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Acidic fracturing fluid and preparation method thereof

A fracturing fluid and acidic technology, which is applied in the direction of chemical instruments and methods, drilling compositions, etc., can solve the problems of incomplete gel breaking and poor flowback effect of fracturing fluid, so as to ensure normal penetration and production, improve Viscosity, the effect of avoiding secondary pollution

Inactive Publication Date: 2019-05-07
PETROCHINA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] In order to solve the problems of incomplete gel breaking and poor flowback effect of the fracturing fluid in the prior art, the embodiment of the present invention provides an acidic fracturing fluid, and the technical solution is as follows:

Method used

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  • Acidic fracturing fluid and preparation method thereof
  • Acidic fracturing fluid and preparation method thereof

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preparation example Construction

[0031] In the second aspect, the embodiments of the present invention provide a method for preparing the acidic fracturing fluid provided in the first aspect, specifically, the preparation method includes:

[0032] dissolving cationic surfactant and citric acid in water to prepare the first solution;

[0033] dissolving the aqueous solution of inorganic acid and iron ion stabilizer in water to prepare the second solution;

[0034] The first solution and the second solution are mixed to obtain an acidic fracturing fluid.

[0035] It should be noted that when the fracturing fluid is used, it is necessary to use a sand mixer to mix the fracturing fluid and the proppant, and the components of the fracturing fluid provided in the embodiment of the present invention contain inorganic acids, so in order to avoid The sand mixer is corroded, which affects the normal use of the equipment. When preparing the acidic fracturing fluid, it is divided into the first solution and the second s...

Embodiment 1

[0044] Add 5g of dodecyltrimethylammonium chloride and 0.5g of citric acid into 45ml of water, stir well until the citric acid and dodecyltrimethylammonium chloride dissolve, and obtain the first solution with a viscosity of 20mPa·s ;

[0045] 25ml of mass fraction of 36% analytically pure hydrochloric acid, 0.5g chloride-1-benzylquinoline salt and 1g iron ion stabilizer are dissolved in 25ml water, fully stirred until the iron ion stabilizer dissolves to obtain a viscosity of 5mPa s second solution;

[0046] Pour the first solution into the second solution and mix thoroughly to obtain an acidic fracturing fluid.

[0047] Viscosity testing was performed on the acidic fracturing fluid obtained in Example 1, and its viscosity at room temperature was 35 mPa·s, greater than 20 mPa·s, which could meet the fracturing requirements of oil and gas fields.

[0048] And further, the acidic fracturing fluid provided in Example 1 is tested for rheological properties, and the results are ...

Embodiment 2

[0050] Add 6g of dodecyl dimethyl quaternary ammonium salt and 0.6 g of citric acid into 45ml of water, stir well until the citric acid and alkyl dimethyl quaternary ammonium salt are dissolved to obtain the first solution with a viscosity of 15mPa·s;

[0051] 16ml mass fraction of 36% analytically pure hydrochloric acid and 7ml mass fraction of 40% analytically pure hydrofluoric acid, 0.6g chloride-1-benzylquinoline salt and 1.2g iron ion stabilizer are dissolved in 20ml water, fully stirred Dissolving to iron ion stabilizer, obtains the second solution that viscosity is 5mPa·s;

[0052] Pour the first solution into the second solution and mix thoroughly to obtain an acidic fracturing fluid.

[0053] Viscosity testing was performed on the acidic fracturing fluid obtained in Example 2, and its viscosity at room temperature was 45 mPa·s, greater than 20 Pa·s, which could meet the fracturing requirements of oil and gas fields.

[0054] The acidic fracturing fluid provided by em...

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Abstract

The invention discloses an acidic fracturing fluid and a preparation method thereof, and relates to the technical field of fracturing stimulation of an oil and gas field. The fracturing fluid comprises the following components by mass in terms of the total mass of the fracturing fluid: 3% to 6% of a cationic surfactant, 0.3% to 1% of citric acid, 9.5% to 15% of inorganic acid and 1% to 2% of an iron-ion stabilizer, with the balance being water. The acidic fracturing fluid provided by the invention uses the cationic surfactant as a thickening agent. According to the invention, through formationof a micelle between the citric acid and cationic surfactant molecules with a hydrogen bond, a network structure is further formed, so the viscosity of the acidic fracturing fluid is improved, and the acidic fracturing fluid has sand-carrying performance; meanwhile, the bond energy of the hydrogen bond is relatively uneasy to be destroyed, so the acid fracturing fluid can realize thorough gel breaking when flowing back, and the defect of incomplete gel breaking for a fracturing fluid in the prior art is overcome; thus, the acidic fracturing fluid can be guaranteed to smoothly flow back, so influence on stratum performances and secondary pollution are avoided, and normal infiltration and exploitation of oil and gas are guaranteed.

Description

technical field [0001] The invention relates to the technical field of fracturing stimulation in oil and gas fields, in particular to an acidic fracturing fluid and a preparation method thereof. Background technique [0002] Acid fracturing technology is a stimulation technology for low-permeability and ultra-low-permeability oil and gas reservoirs, which improves the permeability of oil and gas layers by injecting acidic fracturing fluid into oil and gas layers. Generally, the components of acidic fracturing fluid include acid fluid, thickener and crosslinking agent used to make the fracturing fluid have a certain viscosity and sand-carrying ability. When in use, the fracturing fluid and proppant (such as quartz, etc.) are mixed by a sand mixer, and the fracturing fluid mixed with proppant is injected into the oil and gas layer by a fracturing vehicle. Through the dissolution of the formation by the acidic fracturing fluid and the fluid action of the fracturing fluid itsel...

Claims

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Application Information

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IPC IPC(8): C09K8/68C09K8/584
Inventor 余东合张劲车航刘国华陆强民宁萌萌张丽娜李凝
Owner PETROCHINA CO LTD