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Cross-linking agent for reconstructed wellbore fracturing as well as preparation method and application of cross-linking agent

A cross-linking agent and fracturing technology, which is applied in the direction of chemical instruments and methods, drilling compositions, etc., can solve the problems of small perforation hole diameter, large leakage, and difficulty in adding sand to reduce guanidine Glue use concentration, reduce the use concentration, reduce the effect of residue content

Pending Publication Date: 2022-02-11
中石化石油工程技术服务有限公司 +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In reconstruction wellbore fracturing, there are many fractures near the wellbore and large leakage, and it is difficult to add sand, so high-viscosity fluid is required to control fractures. The frictional resistance is high. If the fracturing fluid is cross-linked on the ground or during the pumping process, the frictional resistance will be too large, it will be difficult to pump, and even damage the equipment. Therefore, the fracturing fluid needs to have the property of delaying cross-linking
[0005] At the same time, the residue content in the guar gum fracturing fluid is relatively high, and the use of high-concentration guar gum is likely to cause reservoir damage to the matrix permeability and fractures, which will affect the stimulation effect. In order to reduce the residue content, one way is to carry out hydroxypropyl guar gum Improvement to increase the purity of guar gum, but the cost of the improved guar gum is higher; another way is to reduce the concentration of guar gum and reduce the residue content through high-efficiency crosslinking agents

Method used

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  • Cross-linking agent for reconstructed wellbore fracturing as well as preparation method and application of cross-linking agent
  • Cross-linking agent for reconstructed wellbore fracturing as well as preparation method and application of cross-linking agent
  • Cross-linking agent for reconstructed wellbore fracturing as well as preparation method and application of cross-linking agent

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] 1. Preparation of cross-linking agent

[0044] (1) In a three-neck flask equipped with a stirrer, a reflux condenser and a constant pressure dropping funnel, add 100ml of water and 15ml of ethylene glycol, and stir evenly to obtain the first mixture.

[0045] (2) Heat the first mixture to 40° C. in a water bath, adjust the rotation speed to 100 r / min, add 15 g of boric acid and 20 ml of 15% sodium carbonate solution with stirring, and stir for 3 hours to obtain the second mixture.

[0046] (3) After the second mixture was stirred evenly, the temperature was raised to 80° C., the rotational speed was adjusted to 200 r / min, 20 g of sodium gluconate was added, and after stirring for 3 hours, it was cooled to room temperature to obtain a transparent liquid as a crosslinking agent.

[0047] In the above preparation method, the polyol is ethylene glycol, boric acid is used as the boron compound to provide borate ions, the alkali solution is 15% sodium carbonate solution, and ...

Embodiment 2

[0055] 1. Preparation of cross-linking agent

[0056] (1) In a three-neck flask equipped with a stirrer, a reflux condenser and a constant pressure dropping funnel, add 100ml of water and 20ml of glycerol, and stir evenly to obtain the first mixture.

[0057] (2) Heat the first mixture to 45°C in a water bath, adjust the rotation speed to 120r / min, add 20g of sodium tetraborate and 15ml of sodium hydroxide solution with a mass fraction of 10% under stirring conditions, and stir for 3h to obtain the first Two mixtures.

[0058] (3) After the second mixture was stirred evenly, the temperature was raised to 80° C., the rotational speed was adjusted to 200 r / min, 20 g of triethanolamine was added, stirred for 3 hours, and then cooled to room temperature to obtain a transparent liquid as a crosslinking agent.

[0059] In the above preparation method, the polyol is glycerol, the boron compound uses borax to provide borate ions; the alkali solution is 10% sodium hydroxide solution, ...

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Abstract

The invention aims to provide a cross-linking agent for reconstructed wellbore fracturing, belonging to the technical field of petroleum and natural gas yield increase. The cross-linking agent is prepared by mutual reaction of a boron compound, polyhydric alcohol and organic ligand, wherein the boron compound is one or two selected from borax and boric acid, the polyol is one or more than one selected from ethylene glycol, glycerol, n-butyl alcohol and amyl alcohol, and the organic ligand is one or more than one selected from mannitol, sodium gluconate, lactic acid, citric acid and triethanolamine. The invention further discloses a guar gum fracturing fluid. The cross-linking agent for reconstructed wellbore fracturing can achieve delayed cross-linking, and cross-linking time is adjustable; and the use amount of guar gum is reduced, the temperature resistance and shear resistance of the guar gum fracturing fluid are improved, the residue content is reduced, and reservoir damage is reduced.

Description

technical field [0001] The invention belongs to the technical field of increasing production of oil and natural gas, and in particular relates to a crosslinking agent for reconstruction of wellbore fracturing, a preparation method and application thereof. Background technique [0002] In recent years, my country's energy consumption structure has been continuously optimized, and natural gas, as a clean energy source, has become the main growth point of my country's energy structure adjustment and the main force of low-carbon transformation. Unconventional natural gas reserves such as shale gas and coalbed methane are abundant and have broad development prospects. [0003] The Fuling shale gas field entered the stage of commercial development in 2013. The second-generation fracturing technology was mainly adopted in the early stage, and the development mode was "multi-stage and few cluster perforation + slug sand addition" fracturing technology. The remarkable effect of the ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K8/68C09K8/88
CPCC09K8/685C09K8/887
Inventor 袁发勇豆瑞杰闫秀钟涛李强
Owner 中石化石油工程技术服务有限公司
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