I. Introduction
In the oilfield injection system, due to the incomplete reaction of alkali and carbon dioxide to form anionic carbonate or bicarbonate, and combined with cations (calcium ions, magnesium ions and barium ions, etc.) in water, inorganic salt scaling occurs in underground reservoirs, pump heads, pump valves, static mixers, injection pumps and wellbores of oil production wells, and in the pipelines of surface oil and gas gathering and transportation equipment. The produced fluid changes with temperature, pH value and friction, resulting in a large amount of fouling in the wellbore. These fouling problems often lead to disruptions to normal production processes, reduced chlorine production, and increased costs. Therefore, the research and use of scale and corrosion inhibitors have always attracted people's attention.
2. Scale and corrosion inhibitor formula 1
Here is a formulation of an efficient, phosphorus-free, environmentally friendly scale and corrosion inhibitor for oilfield systems. It is especially suitable for the oilfield system with high alkalinity, high salinity, high chlorine, serious silicate scale, and the components of the formula of the present invention have good compatibility, synergy and complementarity, and its scale inhibition rate can be as high as 999%, the corrosion inhibition rate can be as high as 985%。
Raw materials: Polymaleic anhydride is a brownish-yellow or brownish-red transparent liquid, which is polymerized from maleic anhydride and can be used as a thickener, preservative, scale inhibitor and dispersant.
Polyepoxy succinic acid is a nitrogen-free, non-phosphorus organic compound, which has the dual effects of scale inhibition and corrosion inhibition, good biodegradation performance and is suitable for high alkali and high metal content water system, and is a green water treatment chemical.
Raw material ratio:
Preparation method: Polymaleic anhydride and water are added to the reaction kettle, and stirred at room temperature for 20 30min to fully hydrolyze;
Add zinc sulfate, sodium diethyl dithiocarbamate, thiourea and disodium ethylenediaminetetraacetic acid to the reaction kettle, stir for 20 30min to fully dissolve the ingredients;
Polyepoxy succinic acid is added to the reaction kettle, and the product is obtained by stirring evenly.
3. Scale and corrosion inhibitor formula 2
The dosing process of this product is simple, the corrosion inhibition and scale inhibition effect is obvious, and the quaternary ammonium salt and zinc salt play a synergistic role.
Raw material ratio:
Dodecyldimethylbenzylammonium chloride (1227) is a cationic surfactant, a non-oxidizing fungicide, with low toxicity, no accumulation of toxicity, soluble in water, with broad-spectrum, efficient sterilization and algae killing ability, can effectively control the reproduction of bacteria and algae in water and the growth of slime sludge, and has a good slime stripping effect and a certain dispersion and penetration effect, and has a certain degreasing, deodorizing ability and corrosion inhibition effect.
Hydroxyethylene diphosphorite has good scale and corrosion inhibition effect, and has the characteristics of high temperature resistance, good oxidation resistance, low toxicity, etc., mainly used for scale and corrosion inhibition of industrial circulating cooling water, because this product can form a stable complex with iron, copper, aluminum, zinc and other metal ions, so it can be used to clean rust and inorganic salt scale in boilers and pipelines.
Preparation method: Mix the two evenly in proportion.