Polyionic liquid nano hydrogel plugging agent and water-based drilling fluid

Abstract

The invention discloses a polyionic liquid nano hydrogel plugging agent and a water-based drilling fluid. The plugging agent used by the water-based drilling fluid is polyion liquid nano hydrogel, andthe polyion liquid nano hydrogel plugging agent is prepared by a step-by-step method; the drilling fluid contains 100 parts by weight of water, 1-10 parts by weight of bentonite, 0.2-1 part by weightof xanthan gum, 0.4-1.2 parts by weight of a salt-resistant filtrate reducer, 0.4-1.2 parts by weight of a temperature-resistant filtrate reducer, 4-10 parts by weight of potassium chloride, 10-20 parts by weight of a polyion liquid nano hydrogel plugging agent, 0.4-2 parts by weight of a lubricant, 20-50 parts of by weight calcium carbonate and 0.1-0.4 part by weight of sodium hydroxide. The polyionic liquid nano hydrogel prepared by the step-by-step method is used as a nano plugging agent, has a particle size distribution of approximately 30-200nm, and micro-sized and nano-sized pores in ashale well wall can be effectively plugged, so that the well wall is stabilized, and collapse is prevented.

Description

technical field

[0001] The invention relates to the technical field of oil and gas field drilling, in particular to a polyionic liquid nano hydrogel plugging agent and a water-based drilling fluid containing the plugging agent. Background technique

[0002] During the development of oil and natural gas resources, the exploitation of shale gas has always been a research hotspot for researchers. Shale is highly susceptible to hydration swelling due to its low permeability and clay-rich matrix in its pores. Drilling fluid can easily enter the formation along the micro-fractures of shale, leading to the propagation and expansion of micro-fractures, resulting in instability of the borehole wall. The stability of shale is a technical difficulty in shale development. Therefore, effective sealing of shale micro-fractures is one of the key measures to solve the instability of shale wellbore. At present, the commonly used plugging agents have the problem of large particle size, whic...

Examples

Embodiment 1

[0021] 1. Synthesis of polyionic liquid nano hydrogel plugging agent: add 2.5g of 1-isopropyl-2-methylimidazole and 3.1g of 4-vinylbenzyl chloride into the reactor, and then add 20mL of deionized Water, nitrogen gas was introduced at 25°C to stir the reaction for 6h, after the reaction was completed, it was left to stand for 24h, then washed with 15mL ether to remove impurities, then transferred to a rotary evaporator, and rotated at 25°C for 40min to remove the solvent, Repeated 3 times to obtain 1-isopropyl 3-(4-vinylbenzyl) imidazole chloride;

[0022] Weigh 24g of sodium hydroxide solid and dissolve it in a reaction vessel filled with 120mL of deionized water, then add 28g of acrylic acid to stir and neutralize, so that the neutralization degree of the acrylic acid solution reaches 0.65;

[0023] Add 3.5g of 1-isopropyl 3-(4-vinylbenzyl)imidazole chloride and 0.077g of N,N'-methylenebisacrylamide to the above solution, stir for 40min under nitrogen protection and then plac...

Embodiment 2

[0027] 1. Synthesis of polyionic liquid nano hydrogel plugging agent: add 3.5g of 1-isopropyl-2-methylimidazole and 4.4g of 4-vinylbenzyl chloride into the reactor, and then add 30mL of deionized Water, nitrogen gas was introduced at 30°C to stir the reaction for 8h, after the end of the reaction, it was left to stand for 24h, then washed with 20mL ether to remove impurities, and finally transferred to a rotary evaporator, and rotated at 30°C for 50min to remove Solvent, repeated 3 times to obtain 1-isopropyl 3-(4-vinylbenzyl) imidazole chloride;

[0028] Weigh 20g of sodium hydroxide solid and dissolve it in a reaction vessel filled with 100mL of deionized water, then add 29g of acrylic acid to stir and neutralize, so that the neutralization degree of the acrylic acid solution reaches 0.8;

[0029] Add 4.5g of 1-isopropyl 3-(4-vinylbenzyl)imidazole chloride and 0.12g of N,N'-methylenebisacrylamide to the above solution, stir for 45min under nitrogen protection and then place ...

technical field

[0001] The invention relates to the technical field of oil and gas field drilling, in particular to a polyionic liquid nano hydrogel plugging agent and a water-based drilling fluid containing the plugging agent. Background technique

[0002] During the development of oil and natural gas resources, the exploitation of shale gas has always been a research hotspot for researchers. Shale is highly susceptible to hydration swelling due to its low permeability and clay-rich matrix in its pores. Drilling fluid can easily enter the formation along the micro-fractures of shale, leading to the propagation and expansion of micro-fractures, resulting in instability of the borehole wall. The stability of shale is a technical difficulty in shale development. Therefore, effective sealing of shale micro-fractures is one of the key measures to solve the instability of shale wellbore. At present, the commonly used plugging agents have the problem of large particle size, whic...

Examples

Embodiment 1

[0021] 1. Synthesis of polyionic liquid nano hydrogel plugging agent: add 2.5g of 1-isopropyl-2-methylimidazole and 3.1g of 4-vinylbenzyl chloride into the reactor, and then add 20mL of deionized Water, nitrogen gas was introduced at 25°C to stir the reaction for 6h, after the reaction was completed, it was left to stand for 24h, then washed with 15mL ether to remove impurities, then transferred to a rotary evaporator, and rotated at 25°C for 40min to remove the solvent, Repeated 3 times to obtain 1-isopropyl 3-(4-vinylbenzyl) imidazole chloride;

[0022] Weigh 24g of sodium hydroxide solid and dissolve it in a reaction vessel filled with 120mL of deionized water, then add 28g of acrylic acid to stir and neutralize, so that the neutralization degree of the acrylic acid solution reaches 0.65;

[0023] Add 3.5g of 1-isopropyl 3-(4-vinylbenzyl)imidazole chloride and 0.077g of N,N'-methylenebisacrylamide to the above solution, stir for 40min under nitrogen protection and then plac...

Embodiment 2

[0027] 1. Synthesis of polyionic liquid nano hydrogel plugging agent: add 3.5g of 1-isopropyl-2-methylimidazole and 4.4g of 4-vinylbenzyl chloride into the reactor, and then add 30mL of deionized Water, nitrogen gas was introduced at 30°C to stir the reaction for 8h, after the end of the reaction, it was left to stand for 24h, then washed with 20mL ether to remove impurities, and finally transferred to a rotary evaporator, and rotated at 30°C for 50min to remove Solvent, repeated 3 times to obtain 1-isopropyl 3-(4-vinylbenzyl) imidazole chloride;

[0028] Weigh 20g of sodium hydroxide solid and dissolve it in a reaction vessel filled with 100mL of deionized water, then add 29g of acrylic acid to stir and neutralize, so that the neutralization degree of the acrylic acid solution reaches 0.8;

[0029] Add 4.5g of 1-isopropyl 3-(4-vinylbenzyl)imidazole chloride and 0.12g of N,N'-methylenebisacrylamide to the above solution, stir for 45min under nitrogen protection and then place ...

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