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High-seepage sandstone oil reservoir compound polymer type profile control agent and use method thereof

A technique for sandstone reservoirs and profile control agents, applied in drilling compositions, chemical instruments and methods, earthwork drilling and production, etc., can solve high water injection pressure, complex oil layer distribution, reduce the swept volume of injected water and oilfield development In order to achieve the effect of increasing the sweep coefficient of water flooding, improving the recovery rate of polymer flooding, and inhibiting the formation of dead oil zones

Inactive Publication Date: 2017-11-24
DALIAN DONGYOU RUIJIA PETROLEUM TECH CO LTD
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Problems solved by technology

However, in the practice of polymer flooding, it is found that for high permeability sandstone reservoirs, the recovery degree is low, indicating that the efficiency of polymer application in high permeability sandstone reservoirs is low; has the following disadvantages:
[0003] 1. The permeability of high-permeability sandstone reservoirs gradually decreases during the production process. The main reason is that the movement of clay particles in the production process blocks the pores of the reservoir, scaling caused by reservoir pressure and temperature changes, and chemical precipitation of calcium and iron. Blockage caused by high water injection pressure in high-permeability sandstone reservoirs, and unblocked pores are prone to channeling, which seriously affects oilfield development benefits
[0004] 2. In the process of water injection development of high permeability sandstone reservoirs, due to the heterogeneity of the reservoir, the injected water will channel and rush along the high permeability zones or channels, seriously reducing the swept volume of the injected water and the development effect of the oil field
[0005] 3. At present, polymer flooding is usually difficult to achieve the ideal oil displacement effect. When the polymer viscosity is low, there will often be ineffective polymer flooding cycles. When the polymer viscosity is high, the plugging will be too tight and the water injection pressure will be too high; and It is difficult to overcome the phenomena of sand production and clay expansion in high permeability sandstone reservoirs by traditional polymer flooding
[0006] 4. There are many dead oil areas. In the conventional water flooding process, most of the displacement fluid flows through the high-permeability zone, resulting in uneven water absorption profiles. Dead oil areas are gradually formed in areas that have not been affected by the displacement fluid. Serious Affect the development effect of high permeability sandstone reservoir

Method used

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  • High-seepage sandstone oil reservoir compound polymer type profile control agent and use method thereof
  • High-seepage sandstone oil reservoir compound polymer type profile control agent and use method thereof
  • High-seepage sandstone oil reservoir compound polymer type profile control agent and use method thereof

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] 1. The method of using the profile control agent: (1) First, carry out oxygen exposure treatment on the prepared water to reduce the dissolved oxygen content in the prepared water to less than 3 mg / L; (2) Add part of the hydrolysis polymer to the prepared water at a temperature of 15°C Acrylamide was stirred at a constant speed for 2 hours, then the additive was added to the prepared water and stirred at a constant speed for 3 hours to obtain the profile control agent; (3) After the preparation was completed, the profile control agent was directly injected into the rock core.

[0037] 2. Prepare water with a salinity of 3126.31mg / L, and the specific ion concentration is as follows:

[0038] Sodium and potassium ion content (mg / L)

1056.85

Magnesium ion content (mg / L)

6.7

Calcium ion content (mg / L)

6.54

Chloride ion content (mg / L)

845.81

Bicarbonate ion content (mg / L)

1023.41

Carbonate ion content (mg / L)

187

...

Embodiment 2

[0067] 1. The method of using the profile control agent: (1) First, carry out oxygen exposure treatment on the prepared water to reduce the dissolved oxygen content in the prepared water to less than 3mg / L; (2) Add part of the hydrolytic polymer to the prepared water at a temperature of 35°C Stir acrylamide at a constant speed for 2.5 hours, then add additives to the prepared water, and stir at a constant speed for 2.5 hours to obtain the profile control agent; (3) After the preparation is completed, inject the profile control agent directly into the core.

[0068] 2. Prepare water with a salinity of 625.2mg / L, and the specific ion concentration is as follows:

[0069] Sodium and potassium ion content (mg / L)

211.37

Magnesium ion content (mg / L)

1.34

Calcium ion content (mg / L)

1.308

Chloride ion content (mg / L)

169.162

Bicarbonate ion content (mg / L)

204.682

Carbonate ion content (mg / L)

37.4

Total hardness (mg / L) ...

Embodiment 3

[0098] 1. The method of using the profile control agent: (1) Firstly, carry out oxygen exposure treatment on the prepared water to reduce the dissolved oxygen content in the prepared water to below 3 mg / L; (2) add part of the hydrolytic polymer to the prepared water at a temperature of 55°C Stir acrylamide at a constant speed for 3 hours, then add additives to the prepared water, and stir at a constant speed for 2 hours to obtain the profile control agent; (3) After the preparation is completed, inject the profile control agent directly into the core.

[0099] 2. Preparation of water: adjust the degree of salinity by adding soluble salts to the distilled water, and the final degree of salinity is 35000mg / L, which is used to simulate the oilfield sewage used in actual production.

[0100] 3. The specific application dosage is:

[0101] Slug A: The composite polymer is composed of three partially hydrolyzed polyacrylamides with different molecular weights, the molecular weights ...

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Abstract

The invention provides a high-seepage sandstone oil reservoir compound polymer type profile control agent and a use method thereof, and relates to field of oil field application chemistry. A compound polymer is formed by mixing three kinds of partially hydrolyzed polyacrylamide with different molecular masses; the compound polymer and additives are mixed for forming the profile control agent; two kinds of profile control agent slugs with different characteristics are prepared through regulating the proportion of the partially hydrolyzed polyacrylamide and the additives. In the implementation process, high-seepage zones and big pore passages of a high-seepage sandstone oil reservoir are sealed and plugged through a prepositive slug; the profile control is implemented by a postpositive slug; the problems of low polymer flooding yield, invalid polymer flooding circulation, clay expansion, dead oil zone generation inhibition and the like of a conventional high-seepage sandstone oil reservoir are solved. The profile control agent has the advantages that the preparation method is simple; before the curing, the viscosity is low; the injection is easy; the adaption to preparation water with the mineralization degree being 500mg / L to 35000mg / L can be realized; in addition, the raw materials are cheap and can be easily obtained.

Description

technical field [0001] The invention relates to a high-permeability sandstone reservoir complex polymer profile control agent and its application method. The profile control agent can improve reservoir adaptability and further improve the oil-increasing effect of high-permeability sandstone reservoirs, and belongs to oilfield applications Chemical field. Background technique [0002] In recent years, polymer flooding technology has been applied and tested on a large scale in Daqing, Shengli, Xinjiang and Bohai oilfields in China, and has achieved obvious effects of increasing oil production and reducing water loss, and the technical and economic effects are very significant. However, in the practice of polymer flooding, it is found that for high permeability sandstone reservoirs, the recovery degree is low, indicating that the efficiency of polymer application in high permeability sandstone reservoirs is low; has the following disadvantages: [0003] 1. The permeability of...

Claims

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Application Information

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IPC IPC(8): C09K8/508C09K8/584E21B33/13E21B37/06
CPCC09K8/5086C09K8/5083C09K8/584E21B33/13E21B37/06
Inventor 黄岩袁鹏飞张晓丽王培龙李天民宋鑫付强鲍春雷
Owner DALIAN DONGYOU RUIJIA PETROLEUM TECH CO LTD
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