Use method of self-generated gel for water plugging profile control and flooding

Abstract

A use method of self-generated gel for water plugging profile control and displacement comprises the following steps: adding sodium alginate into a dispensing tank with wastewater under stirring to form the self-generated gel; adding a polymer in a water plugging profile control and flooding cross-linking system, and uniformly stirring; adding the rest components in the water plugging profile control and flooding cross-linking system 20-400 minutes before extrusion injection, then performing extrusion injection construction, enabling the self-generated gel and the water plugging profile control and flooding cross-linking system to form a mixed multiphase water plugging agent under stirring, and extruding the mixed multiphase water plugging agent into a well under the action of an injectionpump. Sodium alginate in the self-generated gel reacts with calcium and magnesium ions in wastewater to generate self-generated gel particles with very stable performance; therefore, the content of calcium and magnesium ions in the wastewater can be greatly reduced due to the generation of the self-generated gel particles, the concentration of the calcium and magnesium ions is greatly reduced dueto the generation of the self-generated gel particles, and the dissolving speed and viscosity of the polymer in a profile control and flooding system are improved. The investment cost of wastewater treatment can be greatly reduced, the yield increase range is increased, and economic benefits are obviously increased.

Description

technical field [0001] The invention relates to a gel suitable for the environment of high salinity and high calcium and magnesium ion oil field production sewage, in particular to a method for using self-generated gel for water plugging and flooding, which belongs to the technology of water plugging and flooding of oil and water wells in oil fields field. Background technique [0002] Oilfield produced sewage contains high concentrations of calcium and magnesium ions, which will have a very serious negative impact on the performance of the gel system used for water plugging and flooding. Calcium and magnesium ions will seriously affect the solubility of polymers. Due to the high concentration of calcium and magnesium ions in the extracted sewage, it is difficult for the polymer to dissolve, and the dissolution time is too long, which cannot meet the requirements of the operation; it will greatly reduce the solution viscosity of the polymer, and affect the plugging of the ca...

AI Technical Summary

Problems solved by technology

[0002] Oilfield produced sewage contains high concentrations of calcium and magnesium ions, which will have a very serious negative impact on the performance of the gel system used for water plugging and flooding. Calcium and magnesium ions will seriously affect the solubility of polymers. Due to the high concentration of calcium and magnesium ions in the extracted sewage, it is difficult for the polymer to dissolve, and the dissolution time is too long, which cannot meet the requirements of the operation; it will greatly reduce the solution viscosity of the polymer, and affect the plugging of the carried particles in the water plugging system. The characteristics of the agent; it will greatly weaken the cross-linking properties of the gel and the stability of the gel after the gel is formed, and finally greatly reduce the plugging rate and validity period of water plugging and flooding

[0003] Ordinary polymers or polymers with general salt resistance are affected by the high concentration of calcium and magnesium ions in the sewage or the calcium and magnesium ions in the formation, the success rate of water plugging and flooding is low, and the validity period is very short.

[0004] At present, the price of good salt-resistant polymers on the market is very expensive, and the amount of water plugging and flooding is large. If good salt-resistant polymers are used, the cost of measures will be greatly increased, so the application is limited.