Salt-resistant polyacrylamide for oil displacement and preparation method thereof

Abstract

The invention relates to salt-resistant polyacrylamide for oil displacement. The salt-resistant polyacrylamide is prepared from the following components in parts by weight: 770-840 parts of deionizedwater, 150-260 parts of acrylamide, 10-30 parts of an anionic monomer and 5-40 parts of functional monomer microemulsion. The invention further relates to a preparation method for the salt-resistant polyacrylamide for oil displacement. According to the salt-resistant polyacrylamide and the preparation method thereof, the functional monomer is introduced into a polymerization formula, so that sulfate-reducing bacteria, iron bacteria, saprophytic bacteria and the like in sewage can be inhibited, the viscosity retention rate of the salt-resistant polyacrylamide for oil displacment in the sewage for 180 days is greater than 90%, and therefore the viscosity retention rate of the polyacrylamide in the sewage is greatly increased; and meanwhile, the functional monomer adopts a microemulsion preparation mode, blocks in a molecular structure of a product are more uniform, the solubility of the product is greatly improved, and therefore the problem that conventional polyacrylamide is dissolved slowly in the sewage or in high-salinity brine can be solved.

Description

technical field [0001] The invention belongs to the technical field of petroleum exploitation, and in particular relates to a salt-resistant polyacrylamide for oil displacement and a preparation method thereof. Background technique [0002] With the increase of oil field exploitation depth, the temperature and salinity of the oil layer are also increasing, and in the process of oil field development, in order to improve the recovery rate, the method of artificial water injection is often used to replenish energy to the oil layer and increase the pressure of the formation. The water content of crude oil continues to rise. After the produced crude oil is demulsified, the oil and water phases are separated. However, the oilfield produced water contains a large amount of organic substances, which provide a good environment for the growth of a large number of bacteria. Among them, sulfate-reducing bacteria, iron bacteria, and saprophytic bacteria can corrode pipeline equipment a...

AI Technical Summary

Problems solved by technology

However, the oilfield produced water contains a large amount of organic substances, which provide a good environment for the growth of a large number of bacteria. Among them, sulfate-reducing bacteria, iron bacteria, and saprophytic bacteria can corrode pipeline equipment and block oil layers, causing serious consequences to oilfield production.

Moreover, the viscosity retention rate of the polymer mother liquor prepared with existing sewage is low

At the same time, ordinary polyacrylamide is not resistant to temperature and shear, and cannot effectively flush the formation, so that ordinary polymers are no longer suitable for the production of this oil layer, and the oil recovery rate of existing polymers is also constantly declining. Therefore, affected by shear factors such as water quality, some high-temperature oil reservoirs, high-salinity oil reservoirs, and field equipment, higher requirements are placed on the performance of polymer products such as sewage resistance, adaptability, shear resistance, temperature resistance and salt resistance.

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