Environmental-friendly gel plugging agent applicable to low-temperature oil pool and applications of gel plugging agent

Abstract

The invention relates to an environmental-friendly gel plugging agent applicable to a low-temperature oil pool and applications of the gel plugging agent. The gel plugging agent is prepared from 0.2%-0.6% of ampholytic polyacryamide, 0.5%-2.0% of an organic zirconium cross-linking agent solution, and the balance of water. The gel plugging agent is used for deep water shut-off and profile control constructions in the low-temperature oil pool of 25-35 DEG C and by virtue of the plugging agent, the recovery rate of crude oil can be raised. The gel plugging agent can form a non-flowing high-strength gel system at low temperature and has low viscosity and good injectivity; without toxic chemical materials such as chromium type cross-linking agents, the gel plugging agent is conductive to environmental friendliness.

Description

technical field

[0001] The invention relates to a technology for further enhancing crude oil recovery in the technical field of oil and gas field development engineering, in particular to an environment-friendly jelly plugging agent for water shutoff and profile control in low-temperature oil reservoirs and its application. technical background

[0002] my country is one of the countries with a relatively high proportion of oil fields developed by water flooding in the world, and the reserves developed by water flooding account for more than 60% of the total reserves. Oilfields developed by water flooding occupy a pivotal position in my country's oil development. As the water flooding development enters the middle and late stages, the uneven water flooding has further evolved into large channel channeling, which leads to further deterioration of the water flooding development effect. The basis for stable production is weakening. However, there is still a large amount of rem...

Examples

Embodiment 1

[0046] An environment-friendly plugging agent suitable for low-temperature oil reservoirs, composed of 0.2% amphoteric polyacrylamide (LPAM), 0.5% organic zirconium crosslinking agent solution, and 99.3% water. The organic zirconium crosslinking agent is a combination of zirconium citrate and zirconium lactate in a mass ratio of 2:1.

[0047] Preparation:

[0048] Weigh zirconium citrate and zirconium lactate according to the mass ratio of 2:1, add into water under stirring, mix evenly, and make an organic zirconium crosslinking agent solution with a mass fraction of 30%;

[0049] Proportionally, take 10 g of amphoteric polyacrylamide aqueous solution with a mass fraction of 1.0%, add 0.25 g of organic zirconium crosslinking agent solution prepared while stirring, and then add 39.75 g of water and stir to obtain the product.

[0050] The gelling time of the plugging agent system at 25°C is 60 hours, and the gelling strength is grade E; at 30°C, the gelling time is 50 hours, a...

Embodiment 2

[0052] The environmentally friendly plugging agent suitable for low-temperature oil reservoirs is composed of: 0.4% amphoteric polyacrylamide, 1.0% organic zirconium crosslinking agent solution, and 98.6% water. The organozirconium crosslinking agent solution is zirconium citrate and zirconium lactate mixed in a mass ratio of 1:1, added into water under stirring, and mixed evenly to make an organozirconium crosslinking agent solution with a mass fraction of 25%;

[0053] In 20 g of nonionic polyacrylamide aqueous solution with a mass fraction of 1.0%, add 0.5 g of organic zirconium crosslinking agent solution while stirring, and then add 29.5 g of water and stir to obtain the product. The gelling time of the plugging agent system is 40 hours at 25°C, and the gelling strength is G grade; the gelling time is 23 hours at 30°C, and the gelling strength is G grade; the gelling time is 14 hours at 35°C, and the gelling strength is Grade G.

Embodiment 3

[0055] The environmentally friendly plugging agent suitable for low-temperature oil reservoirs is composed of: 0.6% amphoteric polyacrylamide, 2.0% organic zirconium crosslinking agent solution, and 97.4% water. The organic zirconium crosslinking agent solution is a combination of zirconium citrate and zirconium lactate in a mass ratio of 3:1, and water is added to make an organic zirconium crosslinking agent solution with a mass fraction of 20%;

[0056] In 30 g of amphoteric polyacrylamide aqueous solution with a mass fraction of 1.0%, 1.0 g of organic zirconium crosslinking agent solution was added while stirring, and then 19 g of water was added and stirred to obtain the product. The gelling time of the plugging agent system is 15 hours at 25°C, and the gelling strength is H grade; the gelling time is 10 hours at 30°C, and the gelling strength is H grade; the gelling time is 4 hours at 35°C, and the gelling strength is Grade H.

technical field

[0001] The invention relates to a technology for further enhancing crude oil recovery in the technical field of oil and gas field development engineering, in particular to an environment-friendly jelly plugging agent for water shutoff and profile control in low-temperature oil reservoirs and its application. technical background

[0002] my country is one of the countries with a relatively high proportion of oil fields developed by water flooding in the world, and the reserves developed by water flooding account for more than 60% of the total reserves. Oilfields developed by water flooding occupy a pivotal position in my country's oil development. As the water flooding development enters the middle and late stages, the uneven water flooding has further evolved into large channel channeling, which leads to further deterioration of the water flooding development effect. The basis for stable production is weakening. However, there is still a large amount of rem...

Examples

Embodiment 1

[0046] An environment-friendly plugging agent suitable for low-temperature oil reservoirs, composed of 0.2% amphoteric polyacrylamide (LPAM), 0.5% organic zirconium crosslinking agent solution, and 99.3% water. The organic zirconium crosslinking agent is a combination of zirconium citrate and zirconium lactate in a mass ratio of 2:1.

[0047] Preparation:

[0048] Weigh zirconium citrate and zirconium lactate according to the mass ratio of 2:1, add into water under stirring, mix evenly, and make an organic zirconium crosslinking agent solution with a mass fraction of 30%;

[0049] Proportionally, take 10 g of amphoteric polyacrylamide aqueous solution with a mass fraction of 1.0%, add 0.25 g of organic zirconium crosslinking agent solution prepared while stirring, and then add 39.75 g of water and stir to obtain the product.

[0050] The gelling time of the plugging agent system at 25°C is 60 hours, and the gelling strength is grade E; at 30°C, the gelling time is 50 hours, a...

Embodiment 2

[0052] The environmentally friendly plugging agent suitable for low-temperature oil reservoirs is composed of: 0.4% amphoteric polyacrylamide, 1.0% organic zirconium crosslinking agent solution, and 98.6% water. The organozirconium crosslinking agent solution is zirconium citrate and zirconium lactate mixed in a mass ratio of 1:1, added into water under stirring, and mixed evenly to make an organozirconium crosslinking agent solution with a mass fraction of 25%;

[0053] In 20 g of nonionic polyacrylamide aqueous solution with a mass fraction of 1.0%, add 0.5 g of organic zirconium crosslinking agent solution while stirring, and then add 29.5 g of water and stir to obtain the product. The gelling time of the plugging agent system is 40 hours at 25°C, and the gelling strength is G grade; the gelling time is 23 hours at 30°C, and the gelling strength is G grade; the gelling time is 14 hours at 35°C, and the gelling strength is Grade G.

Embodiment 3

[0055] The environmentally friendly plugging agent suitable for low-temperature oil reservoirs is composed of: 0.6% amphoteric polyacrylamide, 2.0% organic zirconium crosslinking agent solution, and 97.4% water. The organic zirconium crosslinking agent solution is a combination of zirconium citrate and zirconium lactate in a mass ratio of 3:1, and water is added to make an organic zirconium crosslinking agent solution with a mass fraction of 20%;

[0056] In 30 g of amphoteric polyacrylamide aqueous solution with a mass fraction of 1.0%, 1.0 g of organic zirconium crosslinking agent solution was added while stirring, and then 19 g of water was added and stirred to obtain the product. The gelling time of the plugging agent system is 15 hours at 25°C, and the gelling strength is H grade; the gelling time is 10 hours at 30°C, and the gelling strength is H grade; the gelling time is 4 hours at 35°C, and the gelling strength is Grade H.

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