Fracturing prepad fluid

Abstract

The invention discloses a fracturing prepad fluid, comprising the following ingredients: 1-10 wt% of biological enzyme, 0.1-1 wt% of clay stabilizing agent, 0.01-0.1 wt% of fluorocarbon surfactant, 0.01-0.5 wt% of wettability reversal agent, 0.01-1 wt% of composite activator, and the balance of water. The fracturing prepad fluid disclosed herein not only overcomes the disadvantages of routine prepad fluids and has the advantage of fracture forming of routine prepad fluids, but also has the effects of peeling off residual oil on the surface of a rock core, cleaning and unblocking oil gas seepage channels, reducing the viscosity of crude oil, changing the wetability of the rock core, reducing the surface and interfacial tension to benefit for flowback, and preventing the clay from expansionand migration, and the like. The more the fracturing prepad fluid enters a reservoir, the larger the spread range is, and the larger the action scopes of the fracturing prepad fluid on cleaning and unblocking of the oil gas seepage channels are. The fracturing prepad fluid is beneficial for increasing the oil gas yield.

Description

technical field

[0001] The invention belongs to the technical field of petrochemical industry, and in particular relates to a fracturing pre-fluid. Background technique

[0002] Fracturing is one of the main measures for increasing production of low-permeability and low-pressure oil and gas reservoirs. The fracturing fluid consists of three parts: pre-fluid, sand-carrying fluid and displacement fluid, and their properties are determined by their functions in the fracturing process. In the fracturing process, the pre-fluid before fracturing treatment is the foreign liquid that first enters the formation, and its quality can easily cause damage to the reservoir. Its function is to break the formation and form cracks of a certain geometric size for the subsequent sand-carrying fluid to enter. In addition, in the formation with higher temperature, it can also play a certain cooling effect. The conventional pre-fluid is to add a certain amount of clay anti-swelling agent and d...

Examples

Embodiment 1

[0024] A fracturing prefluid in this embodiment is made by mixing the following raw materials in mass percentage: 1% of biological enzyme, 0.1% of clay stabilizer, 0.001% of fluorocarbon surfactant, 0.01% of wetting reversal agent, compound Active agent 0.01%, the balance is water; The clay stabilizer is anti-swelling agent COP-1, the fluorocarbon surfactant is fluorocarbon alkyl succinate sulfonate, and the wetting reversal agent is Organosilicon surfactant, the composite active agent is formed by mixing nonylphenol polyoxyethylene ether, sodium dodecylsulfonate and sodium lignosulfonate according to the mass ratio of 1:2:1; the biological enzyme The mass content of protein is 10%, the mass content of alcohol dehydrogenase is 35%, and the mass content of xylanase is 20%.

[0025] The preparation method of the fracturing prefluid of this embodiment is as follows: after mixing the raw materials in proportion, they can be stirred evenly.

[0026] The fracturing pad in this embo...

Embodiment 2

[0028] This embodiment is the same as Example 1, except that the clay stabilizer used is tetramethylammonium chloride, or NH 4 Cl and / or KCl; the fluorocarbon surfactant used is polyether quaternary ammonium salt cationic fluorocarbon surfactant or N,N-dihydroxyethyl perfluoroalkylamide; the wetting reversal agent used is C 12 -C 16 Alkyltrimethylammonium chloride; the complex active agent used is mixed with alkylphenol polyoxyethylene ethers, petroleum sulfonates and modified lignin according to the mass ratio of 1:2 to 4:1, wherein the alkane The base phenol polyoxyethylene ether is octylphenol polyoxyethylene ether, the petroleum sulfonate is sodium dodecylsulfonate or sodium dodecylbenzenesulfonate, and the modified lignin is sodium lignosulfonate or Potassium lignosulfonate.

Embodiment 3

[0030] A fracturing pre-fluid in this embodiment is prepared by mixing the following raw materials in mass percentage: biological enzyme 10%, clay stabilizer 1%, fluorocarbon surfactant 0.1%, wetting reversal agent 0.5%, compound Active agent 1%, balance is water; The clay stabilizer is NH 4 Cl and KCl, the fluorocarbon surfactant is a polyether quaternary ammonium salt cationic fluorocarbon surfactant, the wetting reversal agent is dodecyltrimethylammonium chloride, and the composite active agent It is formed by mixing nonylphenol polyoxyethylene ether, sodium dodecylbenzenesulfonate and potassium lignosulfonate according to the mass ratio of 1:4:1; the mass content of protein in the biological enzyme is 25%, ethanol The mass content of dehydrogenase is 25%, and the mass content of xylanase is 10%.

[0031] The preparation method of the fracturing prefluid of this embodiment is as follows: after mixing the raw materials in proportion, they can be stirred evenly.

[0032] Th...

technical field

[0001] The invention belongs to the technical field of petrochemical industry, and in particular relates to a fracturing pre-fluid. Background technique

[0002] Fracturing is one of the main measures for increasing production of low-permeability and low-pressure oil and gas reservoirs. The fracturing fluid consists of three parts: pre-fluid, sand-carrying fluid and displacement fluid, and their properties are determined by their functions in the fracturing process. In the fracturing process, the pre-fluid before fracturing treatment is the foreign liquid that first enters the formation, and its quality can easily cause damage to the reservoir. Its function is to break the formation and form cracks of a certain geometric size for the subsequent sand-carrying fluid to enter. In addition, in the formation with higher temperature, it can also play a certain cooling effect. The conventional pre-fluid is to add a certain amount of clay anti-swelling agent and d...

Examples

Embodiment 1

[0024] A fracturing prefluid in this embodiment is made by mixing the following raw materials in mass percentage: 1% of biological enzyme, 0.1% of clay stabilizer, 0.001% of fluorocarbon surfactant, 0.01% of wetting reversal agent, compound Active agent 0.01%, the balance is water; The clay stabilizer is anti-swelling agent COP-1, the fluorocarbon surfactant is fluorocarbon alkyl succinate sulfonate, and the wetting reversal agent is Organosilicon surfactant, the composite active agent is formed by mixing nonylphenol polyoxyethylene ether, sodium dodecylsulfonate and sodium lignosulfonate according to the mass ratio of 1:2:1; the biological enzyme The mass content of protein is 10%, the mass content of alcohol dehydrogenase is 35%, and the mass content of xylanase is 20%.

[0025] The preparation method of the fracturing prefluid of this embodiment is as follows: after mixing the raw materials in proportion, they can be stirred evenly.

[0026] The fracturing pad in this embo...

Embodiment 2

[0028] This embodiment is the same as Example 1, except that the clay stabilizer used is tetramethylammonium chloride, or NH 4 Cl and / or KCl; the fluorocarbon surfactant used is polyether quaternary ammonium salt cationic fluorocarbon surfactant or N,N-dihydroxyethyl perfluoroalkylamide; the wetting reversal agent used is C 12 -C 16 Alkyltrimethylammonium chloride; the complex active agent used is mixed with alkylphenol polyoxyethylene ethers, petroleum sulfonates and modified lignin according to the mass ratio of 1:2 to 4:1, wherein the alkane The base phenol polyoxyethylene ether is octylphenol polyoxyethylene ether, the petroleum sulfonate is sodium dodecylsulfonate or sodium dodecylbenzenesulfonate, and the modified lignin is sodium lignosulfonate or Potassium lignosulfonate.

Embodiment 3

[0030] A fracturing pre-fluid in this embodiment is prepared by mixing the following raw materials in mass percentage: biological enzyme 10%, clay stabilizer 1%, fluorocarbon surfactant 0.1%, wetting reversal agent 0.5%, compound Active agent 1%, balance is water; The clay stabilizer is NH 4 Cl and KCl, the fluorocarbon surfactant is a polyether quaternary ammonium salt cationic fluorocarbon surfactant, the wetting reversal agent is dodecyltrimethylammonium chloride, and the composite active agent It is formed by mixing nonylphenol polyoxyethylene ether, sodium dodecylbenzenesulfonate and potassium lignosulfonate according to the mass ratio of 1:4:1; the mass content of protein in the biological enzyme is 25%, ethanol The mass content of dehydrogenase is 25%, and the mass content of xylanase is 10%.

[0031] The preparation method of the fracturing prefluid of this embodiment is as follows: after mixing the raw materials in proportion, they can be stirred evenly.

[0032] Th...

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