Crosslinked polymer microspheres and preparation method thereof

Abstract

The invention provides crosslinked polymer microspheres and a preparation method thereof. The preparation method comprises the following step of: in inert atmosphere, performing polymerization reaction on monomers in aqueous dispersion in which a polymer dispersant, inorganic salt and crosslinking monomers are dissolved to obtain the crosslinked polymer microspheres. When the crosslinked polymer microspheres are actually used, aqueous dispersion containing the crosslinked polymer microspheres or a concentrated solution prepared from crosslinked polymer microsphere powder can be directly adopted, is pumped into a water injection pipeline by a high pressure proportioning pump, and is mixed and diluted on line in field, and the mixed and diluted solution in predesigned mass percentage content is injected into an oil deposit through a water injection well to fulfill the aims of improving the nonhomogeneity of the oil deposit and improving the recovery ratio of crude oil of the oil depositthrough water injection development.

Description

technical field

[0001] The invention relates to a cross-linked polymer microsphere capable of improving the heterogeneity of oil reservoirs and increasing the oil recovery rate of water injection development oil reservoirs and a preparation method thereof, belonging to the field of petroleum industry. Background technique

[0002] At present, the early development of oil fields has gradually entered the middle and late stages of water flooding. How to further improve the volumetric sweep coefficient of injected water and the displacement efficiency within the water sweep volume, and economically and effectively exploit existing oil fields is a major issue to be solved urgently by the petroleum industry. One, in which the development and application of enhanced oil recovery technology has played an important role.

[0003] Enhanced oil recovery technology involves many aspects, and the methods based on improving the displacement effect can be divided into two categories: incr...

Examples

Embodiment 1

[0025] Embodiment 1, the preparation of cross-linked polymer microspheres

[0026] Add 1.50 grams of polyvinylpyrrolidone (K-60), 16.50 grams of ammonium sulfate, 1.50 grams of sodium chloride, and 5.68 grams of acrylamide (AM) in a jacketed reactor equipped with a gas inlet pipe, a thermometer, and a constant speed stirrer , sodium acrylate 1.02 g, 2-acrylamide-2-methylpropanesulfonic acid (AMPS) 3.30 g, N,N'-diallyl-N,N,N',N'-tetramethylhexanedichloride 0.45 g of ammonium chloride, 0.50 mg of disodium edetate as a chelating agent, and 1.0 mg of cosolvent urea, all the above ingredients were dissolved in 68.00 g of ultrapure water (conductivity ≤ 4 μS / cm), and mixed with 35% sodium hydroxide Adjust the pH value of the solution to 7.5-8.5; in the above water dispersion, the mass percentage of ammonium sulfate and sodium chloride is 18.0%; the mass percentage of acrylamide is 5.68%; polyvinylpyrrolidone, sodium acrylate and 2- The mass percent of acrylamide-2-methylpropanesulf...

Embodiment 2

[0030] Embodiment 2, the preparation of cross-linked polymer microspheres

[0031] Add 2.50 grams of polyvinylpyrrolidone (K-17), 17.50 grams of ammonium sulfate, 1.50 grams of sodium chloride, and 5.68 grams of acrylamide (AM) in a jacketed reactor equipped with a gas inlet pipe, a thermometer, and a constant speed stirrer , sodium acrylate 1.02 g, 2-acrylamide-2-methylpropanesulfonic acid (AMPS) 3.30 g, N,N'-diallyl-N,N,N',N'-tetramethylhexanedichloride 0.45 grams of ammonium chloride, 0.50 milligrams of disodium edetate as a chelating agent, and 1.0 milligrams of urea. The above ingredients were dissolved in 66.00 grams of ultrapure water (conductivity ≤ 4 μS / cm), and the solution was adjusted with 35% sodium hydroxide The pH is 7.5-8.5. In the above aqueous dispersion, the mass percentage of ammonium sulfate and sodium chloride is 19.0%; the mass percentage of acrylamide is 5.68%; polyvinylpyrrolidone, sodium acrylate and 2-acrylamide-2-methylpropanesulfonate The mass pe...

Embodiment 3

[0035] Embodiment 3, the preparation of cross-linked polymer microspheres

[0036] The crosslinked polymer microsphere aqueous solution powder was prepared according to the same method as in Example 1.

[0037] The above-prepared cross-linked polymer microspheres with a mass fraction of 400 mg / kg were aged in simulated water of Bohai SZ36-1 oilfield at 60°C for 96 hours to obtain an aqueous solution of cross-linked polymer coils, with a gas permeability of 3.5 μm 2 The simulated oil displacement experiment of the Bohai SZ36-1 oilfield was carried out on artificial cores, and it was measured that the simulated oil recovery could be increased by 18.6% under the experimental conditions.

technical field

[0001] The invention relates to a cross-linked polymer microsphere capable of improving the heterogeneity of oil reservoirs and increasing the oil recovery rate of water injection development oil reservoirs and a preparation method thereof, belonging to the field of petroleum industry. Background technique

[0002] At present, the early development of oil fields has gradually entered the middle and late stages of water flooding. How to further improve the volumetric sweep coefficient of injected water and the displacement efficiency within the water sweep volume, and economically and effectively exploit existing oil fields is a major issue to be solved urgently by the petroleum industry. One, in which the development and application of enhanced oil recovery technology has played an important role.

[0003] Enhanced oil recovery technology involves many aspects, and the methods based on improving the displacement effect can be divided into two categories: incr...

Examples

Embodiment 1

[0025] Embodiment 1, the preparation of cross-linked polymer microspheres

[0026] Add 1.50 grams of polyvinylpyrrolidone (K-60), 16.50 grams of ammonium sulfate, 1.50 grams of sodium chloride, and 5.68 grams of acrylamide (AM) in a jacketed reactor equipped with a gas inlet pipe, a thermometer, and a constant speed stirrer , sodium acrylate 1.02 g, 2-acrylamide-2-methylpropanesulfonic acid (AMPS) 3.30 g, N,N'-diallyl-N,N,N',N'-tetramethylhexanedichloride 0.45 g of ammonium chloride, 0.50 mg of disodium edetate as a chelating agent, and 1.0 mg of cosolvent urea, all the above ingredients were dissolved in 68.00 g of ultrapure water (conductivity ≤ 4 μS / cm), and mixed with 35% sodium hydroxide Adjust the pH value of the solution to 7.5-8.5; in the above water dispersion, the mass percentage of ammonium sulfate and sodium chloride is 18.0%; the mass percentage of acrylamide is 5.68%; polyvinylpyrrolidone, sodium acrylate and 2- The mass percent of acrylamide-2-methylpropanesulf...

Embodiment 2

[0030] Embodiment 2, the preparation of cross-linked polymer microspheres

[0031] Add 2.50 grams of polyvinylpyrrolidone (K-17), 17.50 grams of ammonium sulfate, 1.50 grams of sodium chloride, and 5.68 grams of acrylamide (AM) in a jacketed reactor equipped with a gas inlet pipe, a thermometer, and a constant speed stirrer , sodium acrylate 1.02 g, 2-acrylamide-2-methylpropanesulfonic acid (AMPS) 3.30 g, N,N'-diallyl-N,N,N',N'-tetramethylhexanedichloride 0.45 grams of ammonium chloride, 0.50 milligrams of disodium edetate as a chelating agent, and 1.0 milligrams of urea. The above ingredients were dissolved in 66.00 grams of ultrapure water (conductivity ≤ 4 μS / cm), and the solution was adjusted with 35% sodium hydroxide The pH is 7.5-8.5. In the above aqueous dispersion, the mass percentage of ammonium sulfate and sodium chloride is 19.0%; the mass percentage of acrylamide is 5.68%; polyvinylpyrrolidone, sodium acrylate and 2-acrylamide-2-methylpropanesulfonate The mass pe...

Embodiment 3

[0035] Embodiment 3, the preparation of cross-linked polymer microspheres

[0036] The crosslinked polymer microsphere aqueous solution powder was prepared according to the same method as in Example 1.

[0037] The above-prepared cross-linked polymer microspheres with a mass fraction of 400 mg / kg were aged in simulated water of Bohai SZ36-1 oilfield at 60°C for 96 hours to obtain an aqueous solution of cross-linked polymer coils, with a gas permeability of 3.5 μm 2 The simulated oil displacement experiment of the Bohai SZ36-1 oilfield was carried out on artificial cores, and it was measured that the simulated oil recovery could be increased by 18.6% under the experimental conditions.

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