Polydisperse polyacrylamide microsphere system and preparation method thereof

Abstract

The invention relates to a polydisperse polyacrylamide microsphere system and a preparation method thereof. The invention mainly overcomes the problem that nanometer, micrometer and millimeter polyacrylamide microspheres cannot be prepared in a same system in the prior art. The preparation method comprises the following steps: preparing nanometer polymer microspheres by using a multi-step polymerization method according to the mechanism of reversed-phase microemulsion polymerization; then supplementing a water phase, adjusting a ratio of an oil phase to an emulsifier to the water phase and the usage amount of an initiator and synthesizing submicron polymer microspheres according to the mechanism of reversed-phase emulsion polymerization; and supplementing the water phase and the initiator and continuing synthesis of micrometer to millimeter polymer particles. Thus, the above-mentioned problem is overcome; and the prepared polydisperse polyacrylamide microsphere system has the characteristics of high effective solid content, inclusion of nanometer, micrometer and millimeter polymer microspheres and capacity of meeting requirements of severe heterogeneous formations, and can be directly used or cooperatively used with other oil-field chemicals on site for in-depth profile control, water plugging, oil displacement or other recovery-efficiency-improving operations for tertiary oil recovery in an oil field.

Description

technical field

[0001] The invention relates to a polydisperse polyacrylamide microsphere system and a preparation method thereof. Background technique

[0002] After entering the 1990s, the influence of reservoir heterogeneity on the sweep coefficient of water flooding and chemical flooding fluid became more and more serious. Researchers began to realize that only through deep profile control can the reservoir be adjusted and improved more economically and effectively. The heterogeneity of injection fluid increases the volumetric sweep coefficient, thereby enhancing oil recovery. The theory of deep profile control and water shutoff mainly uses the plugging material to enter the deep part of the formation along with the displacement fluid to block the high-permeability water channel, causing the liquid flow to divert to expand the swept volume of water flooding. Polymer microsphere technology is a new type of deep profile control and water plugging technology developed in r...

Examples

Embodiment 1

[0039] First add 1000g white oil, 320g SPAN80, 60g TWEEN80, HLB value = 6.0 into the reaction kettle; stir until completely mixed, control the temperature in the kettle to 22°C, and the stirring speed to 200rpm. In another container, add 600g of water, 550g of acrylamide, 150g of sodium 2-acrylamido-2-methylpropanesulfonate, 30g of sodium acetate, 0.8g of disodium edetate, 2.5g of isopropanol, and 8g of urea , ammonium persulfate 3.2g, methylene bisacrylamide 2.5g, stir and dissolve evenly as the water phase; dissolve 2.5g sodium bisulfite in 50g water for later use. Add 630g of the water phase to the oil phase in the reactor, stir for a few minutes until emulsified evenly, then add 14g of reducing agent aqueous solution dropwise after 30 minutes of nitrogen gas flow, the temperature rises to 62°C quickly, keeps the reaction for 1.5 hours, and then drops to 22°C; Add 600g of water phase again and mix evenly. After passing nitrogen for 30 minutes, add 15g of reducing agent aque...

Embodiment 2

[0042] First add 1100g cyclohexane, 280g SPAN60, 90g TWEEN60, HLB value = 7.2, stir until completely mixed, control the temperature in the kettle to 25°C, and the stirring speed to 200rpm. In another container, add 610g of water, 520g of acrylamide, 120g of sodium 2-acrylamido-2-methylpropanesulfonate, 50g of acryloyloxyethyltrimethylammonium chloride, 35g of sodium acetate, ethylenediaminetetraacetic acid Disodium 0.8g, isopropanol 2.5g, urea 10g, ammonium persulfate 3.2g, methylenebisacrylamide 2.5g, stir and dissolve evenly as the water phase; dissolve 2.5g sodium bisulfite in 50g water for later use. Add 620g of the water phase to the oil phase in the reactor, stir for a few minutes until the emulsification is uniform, and then add 16.0g of the reducing agent aqueous solution dropwise after 30 minutes of nitrogen gas, the temperature rises to 56°C quickly, keeps the reaction for 1.5 hours, and then drops to 30°C Add 590g of water phase again and mix evenly, drop in 15.0g o...

Embodiment 3

[0045] First add 1080g No. 200 solvent oil, 300g SPAN60, 60g TWEEN80, HLB value = 6.4 into the reaction kettle, stir until completely mixed, control the temperature in the kettle to 25°C, and the stirring speed to 200rpm. In another container, add 570g of water, 600g of acrylamide, 210g of sodium 2-acrylamido-2-methylpropanesulfonate, 70g of N-vinylpyrrolidone, 40g of sodium acetate, 1.2g of disodium edetate, n-hexanol 2.8g of urea, 12g of urea, 3.8g of ammonium persulfate, and 2.8g of polyethylene glycol diacrylate were stirred and dissolved evenly as the water phase; 2.5g of sodium bisulfite was dissolved in 50g of water for later use. Add 670g of the water phase to the oil phase in the reactor, stir for a few minutes until the emulsification is uniform, and then add 16g of the reducing agent aqueous solution dropwise after 30 minutes of nitrogen gas, the temperature rises to 63°C quickly, keeps the reaction for 1.5 hours, and then drops to 25°C; Add 600g of water phase agai...

technical field

[0001] The invention relates to a polydisperse polyacrylamide microsphere system and a preparation method thereof. Background technique

[0002] After entering the 1990s, the influence of reservoir heterogeneity on the sweep coefficient of water flooding and chemical flooding fluid became more and more serious. Researchers began to realize that only through deep profile control can the reservoir be adjusted and improved more economically and effectively. The heterogeneity of injection fluid increases the volumetric sweep coefficient, thereby enhancing oil recovery. The theory of deep profile control and water shutoff mainly uses the plugging material to enter the deep part of the formation along with the displacement fluid to block the high-permeability water channel, causing the liquid flow to divert to expand the swept volume of water flooding. Polymer microsphere technology is a new type of deep profile control and water plugging technology developed in r...

Examples

Embodiment 1

[0039] First add 1000g white oil, 320g SPAN80, 60g TWEEN80, HLB value = 6.0 into the reaction kettle; stir until completely mixed, control the temperature in the kettle to 22°C, and the stirring speed to 200rpm. In another container, add 600g of water, 550g of acrylamide, 150g of sodium 2-acrylamido-2-methylpropanesulfonate, 30g of sodium acetate, 0.8g of disodium edetate, 2.5g of isopropanol, and 8g of urea , ammonium persulfate 3.2g, methylene bisacrylamide 2.5g, stir and dissolve evenly as the water phase; dissolve 2.5g sodium bisulfite in 50g water for later use. Add 630g of the water phase to the oil phase in the reactor, stir for a few minutes until emulsified evenly, then add 14g of reducing agent aqueous solution dropwise after 30 minutes of nitrogen gas flow, the temperature rises to 62°C quickly, keeps the reaction for 1.5 hours, and then drops to 22°C; Add 600g of water phase again and mix evenly. After passing nitrogen for 30 minutes, add 15g of reducing agent aque...

Embodiment 2

[0042] First add 1100g cyclohexane, 280g SPAN60, 90g TWEEN60, HLB value = 7.2, stir until completely mixed, control the temperature in the kettle to 25°C, and the stirring speed to 200rpm. In another container, add 610g of water, 520g of acrylamide, 120g of sodium 2-acrylamido-2-methylpropanesulfonate, 50g of acryloyloxyethyltrimethylammonium chloride, 35g of sodium acetate, ethylenediaminetetraacetic acid Disodium 0.8g, isopropanol 2.5g, urea 10g, ammonium persulfate 3.2g, methylenebisacrylamide 2.5g, stir and dissolve evenly as the water phase; dissolve 2.5g sodium bisulfite in 50g water for later use. Add 620g of the water phase to the oil phase in the reactor, stir for a few minutes until the emulsification is uniform, and then add 16.0g of the reducing agent aqueous solution dropwise after 30 minutes of nitrogen gas, the temperature rises to 56°C quickly, keeps the reaction for 1.5 hours, and then drops to 30°C Add 590g of water phase again and mix evenly, drop in 15.0g o...

Embodiment 3

[0045] First add 1080g No. 200 solvent oil, 300g SPAN60, 60g TWEEN80, HLB value = 6.4 into the reaction kettle, stir until completely mixed, control the temperature in the kettle to 25°C, and the stirring speed to 200rpm. In another container, add 570g of water, 600g of acrylamide, 210g of sodium 2-acrylamido-2-methylpropanesulfonate, 70g of N-vinylpyrrolidone, 40g of sodium acetate, 1.2g of disodium edetate, n-hexanol 2.8g of urea, 12g of urea, 3.8g of ammonium persulfate, and 2.8g of polyethylene glycol diacrylate were stirred and dissolved evenly as the water phase; 2.5g of sodium bisulfite was dissolved in 50g of water for later use. Add 670g of the water phase to the oil phase in the reactor, stir for a few minutes until the emulsification is uniform, and then add 16g of the reducing agent aqueous solution dropwise after 30 minutes of nitrogen gas, the temperature rises to 63°C quickly, keeps the reaction for 1.5 hours, and then drops to 25°C; Add 600g of water phase agai...