Treatment method for oil field acidic sewage

Abstract

The invention discloses a treatment method for oil field acidic sewage. The method is characterized by comprising the steps that firstly, air or nitrogen and oil field acidic sewage form parallel flow for gas-liquid mixing through a tubular static mixer, the gas-liquid volume ratio is controlled to be 2.5-3.0 at the temperature of 55-65 DEG C, the gas-liquid dispersion degree is smaller than 0.5 mm, and the time spent by the parallel flow in passing through the tubular static mixer is 2-5 seconds, the Reynolds number of the gas-liquid mixed flowing state is larger than 3000, then, sewage with acidic gas desorbed through gas-liquid hydrocyclone separation is fed into the flocculation and sedimentation procedures, and finally water with sediments separated out through flocculation and settlement is drained out. The method is adopted for treating the oil field acidic sewage, and the pH value of the sewage can be increased from 5.5-7.0 to 7.0-7.5. Meanwhile, the sewage corrosion rate can be controlled within 0.02 mm / a. According to the method, no alkaline chemical agent is added; the rapid and efficient gas-liquid mixing method is adopted, so that the equipment scaling possibility is effectively decreased. The method is used before flocculation and settlement of oil field sewage, can remarkably improve the flocculation and settlement effect and can effectively lower the dosage of a flocculant.

Description

Technical field: [0001] The invention relates to a technical method for rapidly increasing the pH value of oilfield acid sewage, and belongs to the field of oilfield sewage treatment. technical background: [0002] When oilfield wastewater contains CO 2 When such acid gas is present, the sewage is often acidic and highly corrosive. At the same time, in the process of sewage treatment, due to the existence of acid gas, acid gas overflow occurs continuously, which makes the pH value of sewage continuously increase and change. The acid gas overflow process in sewage is often uncontrolled. When the sewage has a high salt content and has a tendency to scale, it will lead to excessive suspended solids in the subsequent export process. Therefore, as oilfield acid wastewater used for reinjection after treatment, there are often two outstanding problems of corrosion and suspended solids exceeding the standard. A large number of studies have shown that the corrosiveness of acidic s...

AI Technical Summary

Problems solved by technology

This method also has problems such as serious fouling of equipment, and high investment, slow speed and low efficiency

To sum up, in order to improve the pH value of oilfield acidic sewage, the shortcomings of the existing technology are mainly the use of chemical agents, high energy consumption, and high cost, especially in the slow speed of increasing the pH value of sewage. In practical applications, it is inevitable to produce equipment Scaling and other problems

Images