Corrosion inhibitor, injection

In this case, the ion-association model predicted that the connate water would require a minimum dilution with boiler feedwater of 15 percent to prevent halite precipitation (Fig. 8.23). The model also predicted that over-injection of dilution water would promote barite (barium sulfate) formation (Fig. 8.24). Although the well produced F1,S at a concentration of 50 mg/L, the program did not predict the formation of iron sulfide because of the combination of low pH and high temperature. Boiler feedwater was injected into the bottom of the well using the downhole injection valve normally used for corrosion inhibitor injection. Injection of dilution water at a rate of 25 to 30 percent has allowed the well to produce successfully since startup. Barite and iron sulfide precipitation have not been observed, and plugging with salt has not occurred. 

Conversion of cyanide to harmless thiocyanate (SCN") by injection of air or polysulfide solutions at various locations has often produced undesirable side effects, such as accelerated corrosion and fouling at stagnant-flow areas. In contrast, water washing of the compressed wet-gas streams, in conjunction with corrosion inhibitor injection, has been found to be very effective when applied correctly and consistently. 

Oxygen Scavenger Corrosion Inhibitor Figure 10.23 Injection water treatment scheme... 

Wettabihty is defined as the tendency of one fluid to spread on or adhere to a soHd surface (rock) in the presence of other immiscible fluids (5). As many as 50% of all sandstone reservoirs and 80% of all carbonate reservoirs are oil-wet (10). Strongly water-wet reservoirs are quite rare (11). Rock wettabihty can affect fluid injection rates, flow patterns of fluids within the reservoir, and oil displacement efficiency (11). Rock wettabihty can strongly affect its relative permeabihty to water and oil (5,12). When rock is water-wet, water occupies most of the small flow channels and is in contact with most of the rock surfaces as a film. Cmde oil does the same in oil-wet rock. Alteration of rock wettabihty by adsorption of polar materials, such as surfactants and corrosion inhibitors, or by the deposition of polar cmde oil components (13), can strongly alter the behavior of the rock (12). 

To meet sales specifications, gas produced at the wellheads must be free of water and hydrocarbon liquids. Twin turboexpanders are a key component in this process, providing dewpoint control with optimal efficiency. Initial processing takes place at the wellhead platforms, where methanol is injected to inhibit hydrate formation. A corrosion inhibitor is also added to prevent gas from damaging downstream equipment. 

Chemical (and Water) Tank and Pump. The pump injects water, liquid foamers and chemical corrosion inhibitors into the high-pressure air (or gas) line after compression of the air and prior to the standpipe. 

This pump is the same in principle as the piston type but differs in that the gland is at one end of the cylinder making its replacement easier than with the standard piston type. The sealing of piston and ram pumps has been much improved but, because of the nature of the fluids frequently used, care in selecting and maintaining the seal is very important. The piston or ram pump may be used for injections of small quantities of inhibitors to polymerisation units or of corrosion inhibitors to high pressure systems, and also for boiler feed water applications. 

K. C. Koshel, J. S. Bhatia, S. Kumar, and A. K. Samant. Corrosion problem in kalol injection water pipeline system and its control by using corrosion inhibitors. Ongc Bull, 25(2) 115-133, December 1988. 

Earlier corrosion inhibitors limited the maximum strength of the acid to 15% by weight. Improved corrosion inhibitors (see below) have made the use of higher acid concentrations, such as 28% HCl more common. More dilute solutions may initially be injected in sandstone acidizing to reduce the formation of insoluble sodium and potassium fluorosilicates by displacing saline formation water before injection of hydrochloric acid. 

Lubricity Additive - used to help prevent wear of high-pressure fuel injection equipment. Use is not permitted in aviation gasoline and can be used only by permission in civil jet fuel. Use is mandatory in military jet fuel grades. Topically, the corrosion inhibitor also functions in providing adequate fuel lubricity performance. 

Fuel system corrosion inhibitors must have a low tendency toward emulsification with water and toward foam enhancement in turbulent systems. These properties are especially critical whenever inhibitors are used in jet fuel. The sensitivity of jet fuel pumping and injection systems requires that fuel be free of emulsions and foam. 

A fatty acid based corrosion inhibitor can form a tenacious film on the metal surfaces of a fuel injection pump. The tight tolerances in high-pressure injection pumps require very little fluid film for proper lubrication. 

In recent years, the concern over fuel lubricity has led to the use of a high concentration of corrosion inhibitors to improve diesel fuel lubricity performance. The film formed on the metal surface by fatty acid type corrosion inhibitors improves fuel lubricity. However, the result of this overtreatment may lead to sticking of injection pump parts. 

Since HtS dissolved in water is very corrosive to carbon 4 steel, a comprehensive corrosion-control program is being conducted. In the field, each well is treated once per month by displacing inhibitor down to the perfora-. tions with stock tank oil. Corrosion coupons in the flow-lines are inspected every 6 months Little corrosion has been detected in the field. In the plants, corrosion in-hibitor is added daily to the gas-sweetening solvent, the salt water system, and the stabilizer overhead. Inhibitor is -Jj also added to bulk chemicals as received. Numerous corrosion coupons and probes are installed in each facility and are pulled for inspection every 1 to 3 months Corrosion rates have been low (less than I mil/year) asY result of the inhibitor injection program. 

Various chemicals like demulsifiers, scale inhibitors and corrosion Inhibitors arc used. Points of Injection for these chemicals are shown in tne process flow diagram. 

If materials selection depends on corrosion control by process-related measures (such as chemical treatment), these should be indicated on the MSD. Indicate the intended injection points and the type of chemical to be injected. Examples include corrosion inhibitors, scale inhibitors, biocides, pH control chemicals, wash water, etc. Also indicate the location of proposed corrosion monitoring and sampling sites. If anodic or cathodic protection is to be part of the corrosion control design, the MSD or its Notes section should indicate the piping and/or equipment to be protected. 

Another serious problem that arises in all C02 floods, and must be considered here, is corrosion. As is well known, solutions of C02 in water dissociate to form carbonic acid. This is a weak acid and does not cause much trouble in fresh water floods. However, in brine instead of pure water, C02 does become much more corrosive, and the particular composition of the brine has a great effect. These difficulties can be made worse by the presence of surfactant that can remove coatings emplaced by corrosion inhibitors. This difficulty could occur in both the injection as well as in the production facilities. In many fields, special metallurgy has been needed in critical elements of the hardware. Not much in the way of general principles can be given, except that, in designing a C02 flood, the modification of existing problems is to be expected. 

In Chapter 14 the use of additives to combat potential fouling was discussed. In the use of chemical treatment for cooling water there has to be an emphasis on effective and rapid dispersion since the concentration of the additives employed must be low, i.e. a few mg/l where possible, to minimise cost and to reduce potential pollution problems. In general the additive formulation will be based on the need to limit corrosion (i.e. the use of corrosion inhibitors), scale formation (i.e. the use of crystal modifiers, dispersants or threshold chemicals or a combination) and biofouling (i.e. the use of biocides and dispersants). In many installations additives are injected on the suction side of the main pump so that turbulence within the pump will provide rapid mixing. In very large cooling systems multiple injection nozzles will be required to enhance distribution. 

The location of the biocide injection is carefiilly chosen so that the biocide will be active in the tower as well as in the condenser tubes. Active biocides in the tower will reduce the accumulation of biofilms on the tower internals and eliminate problems from Legionella. The pH of the cooling water may also be adjusted by acid (or alkali) addition in the water entering the tower. The point of addition of scale and corrosion inhibitors is shown to be immediately before the water enters the condenser, i.e. to give maximum protection to the heat exchanger surfaces in the condenser. 

Fig. 1.17. Electron microphotograph of LDPE-based melt-blown material modified by a solid corrosion inhibitor (particles were injected into the gas-polymer flow). (1) polymer fiber, (2) a solid inhibitor particle...

Due to the presence of amine compounds in formulations of a number of corrosion inhibitors of metals, they acquire an antioxidant property for thermoplastics entering into chemisorption interactions with metals. The effect of Cl (trade marks GRM, VITAL, IFHANGAZ, MSDA, NDA, VNHL-20) on thermal oxidation and thermal resistance of polymers has been described in [34]. For investigations 5-20 wt% of Cl were introduced into the composite via mechanical mixing with dispersed polymers followed by injection molding or hot pressing of the composition. 

The types of corrosion inhibitors reqnired and their qnantities and injection frequencies... 

The nse of corrosion inhibitors has grown to be one of the foremost methods of combating corrosion. To use them effectively, the corrosion engineer mnst, first of all, be able to identify those problans that can be solved by the use of corrosion inhibitors. Second, the economics involved mnst be considered (i.e., whether the loss due to corrosion exceeds the cost of the inhibitor and the maintenance and operation of the attendant injection systen). Third, the compatibility of inhibitors with the process being nsed must be considered to avoid adverse effects such as foaming, decreases in catalytic activity, degradation of another material, or loss of heat transfer (Klechka 2001). Finally, the inhibitor mnst be applied under conditions that produce maximum effect. 

Continuous injection of corrosion inhibitors is practiced in once-through systems where slugs or batch treatment cannot be distributed evenly through the fluid. This method is used for water supplies, oil field injection water, once-through cooling water, open annulus oil or gas weUs, and gas lift wells. Liquid inhibitors are injected with a chanical injection pump. These pumps are extremely reliable and require little maintenance. Most chemical injection pumps can be adjusted to deliver at the desire injection rate (Chen et al. 2010). 

Hazardous Decomp. Prods. CO, CO2, NO ammonia, nitric acid, nitrosamines, irritating or toxic fumes NEPA Health 3, Elammability 3, Reactivity 0 Storage Store in cool, dry, ventilated area in closed containers, away from heat, flames, sparks do not store in reactive metal containers Uses Intermediate in mfg. of rubber accelerators, surfactants, dyes, polymers, DEET pesticides, textile specialties, petroleum chemicals selective solvent buffer flotation agent polymerization inhibitor in electroplating sol ns. corrosion inhibitor for metals depilatory for hides in food-pkg. adhesives in pharmaceutical injectables catalyst in food-contact PPO resins activator in food-contact rubber articles for repeated use... 

CAS 61791-64-8 EINECS/ELINCS 263-196-9 Synonyms Amines, N-coco alkyltrimethylenedi-, acetates Amines, coco alkyltrimethylenedi-, diacetates Coconut oil alkyl-1,3-propylenediamine diacetate Uses Corrosion inhibitor in waterfloods, salt water disposal systems, oil producing systems, oil field and petrochem. water injection systems biocide Trade Name Synonyms Anedco AC-196 [Anedco]... 

---