High temperature resistant delay crosslinking polymer deep profile control agent

Abstract

The invention relates to the technical field of petrochemical industry, in particular to a high temperature resistant delay crosslinking polymer deep profile control agent, which is used for the conditions that invalid circulation of water injection is increased in the development process of the water injection in oil fields, improves the water absorption profiles of water injection wells when the water content of oil well output liquid is increased and improves the development efficiency of water driving. According to the formula, the profile control agent comprises the following components in percentage by weight: 0.2 percent of anion type partial hydrolysis polyacrylamide, 0.03 percent of phenol, 0.15 percent of urotropin, 0.005 to 0.02 percent of thiocarbamide and the balance of fresh water, wherein the molecular weight of the anion type partial hydrolysis polyacrylamide is between 16 million and 25 million, and the hydrolysis degree is between 25 and 30 percent. The concentration of polymer can be selected between 500 and 3,000 mg / L according to the actual conditions of the oil fields, delay crosslinking can be realized, the viscosity is moderate after the profile control agent is gelled, the transportation of the profile control agent to the deep part of oil deposits is facilitated, and deep profile control is realized. The profile control agent has high temperature resistance, is suitable for the oil deposits at the temperature of between 60 and 120 DEG C, and has a simple construction process, less moved equipment and low cost.

Description

technical field [0001] The invention relates to the technical field of petrochemical industry, and is a deep profile control agent for a high-temperature-resistant delayed cross-linked polymer, which is used for adjusting the water absorption profile of a water injection well during the water injection development process of an oil field, improving the water flooding oil sweep efficiency, and increasing the crude oil recovery rate. Background technique [0002] In the process of water injection development in oil fields, due to the heterogeneity of the formation, when the injected water breaks through in the oil well, the channeling and circumvention of the injected water are serious, often flowing along the high permeability layer and not reaching the oil-bearing low permeability layer, making The water content of oil well production fluid rises sharply, and the recovery rate of water flooding decreases, which not only seriously affects the efficiency of water flooding, but ...

AI Technical Summary

Problems solved by technology

In addition, the high-valent metal ion system usually has a fast gelation time, which is not conducive to the gel entering deep into the oil layer, and high-valent metal ions have a certain degradation effect on the gel, especially at high temperatures, using high-valent metal ions as cross-linking agents is not conducive to long-term stability of the gel

In view of this situation, researchers at home and abroad have developed organic phenolic crosslinking systems in recent years. The commonly used systems are HPAM-phenol-formaldehyde and HPAM-phenol-formaldehyde-resorcinol systems. The optimal reaction temperature of the former is 90°C , but when the temperature is higher than 90°C, the stability of the gel drops sharply, and it will degrade in a short time after the gel is formed. After the latter is gelled, the gel strength increases compared with the former, but it is only suitable for the temperature below 90°C oil reservoir

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