Environment-friendly low-phosphorus composite scale inhibitor suitable for coexistence working condition of calcium carbonate, calcium sulfate and barium sulfate as well as preparation method and application of environment-friendly low-phosphorus composite scale inhibitor

Abstract

The invention discloses an environment-friendly low-phosphorus composite scale inhibitor suitable for the coexistence working condition of calcium carbonate, calcium sulfate and barium sulfate as well as a preparation method and application of the environment-friendly low-phosphorus composite scale inhibitor. The composite scale inhibitor is prepared from the following raw materials in percentage by mass: 15 to 40 percent of a polycarboxylic acid scale inhibitor, 13 to 25 percent of an organic phosphate, 2 to 5 percent of zinc salt and the balance of water. The organic phosphate is a mixture of at least one of 1, 2, 4-tricarboxylic acid-2-phosphoric acid butane and amino trimethylene phosphonic acid and sodium ethylenediamine tetramethylene phosphonate, the polycarboxylic acid scale inhibitor is sodium polyaspartate, and the zinc salt is zinc sulfate. The prepared composite scale inhibitor has excellent scale inhibition effects on CaCO3, CaSO4, BaSO4 and the like at the same time, the scale inhibition rate reaches 90% or above, and the scale inhibitor is in a liquid state, can be directly pumped into a pipeline through a metering pump, and is especially suitable for a working condition environment where multiple scales coexist in an oil field water treatment technology.

Description

technical field [0001] The invention belongs to the technical field of oilfield industrial water treatment, and in particular relates to an environment-friendly low-phosphorus composite scale inhibitor suitable for coexistence conditions of calcium carbonate, calcium sulfate and barium sulfate, and a preparation method and application thereof. Background technique [0002] After the oil field is put into development, with the increase of production time, the energy of the oil layer itself will be continuously consumed, resulting in a continuous drop in the pressure of the oil layer, a large amount of degassing of the underground crude oil, an increase in the viscosity, a great reduction in the production of the oil well, and even the stop of spraying and production, resulting in underground A large amount of dead oil remains and cannot be recovered. In order to make up for the underground deficit caused by the extraction of crude oil, maintain or increase the pressure of the...

AI Technical Summary

Problems solved by technology

These sediments accumulate on the surface of the oil casing and various equipment and will scale, often causing the oil pump to be stuck, the annulus between the well pipe and the sucker rod to be blocked, and the inner diameter of the gathering and transportation pipeline to decrease sharply. It may even cause problems such as serious blockage of equipment and formations, which greatly affects the normal production of oil fields, and even causes oil and gas wells to be forced to stop production in severe cases

[0004] Antiscalants currently on the market generally only target CaCO 3 Scale, CaSO 4 Scale or BaSO 4 A single scale in the scale has a good scale inhibition and dispersion effect

However, in actual working conditions, multiple scales often coexist at the same time. However, the mixed treatment effect of multiple scale inhibitors is not good, and there are problems of adaptation and fusion. In addition, the country has attached great importance to environmental protection in recent years. Therefore, it is urgent to develop a low-efficiency Phosphorus, a composite antiscalant that efficiently removes a variety of scaling coexistence

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