name of BR9000.

[0091] 5# industrial white oil was purchased from Morocco-China 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 Myrel Biochemical Technology Co., Ltd., model 2488. The cross-linking agent cumene hydroperoxide in Example 2 was removed, and the rest remained unchanged.

[0095] Preparation of rubber solution:

[0096] 70 g of butadiene rubber (Yanshan BR9000) and 930 g of 5# industrial white oil were put into a stirring kettle and stirred until the rubber was dissolved. The mixture was stirred evenly to obtain a 7% butadiene rubber white oil solution having a viscosity of 1500 mPa·s at 25°C.

[0097] Preparation of rubber latex plugging agent:

[0098] 400 g of the above-mentioned 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 butadiene rubber emulsion plugging agent.

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

[0100] Evaluation of gelling performance: The emulsion was placed in an ampoule bottle, sealed and placed in an aging box at 150°C. The demulsification and gelling time were recorded. The gelling strength was determined by the visual code method. The results are shown in Table 1.

[0101] Table 1

[0102] Test items Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Viscosity of plugging agent, mPa·s 320 210 95 280 335 Average particle size of plugging agent, μm 1.35 0.98 1.05 3.21 1.34 Stability of the plugging agent after 14 days of placement No stratification No stratification No stratification Layering No stratification Demulsification time of plugging agent, h <![CDATA[0.2 a ]]> <![CDATA[0.1 b ]]> <![CDATA[0.1 b ]]> <![CDATA[0.1 a ]]> <![CDATA[0.1 a ]]> Gel time of plugging agent, h <![CDATA[5 a ]]> <![CDATA[13 b ]]> <![CDATA[7 b ]]> <![CDATA[4 a ]]> <![CDATA[Non-gelling a > Plugging agent gel strength (visual code) I H I I No glue

[0103] 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 rubber latex plugging agent, whose raw materials include rubber, white oil, cross-linking agent, emulsifier, dispersant and water.

2. The rubber latex plugging agent according to claim 1, characterized in that: The rubber is at least one of natural rubber, butadiene rubber, butyl rubber and styrene-butadiene rubber.

3. The rubber latex plugging agent according to claim 1, characterized in that: The kinematic viscosity of the white oil is 3 to 50 mm 2 / s; Preferably, the white oil is at least one of 3# industrial white oil, 5# industrial white oil and 15# industrial white oil.

4. The rubber latex plugging agent according to claim 1, characterized in that: The cross-linking agent is at least one of dipentadiene, cumene hydroperoxide, di-tert-butyl peroxide, diisopropylbenzene peroxide, tert-butyl perbenzoate, sulfur and di-tert-butyl peroxide isopropylbenzene.

5. The rubber latex plugging agent according to claim 1, characterized in that: The emulsifier is at least one of Triton X100, Tween 80, sodium stearate, Span 80, Tween 60, Tween 65, Tween 85, Span 60, Peregal O-20 and sodium oleate.

6. The rubber latex plugging agent according to claim 1, characterized in that: The dispersant is at least one of polyvinyl alcohol, gelatin and polyvinyl pyrrolidone.

7. The rubber latex plugging agent according to claim 1, characterized in that: Taking the total mass of the rubber latex plugging agent as 100%, the total mass of the rubber, white oil and cross-linking 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%.

8. The rubber latex plugging agent according to claim 1, characterized in that: Taking the total weight of the rubber, white oil and cross-linking agent as 100%, the content of the rubber is 5% to 7%, and the content of the cross-linking agent is 0.2% to 1%.

9. A method for preparing the rubber latex plugging agent according to any one of claims 1 to 8, comprising the following steps: 1) mixing rubber, white oil and a cross-linking agent to obtain a rubber solution; 2) The rubber solution is mixed with an emulsifier, a dispersant and water, and emulsified to obtain the rubber latex plugging agent.

10. Use of the rubber latex plugging agent according to any one of claims 1 to 8 or the rubber latex plugging agent prepared by the method according to claim 9 in plugging formation cracks and / or water-flooded channels in rock fracture-cavity oil reservoirs.

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