阅读说明：本技术 纳微米支撑颗粒组合物、纳微米支撑颗粒和水力压裂方法 (Nano-micron support particle composition, nano-micron support particle and hydraulic fracturing method ) 是由 林厉军 黄降水 斯蒂芬妮·于 刘付臣 尹丛彬 龚蔚 于 2020-04-16 设计创作，主要内容包括：本发明提供了一种纳微米支撑颗粒组合物、纳微米支撑颗粒和水力压裂方法。该纳微米支撑颗粒组合物包括液体溶剂、至少一种表面活性剂、颗粒形成化合物、至少一种固化剂和pH控制剂,纳微米支撑颗粒组合物的pH值在11.5以上。通过控制pH控制剂添加量使得纳微米支撑颗粒组合物的pH值在11.5以上,因此可以得到从纳米级别至微米级别的纳微米支撑颗粒,并且其D50为50nm～100μm,所得到的纳微米支撑颗粒中的纳米颗粒可以起到降低压裂液滤失的作用；微米颗粒可以进入或形成在包括微裂缝在内的各种尺寸的裂缝,进而起到充分支撑微裂缝等裂缝的作用,在两种颗粒的共同作用下,显著提高微裂缝导流率,从而提高原油产量。(The invention provides a nano-micron support particle composition, nano-micron support particles and a hydraulic fracturing method. The nano-micron supported particle composition comprises a liquid solvent, at least one surfactant, a particle forming compound, at least one curing agent and a pH control agent, wherein the pH value of the nano-micron supported particle composition is more than 11.5. The pH value of the nano-micron support particle composition is over 11.5 by controlling the addition amount of the pH control agent, so that nano-micron support particles from a nano level to a micron level can be obtained, the D50 is 50 nm-100 mu m, and the nano particles in the obtained nano-micron support particles can play a role in reducing the fluid loss of the fracturing fluid; the micron particles can enter or form cracks with various sizes including micro cracks, so that the micro cracks and other cracks are fully supported, and the micro crack flow conductivity is remarkably improved under the combined action of the two particles, so that the crude oil yield is improved.)

1. A nano-micron supported particle composition, wherein the nano-micron supported particle composition comprises a liquid solvent, at least one surfactant, a particle forming compound, at least one curing agent, and a pH controlling agent, and wherein the pH of the nano-micron supported particle composition is above 11.5.

2. The nano-micron supported particle composition of claim 1, wherein the pH control agent is sodium hydroxide and/or potassium hydroxide.

3. The nano-micron supported particle composition of claim 1, wherein the particle forming compound is selected from the group consisting of a resin entity selected from any one of the group consisting of aliphatic epoxies, epoxy functional resins, polyurethane resins, acrylic resins, phenolic resins, and ether-aldehyde resins, and a diluent selected from any one or more of the group consisting of glycidyl amine epoxies, cycloaliphatic epoxies, anhydrides, bisphenol a diglycidyl ethers, polyglycidyl ethers, glycidyl ethers, bisphenol F diglycidyl ethers.

4. The nano-micron supported particle composition of claim 1, wherein the surfactant is any one or a combination of anionic, cationic, nonionic and amphoteric surfactants.

5. The nano-micron supported particle composition of claim 1, wherein the liquid solvent is selected from the group consisting of water, seawater, brine solution, alcohol solvent selected from any one or more of ethanol, propanol, and butanol.

6. The nano-micron supported particle composition of claim 1, wherein the curing agent is selected from any one of isophorone diamine, boron trifluoride derivatives, imidazolines, thiols, hydrazides, polyamides, monoethanolamine, benzyldimethylamine, lewis acids, tertiary amines, isophorone, imidazole, sulfides, amides, or derivatives thereof.

7. The nano-micron supported particle composition according to any one of claims 1 to 6, wherein the mass content of the particle forming compound and the curing agent in the nano-micron supported particle composition is 10 to 75%, and the mass content of the surfactant is 0.5 to 20%, preferably the mass content of the particle forming compound and the curing agent is 45 to 65%, and the mass content of the surfactant is 2 to 10%.

8. The nano-micron supported particle composition of claim 1, further comprising an adhesion promoter, preferably said adhesion promoter is selected from calcium carbonate nanoparticles, silicate nanoparticles, or a water soluble polymer comprising polyacrylamide or polyvinyl alcohol, preferably said nano-micron supported particle composition has a viscosity of 10 to 60 cPs.

9. A nano-micron support particle formed by curing a nano-micron support particle composition, wherein the nano-micron support particle composition is the nano-micron support particle composition as defined in any one of claims 1 to 8, the D50 of the nano-micron support particle is 50nm to 100 μm, preferably the D50 of the nano-micron support particle is 10 to 95 μm, and preferably the density of the nano-micron support particle is 1.50g/ml or less.

10. A hydraulic fracturing method comprising injecting a hydraulic fracturing fluid into a subterranean formation for fracturing, wherein the hydraulic fracturing fluid comprises an emulsion formed from the nano-micron support particle composition of any one of claims 1 to 8 or the nano-micron support particles of claim 9.

Technical Field

The invention relates to the technical field of hydraulic fracturing, in particular to a nano-micron support particle composition, nano-micron support particles and a hydraulic fracturing method.

Background

Hydraulic fracturing has been an important technique for increasing the production of hydrocarbons in hydrocarbon-bearing formations. In a typical hydraulic fracturing treatment, a hydraulic fracturing fluid containing a solid proppant (e.g., a linear gel and slickwater) is injected into a subterranean formation at a pressure high enough to initiate or enlarge a fracture in the reservoir. When the hydraulic fracturing fluid is removed, the packed proppant may hold the fracture open, allowing fluid to flow from the formation through the proppant to the production wellbore. It can thus be seen that the proppant is very important because it provides long-term conductivity of the fracture.

Chinese patent application publication No. CN 107109203 a discloses a hydraulic fracturing fluid for oilfield applications, the hydraulic fracturing fluid comprising a spherical bead-forming liquid composition characterized by a primary liquid precursor and a secondary liquid precursor, the primary liquid precursor characterized by a micelle-forming surfactant, a bead-forming compound, and a solid-free liquid solvent; and the secondary liquid precursor is characterized by one or more curing agents and one or more co-curing agents. The obtained spherical beads have a particle size of 0.1mm to 30mm, and thus cannot support microcracks.

Disclosure of Invention

The invention mainly aims to provide a nano-micron support particle composition, nano-micron support particles and a hydraulic fracturing method, so as to solve the problem that a liquid composition for forming spherical beads in the prior art cannot support microcracks.

To achieve the above object, according to one aspect of the present invention, there is provided a nano-micro supported particle composition comprising a liquid solvent, at least one surfactant, a particle forming compound, at least one curing agent, and a pH controlling agent, the pH of the nano-micro supported particle composition being above 11.5.

Further, the pH controller is sodium hydroxide and/or potassium hydroxide.

Further, the particle-forming compound is selected from a resin body selected from any one of the group consisting of an aliphatic epoxy, an epoxy functional resin, a polyurethane resin, an acrylic resin, a phenol resin and an ether aldehyde resin, and a diluent selected from any one or more of the group consisting of a glycidyl amine epoxy, a cycloaliphatic epoxy, an acid anhydride, a bisphenol a diglycidyl ether, a polyglycidyl ether, a glycidyl ether, a bisphenol F diglycidyl ether.

Further, the surfactant is any one or combination of more of an anionic surfactant, a cationic surfactant, a nonionic surfactant and an amphoteric surfactant.

Further, the liquid solvent is selected from water, seawater, saline solution and alcohol solvent, and the alcohol solvent is selected from any one or more of ethanol, propanol and butanol.

Further, the curing agent is selected from any one of isophorone diamine, boron trifluoride derivatives, imidazoline, thiol, hydrazide, polyamide, monoethanolamine, benzyldimethylamine, lewis acid, tertiary amine, isophorone, imidazole, sulfide, amide, or derivatives thereof.

Further, in the nano-micron supported particle composition, the mass content of the particle forming compound and the curing agent is 10-75%, the mass content of the surfactant is 0.5-20%, preferably, the mass content of the particle forming compound and the curing agent is 45-65%, and the mass content of the surfactant is 2-10%.

Further, the nano-micron supported particle composition also comprises a tackifier, preferably the tackifier is selected from calcium carbonate nanoparticles, silicate nanoparticles or a water-soluble polymer containing polyacrylamide or polyvinyl alcohol, and the viscosity of the nano-micron supported particle composition is preferably 10-60 cPs.

According to another aspect of the present invention, there is provided a nano-micro supported particle formed by curing a nano-micro supported particle composition, the nano-micro supported particle composition being any one of the nano-micro supported particle compositions described above, the nano-micro supported particle having a D50 of 50nm to 100 μm.

Furthermore, the D50 of the nano-micron support particles is 10-95 μm.

Further, the density of the nano-micron support particles is less than or equal to 1.50 g/ml.

According to a further aspect of the present invention, there is provided a hydraulic fracturing method comprising injecting a hydraulic fracturing fluid into a subterranean formation for fracturing, the hydraulic fracturing fluid comprising an emulsion formed from any one of the compositions of nano-micron support particles or any one of the nano-micron support particles described above.

By applying the solution of the present invention, the particle-forming compound and the curing agent in the above composition are mixed together to form the oil phase in an oil/water emulsion, and the "oil" droplets become nano-micro particles with deformability that effectively prevents the nano-micro particles from being crushed when the cracks try to close after the injection is stopped. Because the nano-micron particle supporting composition contains the pH control agent, the pH value of the nano-micron particle supporting composition is over 11.5 by controlling the adding amount of the pH control agent, nano-micron supporting particles from a nano level to a micron level can be obtained, and the D50 is 50 nm-100 mu m, the nano particles in the obtained nano-micron supporting particles can play a role in reducing the fluid loss of fracturing fluid; the micron particles can enter cracks with various sizes including micro cracks or be formed in the cracks with various sizes including the micro cracks, so that the micro cracks and other cracks are fully supported, and the micro crack flow conductivity is remarkably improved under the combined action of the two particles, so that the crude oil yield is improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic diagram showing a mixed primary proppant of nano-micron proppant particles;

FIG. 2 shows an image of the nano-micron support particles obtained in example 1;

FIG. 3 shows a graph of the size distribution of the nano-micron support particles obtained in example 1;

FIG. 4 shows an image of the nano-micron support particles obtained in example 2;

fig. 5 shows the size distribution diagrams of the spherical particles obtained in comparative examples 1 to 4.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As analyzed in the background of the present application, the present application provides a nano-micro proppant particle composition, a nano-micro proppant particle, and a hydraulic fracturing method, in order to solve the problem that a liquid composition for forming spherical beads in the prior art is difficult to form spherical beads in situ in a fracture or that previously formed spherical beads are difficult to reach a micro fracture, and thus the liquid composition is difficult to exert a sufficient propping effect on the fracture.

In an exemplary embodiment of the present application, a nano-micro supported particle composition is provided, the nano-micro supported particle composition comprising a liquid solvent, at least one surfactant, a particle forming compound, at least one curing agent, and a pH control agent, the pH of the nano-micro supported particle composition being above 11.5.

The particle-forming compound and the curing agent in the above composition are mixed together to form an oil phase in an oil/water emulsion, and the "oil" droplets become nano-micro particles with deformability that effectively prevents the nano-micro particles from being crushed when the cracks attempt to close after the injection is stopped. Because the nano-micron particle supporting composition contains the pH control agent, the pH value of the nano-micron particle supporting composition is over 11.5 by controlling the adding amount of the pH control agent, nano-micron supporting particles from a nano level to a micron level can be obtained, and the D50 is 50 nm-100 mu m, the nano particles in the obtained nano-micron supporting particles can play a role in reducing the fluid loss of fracturing fluid; the micron particles can enter cracks with various sizes including micro cracks or be formed in the cracks with various sizes including the micro cracks, so that the micro cracks and other cracks are fully supported, and the micro crack flow conductivity is remarkably improved under the combined action of the two particles, so that the crude oil yield is improved.

The pH controlling agent used in the present application is mainly for adjusting the pH of the nano-micro support particle composition, and any base capable of pH adjustment may be considered as applicable to the present application as long as it does not affect the particle formation, and in order to simplify the composition system of the nano-micro support particle composition of the present application to make it more stable and save the cost, it is preferable that the pH controlling agent is sodium hydroxide and/or potassium hydroxide.

The components of the particle-forming compounds of the present application can be cured under certain conditions to form deformable particles, and therefore, in the prior art, any of the components of resins, diluents, and the like that are capable of curing at the above pH values are contemplated for use herein, and preferably the particle-forming compounds are selected from the group consisting of resin entities selected from any of the group consisting of aliphatic epoxies, epoxy-functional resins, polyurethane resins, acrylic resins, phenolic resins, and etheraldehyde resins, and diluents selected from any of the group consisting of glycidyl amine epoxies, cycloaliphatic epoxies, anhydrides, bisphenol a diglycidyl ether, polyglycidyl ethers, glycidyl ethers, bisphenol F diglycidyl ether, and combinations thereof.

The surfactant of the present application will distribute at the oil-water interface to stabilize the oil-water emulsion, and the preferred surfactant or combination of surfactants will have chemical properties and HLB values matched to the oil-water system to stabilize the emulsion to form nano-micro particles, and the preferred surfactant may be any one or combination of anionic, cationic, nonionic and amphoteric surfactants.

The liquid solvent used in the present application is mainly for dispersing the particle-forming compound and the curing agent mixture (oil phase) and performing a curing reaction to form particles, and therefore any liquid solvent capable of performing the above-mentioned functions may be considered to be applied to the present application, and preferably, the above-mentioned liquid solvent is selected from water, seawater, a brine solution, an alcohol solvent selected from any one or more of ethanol, propanol and butanol, in order to reduce the cost and improve the compatibility of the system with the fracturing fluid after the composition is cured.

The curing agent functions to accelerate the curing reaction of the particle-forming compound, and therefore, one skilled in the art can select an appropriate curing agent selected from any one of isophorone diamine, boron trifluoride derivatives, imidazoline, thiol, hydrazide, polyamide, monoethanolamine, benzyl dimethylamine, lewis acid, tertiary amine, isophorone, imidazole, sulfide, amide, or derivatives thereof, depending on the composition of the particle-forming compound.

In order to further improve the mechanical strength of the particles formed by the nano-micron supported particle composition, the nano-micron supported particle composition preferably contains 10 to 75% by mass of the particle forming compound and the curing agent and 0.5 to 20% by mass of the surfactant, and the nano-micron supported particle composition preferably contains 45 to 65% by mass of the particle forming compound and the curing agent and 2 to 10% by mass of the surfactant.

In order to further control the particle size formed, the nano-micron supported particle composition preferably further comprises an adhesion promoter, preferably the adhesion promoter is selected from calcium carbonate nanoparticles, silicate nanoparticles or a water-soluble polymer containing polyacrylamide or polyvinyl alcohol, and the viscosity of the nano-micron supported particle composition is preferably 10 to 60 cPs. The viscosity of the composition is adjusted by the tackifier to reduce the collision probability of oil droplet particles, thereby reducing the size of generated particles.

In another exemplary embodiment of the present application, there is provided a nano-micro supported particle formed by curing a nano-micro supported particle composition, the nano-micro supported particle composition being any one of the nano-micro supported particle compositions described above, the nano-micro supported particle having a D50 of 50nm to 100 μm.

The particle-forming compound and the curing agent in the above composition are mixed together to form an oil phase in an oil/water emulsion, and the "oil" droplets become nano-micro particles after curing. Because the nano-micron particle supporting composition contains the pH control agent, the pH value of the nano-micron particle supporting composition is over 11.5 by controlling the adding amount of the pH control agent, nano-micron supporting particles from a nano level to a micron level can be obtained, and D50 is 50 nm-100 mu m, the nano-particles in the obtained nano-micron supporting particles can play a role in reducing the fluid loss of fracturing fluid; the micron particles can enter cracks with various sizes including micro cracks or be formed in the cracks with various sizes including the micro cracks, so that the micro cracks and other cracks are fully supported, and the micro crack flow conductivity is remarkably improved under the combined action of the two particles, so that the crude oil yield is improved.

The nano-micron particle composition can be used as a fracturing fluid component to form nano-micron support particles in situ in a fracture, and the prepared nano-micron support particles can be added into the fracturing fluid to increase the conductivity of nano-sized and micro-sized fractures, be used for keeping the micro-fractures open to supplement the function of a main proppant (shown in figure 1) and be used as a fluid loss additive.

Curing as understood in the art, the components of the composition are mixed, for example, for 3 to 15 minutes, to form an oil/water emulsion which is then left undisturbed in a water bath at 30 to 150 ℃ for 5 to 200 minutes to form the nano-micron support particles.

In one embodiment, they are mixed together for about 10 minutes. In one embodiment, the temperature is 60 ℃. In one embodiment, the emulsion is allowed to stand in the water bath for 60 minutes.

In order to improve the transportability of the nano-micron support particles in hydraulic fracturing application so as to reach a predetermined position and have high support force, the D50 of the nano-micron support particles is preferably 10-95 μm, and the density of the nano-micron support particles is preferably less than or equal to 1.50 g/ml. Optimization of the diameter of the nano-micron support particles reduces the resistance that may be encountered in their transport, while the low density allows the nano-micron support particles to be transported far in hydraulic fracturing at low settling rates.

In another exemplary embodiment of the present application, a hydraulic fracturing method is provided, the hydraulic fracturing method comprising injecting a hydraulic fracturing fluid into a subterranean formation for fracturing, the hydraulic fracturing fluid comprising an emulsion formed from a composition of nano-micron support particles of any of the above or nano-micron support particles of any of the above.

The particle-forming compound and the curing agent in the above composition are mixed together to form an oil phase in an oil/water emulsion, and the "oil" droplets become nano-micro particles with deformability that effectively prevents the nano-micro particles from being crushed when the cracks attempt to close after the injection is stopped. Because the nano-micron particle supporting composition contains the pH control agent, the pH value of the nano-micron particle supporting composition is over 11.5 by controlling the adding amount of the pH control agent, nano-micron supporting particles from a nano level to a micron level can be obtained, and the D50 is 50 nm-100 mu m, the nano particles in the obtained nano-micron supporting particles can play a role in reducing the fluid loss of fracturing fluid; the micron particles can enter cracks with various sizes including micro cracks or be formed in the cracks with various sizes including the micro cracks, so that the micro cracks and other cracks are fully supported, and the micro crack flow conductivity is remarkably improved under the combined action of the two particles, so that the crude oil yield is improved.

The nano-micron particle composition forms emulsion which is added into fracturing fluid and/or filler, so that nano-micron support particles are formed in situ in the fracture, or the nano-micron support particles are added into the filler and/or the fracturing fluid, so that the conductivity of nano and micron fractures is increased, the micro fractures are kept open to supplement the function of a main proppant, and the nano support particles can also play the role of a fluid loss reducer. Thus, the above-described nanoparticle composition or nanoparticle may be used as at least part of a fluid loss additive and at least part of a proppant.

The advantageous effects of the present application will be further described below with reference to examples and comparative examples.

The composition of the composition used to prepare the oil/water emulsion to form the particles is shown in table 1. The components were mixed for 10 minutes to form an emulsion, the pH value thereof was measured, and then allowed to stand in a water bath at 60 ℃ for 1 hour to react to form spherical particles (i.e., nano-micron support particles), the density (absolute density) of which was 1.09 g/ml.

TABLE 1

Wherein the Tween is^TMIs a registered trademark of Croda International plc, Tween^TM20 contains an alkoxy ester and is used as a surfactant.

Hostafrac SF14413 is a product of Clariant Corporation, and includes 10 to 20% by weight of a proprietary component 6615, 10 to 20% by weight of ethoxylated isotridecanol, 1 to 10% by weight of a proprietary component 6715, 1 to 5% by weight of solvent naphtha, and 0.1 to 1% by weight of naphthalene, and is used as a surfactant.

Max CLR^TMIs a trademark of Polymer Composites Corporation. Max CLR^TMA is a modified bisphenol A epoxy resin formulation comprising 90-100% by weight phenol, 4- (1-methylethylidene) bis, a polymer and (methyl chloride) ethylene oxide, 1-5% epoxidized diluent, 0-10% epoxidized modified methyl glyceryl ether, and 0.1-0.5% non-silicone additive.

Max CLR^TMB is an amine modified curing agent comprising about 5 to 15 weight percent benzyl alcohol, 15 to 35 weight percent isophorone associative adduct and 50 to 60 weight percentThe aliphatic amine adduct of (1).

The nano-micron support particles formed in example 1 are shown in fig. 2, and the nano-micron support particles formed in example 2 are shown in fig. 4. The particle size distribution was measured by a Mastersizer 3000 laser particle size analyzer and the results are shown in figure 3. The diameter of the nano-micron support particles formed in example 1 was predominantly distributed between 0.5 μm and 250 μm, and the D50 was 80 μm, as specified in Table 2.

Comparative example 1 resulted in a particle size distribution as shown in figure 5 (pH 9.78), with a particle diameter distribution of predominantly between 40 mesh and 7 mesh (particle size 0.400mm to 2.83mm) and a D50 of about 1.7 mm.

Comparative example 2 gave a particle size distribution as shown in figure 5 (pH 7.84) with a particle diameter distribution of between 40 mesh and 8 mesh (particle size 0.400mm to 2.38mm) and a D50 of about 1.2 mm.

The particle size distributions obtained for comparative examples 3 and 4 are also recorded in figure 5.

The diameter distributions, D50 and density data are shown in table 2.

TABLE 2

From the comparison of the above data, it can be found that the emulsion of the composition forms particles having a larger particle size under acidic conditions, and the particle size decreases as the pH increases, but the particle size increases again after entering the alkaline range; and when the pH value is less than 11.5, D50 increases with the increase of the pH value, but when the pH value exceeds 11.5, D50 does not increase, but decreases to 1mm or less and less than 0.1 mm.

From the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects:

the particle-forming compound and the curing agent in the above composition are mixed together to form an oil phase in an oil/water emulsion, and the "oil" droplets become nano-micro particles with deformability that effectively prevents the nano-micro particles from being crushed when the cracks attempt to close after the injection is stopped. Because the nano-micron particle supporting composition contains the pH control agent, the pH value of the nano-micron particle supporting composition is over 11.5 by controlling the adding amount of the pH control agent, nano-micron supporting particles from a nano level to a micron level can be obtained, and the D50 is 50 nm-100 mu m, the nano particles in the obtained nano-micron supporting particles can play a role in reducing the fluid loss of fracturing fluid; the micron particles can enter or form cracks with various sizes including micro cracks, so that the micro cracks and other cracks are fully supported, and the micro crack flow conductivity is remarkably improved under the combined action of the two particles, so that the crude oil yield is improved.

All of the compositions and methods claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this disclosure have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and methods and in the steps or in the sequence of steps without departing from the concept, spirit and scope of the disclosure. More specifically, it will be apparent that certain agents which are chemically related may be substituted for the agents described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the scope as defined by the appended claims.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.