US3096819A - Method and composition for preventing corrosion - Google Patents

Description

July 9, 1963 w. s. WHITE, JR., r-.TAL 3,096,819

METHOD AND COMPOSITION FOR PREVENTING CORROSION Filed May 22, 1959 /n Ven fari.

UnitedStates Patent O 3,096,819 METHOD AND COMPUSlTION FR PREVENTING CORROSION William S. White, Jr., Midland, and Jackson L. Babb and John H. McGuire, Odessa, Tex., assignors to Champion Chemicals, Inc., Odessa, Tex., a corporation of Texas Filed May 22, 1959, Ser. No. 815,195 3 Claims. (Cl. 166--1) This Iinvention pertains tto corrosion prevention and more particularly to the petroleum industry and the prevention of corrosion in gas carrying lines and wells.

In the petroleum industry a problem exists with oorrosion. Advances have been made toward the prevention of corrosion with liquid petroleum by the introduction of certain polar or iilming amines. These corrosion ininhibiting amines may -be introduced into the liquid petroleum and as they have an ainity for metal they will seek the metal surfaces and form a single molecular coating thereon. Periodically additional inhibitor may be introduced into the liquid to maintain the coating intact. In the case of wells the coating may be introduced into the well by various back-washing techniques or otherwise.

However; this procedure is not adapted to petroleum in a gaseous state. The inhibitors are normally in a solid or liquid state. If the conduit carrying the gas were hozontal, liquid in the line would form a stream along the bottom of the line and not Contact the remainder of the interior of the line fand therefore not coat it. If the conduit were vertical, as in the case of la well, it would not be practical to coat it in this manner.

An object of our invention is to prevent the corrosion of gas carrying conduits.

Another object is to provide a method for coating the interior of conduits carrying gases, said coating being introduced as the conduit is in use.

Another object of our invention is to provide Ia composition of materials adapted to be introduced into the normal gas stream of a gas carrying conduit while in use for the purpose of coating the interior thereof.

Further objects are to achieve the above in a manner that is simple land reliable, not requiring fragile or bulky equipment, yet is inexpensive and easy to operate.

T-he speciiic nature of the invention as well as other objects, uses, and advantages thereof will clearly appear from the following description and the accompanying drawings in which:

FIG. 1 is a schematic representation of a gas well using one form of this invention.

FIG. Z is a schematic representation of a gas well using a second form.

As may be seen in the accompanying drawings, one specific embodiment of this invention pertains to the protection of production string A which extends within a lWell B from the surface to gas bearing sand C, far beneath the surface.

As stated above, the problem is that the gas in the gas bearing sands contains corrosive substances such as carbon dioxide or hydrogen sulfide. There exists today certain corrosion inhibiting materials which are well adapted to prevent corrosion `of the production string A by these substances. An example of such materials is a product of Champion Chemical, Inc. known by its trademark Cortron which is a `form of a polar lming amine. More specifically, the polar iilming lamine may be described' as a primary, secondary, or tertiary amine in form of aliphatic or cyclic molecules containing one or more amine 3,096,819 Patented July 9, 1963 ice groups, normally neutralized with some type high molecular weight organic acid. Such polar filming amines are disclosed in lU.S. Patent No. 2,856,211.

To get these rust inhibitors upon the inside surface of the production string, we insert tube l10 of small diameter within the production string. This tube extends to nozzle =12 at the bottom of the production string. Spacer 14 centers the nozzle within the pipe or string. Liquid inhibitor is introduced at the surface of the ground into the tube 10. The inhibitor may be mixed with diluents or vehicles. The hydrostatic head of the fluid in the tube sometimes will be sufcient to cause it to atomize or break into a very ne spray or mist when it is ejected from the nozzle 12. At other times la pump will be necessary to obtain the pressures necessary. The mist is carried upward by the gas being produced by the well so that it has an opportunity to come in contact with the surface of the conduit. If it is a filming amine, it will be attracted to and :adhere to the surface because of its natural aiinity for metal. Otherwise any other coating will adhere to the surface of the pipe because of its nature. If the well is so deep that it is impractical to introduce all the material at the bottom, additional nozzles 16 may be 'located within the production string A intermediate of the bottom of the Well and the surface of the ground. They likewise cause a line -or atomized mist or spray to be introduced into the gas stream which is the gas being produced by the well.

At the surface of the ground additional nozzles 18 may be introduced through the distribution piping to introduce a iine or atomized mist or spray of corrosion inhibiting material which will coat the inside of the conduit.

Although this invention has been described for coating the insides of conduits carrying petroleum gases it will be understood that it is adaptable for coating the insides of conduits carrying any gaseous materials. The specific rust or corrosion inhibitor would be that adapted to prevent corrosion on the particular material of the conduit and the particular gas being carried by the conduit. By the term corrosion is meant any sort of chemical deterioration which might take place including rusting and oxidation.

FIG. 2 illustrates certain modifications which may be made. Instead of having a tube within the production string, it would also be possible to have a tube 20 extend along the outside of the production string and enter the production string through side openings. Such construction is well within the skill of persons familiar with the art.

Another modification illustrated in FIG. 2 is that 'mstead of introducing only corrosion inhibitor with conventional carriers or vehicles, a foaming agent is mixed into the materials introduced into the tube. Such foam ing agents are well known to the art, as wvell as the re ghting art and are produced by Champion Chemical, Inc. under the trademark Foam'atron. By foaming agent we means a material which will maintain the minute gas bubbles in the liquid and not necessarily the means which introduces the bubbles into the liquid. The foaming agent may be a combination of non-ionic water soluble compounds. Another example of such :a foaming agent would be the Rohm & Haas trademarked product Triton X- which is an alkylphenol wit-h 10 mol of ethylene oxide adduct.

When the materia-l issues from the nozzle, the gas striking the material will entrain a multitude of bubbles within it causing it to foam. The continued flow of gas will carry the foam 22 upward in the production string bringing the inhibitor in contact with the surface of the vconduit thereby coating it. A typical example of such a desirable mixture is -as follows:

Initially rather ylarge amounts of the corrosion inhibitor are used to obtain the initial coating upon the conduit. Periodically thereafter, everyv three for four days, additional treatments :are made to renew the coating.

It Will be apparent that the embodiments shown are only exemplary and that various modiiications can be made in construction, materials, and 'arrangements within the scope of the invention as `defined in the appended claims.

We claim -as our invention: y

1. The method of applying protective coatings to inside walls of gas carrying conduits comprising introducing a mixture of a polar filming amine corrosion inhibitor, Water, and a foaming agent into the flowing gas stream -as the conduit is in normal use and entraining a multitude of minute bubbles Within the mixture thereby causing the introduced material to foam to the end that the inhibitor is carried by a foamy vehicle along the conduit.

2. The method of applying protective coatings to the production string ina gas well to protect it from connosion comprising the steps of introducing ya mixture of a polar filming amine y,corrosioninhibitor, Water, and a foaming agent into the production string at the bottom of the Well by means `of a tube extending to the surface, foaming said mixture by entraining a multitude of minute bubbles Within the mixture so that the inhibitor is carried by a foamy Ivehicle, and moving said foamy vehicle upward by the normal HOW of the owing gas being produced. v

3, The invention las dened'vin claim 2 wherein additional mixture Vof inhibitor, water, and foaming agent is introduced into the production string at points intermediate the bottom and surface.

References ouai in theme of this patent UNITED STATES PATENTS 1,602,190 Eddy yet al. Oct. 5, 1926 2,357,559 Smith Sept. 5, 1944 2,460,259 Kahler Jan. 25, 1949 2,673,817 Burns Mar. 30, 1954 2,839,465 Jones June 17, 1958 OTHER REFERENCES Mills, R.V.A.: Protection of Oil and Gas Field Equip- 4ment Against Corrosion, U.S. Bureau of Mines, Bulletin 233, 1925, page. 82. t

Sluhan, C.A,: Wetting Agents, Their Structure, Characteristics, and Uses, Paper Trade Journal, August 22,

1940; pages 26-3'1.

Claims (1)

1. THE METHOD OF APPLYING PROTECTIVE COATINGS TO INSIDE WALLS OF GAS CARRYING CONDUITS COMPRISING INTRODUCING A MIXTURE OF A POLAR FILMING AMINE CORROSION INHIBITOR, WATER, AND A FOAMING AGENT INTO THE FLOWING GAS STREAM AS THE CONDUIT IS IN NORMAL USE ENTRAINING A MULTITUDE OF MINUTE BUBBLES WITHIN THE MIXTURE THEREBY CAUSING THE INTRODUCED MATERIAL TO FOAM TO THE END THAT THE INHIBITOR IS CARRIED BY A FOAMY VEHICLE ALONG THE CONDUIT.

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