Gemini quaternary-ammonium-salt water injection increasing agent

Abstract

The invention provides a gemini quaternary-ammonium-salt water injection increasing agent, which is an additive applied to injected water of oilfield injection wells. The parts by weight of the components are: 20 to 26 parts of N,N'-butylidene bislauroyl ammonium bromide, 5 to 8 parts of C12 fatty alcohol polyoxyethylene ether sodium acetate, 1.5 to 2.5 parts of ethylene glycol, 4.5 to 7.5 parts of polyoxyethylene (7) nonylphenol ether NPE-7, 4.5 to 8.5 parts of sorbitananhydride monostearate polyoxyethylene ether, 1 to 2.5 parts of ethyl ethylthio sulfonate, 12.5 to 16.5 parts of Monoethanolamine, 45 to 55 parts of distilled water, 0.5 to 1 part of sodium hydroxide, 2.5 to 4.5 parts of polyhydroxypropyl dimethyl ammonium chloride, and 0.05 to 0.1 part of perfluoroalkyl ether carboxylic acid potassium salt FC-5. The agent has the advantages that 0.05 to 0.2 percent of the agent added to the injected water can change the wettability of rock surfaces, enables oil reservoirs to be more hydrophilic, reduces blockage at well bottom and reservoirs, reduces damage to strata, and can drop the well-head pressure of the injection well by 5 to 15 percentage points.

Description

technical field [0001] The invention relates to the technical field of oil production in oil fields, in particular to an additive for injecting water into a water injection well, which is an additive capable of reducing the pressure of water injection in an oil well. Background technique [0002] At present, in the process of oil production in low-permeability oilfields, due to the small throat radius of the reservoir, the fluid permeability of the reservoir is very low, which makes the fluid seepage law deviate from Darcy's law, and there is a threshold pressure gradient, which makes the development of the reservoir difficult. increase. Even if the well pattern can control the sand body, it is still difficult to establish an effective driving system for this part of the formation reserves. In addition, the water-injection formation has poor water absorption capacity and high injection pressure. [0003] Chinese Patent Publication No.: CN1560182. Provided is a profile con...

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Problems solved by technology

[0002] At present, in the process of oil production in low-permeability oilfields, due to the small throat radius of the reservoir, the permeability of the reservoir fluid is very low, which makes the seepage law of the fluid deviate from Darcy's law, and there is a starting pressure gradient, so the de...