Crosslinking agent of polyacrylamide plugging agent, and preparation method and applications thereof

Abstract

The invention relates to a crosslinking agent of a polyacrylamide plugging agent, and a preparation method and applications thereof. The crosslinking agent comprises following components in percentage by weight: 20 to 30% of a chromium nicotinate complex; 3 to 5% of aluminum citrate; 15 to 30% of an organic acid; 0.03 to 0.06% of sodium carboxymethyl cellulose; 15 to 20% of an acidity regulator; and 15 to 47% of deionized water. Weak gel formed by the provided crosslinking agent is resistant to coagulation during the storage process; the gelling time is effectively prolonged; and the formed weak gel has the advantages of good viscoelasticity, excellent water retaining performance, good shearing resistant property, low filter loss, and good injection performance.

Description

technical field

[0001] The invention belongs to the field of chemical auxiliary agents, and in particular relates to a crosslinking agent of polyacrylamide water blocking agent, its preparation method and its application. Background technique

[0002] my country's most important energy source is petroleum. In recent years, petroleum has not only occupied the first place in my country's total energy consumption, but its proportion has been rising continuously. At present, almost all oilfields in my country have entered the stage of tertiary oil recovery. As the oil production enters the middle and late stages, the water injection in the oil well makes the injection profile extremely uneven. In some blocks, the injected water breaks through rapidly along the high permeability layer, which makes the formation heterogeneity further. The expansion caused the oil well to produce a large amount of water, and the water content increased sharply. Water from oil wells has brought many...

Examples

preparation example Construction

[0024] A preparation method of a cross-linking agent of polyacrylamide water blocking agent, comprising the following steps:

[0025] S1, adding deionized water, chromium nicotinate complex, aluminum citrate, sodium carboxymethylcellulose and organic acid into the stirring reactor in sequence, and stirring and reacting at 80°C to 90°C for 6h to 9h; and

[0026] S2, adding an acidity regulator to the mixed solution after the stirring reaction in S1 to adjust to alkalinity to obtain a crosslinking agent product.

[0027] In S2, an acidity regulator is used to adjust the pH of the mixture to 7-8.

[0028] An application of the cross-linking agent in polyacrylamide water blocking agent, the mass ratio of the cross-linking agent to the polyacrylamide is 3-6:7-12.

Embodiment 1

[0030] Select raw materials by weight percentage

[0031] Cr 2 (C 6 h 4 NO 2 ) 3 Cl 3 : 20%

[0032] Aluminum citrate: 5%

[0033] Malonic acid: 15%

[0034] Sodium carboxymethylcellulose: 0.03%

[0035] Ammonia water (0.14×10 -2 mol / L): 15%

[0036] Deionized water: 44.97%

[0037] Concrete preparation steps are:

[0038] (1) Deionized water, Cr 2 (C 6 h 4 NO 2 ) 3 Cl 3 , aluminum citrate, sodium carboxymethylcellulose, and malonic acid were sequentially added into the stirred reactor, and stirred and reacted at 80°C for 6h.

[0039] (2) Add ammonia water to the mixed solution after the stirring reaction in step (1), and adjust to 7 to obtain a crosslinking agent product.

[0040] Preparation of water blocking agent: select polyacrylamide with a molecular weight of 14 million (Japan Sanyo Chemical Company, industrial grade), take 4.5g of the above-mentioned polyacrylamide, add it to 1000mL water, stir to dissolve, and then add 1.6g of cross-linking agent to...

Embodiment 2

[0043] Select raw materials by weight percentage

[0044] Cr 2 (C 6 h4 NO 2 ) 3 Cl 3 : 25%

[0045] Aluminum citrate: 4%

[0046] Malonic acid: 30%

[0047] Sodium carboxymethylcellulose: 0.06%

[0048] Sodium carbonate aqueous solution (0.16×10 -2 mol / L): 15.94%

[0049] Deionized water: 25%

[0050] Concrete preparation steps are:

[0051] (1) Deionized water, Cr 2 (C 6 h 4 NO 2 ) 3 Cl 3 , aluminum citrate, sodium carboxymethylcellulose, and malonic acid were sequentially added into the stirred reactor, and stirred and reacted at 90°C for 9h.

[0052] (2) Add sodium carbonate aqueous solution to the mixed solution after the stirring reaction in step (1), and adjust to 8 to obtain a crosslinking agent product.

[0053] Preparation of water blocking agent: same as Example 1.

[0054] See Table 1 and Table 2 for the viscosity retention rate and gelation time of the weak gel.

technical field

[0001] The invention belongs to the field of chemical auxiliary agents, and in particular relates to a crosslinking agent of polyacrylamide water blocking agent, its preparation method and its application. Background technique

[0002] my country's most important energy source is petroleum. In recent years, petroleum has not only occupied the first place in my country's total energy consumption, but its proportion has been rising continuously. At present, almost all oilfields in my country have entered the stage of tertiary oil recovery. As the oil production enters the middle and late stages, the water injection in the oil well makes the injection profile extremely uneven. In some blocks, the injected water breaks through rapidly along the high permeability layer, which makes the formation heterogeneity further. The expansion caused the oil well to produce a large amount of water, and the water content increased sharply. Water from oil wells has brought many...

Examples

preparation example Construction

[0024] A preparation method of a cross-linking agent of polyacrylamide water blocking agent, comprising the following steps:

[0025] S1, adding deionized water, chromium nicotinate complex, aluminum citrate, sodium carboxymethylcellulose and organic acid into the stirring reactor in sequence, and stirring and reacting at 80°C to 90°C for 6h to 9h; and

[0026] S2, adding an acidity regulator to the mixed solution after the stirring reaction in S1 to adjust to alkalinity to obtain a crosslinking agent product.

[0027] In S2, an acidity regulator is used to adjust the pH of the mixture to 7-8.

[0028] An application of the cross-linking agent in polyacrylamide water blocking agent, the mass ratio of the cross-linking agent to the polyacrylamide is 3-6:7-12.

Embodiment 1

[0030] Select raw materials by weight percentage

[0031] Cr 2 (C 6 h 4 NO 2 ) 3 Cl 3 : 20%

[0032] Aluminum citrate: 5%

[0033] Malonic acid: 15%

[0034] Sodium carboxymethylcellulose: 0.03%

[0035] Ammonia water (0.14×10 -2 mol / L): 15%

[0036] Deionized water: 44.97%

[0037] Concrete preparation steps are:

[0038] (1) Deionized water, Cr 2 (C 6 h 4 NO 2 ) 3 Cl 3 , aluminum citrate, sodium carboxymethylcellulose, and malonic acid were sequentially added into the stirred reactor, and stirred and reacted at 80°C for 6h.

[0039] (2) Add ammonia water to the mixed solution after the stirring reaction in step (1), and adjust to 7 to obtain a crosslinking agent product.

[0040] Preparation of water blocking agent: select polyacrylamide with a molecular weight of 14 million (Japan Sanyo Chemical Company, industrial grade), take 4.5g of the above-mentioned polyacrylamide, add it to 1000mL water, stir to dissolve, and then add 1.6g of cross-linking agent to...

Embodiment 2

[0043] Select raw materials by weight percentage

[0044] Cr 2 (C 6 h4 NO 2 ) 3 Cl 3 : 25%

[0045] Aluminum citrate: 4%

[0046] Malonic acid: 30%

[0047] Sodium carboxymethylcellulose: 0.06%

[0048] Sodium carbonate aqueous solution (0.16×10 -2 mol / L): 15.94%

[0049] Deionized water: 25%

[0050] Concrete preparation steps are:

[0051] (1) Deionized water, Cr 2 (C 6 h 4 NO 2 ) 3 Cl 3 , aluminum citrate, sodium carboxymethylcellulose, and malonic acid were sequentially added into the stirred reactor, and stirred and reacted at 90°C for 9h.

[0052] (2) Add sodium carbonate aqueous solution to the mixed solution after the stirring reaction in step (1), and adjust to 8 to obtain a crosslinking agent product.

[0053] Preparation of water blocking agent: same as Example 1.

[0054] See Table 1 and Table 2 for the viscosity retention rate and gelation time of the weak gel.

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