In the oil industry there are various problems that cause daily losses of millions of dollars caused by fall in crude oil production, as well as failures by wear of pipelines and equipment, predominantly from problems of corrosion and deposition of asphaltenes, which is why a global investigations are aimed at generating solutions through a variety of methods to minimize such problems.
Corrosion is a phenomenon that generates millions of dollars in losses in the oil industry because it occurs in virtually all oil production chain from farm to processing.
Corrosion is considered the progressive wear of a metallic material due to its interaction with the surrounding environment.
The particular case of the production and exploration operations for oil, the corrosion phenomenon is directly related to the presence of inorganic salts, hydrogen sulfide, organosulfur compounds, organic acids and carbon dioxide.
The corrosion phenomenon is also commonly found in transportation and storage of products derived from oil refining as gasoline without desulfurize, gasoline with low sulfur, diesel, alkylated gasoline, jet fuel, kerosene, methyl tertiary butyl ether and others.
Usually in the oil industry, the problems of asphaltene deposition and corrosion have been controlled through the use of chemicals, asphaltene inhibitors and dispersants and corrosion inhibitors, which are composed of two main parts known as the head (hydrophilic part) and tail (hydrophobic part).
The particular case of inhibiting and dispersing asphaltenes, the head (hydrophilic part) is a polar group whose function is to interact with the aromatic rings or polar groups of the asphaltenes, while the tail (hydrophobic part) is an aliphatic chain can be linear or branched and which performs the function of forming a stearic barrier that prevents asphaltene molecules interact with each other.
With regard to the phenomenon of corrosion inhibition, corrosion inhibitors widely used in the oil industry are the type of film that is characterized by its molecular structure a head (hydrophilic part) that interacts with the metal surface through two main mechanisms: physisorption, which occurs through an electrostatic attraction and chemisorption manifested through a coordination bond between metal and an atom capable of transmitting electrons, and a tail (hydrophobic part) that can repel water molecules trying to pass into the metal surface.
Because of one of the most economical methods for the prevention and control of these problems is the use of chemical products, the research in this area focuses on the development of chemical compounds that are able to work with more efficient means increasingly aggressive, in addition to complying with environmental regulations that currently govern their use.
Oil is a complex mixture of organic compounds which are broadly classified as: 1) Saturated, 2) Aromatic, 3) Resins and 4) Asphaltenes.
Of these fractions, asphaltenes play an important role because they are one of the fractions that cause more problems as a result of precipitation originating with this, clogging the pores of reservoir rock, clogging pipes, with a consequent fall in crude oil production and therefore the closure of wells, wear on equipment, high costs of maintenance and repair of equipment, among others.
From a chemical structural point, the asphaltene molecular rings are added polyaromatic containing small amounts of heteroatoms (sulfur, nitrogen and oxygen), trace metals (iron, nickel and vanadium), branching linear paraffin and features held together mainly by the type supramolecular interactions π-π. These structural features lead to the asphaltenes are more polar fraction in crude oil and tend to precipitate to changes in temperature, pressure and composition are presented in collection, transport or processing of crude oil.
The phenomenon of precipitation of asphaltenes in crude oil occurs when favorable conditions of temperature, pressure and composition, asphaltene particles small, low molecular weight, are associated, grow and generate larger and heavier aggregates that become insoluble in the medium. The high molecular weight and polar nature of these asphaltenes generated that they are disseminated to the bottom of the reservoir, piping or equipment and to adhere firmly to the walls themselves. This phenomenon is known by the name of asphaltene deposition.
It is noteworthy that in the literature does not exist examples of chemical compounds that are capable of inhibiting corrosion and inhibit and dis asphaltenes dispersed through the same molecular structure.
Important examples of corrosion inhibitors used in acid characteristic of the oil industry, we have the following references:
U.S. Pat. No. 3,623,979 discloses obtaining compounds of basic 1-aminoalkyl-2-alkyl imidazolines and their use as corrosion inhibitors for ferrous metals in acidic characteristic of the oil industry. The efficiency of corrosion inhibition of these compounds was evaluated by gravimetric techniques.
U.S. Pat. No. 3,629,104 discloses obtaining organic acid salts of basic compounds derived from 1-aminoalkyl-2-alkyl imidazolines and their use as corrosion inhibitors for ferrous metals in acidic characteristic of the oil industry. The efficiency of corrosion inhibition of these compounds was evaluated by gravimetric techniques.
U.S. Pat. No. 3,390,085 discloses the mixture of imidazoline salt prepared from the reaction of a fatty acid having 6 to 18 carbons with imidazoline selected from the group consisting of 1-aminoalkyl-2-alkyl hydroxyalkyl imidazoline and 1-alkyl-2-imidazolines and their application as corrosion inhibitors in acidic characteristic of the oil industry.
U.S. Pat. No. 4,388,214 discloses corrosion inhibitors synthesized from the reaction of imidazoline or imidazoline salts with sulfur. These compounds are particularly useful for inhibiting corrosion of metal containers caused by carbon dioxide and hydrogen sulfide during transport and storage of crude oil.
U.S. Pat. No. 5,062,992 discloses a corrosion inhibiting formulation for oil and water systems, wherein the formulation is resistant to sludge formation and not to stabilize emulsions water/oil. The corrosion inhibitor includes an imidazoline dissolved in an aromatic solvent, a 2-hidroxyalkylcarboxylic acid and glycol. The imidazoline is preferably prepared from the reaction of a long chain fatty acid and a polyamine.
Important examples of corrosion inhibitors used in piping, tanks and other combustible liquid handlers references are presented below:
U.S. Pat. No. 4,214,876 (corrosion inhibiting composition) discloses the development of a formulation of the corrosion inhibition for ferrous metals exposed to hydrocarbon fuels made from 75 to 95% of an unsaturated aliphatic carboxylic acid of 16 to 18 carbons and 5 to 25% of a monoalkenyl succinic acid with a chain from 8 to 18 carbons, and to use as a solvent hydrocarbon compounds.
U.S. Pat. No. 4,509,951 (Corrosion Inhibitor for alcohol-based fuels and gasoline-alcohol mixtures) discloses the development of a formulation of the corrosion inhibition for ferrous metals exposed to liquid motor fuels based on alcohol-gasoline blends alcohol consisting of a carboxylic acid poly-unsaturated aliphatic 18-carbon, and the reaction product of a polyamine with a carboxylic acid alkenyl monounsaturated 18-carbon aliphatic or alkenyl succinic anhydride from 8 to 30 carbons.
U.S. Pat. No. 4,511,366 (Liquids fuels and concentrates containing corrosion inhibitors) discloses the development of a formulation of the corrosion inhibition for ferrous metals exposed to liquid alcohol-based fuel or gasoline-alcohol mixtures composed of an aliphatic carboxylic acid poly-unsaturated 16 to 18 carbons and an alkenyl polyamine.
U.S. Pat. No. 4,737,159 (Corrosion inhibitor for liquid fuels) discloses the development of a formulation of the corrosion inhibition for ferrous metals exposed to liquid hydrocarbon fuels made from 35 to 70% by weight of a succinic acid monoalkenyl with a chain ranging from 8 to 18 carbons and 30 to 65% of aliphatic or cycloaliphatic amine containing from 2 to 12 carbons and solvents and aromatic hydrocarbon compounds alcohols of 1 to 4 carbons.
Examples in the literature that mention the development of chemical compounds and their application in crude oil to inhibit or disperse asphaltene deposits can be mentioned the following patents: U.S. Pat. No. 7,122,113, U.S. Pat. No. 7,122,112, U.S. Pat. No. 7,097,759, U.S. Pat. No. 6,946,524, U.S. Pat. No. 6,313,367, U.S. Pat. No. 6,204,420 and U.S. Pat. No. 6,180,683.
U.S. Pat. No. 7,122,113 relates to the use of dendrimeric compounds to solubilize asphaltenes in a mixture of hydrocarbons. Preferably the dendrimeric compound is a hyperbranched polyester amide preferably constructed from succinic anhydride, diisopropanolamine and functionalized with polyisobutenyl succinic anhydride.
U.S. Pat. No. 7,122,112 relates to the development of compounds of structural formula (1):
that specifically contain within their structure carboxyl and amide groups, and its application as a dispersant of asphaltenes in crude oil. Within the structural formula (1), R5 is a difunctional alkyl group can vary from C1 to C70 and R3 and R4 are independent radicals that can be represented by aryl groups, alkyl, alkyl aryl, heterocyclic or hydrogen. The patent also indicates that these compounds increases demulsibility, reduce viscosity, the formation of sediments, surface fouling and corrosion.
U.S. Pat. No. 7,097,759 relates to the development of compounds of structure formula (2):

Specifically to contain within its structure a carbonyl group, thiocarbonyl, or imine, and its application as a dispersant of asphaltenes in crude oil. Within the structural formula (2), R14 is an alkyl group that may vary from C15 to C21. The patent also indicates that these compounds increases demulsibility, reduce viscosity, the formation of sediments, surface fouling and corrosion.
U.S. Pat. No. 6,946,524 relates a process for producing polyester-amides by reacting a polyisobutylene with a first agent selected from the group consisting of monounsaturated fatty acid having 3 to 21 carbon atoms and derivatives thereof, and a second agent selected group consisting of monoethanolamine and alkylamines of structural formula (3):R—NH2  (3)where R represents an alkyl group having from 1 to 4 carbon atoms. The polyester-amides produced are used as stabilizers of asphaltenes in crude oil and crude oil derivatives.
U.S. Pat. No. 6,313,367 discloses that several esters and reaction products of ethers are excellent asphaltene dispersants or inhibitors and may be used in hydrocarbons such as crude oil. Asphaltene inhibitor compounds include 1) esters formed from the reaction of polyhydric alcohols with carboxylic acids, 2) ethers formed from the reaction of glycidyl ethers or epoxides with polyhydric alcohols and 3) esters formed from the reaction of glycidyl ethers or epoxides with carboxylic acids.
U.S. Pat. No. 6,204,420 discloses the development of a new formulation where the asphaltene dispersing action of carboxylic acids can be greatly improved by the addition of relatively small amounts of esters derived from alkylphosphoric acids. The formulation consists of: A) 5 to 99% by weight of a carboxylic acid having more than 4 carbon atoms, an alkyl ethercarboxylic acids with alkyl substituents of C18-C22, C18-C22 substituents of alkenyl or C6-C18 substituents of alkylaryl, amidecarboxylic acid or a mixture thereof and B) 1 to 95% by weight of a phosphoric acid mono or diester or mixture thereof, which is substituted by an alkyl group of C18-C22, C18-C22 alkenyl, C6 alkylaryl-C18 or alkoxylated. Where the sum of A and B is 10% by weight.
U.S. Pat. No. 6,180,683 discloses the development of a new formulation with synergistic effect as asphaltene dispersant. The formulation is composed of 5 to 95% of a compound of structural formulas I or II.
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