CN110964496B - Fracturing fluid thickening tackifier - Google Patents

Abstract

The invention relates to a fracturing fluid thickening tackifier, which comprises 30 wt% of white oil, 50 wt% of acrylamide monomer, 3 wt% of ethanol, 1.5 wt% of sorbitan fatty acid ester, 0.5 wt% of hexadecyl trimethyl ammonium bromide, 0.5 wt% of suspension stabilizer and 14.5 wt% of water, wherein the suspension stabilizer is composed of Arabic gum and acrylic acid-styrene sodium sulfonate-hydroxyethyl methacrylate. The thickening tackifier disclosed by the invention has the advantages of excellent suspension stability, small required preparation space, low requirement on water quality, good tackifying effect, good sand suspending effect, long retention time, good shearing resistance, high temperature resistance, good salt resistance, wide application range, good compatibility, low construction cost, small influence on environment and wide application prospect.

Description

Fracturing fluid thickening tackifier

Technical Field

The invention relates to a fracturing fluid thickening tackifier, in particular to a thickening tackifier mainly used for preparing a low-cost fracturing fluid system in an oil field fracturing construction process.

Background

Thickening tackifiers are a polymeric adjuvant used to increase the viscosity and modify the rheology of aqueous systems. The apparent viscosity of the system can be obviously increased by adding a little thickening tackifier into the system to be thickened, so that the system can meet the requirement. The method is widely applied to the fields of oil drilling, food industry, agriculture, daily chemical industry, pharmaceutical industry, textile printing and dyeing and the like. Currently, the most widely used synthetic thickening tackifiers are alkali soluble polyacrylic thickening tackifiers. The molecular chain of the thickening tackifier contains a certain amount of carboxyl, and when the thickening tackifier is neutralized by alkali, the thickening tackifier can be quickly converted into a water-soluble transparent viscous body from a low-viscosity dispersion system, and the viscosity of the whole system is suddenly increased. They are characterized by high relative molecular mass, low flow viscosity, good miscibility with various emulsions and water-soluble systems, no biodegradation and obvious thickening effect. The polyacrylate series has the advantages of convenient application, strong thickening capability, good leveling property, low cost and the like, and is developed rapidly in recent years, so that the polyacrylate series becomes the most important synthetic thickening tackifier.

The research on thickening tackifiers at home and abroad has been over forty years old, and the thickening tackifiers are developed from natural polymers to synthetic polymers, so that three types of thickening tackifier systems are mainly formed at present: natural high molecular polymers, biopolymers, and synthetic high molecular polymers.

The natural high molecular polymer mainly comprises vegetable gum and derivatives thereof, and cellulose and derivatives thereof. The vegetable gum comprises guar gum, sesbania gum, fenugreek gum, konjac gum and various vegetable gum derivatives, and mainly comprises galactomannan, because the hydroxyl content on the molecular chain is more, the vegetable gum is easy to form association with water molecules, the vegetable gum stretches and extends in a solution to generate thickening effect, the modified vegetable gum can improve the solubility, temperature resistance and shear resistance of the molecules, and the residue content is reduced, and hydroxypropyl guar gum (HPG) is a modified vegetable gum with wide application.

Cellulose is a nonionic polysaccharide, and under the action of intermolecular hydrogen bonds, the cellulose can only swell but not dissolve in water, and the solubility can be improved by introducing a modifying group into the molecule. Common modified cellulose viscosifying viscosifiers include carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), and carboxymethyl hydroxyethyl cellulose (CMHEC), among others. The modified cellulose polymer has good water solubility, good thermal stability, salt resistance and shear resistance, but the construction friction resistance is high, which is not beneficial to large-scale site construction.

The biopolymer thickening and viscosity increasing agent mainly refers to xanthan gum, also called xanthan gum and xanthan gum, which is microbial polysaccharide produced by fermentation of xanthomonas campestris, has good thickening capability and temperature resistance and shear resistance, is easy to degrade by bacteria and enzyme, and needs to be matched with a bactericide for use.

Compared with natural high molecular polymer, the synthetic high molecular polymer has better temperature resistance and shearing resistance, strong thickening capability, strong sand suspending capability, good gel breaking property, small damage to stratum, insensitivity to bacteria and better performance in all aspects than the natural polymer. At present, many researches on synthetic polymers are carried out at home and abroad, and the main products comprise: acrylamide-based polymers, vinyl polymers, and crosslinked polymers.

Because the international oil price is continuously lowered at present, the development of oil fields faces huge pressure, and the price reduction space of surfactant fracturing fluid researched in two years and guanidine gum fracturing fluid widely used at present is limited, a low-cost fracturing fluid system suitable for a compact oil reservoir needs to be researched so as to meet the development requirement under the condition of low oil price.

Patent document CN104861951A discloses a thickening thickener which is easy to prepare, has a certain salt resistance, rapidly swells when used in a fracturing fluid prepared by mixing with water, has a low demand for prepared water, and does not affect the swelling effect of the thickener even when seawater (containing salt) is used. However, it has been found that the suspension stability of the thickening tackifier is still difficult to meet the high performance standards of the market.

Disclosure of Invention

In order to solve the technical problem that the suspension stability of the thickening tackifier in the prior art still cannot meet the requirement of the high-performance standard of the market, the invention provides the following technical scheme:

a fracturing fluid thickening tackifier comprises 30 wt% of white oil, 50 wt% of acrylamide monomer, 3 wt% of ethanol, 1.5 wt% of sorbitan fatty acid ester, 0.5 wt% of hexadecyl trimethyl ammonium bromide, 0.5 wt% of suspension stabilizer and 14.5 wt% of water.

Preferably, the suspension stabilizer is composed of gum arabic and sodium acrylate-styrene sulfonate-hydroxyethyl methacrylate in a mass ratio of 2: 1.

The invention also provides a preparation method of the fracturing fluid thickening tackifier, which comprises the following steps:

step 1: pouring the white oil into a container, and adding an acrylamide monomer, ethanol and sorbitan fatty acid ester under a stirring state;

step 2: pouring distilled water into a container, adding cetyl trimethyl ammonium bromide under stirring, and adding a suspension stabilizer after full dissolution;

and step 3: and (3) slowly adding the solution obtained in the step (2) into the solution obtained in the step (1) to obtain the fracturing fluid thickening tackifier.

The invention also provides a fracturing fluid which contains the fracturing fluid thickening tackifier.

The invention also provides an application of the fracturing fluid thickening tackifier or the fracturing fluid in an oil field fracturing construction process.

The technical scheme of the invention has the following beneficial effects:

(1) the thickening tackifier disclosed by the invention has the advantages of very good suspension stability, better suspension stability than that of the prior art, small required preparation space, high swelling speed, low requirement on water quality, good tackifying effect, good sand suspension performance, long retention time and wide application prospect.

(2) The thickening tackifier disclosed by the invention has very excellent shear resistance, good high temperature resistance and salt resistance, wide application range, good compatibility and good compounding effect with other fracturing fluid additives.

(3) The thickening tackifier disclosed by the invention is small in using amount, convenient to prepare on site, simple to enter a stratum, capable of saving a large amount of manpower and material resources for site construction, capable of reducing the construction cost, easy to break gel and small in environmental influence.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the following examples and comparative examples.

Example 1

A fracturing fluid thickening tackifier comprises 30 wt% of white oil, 50 wt% of acrylamide monomer, 3 wt% of ethanol, 1.5 wt% of sorbitan fatty acid ester, 0.5 wt% of hexadecyl trimethyl ammonium bromide, 0.5 wt% of suspension stabilizer and 14.5 wt% of water.

Wherein the suspension stabilizer is composed of Arabic gum and acrylic acid-sodium styrene sulfonate-hydroxyethyl methacrylate according to the mass ratio of 2: 1.

The preparation method of the fracturing fluid thickening tackifier comprises the following steps:

step 1: pouring the white oil into a container, and adding an acrylamide monomer, ethanol and sorbitan fatty acid ester under a stirring state;

step 2: pouring distilled water into a container, adding cetyl trimethyl ammonium bromide under stirring, and adding a suspension stabilizer after full dissolution;

and step 3: and (3) slowly adding the solution obtained in the step (2) into the solution obtained in the step (1) to obtain the fracturing fluid thickening tackifier.

The 170 s-viscosity was found to be 85 mPas at room temperature. 100ml of tap water was added with 1g of the fracturing fluid thickening agent, and the mixture was stirred to obtain a 170 s-viscosity of 205 mPas.

Comparative example 1

A fracturing fluid thickening tackifier comprises 30 wt% of white oil, 50 wt% of acrylamide monomer, 3 wt% of ethanol, 1.5 wt% of sorbitan fatty acid ester, 0.5 wt% of hexadecyl trimethyl ammonium bromide, 0.5 wt% of suspension stabilizer and 14.5 wt% of water.

Wherein the suspension stabilizer is composed of Arabic gum and acrylic acid-sodium styrene sulfonate-hydroxyethyl methacrylate according to the mass ratio of 1: 1.

The preparation method of the fracturing fluid thickening tackifier comprises the following steps:

step 1: pouring the white oil into a container, and adding an acrylamide monomer, ethanol and sorbitan fatty acid ester under a stirring state;

step 2: pouring distilled water into a container, adding cetyl trimethyl ammonium bromide under stirring, and adding a suspension stabilizer after full dissolution;

and step 3: and (3) slowly adding the solution obtained in the step (2) into the solution obtained in the step (1) to obtain the fracturing fluid thickening tackifier.

Comparative example 2

A fracturing fluid thickening tackifier comprises 30 wt% of white oil, 50 wt% of acrylamide monomer, 3 wt% of ethanol, 1.5 wt% of sorbitan fatty acid ester, 0.5 wt% of hexadecyl trimethyl ammonium bromide, 0.5 wt% of suspension stabilizer and 14.5 wt% of water.

Wherein the suspension stabilizer is composed of Arabic gum and acrylic acid-sodium styrene sulfonate-hydroxyethyl methacrylate according to the mass ratio of 3: 1.

The preparation method of the fracturing fluid thickening tackifier comprises the following steps:

step 1: pouring the white oil into a container, and adding an acrylamide monomer, ethanol and sorbitan fatty acid ester under a stirring state;

step 2: pouring distilled water into a container, adding cetyl trimethyl ammonium bromide under stirring, and adding a suspension stabilizer after full dissolution;

and step 3: and (3) slowly adding the solution obtained in the step (2) into the solution obtained in the step (1) to obtain the fracturing fluid thickening tackifier.

Comparative example 3

A fracturing fluid thickening tackifier comprises 30 wt% of white oil, 50 wt% of acrylamide monomer, 3 wt% of ethanol, 1.5 wt% of sorbitan fatty acid ester, 0.5 wt% of hexadecyl trimethyl ammonium bromide, 0.5 wt% of suspension stabilizer and 14.5 wt% of water.

Wherein the suspension stabilizer is composed of xanthan gum and acrylic acid-sodium styrene sulfonate-hydroxyethyl methacrylate according to the mass ratio of 2: 1.

The preparation method of the fracturing fluid thickening tackifier comprises the following steps:

step 1: pouring the white oil into a container, and adding an acrylamide monomer, ethanol and sorbitan fatty acid ester under a stirring state;

step 2: pouring distilled water into a container, adding cetyl trimethyl ammonium bromide under stirring, and adding a suspension stabilizer after full dissolution;

and step 3: and (3) slowly adding the solution obtained in the step (2) into the solution obtained in the step (1) to obtain the fracturing fluid thickening tackifier.

Comparative example 4

A fracturing fluid thickening tackifier comprises 30 wt% of white oil, 50 wt% of acrylamide monomer, 3 wt% of ethanol, 1.5 wt% of sorbitan fatty acid ester, 0.5 wt% of hexadecyl trimethyl ammonium bromide, 0.5 wt% of suspension stabilizer and 14.5 wt% of water.

Wherein the suspension stabilizer is composed of Arabic gum and polyester fiber according to the mass ratio of 2: 1.

The preparation method of the fracturing fluid thickening tackifier comprises the following steps:

step 1: pouring the white oil into a container, and adding an acrylamide monomer, ethanol and sorbitan fatty acid ester under a stirring state;

step 2: pouring distilled water into a container, adding cetyl trimethyl ammonium bromide under stirring, and adding a suspension stabilizer after full dissolution;

and step 3: and (3) slowly adding the solution obtained in the step (2) into the solution obtained in the step (1) to obtain the fracturing fluid thickening tackifier.

Comparative example 5

A fracturing fluid thickening tackifier comprises 30 wt% of white oil, 50 wt% of acrylamide monomer, 3 wt% of ethanol, 1.5 wt% of sorbitan fatty acid ester, 0.5 wt% of hexadecyl trimethyl ammonium bromide, 0.5 wt% of suspension stabilizer and 14.5 wt% of water.

Wherein the suspension stabilizer is Arabic gum.

The preparation method of the fracturing fluid thickening tackifier comprises the following steps:

step 1: pouring the white oil into a container, and adding an acrylamide monomer, ethanol and sorbitan fatty acid ester under a stirring state;

step 2: pouring distilled water into a container, adding cetyl trimethyl ammonium bromide under stirring, and adding a suspension stabilizer after full dissolution;

and step 3: and (3) slowly adding the solution obtained in the step (2) into the solution obtained in the step (1) to obtain the fracturing fluid thickening tackifier.

Comparative example 6

A fracturing fluid thickening tackifier comprises 30 wt% of white oil, 50 wt% of acrylamide monomer, 3 wt% of ethanol, 1.5 wt% of sorbitan fatty acid ester, 0.5 wt% of hexadecyl trimethyl ammonium bromide, 0.5 wt% of suspension stabilizer and 14.5 wt% of water.

Wherein the suspension stabilizer is acrylic acid-sodium styrene sulfonate-hydroxyethyl methacrylate.

The preparation method of the fracturing fluid thickening tackifier comprises the following steps:

step 1: pouring the white oil into a container, and adding an acrylamide monomer, ethanol and sorbitan fatty acid ester under a stirring state;

step 2: pouring distilled water into a container, adding cetyl trimethyl ammonium bromide under stirring, and adding a suspension stabilizer after full dissolution;

and step 3: and (3) slowly adding the solution obtained in the step (2) into the solution obtained in the step (1) to obtain the fracturing fluid thickening tackifier.

The following table details the composition of the suspension stabilizer in example 1 and comparative examples 1 to 6.

The following table also reports the results of the test conducted on the suspension stability of the fracturing fluid thickening tackifiers of example 1 and comparative examples 1-6.

Numbering	Standing for 6 months	Standing for 8 months
			Example 1	Not delaminating	Not delaminating
Comparative example 1	Not delaminating	Demixing, separating oil 1.0%
			Comparative example 2	Not delaminating	Demixing, separating oil 0.6%
Comparative example 3	Demixing, separating oil 0.8%	-
			Comparative example 4	Demixing, separating oil 0.5%	-
Comparative example 5	Demixing, separating oil 1.1%	-
			Comparative example 6	Demixing, separating oil 1.4%	-

The above results show that: (1) as can be seen from the comparison of example 1 with comparative examples 5 and 6, the use of gum arabic or sodium acrylate-styrene sulfonate-hydroxyethyl methacrylate as a suspension stabilizer alone did not significantly improve the suspension stability of the thickening tackifier; (2) as can be seen from the comparison of example 1 with comparative examples 3 and 4, not any combination of the vegetable gum type suspension stabilizer and the polyester type suspension stabilizer contributes to satisfactory suspension stability of the thickening and viscosity-increasing agent, such as xanthan gum and polyester fiber; (3) as can be seen from the comparison of example 1 with comparative examples 1 and 2, not within any range of ratios of gum arabic to sodium styrene sulfonate-hydroxyethyl methacrylate can provide the optimum suspension stability for the thickening tackifier, e.g., 1:1 and 3: 1; (4) as the suspension stabilizing effect of the suspension stabilizer depends on the system composition and has certain specificity and uncertainty, the invention discovers that the suspension stability of the thickening tackifier reaches the optimal state and can be stored for a long time when the suspension stabilizer is selected from a compound of Arabic gum and acrylic acid-sodium styrene sulfonate-hydroxyethyl methacrylate within a specific ratio range (2: 1).

Claims (4)

1. The fracturing fluid thickening tackifier is characterized by comprising 30 wt% of white oil, 50 wt% of acrylamide monomer, 3 wt% of ethanol, 1.5 wt% of sorbitan fatty acid ester, 0.5 wt% of hexadecyl trimethyl ammonium bromide, 0.5 wt% of suspension stabilizer and 14.5 wt% of water, wherein the suspension stabilizer is composed of Arabic gum and acrylic acid-sodium styrene sulfonate-hydroxyethyl methacrylate;

in the suspension stabilizer, the mass ratio of Arabic gum to acrylic acid-sodium styrene sulfonate-hydroxyethyl methacrylate is 2: 1.

2. A method of preparing the fracturing fluid thickening viscosifier of claim 1, comprising the steps of:

step 1: pouring the white oil into a container, and adding an acrylamide monomer, ethanol and sorbitan fatty acid ester under a stirring state;

step 2: pouring distilled water into a container, adding cetyl trimethyl ammonium bromide under stirring, and adding a suspension stabilizer after full dissolution;

and step 3: and (3) slowly adding the solution obtained in the step (2) into the solution obtained in the step (1) to obtain the fracturing fluid thickening tackifier.

3. A fracturing fluid comprising the fracturing fluid thickening agent of claim 1.

4. Use of the fracturing fluid thickening viscosifying agent of claim 1 or the fracturing fluid of claim 3 in an oil field fracturing construction process.