Special solid corrosion and scale inhibitor for oilfield reinjection water

Abstract

The invention discloses a special solid corrosion and scale inhibitor for oilfield reinjection water and a preparation method thereof, and belongs to a chemical composition for treatment of oilfield water. The invention particularly relates to a composition for corrosion resistance and scale inhibition in oilfield sewage treatment and reinjection processes. The corrosion and scale inhibitor is prepared from the following raw materials: 20%-50% of 40%-60% 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), 20%-50% of 40%-60% acrylic acid-maleic acid copolymer, 0-10% of 30%-60% alkyl imidazoline inhibitor, 0.1%-10% of zinc sulfate, 3%-40% of inorganic base and 10%-30% of sodium hexametaphosphate. The special solid corrosion and scale inhibitor disclosed by the invention is obtained by the raw materials through processes, such as kneading stirring, evaporating concentrating, shaping, drying and mixing. The inhibitor can be used for the water quality treatment of the oilfield reinjection water of a solid medication system, can be used for effectively reducing the decomposition of sodium hexametaphosphate in the storage period, and has very good corrosion resistance and scale inhibition effects on a reinjection water treatment system and a transportation system.

Description

technical field [0001] The invention belongs to a chemical composition used for oilfield water treatment, in particular to a composition for inhibiting corrosion and scale in the process of oilfield sewage treatment and reinjection. Background technique [0002] Oil production in my country's oilfields has generally entered the third stage, that is, fully mechanized production through reinjection of water to increase ground pressure. Oilfield reinjection water is generally hot water with high salinity, and the water injection system is prone to corrosion and scaling. For this purpose, corrosion and scale inhibitors should be added to the water injection system. The currently used corrosion and scale inhibitors are usually a composite system of organic phosphoric acid, polymeric carboxylic acid and polymeric phosphate, usually an aqueous solution. This system has good limit effect and synergy, and has the advantages of low cost, less dosage, and convenient use, but it also ...

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Problems solved by technology

[0003] 1. Since the dosage form is an aqueous solution, a large number of plastic packaging barrels are required, which leads to high packaging costs and heavy packaging weight

Recycling of packaging is required for this, increasing storage space for packaging and managing transportation costs

[0004] 2. More than 50% of the formula is water, and this part of water is an invalid component, which will increase the transportation cost of materials

[0005] 3. In order to reduce packaging volume and transportation costs, it is usually formulated into a formulation with a high solid content of more than 30%. This formulation is easy to crystallize and solidify in winter in the north, which adds a lot of inconvenience to practical applications

[0011] Although the above inventions have changed the dosage form of the existing corrosion and scale inhibitors, they are mainly for the purpose of slow release and are suitable for downhole treatment of remote oil wells. The advantages are that they can greatly reduce the workload of dosing and increase the stability of scale inhibitors. Disadvantages: ⑴The concentration in the aqueous solution should not be adjusted due to changes in the release rate and water flow, ⑵Due to the slow dissolution rate, it is not suitable for solid dosing equipment for large water treatment

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