Preparation method of fiber composite gelatin for plugging oil coat macropore

Abstract

The invention discloses a method for preparing fiber complex gel used for plugging oil layer large opening, which is formed because of long time water injection and for controlling ineffective cycle of injected water and improving water-drive development effect; the preparation method for fiber complex gel comprises following steps: (1) adding 0.05-1 unit fiber into water of 100 units, stirring evenly to make fiber float on water; (2) adding 0.05-1 unit of water block off agent, stirring for 10 minutes to prepare fiber jellied liquid; (3) heating said liquid until it becomes gelatineous, and preparing fiber complex gel. The addition of fiber into formulation to prepare fiber complex gel after injection into large opening, which greatly increases plugging strength and flushing-endurance of block off agent in large opening and makes subsequent injected water flow to position with low penetration factor of oil layer, enlarges contact volume and drives out more oil.

Description

technical field [0001] The invention relates to the technology of water plugging and profile control in the oil field development process, which is used for plugging the large pores of the oil layer formed by long-term water injection development, controlling the invalid circulation of injected water, and improving the effect of water flooding development, and particularly relates to the fiber used for plugging the large pores of the oil layer Composite gel. Background technique [0002] Due to the characteristics of continental deposits, the original heterogeneity of oil layers in my country is serious. After decades of water flooding development and even strong injection and strong production, the heterogeneity of the reservoir has further deteriorated. The oil layer has experienced long-term water erosion, coupled with clay swelling, particle migration, and even sand production. Some parts of the oil layer gradually form large pores or cracks, resulting in ineffective ci...

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Problems solved by technology

[0004] Although the strong gel described in Document 1 is reliable in gelation and has high strength, the gelation time is short and the cost of plugging agent is high

Since the amount of acrylamide monomer is more than 5%, the cost is 20-50 times that of general polyacrylamide cross-linking plugging agent, and it is difficult to be widely used

[0005] Document 2 refers to polyacrylamide cross-linked gel with weak strength. The concentration of polyacrylamide as the main agent is generally 0.1-0.2%, so the cost is relatively low. It is widely used in oil fields for water plugging and profile control in medium and high permeability layers, but The problem is that the blocking strength in the large pores is not enough, it is easy to be washed away by water, and the construction effect is poor

[0006] Existing technologies cannot meet the requirements of oil field plugging large pores

Although the strong gel is reliable in gelation and has high strength, the gelation time is short and the cost of the plugging agent is high, which is 20-50 times that of the general polyacrylamide cross-linking plugging agent, so it is difficult to be widely used

Polyacrylamide cross-linked gel, although the cost is low, but the blockage strength in the large pores is not enough, it is easy to be washed away by water, and the validity period is short

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