RU2746499C1 - Viscoelastic composition for use in oil and gas production techniques - Google Patents

Abstract

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: proposed invention relates to oil and gas industry, in particular, to thickened water-based compositions for performance of technological operations, such as hydraulic fracturing of formation, directed acid treatment, limitation of water influxes, well killing, and so forth. Viscoelastic composition for use in oil and gas production technologies includes a zwitterionic surfactant, an inorganic water-soluble salt or a combination of inorganic water-soluble salts and water. Additionally, it contains alkanolamine and can contain trivalent metal organic salt, which is represented by chromium acetate, and salts of trivalent metals are used as inorganic water-soluble salts: aluminium (III) chloride or iron (III) chloride, and monovalent metal salts, such as sodium chloride, or potassium chloride, or sodium nitrate, and/or bivalent metals - calcium chloride, can be used, or magnesium chloride, or calcium nitrate, or a mixture of monovalent and/or divalent metal salts. Alkanolamine used is monoethanolamine, or diethanolamine, or triethanolamine, or dimethylethanolamine, or a mixture thereof. Composition is used at following ratio of components, wt. %: Neftenol VUPAV Zwitter-ionic surfactant 1.0–5.0; aluminium (III) chloride, or iron (III) chloride, or chrome (III) acetate 0.01–0.5; sodium chloride, or potassium chloride, or sodium nitrate, or mixture thereof 0.0–20.0; calcium chloride, or magnesium chloride, or calcium nitrate, or mixture thereof 0.0–40.0; monoethanolamine, or diethanolamine, or triethanolamine, or dimethylethanolamine, or mixture thereof 0.01–0.5; fresh water is the balance.

EFFECT: technical result is obtaining more viscous systems with lower concentration of surfactants, which significantly reduces consumption of reagents during process operations on wells.

1 cl, 2 tbl, 7 ex

Description

The viscoelastic composition refers to the oil and gas industry, in particular to water-based thickened compositions for performing technological operations, such as hydraulic fracturing, directional acid treatments, limiting water inflows, killing wells, etc.

Widespread process fluids, for example, for hydraulic fracturing, are mainly aqueous solutions of polymers such as guar gum, hydroxypropyl guar, biopolymers, etc. During hydraulic fracturing operations, such fluids based on polymers are subject to destruction under the action of various destructive reagents. peroxide type.

However, the presence of peroxide-type destructors in the composition of the polymer fracture fluid does not exclude the fact that residues of the undisturbed polymer composition will remain in the treated formation, which in turn leads to a deterioration of the reservoir properties and the resulting cracks.

Well-proven compositions based on surfactants (surfactant) for hydraulic fracturing, which minimize the problems arising from the use of polymer gels. Known composition for hydraulic fracturing, which includes a viscoelastic surfactant based on quaternary amines with a solvent, viscosity enhancer - sodium salicylate, organic destructor - urea or thiourea and water. The thickening composition is the following ratio of components,% wt. [one]:

Surfactants (quaternary amines) 35.0-50.0 viscosity enhancer (sodium salicylate) 3.0-9.5 destructor (urea or thiourea) 0.3-0.6 surfactant solvent - the rest,

moreover, the mass ratio of the specified composition and water in the viscoelastic process fluid is 1: (1.6 ÷ 30), respectively.

The disadvantages of the presented composition based on surfactants are that the composition contains additives that can lead to an increase in the price of the product, for example, sodium salicylate, and also high concentrations of surfactants are used (3.2-38.5% by weight).

The closest to the proposed invention in terms of technical essence is a composition for hydraulic fracturing containing a surfactant, which is a zwitterionic / ampholytic surfactant, such as dihydroxylalkylglycinates, alkylamphoacetate or propionate, alkylbetaine, alkylamidopropylbetaine and alkylamino mono - or dipropropyl some waxes, fats and oils. Surfactants are used in combination with an inorganic water-soluble salt or organic additive such as phthalic acid, salicylic acid or their salts, in the following ratio of components, wt%. [2]:

zwitterionic surfactant 0.5-10.0 water-soluble inorganic salts mono-, di- and trivalent metals, or mixtures thereof 0.1-30.0 phthalic or salicylic acids and their salts 0.1-10.0 water - the rest.

The disadvantages of this composition based on surfactants is that this composition possesses the necessary rheological properties only at high surfactant concentrations, as well as the fact that the composition includes additives of expensive aromatic dicarboxylic acids.

The invention is directed to the creation of a viscoelastic composition, which includes a zwitterionic (ampholytic) surfactant, a water-soluble salt of a trivalent metal, and may contain an inorganic salt of a monovalent metal and / or divalent metal or a combination thereof, fresh water, and additionally contains a structurant - alkanolamine, which makes it possible to obtain more viscous systems with a lower concentration of surfactants.

The features of the invention "Composition of a viscoelastic composition for use in oil and gas production technologies" are:

1. A viscoelastic composition comprising a surfactant, a water-soluble inorganic salt of a monovalent or divalent metal, or a mixture thereof, a water-soluble salt of a trivalent metal, and water.

2. A zwitterionic (ampholytic) surfactant "Neftenol VUPAV", consisting mainly of oleylamidopropyl betaine, is used as a surfactant.

3. As a water-soluble inorganic salt of a monovalent metal, sodium chloride or potassium chloride, or sodium nitrate, or a mixture thereof, are used.

4. The water-soluble inorganic salt of the divalent metal is calcium chloride or magnesium chloride, or calcium nitrate, or a mixture thereof.

5. As the water-soluble trivalent metal salt, inorganic aluminum or iron salts such as aluminum chloride or ferric chloride are used.

6. Chromium acetate is used as the water-soluble trivalent metal salt.

7. An alkanolamine is used as a structurant, namely: monoethanolamine or diethanolamine, or triethanolamine, or dimethylethanolamine, or a mixture thereof.

Features 1-5 are common with the prototype, and features 6-7 are essential distinctive features of the invention.

SUMMARY OF THE INVENTION

A viscoelastic composition is proposed that includes a zwitterionic surfactant, an inorganic water-soluble salt or a combination of inorganic water-soluble salts and water, which additionally contains an alkanolamine and may contain an organic salt of a trivalent metal, which is used as chromium acetate, and as inorganic water-soluble salts are used trivalent metal salts: aluminum (III) chloride or iron (III) chloride, and monovalent metal salts such as sodium chloride or potassium chloride or sodium nitrate and / or divalent metal salts can be used - calcium chloride or magnesium chloride or calcium nitrate , or a mixture of salts of monovalent and / or divalent metals, and monoethanolamine or diethanolamine, or triethanolamine, or dimethylethanolamine, or their mixture in the following ratio of components, wt% are used as alkanolamine:

zwitterionic surfactant

"Neftenol VUPAV" 1.0-5.0

aluminum (III) chloride, or iron (III) chloride, or chromium (III) acetate 0.01-0.5 sodium chloride, or potassium chloride, or sodium nitrate, or a mixture of them 0.0-20.0 calcium chloride, or magnesium chloride, or calcium nitrate, or a mixture of them 0.0-40.0 monoethanolamine, or diethanolamine, or triethanolamine, or dimethylethanolamine, or a mixture thereof 0.01-0.5 fresh water - the rest.

For research used:

1. "Neftenol VUPAV" - is a water-alcohol solution of ampholytic surfactants, mobile liquid from yellow to brown. Produced according to TU 2483-209-54651030-2016.

2. Sodium chloride - white crystalline powder, the content of the basic substance is not less than 99.8% of the mass. Produced in accordance with GOST 4233-77.

3. Potassium chloride is a white crystalline substance, odorless. Produced in accordance with GOST 4568-95.

4. Sodium nitrate is a white crystalline powder with a grayish or yellowish tint, containing at least 99.5-99.8% of the mass. the main substance. Produced in accordance with GOST 828-77.

5. Calcium chloride - white powder or granules, the content of the main substance is not less than 90-96.5% of the mass. Produced in accordance with GOST 450-77.

6. Magnesium chloride - powder, granules or flakes from white to light gray with shades from yellowish to light brown, the content of the main substance is not less than 97% of the mass. Produced in accordance with GOST R 55067-2012.

7. Calcium nitrate is a colorless crystalline powder. 4-aqueous calcium nitrate is produced in accordance with GOST 4142-77 with a basic substance content of at least 98.0-99.0% of the mass.

8. Chloride of aluminum (III) - represents crystals from white to yellow color of 6-aqueous aluminum chloride. 6-aqueous aluminum chloride is produced in accordance with GOST 3759-75 with a basic substance content of at least 96.0-97.0%) mass.

9. Chloride of iron (III) - is a soft crystalline mass or pieces of yellow-brown color of 6-aqueous chloride of iron (III). 6-aqueous iron (III) chloride is produced in accordance with GOST 4147-74.

10. Acetate of chromium (III) - is a viscous liquid from green to dark green, containing at least 30.0% of the mass. the main substance, produced according to TU 0254-031-17197708-96.

11. Monoethanolamine is a colorless or yellowish transparent liquid without mechanical impurities, containing at least 97.0% of the mass. the main substance. Produced according to TU 2423-002-78722668-2010.

12. Diethanolamine is a viscous transparent liquid from colorless to yellow without mechanical impurities, containing at least 97.0% of the mass. the main substance. Produced according to TU 2423-003-78722668-2010.

13. Triethanolamine is a colorless viscous hygroscopic liquid with a specific amine odor, containing at least 90.0% of the mass. the main substance. Produced according to TU 2423-168-00203335-2007.

14. Dimethylethanolamine is a clear oily liquid from colorless to yellow without mechanical impurities, containing at least 99.3% of the mass. the main substance, produced according to TU 2423-004-78722668-2010.

15. Fresh water.

Examples of the preparation of compositions of a viscoelastic composition based on surfactants

Example 1

98.45 g of fresh water is placed in a 250 ml glass beaker. Then, while stirring on a paddle mixer (450-500 rpm), 0.5 g of aluminum (III) chloride, 0.05 g of monoethanolamine and 1.0 g of "Neftenol VES" are sequentially introduced into a glass with water.

After stirring for 10-15 minutes at a paddle mixer rotation speed of 300-350 rpm, the composition is kept under static conditions for 15-20 minutes to remove the bulk of the bubbles in the volume. As a result, a composition is obtained with the following content of components, wt%: "Neftenol VUPAV" - 1.0; aluminum (III) chloride - 0.5; monoethanolamine - 0.05; fresh water is the rest.

Example 2

57.965 g of fresh water is placed in a 250 ml glass beaker. Then, while stirring on a paddle mixer (450-500 rpm), 40.0 g of calcium chloride, 0.015 g of aluminum (III) chloride, 0.02 g of diethanolamine and 2.0 g of "Neftenol VES" are sequentially introduced into a glass of water.

After stirring for 10-15 minutes at a paddle mixer rotation speed of 300-350 rpm, the composition is kept under static conditions for 15-20 minutes to remove the bulk of the bubbles in the volume. As a result, a composition is obtained with the following content of components, wt%: "Neftenol VUPAV" - 2.0; calcium chloride - 40.0; aluminum (III) chloride - 0.015; diethanolamine - 0.02; fresh water is the rest.

Example 3

94.48 g of fresh water is placed in a 250 ml glass beaker. Then, while stirring on a paddle mixer (450-500 rpm), 1.0 g of potassium chloride, 1.0 g of sodium chloride, 0.25 g of calcium chloride, 0.25 g of magnesium chloride, 0, 01 g of iron (III) chloride, 0.005 g of monoethanolamine, 0.005 g of diethanolamine and 3.0 g of "Neftenol VES".

After stirring for 10-15 minutes at a paddle mixer rotation speed of 300-350 rpm, the composition is kept under static conditions for 15-20 minutes to remove the bulk of the bubbles in the volume. As a result, a composition is obtained with the following content of components, wt%: "Neftenol VUPAV" - 3.0; potassium chloride - 1.0; sodium chloride - 1.0; calcium chloride - 0.25; magnesium chloride - 0.25; iron (III) chloride - 0.01; monoethanolamine - 0.005; diethanolamine - 0.005; fresh water is the rest.

Example 4

96.94 g of fresh water is placed in a 250 ml glass beaker. Then, while stirring on a paddle mixer (450-500 rpm), 0.03 g of iron (III) chloride, 0.03 g of dimethylethanolamine and 3.0 g of "Neftenol VES" are sequentially introduced into a glass with water.

After stirring for 10-15 minutes at a paddle mixer rotation speed of 300-350 rpm, the composition is kept under static conditions for 15-20 minutes to remove the bulk of the bubbles in the volume. As a result, a composition is obtained with the following content of components, wt%: "Neftenol VUPAV" - 3.0; iron (III) chloride - 0.03; dimethylethanolamine - 0.03; fresh water is the rest.

Example 5

75.98 g of fresh water is placed in a 250 ml glass beaker. Then, while stirring on a paddle mixer (450-500 rpm), 20.0 g of sodium chloride, 0.01 g of aluminum (III) chloride, 0.01 g of monoethanolamine and 4.0 g of Neftenol VES ".

After stirring for 10-15 minutes at a paddle mixer rotation speed of 300-350 rpm, the composition is kept under static conditions for 15-20 minutes to remove the bulk of the bubbles in the volume. As a result, a composition is obtained with the following content of components, wt%: "Neftenol VUPAV" - 4.0; sodium chloride - 20.0; aluminum (III) chloride - 0.01; monoethanolamine - 0.01; fresh water is the rest.

Example 6

53.50 g of fresh water are placed in a 250 ml glass beaker. Then, while stirring on a paddle mixer (450-500 rpm), 0.5 g of sodium nitrate, 40.0 g of calcium nitrate, 0.5 g of chromium acetate, 0.2 g of monoethanolamine, 0.2 g diethanolamine, 0.1 g triethanolamine and 5.0 g "Neftenol VES".

After stirring for 10-15 minutes at a paddle mixer rotation speed of 300-350 rpm, the composition is kept under static conditions for 15-20 minutes to remove the bulk of the bubbles in the volume. As a result, a composition is obtained with the following content of components, wt%: "Neftenol VUPAV" - 5.0; sodium nitrate - 0.5; calcium nitrate - 40.0; chromium acetate - 0.5; monoethanolamine - 0.2; diethanolamine - 0.2; triethanolamine - 0.1; fresh water is the rest.

Example 7 (prototype)

91.5 g of fresh water are placed in a 250 ml glass beaker. Then, while stirring on a paddle mixer (450-500 rpm), 3.0 g of potassium chloride, 0.5 g of phthalic acid and 5.0 g of oleylamidopropyl betaine are sequentially introduced into a glass of water.

After stirring for 10-15 minutes at a paddle mixer rotation speed of 300-350 rpm, the composition is kept under static conditions for 15-20 minutes to remove the bulk of the bubbles in the volume. As a result, a composition was obtained with the following content of ingredients, wt%: oleylamidopropyl betaine - 5.0; potassium chloride - 3.0; phthalic acid - 0.5; fresh water is the rest.

The compositions of the viscoelastic composition based on surfactants are presented in Table 1.

In laboratory conditions, the effective viscosity (at a shear rate of 100 s ^-1 ) of the compositions presented in table 1 was determined.

The effective viscosity was determined on a "Rheotest" rotary viscometer using a cylindrical measuring system according to the instructions for the device.

As follows from tables 1-2, the proposed composition, with the same surfactant content (composition No. 6), has a much higher viscosity (more than 1.85 times) compared to the prototype and retains high viscosity with a significantly lower surfactant content (1 , 0-4.0%, compositions No. 1-5) than that of the prototype, which will significantly reduce the consumption of reagents during technological operations on wells.

Sources of information taken into account

1. Pat. 5979555 US, E21B 43/26. Surfactants for hydraulic fractoring compositions / James F. Gadberry, Michael D. Hoey (Amhem, Netherlands, Akzo Nobel NV). 12/02/1997 - analogue.

2. RF patent No. 2198906, C09K 7/02 (2000.01). Priority from 10.06.1997. Published on February 20, 2003. Bul. # 5 - prototype.

Claims (2)

A viscoelastic composition for use in oil and gas production technologies, including a zwitterionic surfactant, an inorganic water-soluble salt or a combination of inorganic water-soluble salts and water, characterized in that it additionally contains an alkanolamine and may contain an organic salt of a trivalent metal, which is used as chromium acetate, and trivalent metal salts are used as inorganic water-soluble salts: aluminum (III) chloride or iron (III) chloride, and monovalent metal salts such as sodium chloride or potassium chloride or sodium nitrate and / or bivalent metals - calcium chloride, or magnesium chloride, or calcium nitrate, or a mixture of salts of monovalent and / or divalent metals, and monoethanolamine, or diethanolamine, or triethanolamine, or dimethylethanolamine, or their mixture in the following ratio of components, wt% is used as an alkanolamine: zwitterionic surfactant "Neftenol VUPAV" 1.0-5.0 aluminum (III) chloride, or iron (III) chloride, or chromium (III) acetate 0.01-0.5 sodium chloride, or potassium chloride, or sodium nitrate, or a mixture of them 0.0-20.0 calcium chloride, or magnesium chloride, or calcium nitrate, or a mixture of them 0.0-40.0 monoethanolamine, or diethanolamine, or triethanolamine, or dimethylethanolamine, or a mixture thereof 0.01-0.5 fresh water - the rest