Emulsion type crosslinking system, profile control system and preparation method

Abstract

The invention discloses an emulsion type crosslinking system, a profile control system and a preparation method, and belongs to the technical field of oil gas. The emulsion type cross-linking system comprises a phenolic emulsion, a hexamethylenetetramine emulsion and an ammonium chloride emulsion. The three are water-in-oil type emulsions, the phenolic emulsion comprises a first oil phase and a first water phase, and the first water phase comprises resorcinol and / or hydroquinone; the hexamethylenetetramine emulsion comprises a second oil phase and a second water phase, and the second water phase comprises hexamethylenetetramine; the ammonium chloride emulsion includes a third oil phase and a third aqueous phase, the third aqueous phase including ammonium chloride. The emulsion type cross-linking system is suitable for high-temperature oil reservoirs, and can still achieve a good plugging effect at a high temperature.

Description

Technical Field

[0001] The invention belongs to the field of oil and gas technology, and in particular relates to an emulsion type cross-linking system, a profile control system and a preparation method. Background Art

[0002] For oil reservoirs with strong heterogeneity, the water injection has a small swept area, making it very easy to pass along the high permeability area of ​​the oil reservoir, gradually forming a high permeability strip, resulting in ineffective water circulation, while the remaining oil in the low permeability area is difficult to be swept. In order to adjust the drive and plugging of the oil reservoir to improve the water drive development effect of heterogeneous oil reservoirs, mobile gels, microspheres, pre-crosslinked gel particles and other technical means are often used. Among them, microsphere products have good mobility but weak plugging; pre-crosslinked granular plugging materials have strong plugging but poor mobility; polymers and crosslinkers in the mobile gel system need to be pre-prepared into aqueous solutions on the ground, especially polymer dry powder reagents require a certain dissolution and swelling time. After injection into the formation, due to formation adsorption, shearing, dilution and chromatographic separation, the underground gelation becomes complicated and the gelation process is uncontrollable.

[0003] The related technology provides a multiple emulsion cross-linking agent, which uses chromium lactate, white oil, anhydrous sorbitan fatty acid ester, polyoxyethylene sorbitan monooleate, deionized water, and polyethylene glycol as raw materials to prepare a water-in-oil-in-water double emulsion cross-linking agent. The chromium lactate is located in the inner water phase. Because it is isolated by two interfaces, it can delay cross-linking, thereby achieving drive and plugging adjustment.

[0004] However, the temperature resistance of the multiple emulsion cross-linking agent provided by the related art is poor and is not suitable for high-temperature oil reservoirs. Summary of the invention

[0005] In view of this, the present invention provides an emulsion-type cross-linking system, a profile control system and a preparation method, which can solve the technical problems existing in the related technologies.

[0006] Specifically, the following technical solutions are included:

[0007] On the one hand, an emulsion-type cross-linking system is provided, wherein the emulsion-type cross-linking system comprises a phenolic emulsion, a hexamethylenetetramine emulsion, and an ammonium chloride emulsion;

[0008] The phenolic emulsion is a water-in-oil emulsion, comprising a first oil phase and a first water phase dispersed in the first oil phase, wherein the first water phase comprises resorcinol and / or hydroquinone;

[0009] The hexamethylenetetramine emulsion is a water-in-oil emulsion, comprising a second oil phase and a second water phase dispersed in the second oil phase, wherein the second water phase comprises hexamethylenetetramine;

[0010] The ammonium chloride emulsion is a water-in-oil emulsion, comprising a third oil phase and a third water phase dispersed in the third oil phase, wherein the third water phase comprises ammonium chloride.

[0011] In some possible implementations, the first oil phase includes a first emulsifier and a first emulsified oil, and the first water phase also includes water and sodium sulfite;

[0012] The volume ratio of the first aqueous phase to the phenolic emulsion is 20%-50%, the volume ratio of the first oil phase to the phenolic emulsion is 50%-80%, the mass ratio of the first emulsifier to the first oil phase is 5%-12%, the mass ratio of the resorcinol and / or hydroquinone to the first aqueous phase is 5%-30%, and the mass ratio of the sodium sulfite to the first aqueous phase is 1%-2%.

[0013] In some possible implementations, the first emulsifier is a mixture of at least one of Span80 and Span60 and an oligoester emulsifier P135.

[0014] In some possible implementations, the second oil phase includes a second emulsifier and a second emulsified oil, and the second water phase also includes water;

[0015] The volume ratio of the second aqueous phase to the phenolic emulsion is 20%-50%, the volume ratio of the second oil phase to the phenolic emulsion is 50%-80%, the mass ratio of the second emulsifier to the second oil phase is 3%-10%, and the mass ratio of hexamethylenetetramine to the second aqueous phase is 5%-30%.

[0016] In some possible implementations, the second emulsifier is a mixture of at least one of Span80 and Span60 and at least one of Tween80 and Tween60.

[0017] In some possible implementations, the third oil phase includes a third emulsifier and a third emulsified oil, and the third water phase also includes water;

[0018] The volume ratio of the third water phase to the phenolic emulsion is 20%-50%, the volume ratio of the third oil phase to the phenolic emulsion is 50%-80%, the mass ratio of the third emulsifier to the third oil phase is 1%-5%, and the mass ratio of ammonium chloride to the third water phase is 5%-30%.

[0019] In some possible implementations, the third emulsifier includes Span 80 emulsifier.

[0020] On the other hand, a method for preparing any of the above-mentioned emulsion-type cross-linking systems is also provided, the preparation method comprising: preparing a phenolic emulsion, a hexamethylenetetramine emulsion and an ammonium chloride emulsion respectively;

[0021] The preparation methods of the phenolic emulsion, the hexamethylenetetramine emulsion and the ammonium chloride emulsion all include:

[0022] uniformly dispersing the emulsifier in the emulsified oil to obtain a corresponding oil phase;

[0023] Dispersing resorcinol and / or hydroquinone, hexamethylenetetramine or ammonium chloride uniformly in water to obtain a corresponding aqueous phase;

[0024] Under homogenizing conditions, the water phase is added dropwise to the oil phase to obtain the phenol emulsion, the hexamethylenetetramine emulsion or the ammonium chloride emulsion.

[0025] In some possible implementations, the homogenization conditions include at least one of the following conditions: using a homogenizing device, a stirring speed of 3000 r / min-15000 r / min, and a stirring time of 5 min-20 min.

[0026] In yet another aspect, a profile control system is provided, comprising any one of the above-mentioned emulsion-type cross-linking systems and a polymer emulsion for profile control.

[0027] The beneficial effects of the technical solution provided by the embodiment of the present invention include at least:

[0028] The emulsion cross-linking system provided by the embodiment of the present invention uses resorcinol and / or hydroquinone and hexamethylenetetramine as cross-linking agents, and uses ammonium chloride as a cross-linking auxiliary agent. These active ingredients are all located in the water phase and are wrapped by the oil phase, which can delay cross-linking. When used, the emulsion cross-linking system is injected into the formation together with the polymer emulsion for profile control. Based on its delayed cross-linking effect, the emulsion cross-linking system and the polymer emulsion for profile control can be injected deep into the formation, so that a cross-linking reaction occurs deep in the formation to generate a colloid, thereby playing a role in shear resistance, reducing formation adsorption and dilution, and achieving deep oil field displacement and profile control. Moreover, the emulsion cross-linking system is suitable for high-temperature reservoirs, and after cross-linking reaction with the polymer emulsion for profile control at high temperature, it can still achieve a good plugging effect. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0030] On the one hand, an embodiment of the present invention provides an emulsion-type crosslinking system, which includes a phenolic emulsion, a hexamethylenetetramine emulsion, and an ammonium chloride emulsion. Among them, the phenolic emulsion is an oil-in-water emulsion, and the phenolic emulsion includes a first oil phase and a first water phase dispersed in the first oil phase, and the first water phase includes resorcinol and / or hydroquinone; the hexamethylenetetramine emulsion is an oil-in-water emulsion, and the hexamethylenetetramine emulsion includes a second oil phase and a second water phase dispersed in the second oil phase, and the second water phase includes hexamethylenetetramine; the ammonium chloride emulsion is an oil-in-water emulsion, and the ammonium chloride emulsion includes a third oil phase and a third water phase dispersed in the third oil phase, and the third water phase includes ammonium chloride.

[0031] The emulsion cross-linking system provided by the embodiment of the present invention uses resorcinol and / or hydroquinone and hexamethylenetetramine as cross-linking agents, and uses ammonium chloride as a cross-linking auxiliary agent. These active ingredients are all located in the water phase and are wrapped by the oil phase, which can delay cross-linking. When used, the emulsion cross-linking system is injected into the formation together with the polymer emulsion for profile control. Based on its delayed cross-linking effect, the emulsion cross-linking system and the polymer emulsion for profile control can be injected deep into the formation, so that a cross-linking reaction occurs deep in the formation to generate a colloid, thereby playing a role in shear resistance, reducing formation adsorption and dilution, and achieving deep oil field displacement and profile control. Moreover, the emulsion cross-linking system is suitable for high-temperature reservoirs, and after cross-linking reaction with the polymer emulsion for profile control at high temperature, it can still achieve a good plugging effect.

[0032] The phenolic emulsion comprises a first water phase and a first oil phase, wherein the first oil phase comprises a first emulsifier and a first emulsified oil, resorcinol and / or hydroquinone are present in the first water phase, and the first water phase further comprises water and sodium sulfite, and the sodium sulfite plays a role in stabilizing the emulsion.

[0033] In some examples, the volume ratio of the first water phase to the phenolic emulsion is 20%-50%, the volume ratio of the first oil phase to the phenolic emulsion is 50%-80%, the mass ratio of the first emulsifier to the first oil phase is 5%-12% (for example, 6%-12%), the mass ratio of resorcinol and / or hydroquinone to the first water phase is 5%-30%, and the mass ratio of sodium sulfite to the first water phase is 1%-2%. By setting the above ratios in this way, it has the advantages of homogeneity and stability.

[0034] In some examples, the first emulsifier is a mixture of at least one of Span80 and Span60 and oligoester emulsifier P135, thereby achieving excellent emulsification effect on resorcinol and hydroquinone. Among them, oligoester emulsifier P135 (referred to as emulsifier P135) is also called polyethylene glycol (30) dipolyhydroxystearate.

[0035] For example, the mass ratio of at least one of Span80 and Span60 to the oligoester emulsifier P135 can be 4-12:1.

[0036] The hexamethylenetetramine emulsion includes a second aqueous phase and a second oil phase, the second oil phase includes a second emulsifier and a second emulsified oil, hexamethylenetetramine is present in the second aqueous phase, and the second aqueous phase also includes water. In some examples, the volume ratio of the second aqueous phase to the phenolic emulsion is 20%-50%, the volume ratio of the second oil phase to the phenolic emulsion is 50%-80%, the mass ratio of the second emulsifier to the second oil phase is 3%-10% (for example, 4%-8%), and the mass ratio of hexamethylenetetramine to the second aqueous phase is 5%-30%. By setting the above-mentioned ratios in this way, it has the advantages of homogeneity and stability.

[0037] In some examples, the second emulsifier is a mixture of at least one of Span80 and Span60 and at least one of Tween80 and Tween60, thereby achieving excellent emulsification effect on hexamethylenetetramine. For example, the mass ratio of at least one of Span80 and Span60 to at least one of Tween80 and Tween60 is 5-9:1.

[0038] The ammonium chloride emulsion includes a third water phase and a third oil phase, the third oil phase includes a third emulsifier and a third emulsified oil, ammonium chloride is present in the third water phase, and the third water phase also includes water; in some examples, the volume ratio of the third water phase to the phenolic emulsion is 20%-50%, the volume ratio of the third oil phase to the phenolic emulsion is 50%-80%, the mass ratio of the third emulsifier to the third oil phase is 1%-5% (for example, 2%-4%), and the mass ratio of ammonium chloride to the third water phase is 5%-30%. By setting the above ratios in this way, it has the advantages of homogeneity and stability.

[0039] In some examples, the third emulsifier includes Span 80 emulsifier, which has an excellent emulsification effect on ammonium chloride.

[0040] The emulsion crosslinking system provided in the embodiment of the present invention is a phenolic crosslinking agent emulsion, which is prepared by respectively preparing each active component of the organic phenolic formaldehyde participating in the crosslinking reaction into an oil-in-water emulsion. Based on the structural characteristics of the oil-in-water emulsion, the emulsion crosslinking system has excellent effects in the following aspects:

[0041] The presence of an outer layer of oil phase in the water-in-oil emulsion will reduce the adsorption of chemical components on the water-wet rock surface compared to aqueous plugging agent products.

[0042] The emulsion-type cross-linking system can be used in conjunction with conventional polymer emulsions for profile control. The two have the same oil-in-water structure and can maintain the same migration velocity in the formation, thereby avoiding the change in the component ratio of the aqueous solution of the polymer and the cross-linking agent in the movable gel plugging agent in the related technology due to the difference in migration velocity, which affects the gelling effect and effectively improves the gelling effect.

[0043] When the emulsion-type cross-linking system and the polymer emulsion for profile control are used in coordination, they can adapt to the temperature conditions of high-temperature reservoirs (the applicable reservoir temperature is 90°C-120°C). The two break the emulsion under the temperature conditions of high-temperature reservoirs and the dilution effect, releasing the effective components in the inner water phase. At this time, the polymer molecules and the active components in the cross-linking system contact each other to undergo a cross-linking reaction, thereby forming a colloid with viscoelasticity, achieving the purpose of deep plugging and control, thereby significantly improving the plugging effect of the flooding and profile control agents.

[0044] According to tests, the emulsion crosslinking system provided by the embodiment of the present invention has a stable time of up to 30 days to 60 days at room temperature. For example, when a polymer emulsion with a molecular weight of 3 million to 5 million is used for profile control and the effective concentration of the polymer is 3000 mg / L to 6000 mg / L, it is crosslinked with the emulsion crosslinking system at 100°C to 120°C, and the viscosity of the formed colloid is 2817 mPa·s to 8184 mPa·s.

[0045] By adjusting the concentration of the polymer emulsion for profile control and the ratio of the emulsion-type cross-linking system, colloids with different gelling viscosities can be prepared to meet the requirements of profile control and displacement in different high-temperature reservoirs.

[0046] On the other hand, an embodiment of the present invention further provides a method for preparing any of the above-mentioned emulsion-type cross-linking systems, and the method for preparing the emulsion-type cross-linking system comprises: preparing a phenolic emulsion, a hexamethylenetetramine emulsion and an ammonium chloride emulsion respectively.

[0047] Among them, the preparation methods of phenolic emulsion, hexamethylenetetramine emulsion and ammonium chloride emulsion all include:

[0048] The emulsifier is uniformly dispersed in the emulsified oil to obtain the corresponding oil phase; resorcinol and / or hydroquinone, hexamethylenetetramine or ammonium chloride is uniformly dispersed in water to obtain the corresponding water phase; under homogenous conditions, the water phase is dropped into the oil phase to obtain a phenolic emulsion, a hexamethylenetetramine emulsion or an ammonium chloride emulsion.

[0049] Specifically, the preparation of the phenolic emulsion includes: uniformly dispersing the first emulsifier in the first emulsified oil to obtain a first oil phase; uniformly dispersing resorcinol and / or hydroquinone in water to obtain a first aqueous phase; under homogenous conditions, dropping the first aqueous phase into the first oil phase to obtain a phenolic emulsion.

[0050] The preparation of the hexamethylenetetramine emulsion includes: uniformly dispersing the second emulsifier in the second emulsified oil to obtain the second oil phase; uniformly dispersing the hexamethylenetetramine in water to obtain the second water phase; and under homogenous conditions, dropping the second water phase into the second oil phase to obtain the hexamethylenetetramine emulsion.

[0051] The preparation of ammonium chloride emulsion includes: uniformly dispersing the third emulsifier in the third emulsified oil to obtain the third oil phase; uniformly dispersing ammonium chloride in water to obtain the third water phase; under homogenous conditions, dropping the third water phase into the third oil phase to obtain ammonium chloride emulsion.

[0052] It can be seen that the oil phase is composed of an emulsifier and an emulsified oil, and resorcinol and / or hydroquinone, hexamethylenetetramine or ammonium chloride are uniformly dispersed in water to obtain a corresponding water phase, and the water phase is slowly added dropwise to the oil phase to form a water-in-oil emulsion.

[0053] In some examples, the emulsifier is at least one of a Span emulsifier, a Tween emulsifier, and an oligoester emulsifier P135.

[0054] For example, the first emulsifier is a mixture of at least one of Span80 and Span60 and oligoester emulsifier P135, thereby having an excellent emulsification effect on resorcinol and hydroquinone. The second emulsifier is a mixture of at least one of Span80 and Span60 and at least one of Tween80 and Tween60, thereby having an excellent emulsification effect on hexamethylenetetramine. The third emulsifier includes Span80 emulsifier, thereby having an excellent emulsification effect on ammonium chloride.

[0055] In some examples, the first emulsified oil, the second emulsified oil, and the third emulsified oil may be selected from at least one of white oil and liquid paraffin.

[0056] In order to ensure that the emulsifier can be evenly dispersed in the oil phase, the homogenization conditions include at least one of the following conditions: using a homogenizing device, a stirring speed of 3000 r / min-15000 r / min, and a stirring time of 5 min-20 min.

[0057] For phenolic emulsions, some preferred stirring speeds are 8000 r / min-12000 r / min, for example, this includes but is not limited to 8000 r / min, 8500 r / min, 9000 r / min, 9500 r / min, 10000 r / min, 10500 r / min, 11000 r / min, 11500 r / min, 12000 r / min, etc.

[0058] For hexamethylenetetramine emulsion, some preferred stirring speeds are 5000 r / min-8000 r / min, for example, this includes but is not limited to 5000 r / min, 5500 r / min, 6000 r / min, 6500 r / min, 7000 r / min, 7500 r / min, 8000 r / min, etc.

[0059] For ammonium chloride emulsion, some preferred stirring speeds are 3000 r / min-5000 r / min, for example, this includes but is not limited to 3000 r / min, 3500 r / min, 4000 r / min, 4500 r / min, 5000 r / min, etc.

[0060] In yet another aspect, an embodiment of the present invention further provides a profile control system, which includes any one of the above-mentioned emulsion-type cross-linking systems and a polymer emulsion for profile control.

[0061] The polymer emulsion for profile control can be a polymer emulsion for water plugging and profile control in oil and water wells known in the art. For example, anionic polyacrylamide gel system is widely used as a chemical water plugging and profile control agent in oil and water wells. The embodiment of the present invention can use a polyacrylamide-based polymer emulsion for profile control, that is, the active ingredient of this type of polymer emulsion for profile control is polyacrylamide.

[0062] By using the emulsion-type cross-linking system and the polymer emulsion for profile control provided in the above embodiment of the present invention in coordination, it is possible to adapt to high-temperature reservoir temperature conditions (the applicable reservoir temperature is 90°C-120°C). The two break emulsions under high-temperature reservoir temperature conditions and dilution, releasing the effective components in the inner water phase. At this time, the polymer molecules and the active components in the cross-linking system contact each other to undergo a cross-linking reaction, thereby forming a colloid with viscoelasticity, achieving the purpose of deep plugging and control, thereby significantly improving the plugging effect of the flooding and profile control agents.

[0063] In some examples, the concentration of resorcinol and / or hydroquinone in the phenolic emulsion in the profile control system is 1000 mg / L-3000 mg / L, including but not limited to 1000 mg / L, 1500 mg / L, 2000 mg / L, 2500 mg / L, and 3000 mg / L.

[0064] In some examples, the concentration of hexamethylenetetramine in the hexamethylenetetramine emulsion in the profile control system is 3000 mg / L-5000 mg / L, which includes but is not limited to 3000 mg / L, 3500 mg / L, 4000 mg / L, 4500 mg / L, 5000 mg / L, etc.

[0065] In some examples, the concentration of ammonium chloride in the ammonium chloride emulsion in the profile control system is 3000 mg / L-8000 mg / L, which includes but is not limited to 3000 mg / L, 3500 mg / L, 4000 mg / L, 4500 mg / L, 5000 mg / L, 5500 mg / L, 6000 mg / L, 6500 mg / L, 7000 mg / L, 8000 mg / L, etc.

[0066] In some examples, the concentration of the polymer in the profile control polymer emulsion in the profile control system is 3000 mg / L-6000 mg / L, which includes but is not limited to 3000 mg / L, 3500 mg / L, 4000 mg / L, 4500 mg / L, 5000 mg / L, 5500 mg / L, 6000 mg / L, etc.

[0067] In the embodiments of the present invention, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. The term "plurality" refers to two or more than two, unless otherwise clearly defined.

[0068] The term "and / or" in the embodiment of the present invention is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0069] The specific embodiments of the present invention will be described in more detail below. Although the specific embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. The specific techniques or conditions not specified in the embodiments are carried out according to the techniques or conditions described in the documents in this area or according to the product specification. The reagents used or the instruments not specified by the manufacturer are all conventional products that can be obtained commercially.

[0070] Example 1

[0071] This embodiment 1 provides an emulsion-type crosslinking system and a profile control system, wherein the emulsion-type crosslinking system includes resorcinol emulsion, hexamethylenetetramine emulsion, and ammonium chloride emulsion, all of which are water-in-oil emulsions.

[0072] The resorcinol emulsion was prepared by the following method:

[0073] Step (1): add 3.3 g of emulsifier Span80 and 0.8 g of emulsifier P135 to a mixture of 60 mL of white oil and liquid paraffin, wherein the volume ratio of white oil to liquid paraffin is 1:1, place the mixed solution in a homogenizer for homogenization at a stirring rate of 3500 r / min and a stirring time of 10 min to obtain a first oil phase.

[0074] Step (2): 3.5 g of resorcinol and 0.5 g of sodium sulfite were placed in 35 mL of water, and stirred evenly to dissolve them completely, thereby obtaining a second aqueous phase.

[0075] Step (3): placing the first oil phase in a homogenizer, slowly adding the first water phase to the first oil phase for homogenization, with a stirring rate of 8000 r / min and a stirring time of 10 min, to obtain a resorcinol emulsion. The resorcinol emulsion can be stably placed at room temperature for 30 days without any stratification.

[0076] The hexamethylenetetramine emulsion is prepared by the following method:

[0077] Step (1): Add 2.3 g of emulsifier Span 80 and 0.4 g of Tween 80 to 60 mL of liquid paraffin, and then place the mixed solution in a homogenizer for homogenization at a stirring rate of 4000 r / min and a stirring time of 10 min to obtain a second oil phase.

[0078] Step (2): Weigh 8 g of hexamethylenetetramine into 40 mL of water, stir evenly to dissolve it completely, and obtain a second aqueous phase.

[0079] Step (3): placing the second oil phase in a homogenizer, slowly dropping the second water phase into the second oil phase for homogenization, with a stirring rate of 5000 r / min and a stirring time of 10 min, to obtain a hexamethylenetetramine emulsion. The hexamethylenetetramine emulsion can be stably placed at room temperature for 30 days without stratification.

[0080] Ammonium chloride emulsion is prepared by the following method:

[0081] Step (1): 1.4 g of emulsifier Span80 was added to 60 mL of white oil, and then the mixed solution was placed in a homogenizer for homogenization at a stirring rate of 3000 r / min and a stirring time of 5 min to obtain a third oil phase.

[0082] Step (2): Place 8 g of ammonium chloride in 40 mL of water and stir evenly to dissolve it completely to obtain a third aqueous phase.

[0083] Step (3): placing the third oil phase in a homogenizer, slowly adding the third water phase to the third oil phase for homogenization, with a stirring rate of 3000 r / min and a stirring time of 10 min, to obtain an ammonium chloride emulsion. The ammonium chloride emulsion can be stably placed at room temperature for 52 days without stratification.

[0084] The profile control system provided in Example 1 includes the resorcinol emulsion, hexamethylenetetramine emulsion and ammonium chloride emulsion prepared above, and a polymer emulsion for profile control. The polymer emulsion for profile control is purchased from Shandong Jingyu Chemical Co., Ltd., with a model of TC938, a molecular weight of 3 million to 5 million, and a solid content of 30%.

[0085] According to the following concentrations, a certain amount of polymer emulsion for profile control, ammonium chloride emulsion, hexamethylenetetramine emulsion, and resorcinol emulsion were weighed and uniformly mixed. Among them, the concentration of the polymer in the profile control system in the polymer emulsion for profile control is 3000 mg / L, the concentration of ammonium chloride in the profile control system is 3000 mg / L, the concentration of hexamethylenetetramine in the profile control system is 3000 mg / L, and the concentration of resorcinol in the profile control system is 1000 mg / L.

[0086] The uniformly mixed profile control system was placed in an oven at 100°C for aging for 3 days to generate a colloid through a cross-linking reaction. The colloid was taken out and cooled to room temperature. The viscosity of the colloid was tested to be 2817 mPa·s, which shows that the colloid has excellent temperature resistance and viscoelasticity, and can achieve the purpose of deep plugging, thereby significantly improving the plugging effect of the profile control system on the formation.

[0087] Example 2

[0088] This embodiment 2 provides an emulsion-type crosslinking system and a profile control system, wherein the emulsion-type crosslinking system includes resorcinol-hydroquinone emulsion, hexamethylenetetramine emulsion, and ammonium chloride emulsion, all of which are water-in-oil emulsions.

[0089] The resorcinol-hydroquinone emulsion is prepared by the following method:

[0090] Step (1): add 5.95 g of emulsifier Span80 and 0.85 g of emulsifier P135 to a mixture of 60 mL of white oil and liquid paraffin, wherein the volume ratio of white oil to liquid paraffin is 1:1, place the mixed solution in a homogenizer for homogenization at a stirring rate of 3500 r / min and a stirring time of 10 min to obtain a first oil phase.

[0091] Step (2): 1.2 g of resorcinol, 0.55 g of hydroquinone, and 0.5 g of sodium sulfite were placed in 35 mL of water, and stirred evenly to dissolve them completely, thereby obtaining a second aqueous phase.

[0092] Step (3): placing the first oil phase in a homogenizer, slowly dropping the first water phase into the first oil phase for homogenization, with a stirring rate of 10000 r / min and a stirring time of 10 min, to obtain a resorcinol-hydroquinone emulsion. The resorcinol-hydroquinone emulsion can be stably placed at room temperature for 32 days without any stratification phenomenon.

[0093] The hexamethylenetetramine emulsion is prepared by the following method:

[0094] Step (1): Add 3.5 g of emulsifier Span 80 and 0.6 g of Tween 60 to 60 mL of liquid paraffin, and then place the mixed solution in a homogenizer for homogenization at a stirring rate of 4000 r / min and a stirring time of 10 min to obtain a second oil phase.

[0095] Step (2): Weigh 10 g of hexamethylenetetramine into 40 mL of water, stir evenly to dissolve it completely, and obtain a second aqueous phase.

[0096] Step (3): placing the second oil phase in a homogenizer, slowly adding the second water phase to the second oil phase for homogenization, with a stirring rate of 7000 r / min and a stirring time of 10 min, to obtain a hexamethylenetetramine emulsion. The hexamethylenetetramine emulsion can be stably placed at room temperature for 36 days without stratification.

[0097] Ammonium chloride emulsion is prepared by the following method:

[0098] Step (1): 1.7 g of emulsifier Span80 was added to 50 mL of white oil, and then the mixed solution was placed in a homogenizer for homogenization at a stirring rate of 4000 r / min and a stirring time of 5 min to obtain a third oil phase.

[0099] Step (2): Place 12.5 g of ammonium chloride in 50 mL of water and stir evenly to dissolve it completely to obtain a third aqueous phase.

[0100] Step (3): placing the third oil phase in a homogenizer, slowly adding the third water phase to the third oil phase for homogenization, with a stirring rate of 4000 r / min and a stirring time of 10 min, to obtain an ammonium chloride emulsion. The ammonium chloride emulsion can be stably placed at room temperature for 60 days without stratification.

[0101] The profile control system provided in Example 2 includes the resorcinol-hydroquinone emulsion, hexamethylenetetramine emulsion and ammonium chloride emulsion prepared as above, and a polymer emulsion for profile control, wherein the polymer emulsion for profile control is the same as the polymer emulsion for profile control used in Example 1.

[0102] According to the following concentrations, a certain amount of polymer emulsion for profile control, ammonium chloride emulsion, hexamethylenetetramine emulsion, and resorcinol emulsion were weighed and uniformly mixed. Among them, the concentration of the polymer in the profile control system in the polymer emulsion for profile control is 6000 mg / L, the concentration of ammonium chloride in the profile control system is 6000 mg / L, the concentration of hexamethylenetetramine in the profile control system is 4000 mg / L, and the concentration of the mixture of resorcinol-hydroquinone in the profile control system is 2000 mg / L.

[0103] The uniformly mixed profile control system was placed in an oven at 110°C for aging for 3 days to generate a colloid through a cross-linking reaction. The colloid was taken out and cooled to room temperature. The viscosity of the colloid was tested to be 5468 mPa·s, which shows that the colloid has excellent temperature resistance and viscoelasticity, and can achieve the purpose of deep plugging control, thereby significantly improving the plugging effect of the profile control system on the formation.

[0104] Example 3

[0105] This embodiment 3 provides an emulsion-type crosslinking system and a profile control system, wherein the emulsion-type crosslinking system includes resorcinol emulsion, hexamethylenetetramine emulsion, and ammonium chloride emulsion, all of which are water-in-oil emulsions.

[0106] The resorcinol emulsion was prepared by the following method:

[0107] Step (1): add 7.5 g of emulsifier Span80 and 0.7 g of emulsifier P135 to a mixture of 60 mL of white oil and liquid paraffin, wherein the volume ratio of white oil to liquid paraffin is 1:1, place the mixed solution in a homogenizer for homogenization at a stirring rate of 3500 r / min and a stirring time of 10 min to obtain a first oil phase.

[0108] Step (2): 3 g of resorcinol and 0.7 g of sodium sulfite were placed in 35 mL of water, and stirred evenly to dissolve them completely, thereby obtaining a second aqueous phase.

[0109] Step (3): placing the first oil phase in a homogenizer, slowly adding the first water phase to the first oil phase for homogenization, with a stirring rate of 12000 r / min and a stirring time of 10 min, to obtain a resorcinol emulsion. The resorcinol emulsion can be stably placed at room temperature for 30 days without any stratification.

[0110] The hexamethylenetetramine emulsion is prepared by the following method:

[0111] Step (1): Add 4 g of emulsifier Span 60 and 0.5 g of Tween 60 to 50 mL of liquid paraffin, and then place the mixed solution in a homogenizer for homogenization at a stirring rate of 4000 r / min and a stirring time of 10 min to obtain a second oil phase.

[0112] Step (2): Weigh 8 g of hexamethylenetetramine into 40 mL of water, stir evenly to dissolve it completely, and obtain a second aqueous phase.

[0113] Step (3): placing the second oil phase in a homogenizer, slowly adding the second water phase to the second oil phase for homogenization, with a stirring rate of 8000 r / min and a stirring time of 10 min, to obtain a hexamethylenetetramine emulsion. The hexamethylenetetramine emulsion can be stably placed at room temperature for 30 days without stratification.

[0114] Ammonium chloride emulsion is prepared by the following method:

[0115] Step (1): 3.2 g of emulsifier Span80 was added to 70 mL of white oil, and then the mixed solution was placed in a homogenizer for homogenization at a stirring rate of 3000 r / min and a stirring time of 5 min to obtain a third oil phase.

[0116] Step (2): Place 9 g of ammonium chloride in 30 mL of water and stir evenly to dissolve it completely to obtain a third aqueous phase.

[0117] Step (3): placing the third oil phase in a homogenizer, slowly adding the third water phase to the third oil phase for homogenization, with a stirring rate of 5000 r / min and a stirring time of 10 min, to obtain an ammonium chloride emulsion. The ammonium chloride emulsion can be stably placed at room temperature for 65 days without stratification.

[0118] The profile control system provided in Example 3 includes the resorcinol emulsion, hexamethylenetetramine emulsion and ammonium chloride emulsion prepared as above, and a polymer emulsion for profile control, wherein the polymer emulsion for profile control is the same as the polymer emulsion for profile control used in Example 1.

[0119] According to the following concentrations, a certain amount of polymer emulsion for profile control, ammonium chloride emulsion, hexamethylenetetramine emulsion, and resorcinol emulsion were weighed and uniformly mixed. Among them, the concentration of the polymer in the profile control system in the polymer emulsion for profile control is 6000 mg / L, the concentration of ammonium chloride in the profile control system is 8000 mg / L, the concentration of hexamethylenetetramine in the profile control system is 4000 mg / L, and the concentration of resorcinol in the profile control system is 2000 mg / L.

[0120] The uniformly mixed profile control system was placed in an oven at 120°C for aging for 2 days to generate a colloid through a cross-linking reaction. The colloid was taken out and cooled to room temperature. The viscosity of the colloid was tested to be 8184 mPa·s, which shows that the colloid has excellent temperature resistance and viscoelasticity, and can achieve the purpose of deep plugging, thereby significantly improving the plugging effect of the profile control system on the formation.

[0121] The above description is only for the purpose of facilitating those skilled in the art to understand the technical solution of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An emulsion type cross-linking system, characterized in that: The emulsion type cross-linking system includes phenolic emulsion, hexamethylenetetramine emulsion, and ammonium chloride emulsion; The phenolic emulsion is a water-in-oil emulsion, comprising a first oil phase and a first water phase dispersed in the first oil phase, wherein the first water phase comprises resorcinol and / or hydroquinone; The hexamethylenetetramine emulsion is a water-in-oil emulsion, comprising a second oil phase and a second water phase dispersed in the second oil phase, wherein the second water phase comprises hexamethylenetetramine; The ammonium chloride emulsion is a water-in-oil emulsion, comprising a third oil phase and a third water phase dispersed in the third oil phase, wherein the third water phase comprises ammonium chloride.

2. The emulsion cross-linking system according to claim 1, characterized in that: The first oil phase includes a first emulsifier and a first emulsified oil, and the first water phase also includes water and sodium sulfite; The volume ratio of the first aqueous phase to the phenolic emulsion is 20%-50%, the volume ratio of the first oil phase to the phenolic emulsion is 50%-80%, the mass ratio of the first emulsifier to the first oil phase is 5%-12%, the mass ratio of the resorcinol and / or hydroquinone to the first aqueous phase is 5%-30%, and the mass ratio of the sodium sulfite to the first aqueous phase is 1%-2%.

3. The emulsion cross-linking system according to claim 2, characterized in that: The first emulsifier is a mixture of at least one of Span80 and Span60 and oligoester emulsifier P135.

4. The emulsion cross-linking system according to claim 1, characterized in that: The second oil phase includes a second emulsifier and a second emulsified oil, and the second water phase also includes water; The volume ratio of the second aqueous phase to the phenolic emulsion is 20%-50%, the volume ratio of the second oil phase to the phenolic emulsion is 50%-80%, the mass ratio of the second emulsifier to the second oil phase is 3%-10%, and the mass ratio of hexamethylenetetramine to the second aqueous phase is 5%-30%.

5. The emulsion cross-linking system according to claim 4, characterized in that: The second emulsifier is a mixture of at least one of Span80 and Span60 and at least one of Tween80 and Tween60.

6. The emulsion cross-linking system according to claim 1, characterized in that: The third oil phase includes a third emulsifier and a third emulsified oil, and the third water phase also includes water; The volume ratio of the third water phase to the phenolic emulsion is 20%-50%, the volume ratio of the third oil phase to the phenolic emulsion is 50%-80%, the mass ratio of the third emulsifier to the third oil phase is 1%-5%, and the mass ratio of ammonium chloride to the third water phase is 5%-30%.

7. The emulsion cross-linking system according to claim 6, characterized in that: The third emulsifier includes Span 80 emulsifier.

8. The method for preparing the emulsion crosslinking system according to any one of claims 1 to 7, characterized in that: The preparation method comprises: preparing phenolic emulsion, hexamethylenetetramine emulsion and ammonium chloride emulsion respectively; The preparation methods of the phenolic emulsion, the hexamethylenetetramine emulsion and the ammonium chloride emulsion all include: uniformly dispersing the emulsifier in the emulsified oil to obtain a corresponding oil phase; Dispersing resorcinol and / or hydroquinone, hexamethylenetetramine or ammonium chloride uniformly in water to obtain a corresponding aqueous phase; Under homogenizing conditions, the water phase is added dropwise to the oil phase to obtain the phenol emulsion, the hexamethylenetetramine emulsion or the ammonium chloride emulsion.

9. The preparation method according to claim 8, characterized in that: The homogenization conditions include at least one of the following conditions: using a homogenization device, a stirring speed of 3000 r / min-15000 r / min, and a stirring time of 5 min-20 min.

10. A profile control system, characterized in that: The profile control system comprises the emulsion crosslinking system according to any one of claims 1 to 7 and a polymer emulsion for profile control.