Oil and Gas Water Treatment Analysis 2018
Relying on the formation of natural pressure oil production is called “primary oil recovery.” As the formation pressure drops, it is necessary to use the water injection pressure method to produce oil called “secondary oil recovery”. According to calculations, primary oil recovery can only reach 20%-30% recovery, and secondary oil recovery can only reach one-third of formation reserves.
In order to extract the remaining reserves, physical, chemical and biological methods are needed to enhance the recovery factor, called EOR, or “third oil recovery”. Most of the developed oil fields have entered the middle and late stage of oil recovery, but they are still in the stage of secondary oil recovery.
Oil and gas water treatment is mainly oily sewage treatment. In particular, the water-bearing process requires a large amount of water to re-inject the formation, and the use of oily wastewater re-injection will cause pollution of the underground oil layer and requires pre-treatment. Water injection and oil recovery are commonly used, so sewage treatment reinjection is extremely important for oil recovery.
Demulsifiers: Although there are many types of demulsifiers, the main types of demulsifiers are the following: oils and derivatives, sulfonates, petroleum sulfonates, alkylnaphthalenesulfonates, alkylphenol ethoxylates, polyoxyethylenes. , polyoxypropylene block copolymer, sodium naphthenate, and the like.
Fungicide: The bactericide used in oilfield refilling water includes organic and inorganic, inorganic is mainly chlorine, and organic includes aldehyde, quaternary ammonium salt, phenol, imidazoline, strontium salt and the like. The use of fungicides in water treatment in oil fields is less than in foreign countries. Mainly used quaternary ammonium salt fungicides and their compound products. In recent years, many units have cooperated with oil fields or developed some new fungicides. Usually, the dosing concentration is several tens of milligrams per liter.
Corrosion inhibitor: In the oilfield development process (especially secondary oil recovery), the sewage from the crude oil is an important source of oilfield water injection. However, due to the high salinity of the sewage, the high temperature, and the dissolution of certain corrosive substances, the sewage treatment equipment, and pipelines are seriously corroded, and corresponding anti-corrosion measures are required.
Adding corrosion inhibitors is commonly used at home and abroad. A simple, economically viable method. A variety of corrosion inhibitors have been developed for different corrosive media, mainly organic salts of fatty amines, fatty amides, adducts of fatty amines and ethylene oxide, imidazoline derivatives, quaternary ammonium salts, amine-substituted thio Phosphonates, phosphinates or thioethers, nitrogen-containing polycyclic rings with lipophilic groups.
Flocculant: inorganic substances mainly include iron salts and aluminum salts such as ferric chloride, aluminum sulfate, ferrous sulfate, polyaluminum chloride, potassium vanadium; organic compounds are mostly water-soluble polymers, such as cellulose, galactomannan Glycans, partially hydrolyzed polyacrylamides, and the like. For example, high-molecular-weight polysaccharides such as high-molecular-weight polysaccharides and cellulose derivatives in Shengli Oilfield, CG-A high-efficiency flocculant, are widely used in oil fields.
Drag reducing agent: multi-line polymer. In the 1980s, Chengdu University of Science and Technology developed a high-grade acrylic drag reducing agent, which has a good effect in Daqing Oilfield; many research units are engaged in this research. However, it has not been applied on a large scale.
The oil and gas water control method includes water softening technology, magnetic anti-scaling technology, and adding water treatment chemical corrosion and scale inhibitor. It is generally accepted that the most promising measures to control corrosion and scaling are suitable corrosion inhibitors and choices for scale inhibitors. The high-efficiency compound scale inhibitor is developed for the specificity of oilfield wastewater. Considering the corrosion and scale inhibition and oil production working conditions, it can effectively control oil and gas water pollution. The dosage is small, the cost is low, the corrosion inhibition and scale inhibition effect are good, and the product has good value.