Composite water deoxidizing agent for wet steam generator

Abstract

A composite water-deoxidizing agent as a kind of compositve water treating agent consists of ammonium sulfite 15-40 wt% and organic amine 0-10 wt% beside the rest of water. It is used in water treatment of steam boiler and can reduce oxygen content in water from 0.1-0.4 mg / l to less than 0.01 mg / l and raise water pH value from 7.0-7.5 to 8.3-9.0. The treated water has no corrosion to pipeline and no damage to oil layer. Its ammonium sulfite may be produced by absorbing SO2 in waste gas with ammonia water, and this can protect environmental and reduce water treating cost. The composite water deoxidizing agent of the present invention has high deoxidizing effect and reduced corrosion to pipeline.

Description

technical field [0001] The invention provides a water quality composite treatment agent, especially an oxygen scavenger. Background technique [0002] In order to exploit heavy oil, crude oil production enterprises need to inject wet steam downhole. The wet steam generator (steam injection boiler for short) is a high-temperature and high-pressure equipment with an operating pressure of 17.2 MPa and generates wet steam with a dryness of 80%. It has very strict requirements on the water quality of steam production water. The key indicators are: hardness of zero milligrams per liter, oxygen content less than 0.01 mg / l, and pH value between 8.3 and 9.0. Because the water quality did not meet the requirements and the pipelines were seriously corroded, the furnace tubes and steam injection pipe network explosion accidents occurred many times in crude oil production enterprises, which not only caused serious economic losses, but also brought considerable damag...

AI Technical Summary

Problems solved by technology

The disadvantage of using sodium sulfite as an oxygen scavenger in domestic oil fields is that when the oxygen content in water is less than 1mg / l, a large excess of sodium sulfite is needed, and when the pressure exceeds 7MPa, the excess sodium sulfite is easy to decompose, resulting in extremely corrosive Strong hydrogen sulfide, sulfur dioxide and other compounds will cause acidic corrosion to pipelines, while the decomposed sodium ions will form extremely strong alkaline substances, which not only easily cause "alkali embrittlement" corrosion of steel pipelines and equipment, but also Afterwards, the formation will be corroded, causing dissolution and subsidence in the near area and condensation blockage in the far area, reducing the permeability of the formation and affecting the oil recovery rate