Scale and corrosion inhibition method combining chemical huff and puff with water-shutoff

Abstract

The invention discloses a chemical throughput and water-block combined dirty-proof corrosion-abating method, which is realized by providing dirty-proof corrosion-abating agent, selective block agent and corresponding working-liquid injection technology. The dirty-proof corrosion-abating agent is diethylenetriamine five methylene phosphinic acid, the selective block agent is a copolymer of acrylamide and 3-acrylamide base-3-methyl butyl three-methyl ammonium chloride. The injection technology is that brine mixed with clay anti-swelling agent as an ahead fluid is injected to ground layer, dirty-proof corrosion-abating liquid is then injected, right amount of ground layer water or brine as post liquid is injected afterward, and selective block agent is injected finally. The oil well is closed and stewed for 16 to 24 hours after injection before reproduction. By employing said technology, the dirty-proof corrosion-abating agent is injected into near wellbore zone of the oil well, the block agent selectively blocks the water and the dirty-proof corrosion-abating agent is sealed and blocked in pore space medium of the ground layer, and the dirty-proof corrosion-abating agent is brought into borehole, ground pipe line and equipment by the ground layer fluid continuously, which carries out continuously releasing with long-time dirty-proof corrosion-abating efficiency.

Description

Technical field: [0001] The invention relates to a method for solving fouling and corrosion of well shafts, surface pipelines and equipment in the technical field of oil and gas field development engineering. Background technique: [0002] With the continuous implementation of water injection development in oilfields, the water content in the oil well produced fluid is getting higher and higher, which causes scaling and corrosion problems in the wellbore and surface pipeline equipment to become more and more serious. [0003] There are mainly physical and chemical methods for oilfield scaling and corrosion prevention and control. Because the chemical method has the advantages of low cost and obvious effect, it is widely used in oil fields. The scale and corrosion inhibition effect of chemical method is not only related to the type and amount of scale and corrosion inhibitor used, but also has a lot to do with the way of adding scale and corrosion inhibitor. There are two w...

AI Technical Summary

Problems solved by technology

The advantage of the continuous injection method is that the concentration of the scale and corrosion inhibitor is easy to control, but the disadvantage is that the operation is complicated; the advantage of the solid block method is that the operation is simple, but the disadvantage is that the concentration of the scale and corrosion inhibitor is not easy to control

Regardless of the continuous injection method or the solid block intermittent input method, they only add scale and corrosion inhibitors in the wellbore or at the bottom of the well, and there is no way to squeeze the scale and corrosion inhibitors into the formation near the wellbore

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