A kind of polyacrylamide copolymer, polymer profile control agent and preparation method thereof

Abstract

The invention relates to a polyacrylamide copolymer, a polymer profile control agent and a preparation method thereof, belonging to the technical field of oil field chemistry. The method: mix acrylamide, acrylic acid and water uniformly, then add a ternary functional mixed solution and mix uniformly to obtain a solution to be polymerized; the ternary functional mixed solution is composed of the first functional monomer, the second functional unit It is formed by mixing the monomer, the third functional monomer and water; the solution to be polymerized is passed through nitrogen to remove oxygen, and then a chain transfer agent and an initiator are added to initiate the polymerization reaction to obtain a polymerized gel; the polymerized gel is granulated, and then hydrolyzed The agent is hydrolyzed to obtain a hydrolyzate; the hydrolyzate is dried and ground to obtain a polyacrylamide copolymer. The polyacrylamide copolymer prepared by the present invention has excellent salt-resistant and temperature-resistant properties. The profile control agent prepared by using the polyacrylamide copolymer has high strength after gelling under high-temperature formation conditions, and can be placed at 120°C for three The monthly viscosity retention rate is above 74%.

Description

technical field [0001] The invention relates to the technical field of oilfield chemistry, in particular to a polyacrylamide copolymer, a polymer profile control agent and a preparation method thereof. Background technique [0002] Petroleum is a dark brown viscous liquid, which is widely used in industry and is known as "industrial blood". With the late stage of oil exploitation and the in-depth development of water injection, the heterogeneity of the reservoir and the water-oil mobility ratio cause a large amount of water to flow into high-permeability areas, often causing water flooding and water discharge from oil wells, which affect the stable production of oil and cause economic problems. Benefits are getting worse. In order to reduce the heterogeneity of the reservoir and increase the oil recovery, profile control and water shutoff operations are required. [0003] At present, after the conventional polymer profile control agent is injected into the oil field, the v...

AI Technical Summary

Problems solved by technology

[0003] At present, after the conventional polymer profile control agent is injected into the oil field, the viscosity will decrease due to the shearing of the formation void and the change of the salinity in the formation, and the performance of the conventional polymer profile control agent is unstable when it is applied in high temperature reservoir conditions. After the agent reaches the area to be flooded, its own performance loss is relatively serious, so the expected effect cannot be achieved.

Even conventional polymer profile control agents have been cross-linked before the expected cross-linking time, resulting in a short effective period of profile control. Under complex reservoir conditions, after profile control, the subsequent injected fluid flows back into the high-permeability layer , and the conventional polymer profile control agent is limited by the high salt of the configuration liquid and the configuration of sewage, there are a series of problems, and it cannot meet the needs of the oilfield site

[0004] Chinese patent application CN105367708A discloses a profile control agent and its manufacturing method and a tetrapolymer and its manufacturing method. Although the tetrapolymer prepared by the patent application is made into a profile control agent, it can It maintains a certain stability after the degree of salinity in the oil reservoir, but in the mineralized water with a salinity of 8000mg / L, the strength after gelation can only reach 13271mPa·s, and the strength after gelation needs to be further improved; in addition, the patent application is The four kinds of polymerized monomers are all prepared into deionized aqueous solution and then added dropwise to the emulsion. After the polymerization reaction is completed, it is necessary to wash and dry with ethanol, and washing with ethanol will remove excess emulsifier, white oil, etc. removal, which will cause a waste of resources and is not suitable for industrial production; in addition, the preparation process of the tetrapolymer in this patent application requires a hydrocarbon solvent as a reaction medium, there are dangerous factors in the product preparation process, and it will cause environmental pollution. Pollution, also not suitable for industrial production

Images