A suspension emulsion for fracturing fluid and preparation method thereof

Abstract

The present invention provides a suspension emulsion for fracturing fluid, comprising: 40-60 parts by weight of white oil; 30-60 parts by weight of a thickener; 1-5 parts by weight of a nonionic emulsifier; 1-3 parts by weight of bentonite; 0.5-2 parts by weight of a suspending agent; 0.5-2 parts by weight of a dispersant; and 0.1-1.2 parts by weight of a cosolvent. Compared with the prior art, the suspension emulsion for fracturing fluid provided by the present invention has good suspension stability and a fast swelling rate. It can be prepared and injected on-site without residual liquid, thus avoiding waste of fracturing fluid and reducing transportation costs and tank cleaning fees. Furthermore, by reducing the amount of bentonite used, damage to the reservoir is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield chemistry, and in particular relates to a suspension emulsion for fracturing fluid and a preparation method thereof. Background Art

[0002] Hydraulic fracturing is a common method for increasing oil and gas reservoir production. Thickeners available for hydraulic fracturing come in three formulations: powders, invert emulsions, and suspoemulsions. However, powder thickeners (such as polyacrylamide and plant gums) take too long to dissolve, exhibit poor time-to-use, are prone to dust pollution, and are prone to "fish-eye" formation during the dissolution process, making them unsuitable for continuous mixing and large-volume fracturing operations. While invert emulsion thickeners have a shorter dissolution time, they contain a low effective content of the polyacrylamide, making product quality difficult to control and resulting in poor stability. Suspoemulsion systems have a high solids content, relatively fast swelling rates, and no residual waste, making them suitable for continuous mixing on-site. However, existing suspoemulsions typically experience delamination and bottom sedimentation within two months, resulting in poor stability and dissolution rates of approximately 30 to 60 seconds, making them less than ideal for rapid on-site mixing. Therefore, a stable and rapidly dissolving suspoemulsion is needed for continuous mixing and large-volume fracturing fluid thickeners.

[0003] Therefore, how to improve the suspension stability and dissolution rate of the suspension emulsion thickener to meet the requirements of the continuous mixing "ready-to-mix and inject" fracturing process is one of the problems that technicians in this field urgently need to solve. Summary of the Invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a suspension emulsion for fracturing fluid with good suspension stability, quick dissolution performance and low damage to reservoirs and a preparation method thereof.

[0005] The present invention provides a suspension emulsion for fracturing fluid, comprising:

[0006] 40-60 parts by weight of white oil;

[0007] 30-60 parts by weight of thickener;

[0008] 1-5 parts by weight of nonionic emulsifier;

[0009] 1-3 parts by weight of bentonite;

[0010] 0.5-2 parts by weight of suspending agent;

[0011] 0.5-2 parts by weight of dispersant;

[0012] 0.1~1.2 parts by weight of cosolvent.

[0013] Preferably, the particle size of the thickener is 100-150 μm; and the dispersant is a single-layer flake structure.

[0014] Preferably, the thickener is selected from polyacrylamide thickeners and / or guar gum thickeners;

[0015] The nonionic emulsifier is a polyoxyethylene ether emulsifier;

[0016] The suspending agent is a polysaccharide suspending agent;

[0017] The dispersant is selected from silicate dispersants and / or aluminosilicate dispersants;

[0018] The cosolvent is a small molecule alcohol.

[0019] Preferably, the white oil is selected from one or more of 3# white oil, 5# white oil, 7# white oil, 10# white oil, 15# white oil, 20# white oil, 22# white oil, 26# white oil and 32# white oil;

[0020] The thickener is selected from one or more of polyacrylamide thickeners, carboxymethyl guar gum, hydroxypropyl guar gum and carboxymethyl hydroxypropyl guar gum;

[0021] The nonionic emulsifier is selected from one or more of fatty alcohol polyoxyethylene ether, cocamide polyoxyethylene ether, Tween 80, coconut oil polyoxyethylene ether, isomeric tridecyl alcohol polyoxyethylene ether and polyoxypropylene polyoxyethylene propylene glycol ether;

[0022] The bentonite is selected from sodium bentonite and / or calcium bentonite;

[0023] The suspending agent is selected from one or more of carboxymethyl cellulose, hydroxypropyl cellulose, sodium hydroxypropyl methylcellulose and maltodextrin;

[0024] The dispersant is selected from one or more of sodium aluminosilicate, sodium silicate, magnesium aluminum silicate, magnesium hexasilicate and sodium metasilicate pentahydrate;

[0025] The co-solvent is selected from one or more of methanol, ethanol, ethylene glycol, propylene glycol, glycerol and isopropanol.

[0026] Preferably, including:

[0027] 43-53 parts by weight of white oil;

[0028] 40-50 parts by weight of thickener;

[0029] 2-3 parts by weight of nonionic emulsifier;

[0030] 1.8 parts by weight of bentonite;

[0031] 0.8-1.2 parts by weight of suspending agent;

[0032] 0.8-1.2 parts by weight of dispersant;

[0033] 0.4~0.8 parts by weight of cosolvent.

[0034] Preferably, the density of the suspension emulsion for fracturing fluid is 0.95-0.97 g / cm 3 .

[0035] Preferably, the bulk viscosity of the fracturing fluid suspension emulsion is 350-500 mPa·s.

[0036] Preferably, the viscosity of the fracturing fluid suspension emulsion after stirring for 15 to 30 seconds is more than 80% of the final viscosity.

[0037] The present invention also provides a method for preparing a suspension emulsion for fracturing fluid, comprising:

[0038] White oil, thickener, nonionic emulsifier, bentonite, suspending agent, dispersant and co-solvent are mixed and stirred at high speed to obtain a suspension emulsion for fracturing fluid.

[0039] Preferably, the mixing speed is 200-2000 r / min; the high-speed stirring speed is 2000-8000 r / min; the high-speed stirring time is 20-100 min; and the high-speed stirring temperature is 10° C.-80° C.

[0040] The present invention provides a suspension emulsion for fracturing fluid, comprising: 40-60 parts by weight of white oil; 30-60 parts by weight of a thickener; 1-5 parts by weight of a nonionic emulsifier; 1-3 parts by weight of bentonite; 0.5-2 parts by weight of a suspending agent; 0.5-2 parts by weight of a dispersant; and 0.1-1.2 parts by weight of a cosolvent. Compared with the prior art, the suspension emulsion for fracturing fluid provided by the present invention has good suspension stability and a fast swelling rate. It can be prepared and injected on-site immediately without residual liquid, thus avoiding waste of fracturing fluid and reducing transportation costs and tank cleaning fees. Furthermore, by reducing the amount of bentonite used, damage to the reservoir is reduced.

[0041] Experimental results show that the suspension emulsion for fracturing fluid provided by the present invention does not stratify, settle, or harden after being left to stand for 6 months, and the performance of the suspension emulsion is not affected. The viscosity of the polyacrylamide suspension emulsion can reach more than 80% of the final viscosity after stirring for 15 seconds, and the plant gum emulsion can be stirred for 30 seconds. They can be prepared and injected on site without residual liquid, avoiding waste of fracturing fluid and reducing transportation costs, tank cleaning fees, etc.; by reducing the amount of bentonite used, the damage of the suspension emulsion to the reservoir is reduced, and the damage rate of the polyacrylamide suspension emulsion and the plant gum suspension emulsion to the reservoir is less than 10%. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a state diagram of the suspension emulsion prepared in Examples 1 to 3 of the present invention after being placed for 6 months;

[0043] Figure 2 Figure 3 is a diagram showing the state of the suspension emulsions prepared in Examples 4 and 5 of the present invention after being placed for 6 months. DETAILED DESCRIPTION

[0044] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] The present invention provides a suspension emulsion for fracturing fluid, comprising:

[0046] 40-60 parts by weight of white oil;

[0047] 30-60 parts by weight of thickener;

[0048] 1-5 parts by weight of nonionic emulsifier;

[0049] 1-3 parts by weight of bentonite;

[0050] 0.5-2 parts by weight of suspending agent;

[0051] 0.5-2 parts by weight of dispersant;

[0052] 0.1~1.2 parts by weight of cosolvent.

[0053] The present invention uses white oil as the dispersing medium for the thickening agent. The content of the white oil in the fracturing fluid suspoemulsion is preferably 40 to 55 parts by weight, more preferably 43 to 53 parts by weight. In embodiments provided herein, the content of the white oil in the fracturing fluid suspoemulsion is specifically 52.8 parts by weight, 48 parts by weight, or 43.4 parts by weight. The white oil is preferably one or more of 3# white oil, 5# white oil, 7# white oil, 10# white oil, 15# white oil, 20# white oil, 22# white oil, 26# white oil, and 32# white oil, more preferably two of 3# white oil, 5# white oil, 26# white oil, and 32# white oil, or one of 7# white oil, 10# white oil, and 15# white oil. The specific white oil selected in the present invention maximizes the density of the white oil (solvent) while ensuring a moderate emulsion viscosity, thereby achieving better suspension stability.

[0054] The thickener is an active ingredient in the fracturing fluid suspension emulsion, used to increase the viscosity of the fracturing fluid and carry the proppant into the formation during the fracturing operation. The thickener is preferably a polyacrylamide thickener and / or a guar gum thickener, more preferably one or more of polyacrylamide thickeners, carboxymethyl guar gum, hydroxypropyl guar gum and carboxymethyl hydroxypropyl guar gum. In the present invention, the fracturing fluid suspension emulsion can be divided into polyacrylamide suspension emulsion and plant gum suspension emulsion according to the type of thickener. The thickener is a dry powder thickener with a particle size of 100-150 μm. The content of the thickener in the fracturing fluid suspension emulsion is preferably 35-55 parts by weight, more preferably 40-50 parts by weight.

[0055] The fracturing fluid suspoemulsion provided by the present invention contains a nonionic emulsifier, which can be adsorbed on the surface of the thickener dry powder particles to form a layer of emulsifier molecules, so that each small particle can be stably dispersed and suspended in the medium; the type of the nonionic emulsifier is preferably a polyoxyethylene ether emulsifier, more preferably one or more of fatty alcohol polyoxyethylene ether, cocamide polyoxyethylene ether, Tween 80, coconut oil polyoxyethylene ether, isomeric tridecyl alcohol polyoxyethylene ether and polyoxypropylene polyoxyethylene glycol ether; the content of the nonionic emulsifier in the fracturing fluid suspoemulsion is preferably 1.5 to 4 parts by weight, more preferably 2 to 4 parts by weight, and even more preferably 2 to 3 parts by weight; in the embodiments provided by the present invention, the content of the fracturing fluid suspoemulsion is specifically 3 parts by weight, 2.6 parts by weight or 2 parts by weight.

[0056] Bentonite can enhance the thixotropy and suspension properties of the fracturing fluid suspension emulsion system, making the system more stable in temperature resistance, shear resistance, and suspension performance; the bentonite is preferably sodium-based bentonite and / or calcium-based bentonite; the content of the bentonite in the fracturing fluid suspension emulsion is preferably 1.5 to 2.5 parts by weight, more preferably 1.8 to 2 parts by weight; in the embodiments provided by the present invention, the content of the bentonite in the fracturing fluid suspension emulsion is specifically 1.8 parts by weight.

[0057] The suspending agent in the suspoemulsion for fracturing fluid provided by the present invention is preferably a polysaccharide suspending agent, more preferably one or more of carboxymethyl cellulose, hydroxypropyl cellulose, sodium hydroxypropyl methylcellulose and maltodextrin; the content of the suspending agent in the suspoemulsion for fracturing fluid is preferably 0.5 to 1.5 parts by weight, more preferably 0.8 to 1.2 parts by weight, and even more preferably 1 part by weight.

[0058] The dispersant in the suspension emulsion for fracturing fluid provided by the present invention is preferably a single-layer flaky structure. Compared with a curled or overlapping structure, the spread-out single-layer structure has the characteristic of a larger interlayer spacing, which can separate the suspended particles layer by layer, so that the thickener dry powder is evenly dispersed in the white oil solvent, effectively inhibiting the thickener from settling and agglomerating, and achieving a better suspension stabilization effect. In the present invention, the type of the dispersant is preferably a silicate dispersant and / or an aluminosilicate dispersant, more preferably one or more of sodium aluminosilicate, sodium silicate, magnesium aluminum silicate, magnesium hexasilicate and sodium metasilicate pentahydrate; the content of the dispersant in the suspension emulsion for fracturing fluid is preferably 0.5 to 1.5 parts by weight, more preferably 0.8 to 1.2 parts by weight, and even more preferably 1 part by weight.

[0059] The cosolvent in the fracturing fluid suspoemulsion provided by the present invention is preferably a small molecule alcohol. The addition of the small molecule alcohol can slightly swell the thickener powder, preparing it for dissolution in the later preparation of the fracturing fluid, accelerating the dissolution rate of the suspoemulsion, and also increasing / adjusting the viscosity of the emulsion to achieve a better suspension effect. The cosolvent is more preferably one or more of methanol, ethanol, ethylene glycol, propylene glycol, glycerol, and isopropanol; the content of the cosolvent in the fracturing fluid suspoemulsion is preferably 0.2 to 1 parts by weight, more preferably 0.4 to 0.8 parts by weight.

[0060] According to the present invention, further preferably, the suspension emulsion for fracturing fluid comprises:

[0061] 43-53 parts by weight of white oil;

[0062] 40-50 parts by weight of thickener;

[0063] 2-3 parts by weight of nonionic emulsifier;

[0064] 1.8 parts by weight of bentonite;

[0065] 0.8-1.2 parts by weight of suspending agent;

[0066] 0.8-1.2 parts by weight of dispersant;

[0067] 0.4~0.8 parts by weight of cosolvent.

[0068] The density of the suspension emulsion for fracturing fluid provided by the present invention is preferably 0.95-0.97 g / cm 3 Its density and state vary slightly depending on the type and content of the thickener. When the thickener is 40% polyacrylamide thickener, the fracturing fluid suspension emulsion is a milky white viscous liquid with a density of 0.957 g / cm 3 When the thickener is 40% guar gum thickener, the fracturing fluid suspension emulsion is a khaki viscous liquid with a density of preferably 0.966 g / cm3 .

[0069] The bulk viscosity of the suspension emulsion for fracturing fluid provided by the present invention is preferably 350-500 mPa·s and is adjustable within this range.

[0070] The viscosity of the suspension emulsion for fracturing fluid provided by the present invention after stirring for 15 to 30 seconds is preferably more than 80% of the final viscosity.

[0071] The suspension emulsion for fracturing fluid provided by the present invention has good suspension stability and fast swelling speed, can be prepared and injected on site without residual liquid, thus avoiding waste of fracturing fluid and reducing transportation costs, tank cleaning costs, etc.; and reduces damage to reservoirs by reducing the amount of bentonite used.

[0072] The present invention also provides a method for preparing the above-mentioned suspension emulsion for fracturing fluid, comprising: mixing white oil, a thickener, a nonionic emulsifier, bentonite, a suspending agent, a dispersant and a co-solvent, and then stirring at high speed to obtain the suspension emulsion for fracturing fluid.

[0073] The present invention has no particular limitation on the sources of all raw materials, and any commercially available raw materials are sufficient. The white oil, thickener, nonionic emulsifier, bentonite, suspending agent, dispersant and cosolvent are the same as those described above and will not be described in detail here.

[0074] White oil, thickener, nonionic emulsifier, bentonite, suspending agent, dispersant and cosolvent are mixed; the mixing speed is preferably 200-2000 r / min, more preferably 500-1500 r / min, and even more preferably 700-1100 r / min; the mixing is preferably carried out in a reactor.

[0075] After mixing, high-speed stirring is performed to obtain a suspension emulsion for fracturing fluid; the rotation speed of the high-speed stirring is preferably 2000-8000 r / min, more preferably 2000-7000 r / min, and even more preferably 3000-6000 r / min; the time of the high-speed stirring is preferably 20-100 min, more preferably 30-70 min, and even more preferably 30-60 min; the temperature of the high-speed stirring is preferably 10°C-80°C, more preferably 20°C-70°C, and even more preferably 25°C-50°C.

[0076] The polymer suspension emulsion and guar gum suspension emulsion provided by the present invention have the characteristics of fast dissolution speed (less than 15 seconds) and long stability period (more than 6 months). In continuous mixing and large-volume construction, they can be prepared and injected on site as thickeners, effectively avoiding the costs of liquid preparation, transportation, tank cleaning, etc. caused by pre-prepared liquid.

[0077] To further illustrate the present invention, the following describes in detail a suspension emulsion for fracturing fluid and a preparation method thereof in conjunction with examples.

[0078] All reagents used in the following examples are commercially available. The white oils (3#, 5#, 7#, 10#, 15#, 26#, and 32#) used in the examples were provided by Shandong Taichang Petrochemical Technology Co., Ltd.; bentonite (sodium-based) was provided by Lingshou Yiran Mineral Products Processing Plant; emulsifiers (coconut oil polyoxyethylene ether 26L, isomeric tridecanol polyoxyethylene ether E-1303) were provided by Jiangsu Hai'an Petrochemical Plant; suspending agents (hydroxypropyl methylcellulose sodium HPMC) were provided by Northern Chemical Co., Ltd.; dispersants (sodium silicate, sodium metasilicate pentahydrate) were provided by Shandong Duofeng Chemical Co., Ltd.; cosolvents (glycerol, ethylene glycol, ethanol) and polyacrylamide powder (anion C powder) were provided by Aisen (China) Flocculant Co., Ltd.; carboxymethyl hydroxypropyl guar gum powder and hydroxypropyl guar gum powder were provided by Beijing Baofengchun Petroleum Technology Co., Ltd. All of the above raw materials are commercially available industrial products. The particle size of the thickener powder used in the examples was 100-200 mesh.

[0079] Example 1

[0080] The polymer suspension emulsion components are: in parts by weight, 52.8 parts of white oil, 40 parts of thickener dry powder, 1.8 parts of bentonite, 3 parts of emulsifier, 1 part of suspending agent, 1 part of dispersant, and 0.4 parts of cosolvent; the white oil includes 30 parts of 3# white oil, 22.6 parts of 32# white oil, the thickener dry powder is polyacrylamide, the bentonite is sodium bentonite, the emulsifier is coconut oil polyoxyethylene ether, the suspending agent is sodium hydroxypropyl methylcellulose, the dispersant is sodium silicate, and the cosolvent is glycerol.

[0081] The preparation method is as follows: place 3# white oil and 32# white oil in a beaker, set the speed to 700 r / min, add bentonite, emulsifier, suspending agent, dispersant, cosolvent, and dry powder in sequence, and continue stirring at 3000 r / min and 50°C for 50 minutes to obtain a polyacrylamide suspension emulsion with a 40% effective content.

[0082] Example 2

[0083] The polymer suspension emulsion components are: in parts by weight, 48 parts of white oil, 45 parts of thickener dry powder, 1.8 parts of bentonite, 2.6 parts of emulsifier, 1 part of suspending agent, 1 part of dispersant, and 0.6 part of cosolvent; the white oil includes 24 parts of 5# white oil, 24 parts of 26# white oil, the thickener dry powder is polyacrylamide, the bentonite is sodium bentonite, the emulsifier is coconut oil polyoxyethylene ether, the suspending agent is sodium hydroxypropyl methylcellulose, the dispersant is sodium silicate, and the cosolvent is ethylene glycol.

[0084] The preparation method is as follows: place 5# white oil and 26# white oil in a beaker, set the speed to 800 r / min, add bentonite, emulsifier, suspending agent, dispersant, cosolvent, and dry powder in sequence, and continue stirring at 4000 r / min and 40°C for 40 minutes to obtain a polyacrylamide suspension emulsion with an effective content of 45%.

[0085] Example 3

[0086] The polymer suspension emulsion components are: in parts by weight, 43.4 parts of white oil, 50 parts of thickener dry powder, 1.8 parts of bentonite, 2 parts of emulsifier, 1 part of suspending agent, 1 part of dispersant, and 0.8 part of cosolvent; the white oil includes 30 parts of 7# white oil, 13.4 parts of 26# white oil, the thickener dry powder is polyacrylamide, the bentonite is sodium bentonite, the emulsifier is isomeric tridecyl alcohol polyoxyethylene ether, the suspending agent is sodium hydroxypropyl methylcellulose, the dispersant is sodium metasilicate pentahydrate, and the cosolvent is ethanol.

[0087] The preparation method is as follows: place white oil in a beaker, set the speed to 900 r / min, add bentonite, emulsifier, suspending agent, dispersant, cosolvent, and dry powder in sequence, and continue stirring at 6000 r / min and 25°C for 30 minutes to obtain a polyacrylamide suspension emulsion with a 50% effective content.

[0088] Example 4

[0089] The components of the guar gum suspension emulsion are: in parts by weight, 52.8 parts of white oil, 40 parts of thickener dry powder, 1.8 parts of bentonite, 3 parts of emulsifier, 1 part of suspending agent, 1 part of dispersant, and 0.4 parts of cosolvent; the white oil is 10# white oil, the thickener dry powder is carboxymethyl hydroxypropyl guar gum, the bentonite is sodium bentonite, the emulsifier is isomeric tridecyl alcohol polyoxyethylene ether, the suspending agent is sodium hydroxypropyl methylcellulose, the dispersant is sodium silicate, and the cosolvent is ethanol.

[0090] The preparation method is as follows: white oil is placed in a beaker, the rotation speed is set to 1000 r / min, bentonite, emulsifier, suspending agent, dispersant, cosolvent, and thickener dry powder are added in sequence, and stirring is continued at 3500 r / min and 45°C for 35 minutes to obtain a carboxymethyl hydroxypropyl guar gum suspension emulsion with a 40% effective content.

[0091] Example 5

[0092] The components of the guar gum suspension emulsion are: in parts by weight, 43.4 parts of white oil, 50 parts of thickener dry powder, 1.8 parts of bentonite, 2 parts of emulsifier, 1 part of suspending agent, 1 part of dispersant, and 0.8 part of cosolvent; the white oil is 15# white oil, the thickener dry powder is hydroxypropyl guar gum, the bentonite is sodium bentonite, the emulsifier is isomeric tridecyl alcohol polyoxyethylene ether, the suspending agent is sodium hydroxypropyl methylcellulose, the dispersant is sodium metasilicate pentahydrate, and the cosolvent is glycerol.

[0093] The preparation method is as follows: white oil is placed in a beaker, the rotation speed is set to 1100 r / min, bentonite, emulsifier, suspending agent, dispersant, cosolvent, and thickener dry powder are added in sequence, and stirring is continued at 4000 r / min and 30°C for 40 minutes to obtain a hydroxypropyl guar gum suspension emulsion with a 50% effective content.

[0094] Performance testing:

[0095] (1) Swelling rate test

[0096] Test method: Take 350mL of 20℃ clean water and add it to the mixer measuring cup. Adjust the mixer speed to 1700r / min, add the calculated amount of thickener, start timing, stop stirring after 20s, pour the liquid into a six-speed viscosity measuring cup within 10s and install a six-speed viscometer for measurement. Record the apparent viscosity of the solution at 0.5min, 1min, 2min, and 3min at 100r / min, and compare it with the apparent viscosity at 4h to calculate the swelling rate.

[0097] Table 1 Viscosity and swelling rate test of polyacrylamide suspension emulsion

[0098]

[0099] Table 2 Viscosity and swelling rate test of guar gum suspension emulsion

[0100]

[0101] (2) Suspension stability test: After standing for 6 months, observe whether the suspension emulsion product appears. If the separation is less than 5% and there is no sedimentation or hardening at the bottom, it is considered qualified. Figure 1 、 Figure 2 As shown, Figure 1 From left to right, the suspension emulsions prepared in Examples 1, 2, and 3 are stored for 6 months. Figure 2 From left to right in the middle are the states of the suspension emulsions prepared in Examples 4 and 5 after being placed for 6 months. It can be seen that the suspension emulsions are still stable after being placed for 6 months, with basically no stratification, and have almost no difference in appearance from the suspension emulsions just prepared, reflecting good suspension stability.

[0102] (3) Damage test: The matrix permeability damage rate of the suspension emulsion was tested with reference to the standard SY / T 5107-2016 “Performance evaluation method of water-based fracturing fluid”. The results are shown in Table 3. It can be seen that the matrix permeability damage rate of the suspension emulsion prepared by this method is low, and it belongs to low-damage fracturing fluid.

[0103] Table 3 Test results of matrix permeability damage rate of suspension emulsion

[0104]

[0105] In summary, the present invention provides a new method for preparing a suspension emulsion, which has the advantages of fast dissolution speed, good suspension performance and low cost, and meets the technical requirements of continuous mixing and large-volume hydraulic fracturing construction.

[0106] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A suspension emulsion for fracturing fluid, characterized in that: include: 40-60 parts by weight of white oil; 30-60 parts by weight of thickener; 1-5 parts by weight of nonionic emulsifier; 1-3 parts by weight of bentonite; 0.5-2 parts by weight of suspending agent; 0.5-2 parts by weight of dispersant; 0.1-1.2 parts by weight of cosolvent; The thickener is selected from polyacrylamide thickeners and / or guar gum thickeners; The nonionic emulsifier is a polyoxyethylene ether emulsifier; The suspending agent is selected from one or more of carboxymethyl cellulose, hydroxypropyl cellulose, sodium hydroxypropyl methylcellulose and maltodextrin; The dispersant is selected from silicate dispersants and / or aluminosilicate dispersants; The cosolvent is a small molecule alcohol.

2. The suspension emulsion for fracturing fluid according to claim 1, characterized in that The particle size of the thickener is 100-150 μm; the dispersant is a single-layer flake structure.

3. The suspension emulsion for fracturing fluid according to claim 1, characterized in that The white oil is selected from one or more of 3# white oil, 5# white oil, 7# white oil, 10# white oil, 15# white oil, 20# white oil, 22# white oil, 26# white oil and 32# white oil; The thickener is selected from one or more of polyacrylamide thickeners, carboxymethyl guar gum, hydroxypropyl guar gum and carboxymethyl hydroxypropyl guar gum; The nonionic emulsifier is selected from one or more of fatty alcohol polyoxyethylene ether, cocamide polyoxyethylene ether, Tween 80, coconut oil polyoxyethylene ether, isomeric tridecyl alcohol polyoxyethylene ether and polyoxypropylene polyoxyethylene propylene glycol ether; The bentonite is selected from sodium bentonite and / or calcium bentonite; The dispersant is selected from one or more of sodium aluminosilicate, sodium silicate, magnesium aluminum silicate, magnesium hexasilicate and sodium metasilicate pentahydrate; The co-solvent is selected from one or more of methanol, ethanol, ethylene glycol, propylene glycol, glycerol and isopropanol.

4. The suspension emulsion for fracturing fluid according to claim 1, characterized in that include: 43-53 parts by weight of white oil; 40-50 parts by weight of thickener; 2-3 parts by weight of nonionic emulsifier; 1.8 parts by weight of bentonite; 0.8-1.2 parts by weight of suspending agent; 0.8-1.2 parts by weight of dispersant; 0.4~0.8 parts by weight of cosolvent.

5. The suspension emulsion for fracturing fluid according to claim 1, characterized in that: The density of the fracturing fluid suspension emulsion is 0.95-0.97 g / cm 3 .

6. The suspension emulsion for fracturing fluid according to claim 1, characterized in that The bulk viscosity of the fracturing fluid suspension emulsion is 350-500 mPa·s.

7. The suspension emulsion for fracturing fluid according to claim 1, characterized in that: The viscosity of the fracturing fluid suspension emulsion after stirring for 15 to 30 seconds is more than 80% of the final viscosity.

8. A method for preparing the suspension emulsion for fracturing fluid according to claim 1, characterized in that: include: White oil, thickener, nonionic emulsifier, bentonite, suspending agent, dispersant and co-solvent are mixed and stirred at high speed to obtain a suspension emulsion for fracturing fluid.

9. The preparation method according to claim 8, characterized in that The mixing speed is 200-2000 r / min; the high-speed stirring speed is 2000-8000 r / min; the high-speed stirring time is 20-100 min; and the high-speed stirring temperature is 10° C.-80° C.

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