US3653452A

US3653452A - Method for reducing erosion and corrosion of metal surfaces during gas drilling

Info

Publication number: US3653452A
Application number: US44661A
Authority: US
Inventors: Paul W Fischer; George P Maly; Delbert E Pyle
Original assignee: DELBERT E PYLE; GEORGE P MALY
Current assignee: DELBERT E PYLE; GEORGE P MALY
Priority date: 1970-06-08
Filing date: 1970-06-08
Publication date: 1972-04-04
Anticipated expiration: 1989-04-04

Abstract

Erosion and corrosion of metal surfaces exposed to a flowing stream of hot gases containing dispersed particles of solid material is reduced by introducing into the flowing stream an additive that decomposes at the temperature and pressure of the gas to release ammonia or a vaporous amine and form a resinous residue. The additive is preferably introduced into the gas in an inert carrier liquid. The method is especially useful in reducing erosion and corrosion of metal drill pipe used in the gas drilling of wells into high temperature earth formations, such as are encountered in gas drilling wells into subterranean steambearing formations.

Description

United States Patent Fischer et al.

[ 51 Apr. 4, 1972 [54] METHOD FOR REDUCING EROSION AND CORROSION OF METAL SURFACES DURING GAS DRILLING [72] lnventors: Paul W. Fischer, 836 W. Beverly Blvd.,

Whittier, Calif. 90601; George P. Maly, 800 Bison St., Newport Beach, Calif. 92660; Delbert E. Pyle, 283 Oaktree Drive, Santa Rosa, Calif. 95401 [22] Filed: June8, 1970 [21] Appl.No.: 44,661

[52] US. Cl ..175/69, 175/71 [51] Int. Cl ..E21b 21/04 [58] Field of Search ..175/71, 69, 65; 23/27; 252/855 E [56] References Cited UNITED STATES PATENTS 3,151,138 9/1964 Fischer ..252/8.55 E

3,203,904 8/1965 Brown....

3,210,421 10/1965 Rainer ..2l/2.7 UX

Primary ExaminerStephen J. Novosad Attorney-Milton W. Lee, Richard C. Hartman, Lannas S. Henderson, Dean Sandford and Robert E. Strauss 57 ABSTRACT Erosion and corrosion of metal surfaces exposed to a flowing stream of hot gases containing dispersed particles of solid material is reduced by introducing into the flowing stream an additive that decomposes at the temperature and pressure of the gas to release ammonia or a vaporous amine and form a resinous residue. The additive is preferably introduced into the gas in an inert carrier liquid. The method is especially useful in reducing erosion and corrosion of metal drill pipe used in the gas drilling of wells into high temperature earth formations, such as are encountered in gas drilling wells into subterranean steam-bearing formations.

17 Claims, N0 Drawings METHOD FOR REDUCING EROSION AND CORROSION F METAL SURFACES DURING GAS DRILLING This invention relates to inhibiting erosion and corrosion of metal surfaces, and more particularly to inhibiting erosion and corrosion of metal surfaces exposed to a hot flowing gas containing dispersed particles of solid material. This invention further relates to reducing erosion and corrosion of drill pipe employed in gas drilling wells into hightemperature subterranean formations, and especially in the gas drilling of wells into steam-bearing formations.

Substantial erosion and corrosion of metal drill pipe is often experienced when gas drilling into high-temperature subterranean formations. In gas drilling, air, nitrogen, natural gas, or other gaseous fluids are utilized as the drilling fluid. The gas is passed from the surface downwardly through the drill pipe,

outwardly through a rotary bit attached, to the lower end of the drill pipe, and then upwardly through the annulus on the exterior of the drill pipe at a pressure and volumetric flow rate sufficient to cool the bit and lift the particulate drill bit cuttings to the surface, but which are not sufficiently high as to cause fracturing of the formation.

Gas and entrained solid cuttings pass upwardly through the well annulus at velocities which are typically between and 100 feet per second, or higher. The particles of solid material transported at these gas velocities are highly abrasive. Also, high temperatures are often encountered. Bottomhole temperatures above about 300 F. are not unusual, and are sometimes in excess of 500 F. These conditions, combined with the corrosive brines, sulfurous compounds and oxygen which are often present in the bore hole, are conducive to excessive erosion and corrosion of the drill pipe, casing and other metal parts. The life expectancy of drill pipe employed under these conditions is relatively short, requiring frequent inspection and replacement. Furthermore, an even more serious problem is the failure of the drill pipe in service wherein the drill pipe breaks leaving a lower section of the drill pipe in the well. Drill pipe failures interrupt the drilling operation, often requiring expensive fishing operations to recover the pipe remaining in the well, and on occasion, if the fishing operation is not successful, necessitate abandonment of the well.

The problems associated with gas drilling are further accentuated when drilling into steam-bearing strata, such as are encountered in developing geothermal reservoirs. Not only are the temperatures of these strata generally above about 500 F., but also steam enters the well from the surrounding strata increasing the velocity of the gas passing upwardly in the well annulus to as high as sonic velocities, which further increases the erosion of the metal surfaces exposed to the solids-containing gas. The intrusion of steam into the well seriously promotes drill pipe erosion and corrosion, and in many instances the presence of steam is so detrimental that gas drilling becomes impractical requiring the use of slower and more costly techniques employing liquid or mud-type drilling fluids.

Various techniques for ameliorating the problems associated with high velocity, solids carrying gas streams have been attempted. Most of this effort, however, has been restricted to changing the performance characteristics of the metal parts exposed to the flowing stream. For example, it has been proposed to make the metal parts thicker, thereby prolonging the life of the part, or alternatively to harden the metal surface by heat treating, or with special alloys, and to introduce corrosion inhibitors into the flowing stream to at least reduce corrosion. in gas drilling, it has been proposed to reduce the circulating gas velocity by incorporating foaming agents into the drilling gas. However, these techniques are costly and at best are only marginally effective. Thus, need ex ists for an inexpensive method for reducing erosion andcorrosion of metal surfaces contacted by a relatively high-temperature, high-velocity, solids-carrying gas stream.

Accordingly, it is a principal object of this invention to provide a method for reducing erosion and corrosion of metal surfaces exposed to a flowing gas stream containing dispersed solid particles. It is another object of the invention to provide a method for reducing erosion and corrosion of metal surfaces exposed to a flowing stream of relatively high-temperature gas and dispersed solid abrasive particles. It is still another object of this invention to provide an improved gas drilling method for drilling wells into an earth formation. A further object of this invention is to provide a method for reducing the erosion and corrosion of drill'pipe employed in gas drilling. A still further object of the invention is to provide a method for reducing erosion and corrosion of the drilling apparatus employed in the gas drilling of steam producing wells. A yet further object of the invention is to provide a method for reducing erosion and corrosion of the subsurface metal parts employed in gas drilling wells into geothermal reservoirs. Other objects and advantages of the invention will be apparent to those skilled in the art from the description thereof which follows.

The aforementioned objects and their attendant advantages can be realized by introducing into the flowing gas-particle stream an additive that decomposes at the temperature and pressure of the gas to release ammonia or a vaporous amine and form a resinous residue. The additive is preferably introduced into the gas in an inert carrier liquid. While the method of this invention has broad general application in reducing corrosion and erosion of metal surfaces that are exposed to particle-containing gas streams, it is especially useful in reducing erosion and corrosion of metal drill pipe used in gas drilling wells into high-temperature earth formations, such as are encountered in gas drilling wells into subterranean steam-bearing formations.

While the exact mechanism by which the method of this invention ameliorates erosion and corrosion is not completely understood, it is believed that the ammonia or vaporous amine released when the additive is heated to a temperature above its decomposition temperature contacts the metal surfaces exposed to the gas and functions as a corrosion inhibitor protecting these metal surfaces from attack by corrosive and oxidative agents in the gas, and that the non-volatilized portion of the additive reacts or polymerizesto form a resinous residue that is deposited in part on the exposed metal surfaces and on the solid particlessuspended in the gas, thereby reducing erosion of the metal parts. However, while the exact mechanism by which the invention functions to reduce erosion and corrosion may not be completely understood, it has nevertheless been demonstrated that erosion and corrosion of metal parts exposed to a solids-carrying gas stream can be effectively reduced by the practice of the invention.

Many organic compounds exhibit the properties required of the additive used in the practice of this invention,'and additives suitable for use under specific application conditions can be determined by a simple screening test, which is hereinafter more fully described. Generally, the'organic compounds useful as erosion and corrosion inhibitors are tertiary amines having molecular weights above about 260, and usually above about 300. Organic compounds that have been found particularly useful in the practice of the invention are ammonium or amine salts of a complex tertiary amine containing at least one functional carboxylic acid group.

More preferably, the erosion and corrosion inhibitor used in the practice of the invention is an ammonium or an amine salt of a complex tertiary amine having at least one univalent radical containing a functional carboxylic acid group with an ester, amine or amide linkage, and the tertiary amine can also contain one or more univalent organic radicals, or a bivalent organic radical which forms a ring structure with the tertiary nitrogen. These compounds can be conveniently represented by the following generalized formula:

)n( 1)m( 2)P wherein:

R is a univalent organic radical selected from column 1 of Table 1; R is a univalent organic radical selected from column 2 of Table 1; R is a bivalent organic radical selected from column 3 of Table l; n is l, 2 or 3; v

m is 0, l r 2; wherein llg iljafigare the differentsubstituents P is 0 or 1; and the sum of n+m+2p equals 3. i selected from hydrogen; an alkyl containing about one to four Thus, in one preferred embodiment of the invention, the terticarbon atoms, exemplary of which are methyl, ethyl, propyl,

ary amine is comprised of a tertiary nitrogen having attached isopropyl and butyl; an aminoalkyl containing about two to thereto at least one univalent organic radical containing a carfoulcarbon atoms, exemplary f hi h are mi gh l, boxylic acid functional group selected from column 1 of Table jaminopropyl, aminoisopmpyl and aminobuty]; and an hydrol, and the tertiary nitrogen can also have attached thereto one llyalkyl containing about 2 to 4 carbon m exemplary f or two univalent radicals selected from column 2 of Table l, which are hydroxyethyl, hydroxypropyl hydroxyisopmpyl, or a bivalent radical selected from column 3 of Table l, which and hydmXybutyL forms a Structure wlth the ternary hhrogehso A preferred class of compounds for use in the practice of the inv nti n amine lts f idi i ter of 3 TABLE 1 e o are the poly sa 0 anac ctres trialkanol amine, which are generally represented by the fol- COlUJlln 1 Column 2 Column 3 lowing formula; Carboxylic acid radicals Univalent radicals Bivalent 5 "m 7 V m V 7 h 7 V radicals R4OOCR:4COOH -R5COH -Il 4 R4OOCR3COOH-A -R4 N-R4OOCR3COOH-A Ih R COORs R4\ RiOOCRsCOOH-A -RrNR COOH R5CONH1 O -R| O R R wherein R and R are defined above and A is ammonia or a water-soluble amine containing from one to 15 carbon atoms,

"RlNHCRaOOOH N exemplary of which are the above-described amines. In a par- R1// ticularly preferred embodiment R in the above formula is w J ethylene. While the polyamine compounds can be generally I TABLE 1 described by the above generalized formula, it is recognized that when polydentate water-soluble amines are used to form the salt, cross-linking between two or more of the polyamine molecules may occur. Thus, when these amines are employed, the polyamine compounds may have repeating acidic triester units.

Particularly preferred polyamine salts are the morpholine, ethylenediamine, N-butylaminoethanol, trimethylamine, dimethylamine, pyridine, triethanolamine, diethylenetriamine, and diethylaminoethanol salts of an acidic triester of triethanolamine, wherein the acidic triester is obtained by esterifying triethanolamine with a long-chain dibasic acid obtained by dimerizing linoleic or isolinoleic acid.

The preparation of polyamine salts of a complex tertiary amine having the above generalized formula, as well as other exemplary polyamine salts which can be used in the practice of this invention, are disclosed in US. Pat. No. 3,151,138, which is herein incorporated by reference.

Organic compounds which possess the requisite properties R represents a bivalent hydrocarbyl radical containing of decompfsing to Felease ammoni? or a a amin? f from one to 50 Carbon atoms, and can include bivalent y form a resinous residue under specific application conditions aliphatic, alicyclic and aromatic radicals, specific examples of 50i can be dammed by a relatively slmple screemng test In R represents a bivalent hydrocarbyl radical containing from about eight to 44 carbon atoms, exemplary of which are bivalent aliphatic hydrocarbon radicals, such as octylene, dodecylene, pentadecylene, octadecylene, eicosylene, tetracosylene, hexacosylene, octacosylene, tricontylene, tetratriacontylene, hexatriacontylene, octatriacontylene, tetracontylene, dotetracontylene, methyl octadecylene, dimethylethyl eicosylene, and the like; bivalent alicyclic hydrocarbon radicals such as the bivalent radicals ofcyclohexane, amylcyclobutane, l,2-diamylcyclobutane, 1,2 dihexylcyclobutanc, 1,2-diheptylcyclobutane, 1,3-diaryl- 0 cyclohexane, 1,3-dihexylcyclohexane, and the like; and bivalent aromatic radicals such as Z-phenolethylenc, 2,3- diphenoloctylene, paramethylphenol-2-octylcne, 1,4-diphenyltetracosylene, bivalent paradiamylbenzene, and the like;

R represents an alkylene containing from one to four can 45 bon atoms, exemplary of which are methylene, ethylene, propylene, methylethylene, butylene, and the like;

which are listed in the above definition of RT l cordance with this test, 10 grams of the selected organic agent R represents a univalent hydrocarbyl radical containing 1 fllspel'sed ih 100 mllhhters of weter'ahd Placed a 250 from one to carbon atoms, and can include univalent lihter reaction vessel. This material 15 then heated to a temaliphatic alicyclic and aromatic radicals; and perature corresponding to the application temperature under R represents a trivalent aliphatic hydrocarbyl radical con- SSi Pressure Correspohdlhg to the application P The raining from one to four carbon atoms having a univalent ter- Vapors evolved are Collected and analyzed for the Presence 0f i l carbon d a bi l i l b i ammonia or amine, and the nature of the residue remaining in Preferred univalent organic radicals containing a functional h mafiti n fla k is isually observed. Those compounds b li id group are b i d f h hydfoggfhgg ,which release ammonia or a vaporous amine and form a tenaresidue of dimerized conjugated hydrocarbons containing ii cious resinous material under the test conditions can be embetween about eight and 44 carbon atoms. Also preferred are lployed o reduce erosion and corrosion in a flowing stream of univalent organic radicals obtained from conjugated fatty gas containing dispersed particles of solid material under conacids such as linoleic acid, isolinoleic acid, and the like. iclitions of em erature and pressure corresponding to the test The carboxylic acid functional groups in the abova- 'ccnditions. described tertiary amine are neutralized by reaction with arm 63 v In the practice of the invention, the organic agent can be inmonia or a water-soluble amine containing from one to 15 car jectezi directly into the flowing gas-particle stream, or alternabon atoms to form ammonium or amine salts of the tertiary tively, the agent can be mixed with a carrier liquid and this adamine. Exemplary of the amines which can be employed are mixture injected into the gas stream, While some of the orp i Substituted morpholines having from five i0 ganic agents useful in reducing erosion and corrosion decom- Cafbon atoms, py py and i p prim y. pose to release ammonia or a vaporous amine and form a s o y e tertiary amines having the following formula: resinous residue at temperatures less than about 200 F., the

R9 method of this invention is most'applicable to reducing ero- R8mN/ sion and corrosion of metals contacted by a solids-containing gas at a temperature in excess of 250 F., and more preferably Rio ineVXQeEe ETQQQiE-H M. i.

The carrier liquids with which the organic agents are admixed preferably are relatively inert to the organic agents, are relatively stable at the application conditions, and are sufficiently polar to facilitate dispersion of the organic agent in the liquid. Exemplary of the carrier liquids that can be employed in the practice of the invention are water; ammonia; monohydroxy aliphatic alcohols having from one to carbon atoms, such as methanol, ethanol, propanol, isopropanol, butanol, hexanol, octanol, and the like; aliphatic amines having from one to 10 carbon atoms, such as methylamine, ethylamine, propylamine, isopropylamine, butylamine, hexylamine, octylamine, and the like; aliphatic carboxylic acids having from one to 10 carbon atoms, such as formic acid, acetic acid, propionic acid, butyric acid, caproic acid, and the like; aliphatic aldehydes having between one and 10 carbon atoms, such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, and the like; ketones having from one to 10 carbon atoms, such as acetone and methyl ethyl ketone, and the like; and mixtures thereof, and especially aqueous mixtures thereof. Where the gas into which the additive is injected contains appreciable amounts of oxygen, such as the case in air drilling, it is preferred that the carrier liquid be nonflammable to avoid the formation of explosive mixtures.

In generalgthe organic agent is admixed with the carrier liquid in the proportion of about 0.001 to 25 weight percent of organic agent based upon the weight of the mixture, and more preferably between about 0.005 and about 10 weight percent. Since many of the organic agents and carrier liquids are slightly acidic, it is preferred that the pH of the liquid dispersions be maintained between about 7 and 12, and more preferably between about 8 and 11; however, it is recognized that in some instances it may be advantageous to maintain the pH of the dispersion below 7.

The erosion and corrosion inhibiting additive can be prepared at the location of use, or alternatively, a concentrated mixture of the organic agent in carrier liquid can be shipped to the site and then diluted with an additional quantity of carrier liquid. Although the additive mixture can be introduced into the flowing gas stream in any convenient manner that provides distribution of the additive in the gas, preferably the additive is injected into the gas in aerosol form, e.g., the additive is sprayed into the gas stream by means of a spray nozzle, or is dispersed into a separate quantity of gas and this aerosol mixture introduced into the flowing stream of gas. Erosion and corrosion of the metal parts In to a flowing stream of gas containing dispersed particles of solid material can be substantially reduced by introducing into the gas from about 0.001 to 1 gallons of the above described additive mixture per 1,000 standard cubic feet of gas. The exact amount of additive necessary in any particular application can be determined by laboratory tests simulating the application conditions, or by determining the required treatment by tests conducted under the actual application conditions. However, in either case, it is desired that the quantity of additive employed be sufficient to effect a substantial in the erosion and corrosion of the metal parts contacted by the solids-containing gas.

The erosion and corrosion inhibiting method of this ifivfi tion is particularly useful in reducing erosion and corrosion of metal parts employed in gas drilling wells into high temperature subterranean formations, such as geothermal reservoirs. In this application, the additive is injected into the circulating gas at the surface and passed downwardly through the drill pipe with the gas. Preferably, the additive is introduced into the gas in an amount equivalent to about 0.001 to 1 gallon addi tive, i.e., organic agent in thecarrier liquid, for e hl OOQstandard cubic feet of g aseous drilling fluid. The erosion-corrosion inhibitor can be injected into the circulating medium at the inhibitor. For example, small amounts of particulate matter can be injected into the circulating medium to impart desired caking properties to the gas. Also, a minor amount of an inorganic friction reducing agent, such as graphite, molybdenum disulfide, and the like, can be injected into the circulating medium. Also, foaming agents can be added to the circulating gas to improve its capacity for carrying solids from the drilling zone to the surface.

The invention is further described by the following examples which are illustrative of specific aspects of the invention and are not intended as limiting the scope of the invention defined by the appended claims.

EXAMPLE 1 The effectiveness of the method of this invention in reducing erosion and corrosion of drill pipe used in air drilling wells is demonstrated by a series of well drilling tests. In each test a well is drilled through a subterranean formation to a depth of between about 4,000 and 6,000 feet with a rotary bit mounted on 4 /2 inch drill pipe. Each well traverses several steam-bearing zones. Air is supplied to the drill pipe from a bank of five primary and two booster compressors at a rate of approximately 3,000 standard cubic feet per minute and at a pressure of about 150 to 1,250 psig. Approximately 21 gallons per hour of erosion-corrosion inhibitor and 2 pounds per hour of finely divided graphite are injected into the air employed in drilling wells number 3 through 10, the additive injection being commenced when the bottomhole temperature reaches 500 F. N o additive is employed in drilling wells number 1 and 2.

The erosion-corrosion inhibitor employed in these drilling tests is prepared by admixing 75 weight percent water, 10 weight percent diethylene triamine and 15 weight percent of an acidic triester prepared by the condensation of triethanolamine and dimerized linoleic acid. The additive is then diluted with water in the proportion of approximately 30 gallons of additive to each 10 barrels of water.

Upon completion of each well, the drill pipe is removed from the well and inspected for erosion and corrosion. The results of these inspections are reported in Table 2.

beginning of the drilling process, however, it is preferred to defer inhibitor injection until the bottomhole temperature of the well exceeds about 250 F., and more preferably until the bottomhole temperature exceeds 300 F or even 400 F.

Other agents can be introduced into the drilling gas without TABLE 2 Pipe sections Inhibitor Pipe l'ound rate, sections unsatis- Replacement gallons/ observed, factory, factor, Well N0. hr. number number percent The addition of the erosion-corrosion inhibitor to the circulating drilling gas reduced the erosion, pitting and corrosion of the drill pipe resulting in a substantial reduction in the number of drill pipe sections requiring replacement.

EXAMPLE 2 temperature for 1 hour, and the nature of the residue in the reaction vessel visually observed. The results of these tests are adversely affecting the performance of the erosion-corrosion p r n Tabl 3.

TABLE 3 Test Amine temperpresent Nature ature, in Tertiary amine salt F. vapors residue Ethylene diamine salt of 'ID'I 250 Yes. Resinous. N-butylaminoethanol salt of TDT 390 YeS.. Do. Mo hollne salt of Do. Pyridine salt of TDT Do. Diethylene tiiamlne salt of TDT D0. Ammonium salt of TDT Do. Diethylarnlno ethanol salt of TDT 330 Yes Do. N-etliylbutylamine salt of TDT 230 Yes Do. Dimethylaminopropylamlne salt of TDT 330 Yes. Do. 10. N-propylaminoethanol salt of TDT 300 Yes. Do.

1 TDT designates the dlmerized linoleic acid triester of triethanolamlne. I Ammonia detected in vapors.

An erosion-corrosion inhibitor is prepared by dissolving equal molar quantities of 4-morpholine ethanol and suberic i acid in an equal volume of kerosene extract (aromatic extract boiling in the range of 400600 F.), and the solution charged to a jacketed kettle and heated under nitrogen blanket to a temperature of 320 F. for 6 hours, with stirring, by hot oil circulated through the jacket. Completion of the reaction is inf dicated by an approximate theoretical reduction in the acid value of the reaction mixture. The kerosene is then removed 3 by vacuum d'stillation and an equal molar quantity of N-butylamine ethanol in aqueous solution added to the residue to produce a tertiary amine having the following formula:

This reaction product releases a vaporous amine and forms a resinous residue upon heating to a temperature of 500 F. at atmospheric pressure.

A portion of the reaction product is dispersed in isopropyl alcohol and added to a flowing stream of gas containing abrasive solid particles, the agent being added to the gas in the proportion of 1 gallon per 1,000 standard cubic feet of gas.

While particular embodiments of the invention have been described, it will be understood that the invention is not limited thereto since many modifications can be made and it is i intended to include within the invention any such embodi- Caz-CH,

. w' hi th c e f the claims. HOC:H4(C4H )NH-HOOC(CHQeCOOOHzCHgN 'memsasfa es CHI-CH1 The invention having been thus described, we claim: k 1. In the gas drilling of a well into a high-temperature sub- A portion of the reaction product is heated in a reaction I vessel to a temperature of 500 F. at atmospheric pressure. The vapor emitted from the reaction vessel is analyzed and found to contain an amine. After heating for 1 hour, a resinous added to the gas in an amount equivalent to 0.01 gallons per 1,000 standard cubic feet of gas.

EXAMPLE 4 The method of Example 3 is repeated except that the initial reactants are equal molar quantities of 2-diethylamino ethanol and 8-carboxy octaneamide. The compound resulting from 3 reaction with N-butylamine ethanol is a tertiary amine having the f lowi u a;

EKA L EL.

The method of Example 3 is repeated except that the initial reactants are equal molar quantities of 2-heptyl2-phenylamino ethanol and 8-carboxy-N-methyl octylamine. The compound resulting from reaction with pyridine is a tertiary amine having the following formula:

terranean formation wherein a gaseous drilling fluid is passed downwardly through a corrodible metal drill pipe to a drilling zone and then upwardly through the annulus surrounding the drill pipe to remove drill bit cuttings from the drilling zone, the

pipe comprises introducing into said gaseous drilling fluid an organic agent that releases ammonia or a vaporous amine and forms a resinous residue at the elevated temperature and pres- [su of said gas 2. The method defined in claim 1 wherein said well traverses at least one strata having a temperature above about 400 3. The method defined in claim 2 wherein said strata contains steam.

residue is observed in the bong, QmhiractiQLmLkfi 40 improvement of reducing erosion and corrosion of the drill 4. The method defined in claim 3 wherein said organic agent is a polyamine salt of an acidic triester of a C to C, trialkanol amine.

MW page a NE a, .a. as. 5. The method defined in claim 2 wherein the pH of said additive is maintained between about 7 and 11.

6. The method defined in claim 1 wherein said organic agent is admixed with an inert carrier liquid, and wherein said admixture contains between about 0.001 and 25 weight perwashe s a cent of said organic agent.

7. The method defined in claim 6 wherein said organic L agent is a tertiary amine having the generalized formula:

R is a univalent organic radical selected from column 1 of Table 1;

R is a univalent organic radical selected from column 2 of Table 1;

R is a bivalent organic radical selected from column 3 of Table l;

n is l, 2 or 3;

m is 0 or 1;

p is 0, 1 or 2; and the sum of n+m+2p equals 3. 8. The method defined in claim 7 wherein said polyamine salt has the following formula:

RiOOCRaCOOH-A NR4OOCR COOH-A RiOOCRaCOOH-A wherein R is a divalent hydrocarbyl radical containing between about eight and 44 carbon atoms, R, is an alkylene having from one to about four carbon atoms, and A is a watersoluble amine or ammonia.

9. The method defined in claim 8 where R, is ethylene.

10. The method defined in claim 9 wherein said water-soluble amine is selected from the group consisting of morpholine, pyrrolidine, pyridine and amines having the formula:

13. The method defined in claim 1 wherein a minor portion of an inorganic friction reducing agent is also introduced into said gaseous drilling fluid.

14. The method defined in claim 1 wherein said organic agent is continuously introduced into the gaseous drilling fluid passed downwardly through said drill pipe.

15. The method defined in claim 1 wherein said gaseous drilling fluid is air.

16. The method defined in claim 1 wherein said carrier liquid is selected from the group consisting of water and aliphatic alcohols, amines, carboxylic acids and aldehydes containing between about one and 10 carbon atoms.

17. A method for drilling a well into an earth formation containing steam-bearing strata having a temperature above about 400 F which comprises:

rotary drilling into said earth formation with a bit mounted on a drill pipe;

passing a gaseous drilling fluid downwardly through said drill pipe to said bit, outwardly through said bit, then upwardly in the well on the exterior of said drill pipe to remove drill bit cuttings from the well; and

upon drilling to the depth of said steam-bearing strata, in-

troducing into said gaseous drilling fluid between about 0.001 and 0.1 gallons of an aqueous additive per 1,000 standard cubic feet of said gaseous drilling fluid, said additive comprising water and about 0.005 to 10 weight percent of an organic amine prepared by reacting diethyle ne triamine with the condensation product of triethanolamine and dimerized linoleic acid.

Claims

2. The method defined in claim 1 wherein said well traverses at least one strata having a temperature above about 400* F.
3. The method defined in claim 2 wherein said strata contains steam.
4. The method defined in claim 3 wherein said organic agent is a polyamine salt of an acidic triester of a C1 to C4 trialkanol amine.
5. The method defined in claim 2 wherein the pH of said additive is maintained between about 7 and 11.
6. The method defined in claim 1 wherein said organic agent is admixed with an inert carrier liquid, and wherein said admixture contains between about 0.001 and 25 weight percent of said organic agent.
7. The method defined in claim 6 wherein said organic agent is a tertiary amine having the generalized formula: N(R)n(R1)m(R2)p wherein: R is a univalent organic radical selected from column 1 of Table 1; R1 is a univalent organic radical selected from column 2 of Table 1; R2 is a bivalent organic radical selected from column 3 of Table 1; n is 1, 2 or 3; m is 0 or 1; p is 0, 1 or 2; and the sum of n+ m+2p equals 3.
8. The method defined in claim 7 wherein said polyamine salt has the following formula: wherein R3, is a divalent hydrocarbyl radical containing between about eight and 44 carbon atoms, R4 is an alkylene having from one to about four carbon atoms, and A is a water-soluble amine or ammonia.
9. The method defined in claim 8 where R4 is ethylene.
10. The method defined in claim 9 wherein said water-soluble amine is selected from the group consisting of morpholine, pyrrolidine, pyridine and amines having the formula: wherein R8, R9 and R10 are the same or different substituents selected from the group consisting of hydrogen, an alkyl containing between about one and four carbon atoms, an aminoalkyl containing between about two and four carbon atoms, or a hydroxylalkyl containing between about two and four carbon atoms.
11. The method defined in claim 9 wherein said divalent hydrocarbyl radical is the esterified hydrocarbon residue of a dimerized conjugated fatty acid.
12. The method defined in claim 1 wherein said organic agent is a tertiary amine having a molecular weight above about 260.
13. The method defined in claim 1 wherein a minor portion of an inorganic friction reducing agent is also introduced into said gaseous drilling fluid.
14. The method defined in claim 1 wherein said organic agent is continuously introduced into the gaseous drilling fluid passed downwardly through said drill pipe.
15. The method defined in claim 1 wherein said gaseous drilling fluid is air.
16. The method defined in claim 1 wherein said carrier liquid is selected from the group consisting of water and aliphatic alcohols, amines, carboxylic acids and aldehydes containing between about one and 10 carbon atoms.
17. A method for drilling a well into an earth formation containing steam-bearing strata having a temperature above about 400* F., which comprises: rotary drilling into said earth formation with a bit mounted on a drill pipe; passing a gaseous drilling fluid downwardly through said drill pipe to said bit, outwardly through said bit, then upwardly in the well on the exterior of said drill pipe to remove drill bit cuttings from the well; and upon drilling to the depth of said steam-bearing strata, introducing into said gaseous drilling fluid between about 0.001 and 0.1 gallons of an aqueous additive per 1,000 standard cubic feet of said gaseous drilling fluid, said additive comprising water and about 0.005 to 10 weight percent of an organic amine prepared by reacting diethylene triamine with the condensation product of triethanolamine and dimerized linoleic acid.