Repeated fracturing temporary plugging agent and preparation method thereof

A technology of repeated fracturing and temporary plugging agent, applied in chemical instruments and methods, drilling composition and other directions, can solve the problems of difficult dissolution and plugging removal, low recovery rate, unsuitable for medium and low temperature reservoirs, etc. The effect of less product, faster water absorption and expansion, and enhanced mechanical properties

Inactive Publication Date: 2020-02-21
BEIJING DADE GUANGYUAN PETROLEUM TECH SERVICE
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] At present, the temporary plugging agents for fracturing developed by domestic and foreign counterparts in the early stage are generally suitable for reservoirs with high temperature, but not for medium and low temperature reservoirs, mainly because the temporary plugging agents suitable for high temperature reservoirs are used for low temperature reservoirs. After the existing cracks are plugged, it is difficult to dissolve and remove the plugs, resulting in an extremely low recovery rate

Method used

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  • Repeated fracturing temporary plugging agent and preparation method thereof
  • Repeated fracturing temporary plugging agent and preparation method thereof
  • Repeated fracturing temporary plugging agent and preparation method thereof

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Embodiment approach

[0035] According to a preferred embodiment of the present invention, the temporary plugging agent is prepared from the following components by weight:

[0036]

[0037] Preferably, the temporary plugging agent is prepared from the following components by weight:

[0038]

[0039] More preferably, the temporary plugging agent is prepared from the following components by weight:

[0040]

[0041] According to a preferred embodiment of the present invention, the auxiliary monomer is a monomer that can adjust the phase transition temperature of poly-N-isopropylacrylamide.

[0042] In the present invention, in order to improve the temperature sensitivity of the poly-N-isopropylacrylamide polymer, an auxiliary monomer and N-isopropylacrylamide monomer are added for cross-linking, so as to improve the response temperature of the temporary plugging agent, make it suitable for medium and low temperature reservoirs.

[0043] In a further preferred embodiment, the auxiliary mo...

Embodiment 1

[0111] In the preparation raw material of the repeated fracturing temporary plugging agent, the auxiliary monomer is acrylamide, the first crosslinking agent is polyacrylic acid microgel, the first initiator is azobisisobutyronitrile, the catalyst is ammonium sulfite, and the solvent is Deionized water. Among them, the mass of N-isopropylacrylamide monomer is 20g, acrylic monomer is 7g, polyacrylic acid microgel is 5g, azobisisobutyronitrile is 0.2g, ammonium sulfite is 0.4g, deionized water is is 75mL.

[0112] Wherein, polyacrylic acid microgel is prepared according to the following method:

[0113] Weigh 7.2g of acrylic monomer, 0.25g of 2-isopropylthioxanthone and 9.2g of N,N-methylenebisacryloyl in turn, put them in deionized water to mix, then adjust the pH to 1.3, and pass nitrogen for 15min , placed under a 250W high-pressure mercury lamp for 30 minutes, and nitrogen was continuously passed through during the reaction to obtain polyacrylic acid microgels.

[0114] T...

Embodiment 2

[0120] In the preparation raw material of the repeated fracturing temporary plugging agent, the auxiliary monomer is acrylamide, the first crosslinking agent is polyacrylic acid microgel, the first initiator is azobisisobutyronitrile, the catalyst is ammonium sulfite, and the solvent is Deionized water. Among them, the mass of N-isopropylacrylamide monomer is 20g, acrylic monomer is 7g, polyacrylic acid microgel is 5g, azobisisobutyronitrile is 0.1g, ammonium sulfite is 0.4g, deionized water is 80mL.

[0121] Wherein, polyacrylic acid microgel is prepared according to the following method:

[0122] Weigh 7.2g of acrylic monomer, 0.25g of 2-isopropylthioxanthone and 9.2g of N,N-methylenebisacryloyl in turn, put them in deionized water to mix, then adjust the pH to 1.3, and pass nitrogen for 15min , placed under a 250W high-pressure mercury lamp for 30 minutes, and nitrogen was continuously passed through during the reaction to obtain polyacrylic acid microgels.

[0123] The ...

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Abstract

The invention discloses a repeated fracturing temporary plugging agent and a preparation method thereof, wherein the temporary plugging agent is prepared from the following components by weight: 20 parts of an N-isopropylacrylamide monomer, 5-10 parts of an auxiliary monomer, 2-7 parts of a first cross-linking agent, 0.05-0.5 part of a first initiator, 0.1-0.8 part of a catalyst and 50-100 parts of a solvent. According to the invention, the plugging strength and the response temperature of the temporary plugging agent can be remarkably improved through the first cross-linking agent, and the application range of the temporary plugging agent can be widened by adding the auxiliary monomer, so that the temporary plugging agent is suitable for medium-low-temperature reservoirs; and the preparation method has advantages of simple steps, convenience in operation, few reaction byproducts and low requirements on equipment.

Description

technical field [0001] The invention belongs to the technical field of oilfield chemistry, in particular to a temporary plugging agent for repeated fracturing and a preparation method thereof. Background technique [0002] With the increasing demand for crude oil in the international community and the rise in international oil prices, increasing the production of low-permeability oil fields has once again become the focus of research. Currently, hydraulic fracturing is the most commonly used technique for enhancing oil recovery in low-permeability oilfields. With the progress of production and development, hydraulic fractures gradually fail, and there is still a certain amount of oil in the reservoir, which requires refracturing. [0003] In recent years, major oilfields have adopted multi-fracture technology or fracture diversion technology in fracturing construction to increase the stimulation of low-permeability layers and maximize reservoir production. Temporary pluggi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K8/512C08F265/10C08F220/54
CPCC08F265/10C09K8/5083C09K8/512C08F220/54
Inventor 刘亚东孙晓东
Owner BEIJING DADE GUANGYUAN PETROLEUM TECH SERVICE
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