US2106243A - Process for breaking petroleum emulsions - Google Patents

Description

' itent diiap. 55, 1938 UNITE STATES PROCESS FOR PATENT OFFICE,

BREAKING PETROLEUM EMULSION S Melvin De Groote, St. Louis, Mo., assignor to The 'l'rct-O-Lite Company, Webster Groves, M a

corporation of Missouri" No Drawing. Application June 21, 1937,

. Serial No. 149,472

Claims.- (0!. 196-4) curring waters or brines, dispersed in a more orless permanent state throughout the oil which constitutes the continuous phase of the emulsion. 10 They are obtained from producing wells and from the bottom of oil storage tanks, and are commonly referred to as fcut oil", "roily oil, emulslfled;oil and bottom settlings.

The object of my invention is to provide a novel and inexpensive process for separating emulsions of the character referred to into their component parts of oil and water or brine. Briefly described, my process consists in subjecting a petroleum emulsion of the water-in- 011 type to the action of a treating agent or demulsifying agent of the kind hereinafter described, thereby causing the emulsion to break down and separate into its component parts of oil and water or brine, when the emulsion is permitted to remain in a quiescent state after treatment, or is subjected to other equivalent separatory procedures. v

The treating agent or demulsifying agent contemplated by my process consists of a sulfopolyhydric alcohol ester of a detergent-forming carboxy acid, of the kind hereinafter described in detail.

It has long been known that various organic acids of fairly high molecular weight, combine with alkalis to produce soap or detergent-like materials. Such acids include the higher fatty acids derived from animal or vegetable sources, such as oleic acid, stearic acid, palmitic acid, rlcinoleic acid, etc. Acids derived from rosins such as .abietic acid represents another class.

Similarly, carboxy acids derived from petroleum,

the formation of a detergent as abietic acid itself, and such functional derivatives are considered as detergent-forming acids. Reference is made to U. S. Patent #1,988,835, to De Groote and Wirtel, dated January 22, 1935. 5 This particular patent describes a process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing a sulfo-aliphatic ester of a fatty acid of the type 10 R".C00(T.SO3.Z), in which R" is a fatty acid radical, C00 is a carboxyl residue, T is the aliphatic residue, 5031s the conventional sulfonic acid residue, Z represents the acidic hy-' drogen atom of thesulfonic acid or its equiva- 15 lentwand (T.SOa.Z) replaces the carboxylic hydrogen.

. Reference is also made to U. S. Patent #2,077,- 745, to De Groote, dated April 20, 1937. This particular patent describes a process for breaking 20 petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent of the kind ink dicated by the type formula:

R.COO.T(OH)1i(SO4.Z )m

in which RG00 is the carboxy acid radical derived from a detergent-forming carboxy acid; T(OH) is the residue from a polyhydric alcohol; S04 is the sulfate radical; and Z is the 30 ionizable hydrogen equivalent; 1!. represents the numeral 0, 1 or more; and m represents the numeral 1 or more.

Reference is also made to U. S. Patent #2,052,- 284, to De Groote, dated August 25, 1936, which 7 35 describes a process for breaking petroleum emulsions by the action of a demulsifying agent comprising a chemical compound of the formula type: (R1100) m.T.(OH) m, in which R.COO represents a non-sulfo, detergent-forming, monocarboxy acid radical, T represents a polyhydric alcohol residue, and m indicates the numeral 1 or more, and R and T being additionally characterized by freedom from an extraneous acid residue.

I have found that certain oil field emulsions which, although susceptible to -1 or more of .the types of demulsifying agent previously described, are even more susceptible to a reagent characmrized by being of the following type formula:

in which R.COO is a carboxy acid radical derived from a detergent-forming carboxy acid,

T(0H)1l is a residue derived from a polyhydric alcohol of the kind which in unaltered form contains at least three hydroxyls, n being the numeral 1, 2, or 3, and SO3Z being the typical sulfonic acid radical, in which Z represents 'an ionizable hydrogen atom equivalent.

Compounds of the kind contemplated for use as demulsifying agents in the present process may be prepared in any suitable manner. Various methods are known for the preparation of soluble salts of 1:2 dihydroxy propane :3 sulfonic acid. Such material can be esterified with a mole of any suitable detergent-forming carboxy acid, and particularly various fatty acids or modified fatty acids of the kind previously described. Another suitable procedure is to treat the soluble salts of l halogen :2 hydroxy propane :3 sulfonic acid with suitable fatty acid salts or the like, so as to eliminate an inorganic halide, such as sodium chloride.

Examples of well known procedures for producing reagents of the kind herein contemplated as demulsifying agents include the following:

Example 1 180 parts of the sodium salt of glycerol sulfonic acid (sodium 1:2-dihydroxy propane 3-sulfonate, prepared by heating alpha-chlorohyclrin derived from glycerol with aqueous NazSOa solution and subsequent removal of water) are heated at 150 to 225 C. for 6 hours with stirring with 210 parts of the fatty acids from cocoanut oil, the water evolved in the reaction being allowed to escape and the fatty acids being returned to the reacting chamber by suitable reflux condensation. The product of this reaction is then purified by washing with cold ethyl alcohol or other low-boiling alcohol, or preferably by dissolving in hot ethyl alcohol, filtering to remove insoluble inorganic salts, or other insoluble matter and crystallizing from the acoholic solution.

Example 2 200 parts of the sodium salt of 1-chloro 2-hydroxy propane: 3-sulfonic acid (prepared by first treating one mole of glycerine with two moles of chlorine to form CH2ClCHOH-CH2C1, and then reacting one mole of this product with one mole of sodium sulfite to form are heated at to 200 C. with stirring for 5 hours with 300 parts of sodium soap prepared from tallow. The product of the reaction may then be purified as in Example 1.

Example 3 A triethanolammonium (sometimes called triethanolamine) compound may be formed as follows:

290 parts of the sodium salt of commercial stearic acid are heated at about C., with stirring for 4 hours with 325 parts of the triethanolammonium salt of l-chloro 2-hydroxy propane 3-su1fonic acid (prepared by heating 1:3 dichlorohydrin with triethanolammonium sulfite). The product of the reaction may be purified as in Example 1.

In some instances it is more economical to employ the dichlorhydrin as the raw material rather than the monochlorhydrin. The reason is that the dichlorhydrin can be prepared very economically by means of sulfur monochloride. See Systematic Organic Chemistry, Cumming, Hopper, Wheeler, 1931, p. 335.

It is obvious that other polyhydroxylated materials may replace glycerol provided that they containat least three alcoholic hydroxyls. For instance, one could prepare the monbchlorhydrin or the dichlorhydrin from diglyc'erol, which is an ether alcohol, and employ such material just as advantageously as a corresponding compound derived from glycerol. Similarly, one couldt prepare an ether alcohol from diglycerol and -a monohydric alcohoL-such as ethyl alcohol, and employ such ether alcohol in place of glycerol, provided that the compound contained at least three alcoholic hydroxyls and provided that it could be converted readily so as to yield amonochlorhydrin and a dichlorhydrin. Similarly, ether alcohols could be obtained by reaction between a glycol, such as ethylene glycol, propylene glycol, or the like, and glycerol. The ether alcohols so obtained could be converted into a monochlorhydrin or a dichlorhydrin and these materials employed in the manner previously described.

It is understood that reference to a polyhydric alcohol or a polyhydric alcohol residue refers to the ether type as well as the non-ether type. Whenever it is intended to limit the meaning to polyhydric alcohols or polyhydric alcohol residues, as differentiated from the polyhydric alcohol ethers or polyhydric alcohol ether residues, the expression free from an ether linkage will be employed.

Although it has been pointed out that the detergent-forming carboxy acid may be supplied by a resin acid, such as abietic acid, chlorabietic acid, sulfoabetic acid, or the like, or may be furnished by a petroleum carboxy acid, such as naphthenic acid, sulfonaphthenic acid, or the The expression modified fatty acids" is wellunderstood by those skilled in the art of resolving petroleum emulsions of the water-in-oil type, and has been used frequently in the patent literature to designate a certain Well known class of materials. Briefly described, modified fatty acids are modifications of fatty acids obtained by chemical reaction on a fatty acid or its equivalent, so as to result in an addition product or substitution product, and they bear a simple genetic relationship to each other or to the parent fatty acid or fatty acid compound from which they were derived. Modified fatty acids do not include salts of unmodified fatty acids, such as soaps, because a salt of a fatty acid is not an addition product. Likewise, it is not a substitution product, because substitution products" in the sense that such term is used. in organic chemistry, is applied not to salts, but to undissociable or indiiferent compounds. Furthermore, whereas the acid hydrogen involved in salt formation can be replaced only by metals or metal-like groups, that is, elements or radicals which are electropositive, substitution may replace the hydrogen of organic compounds by a variety of elements and groups which may be electro-negative.

The treating agent or demulsifying agent contemplated by my process includes esters of the specific kind described, and may be derived from employed as the demulsifying agent of my process.

I desire to point out that the superiority of the reagent or demulsifying agent contemplated in my process is based upon its ability to treat certain emulsions more advantageously and at a somewhat lower cost than is possible with other available demulsifiers, or conventional mixtures thereof. It is believed that the particular demulsifying agent or treating agent herein described will find comparatively limited application, so far as the majority of oil field emulsions are concerned; but I have found that such a demulsifying agent has commercial value, as it will economically break or resolve oil field emulsions in a number of cases which cannot be treated as easily or at so low a cost with the demulsifying agents heretofore available.

In practising my process, a treating agent or demulsifying agent of the kind described above may be brought in contact with the emulsion to be treated in any of the numerous ways now employed in the treatment of petroleum emulsions of the water-ln-oil type with chemical demulsifying agents, such, for example, as by introducing the treating agent into the well in which the emulsion is produced; introducing the treating agent into a conduit through which the emulsion is flowing; introducing the treating agent into a tank in which the emulsion is stored; or introducing the treating agent into a container that holds a sludge obtained from the bottom of an oil storage tank. In some instances, it may be advisable to introduce the treating agent into at producing well in such a way that it will become mixed with water and oil that are emerging from the surrounding strata, before said water and oil enter the barrel of the well pump or the tubing up through which said water and oil flow to the surface of the ground. After treatment, the emulsion is allowed to stand in a quiescent state, usually in a settling tank, and usually at a temperature varying from atmospheric temperature to about 200 0., so as to permit the water or brine to separate from the oil, it being preferable to keep the temperature low enough to prevent the volatilization of valuable constituents of the oil. If desired, the treated emulsion may be acted upon by one or more of the various kinds of apparatus now used in the operation of breaking petroleum. emulsions, such as homogenizers, hay tanks, gun barrels, filters, centrifuges, or electrical dehydrators.

The amount of treating agent that may be required to break, the emulsion may vary from approximately one part of treating agent to 500 parts of emulsion, up to one part of treating agent to 20,000, or even 30,000 parts of emulsion. The proportion depends on the type of emulsion being treated, and also upon the equipment being used, and the temperature employed. In treating exceptionally refractory emulsions of the kinds known as tank bottoms and residual pit oils, the ratio of 1:500, above referred to, may be required. In treating fresh emulsion, l. e., emulsions that will yield readily to the action of chemical demulsifying agents, the ratio of 1:30,000, above referred to, may be sufllcient to produce highly satisfactory results. In general, I have found that for an average petroleum emulsion a ratio of one part of treating agent to 5,000 parts or 10,000 parts of emulsion will usually be found to produce commercially satisfactory results.

aioacas Having thus described my invention, what I claim new and desire to secure by Letters Pat out is:

1. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent comprising a compound of the formula type:

in which H.000 is a carboxy acid radical derived from a detergent-forming carboxy acid; T(OH)7= is a residue derived from a polyhydric alcohol of the kind which in unaltered form contains at least three hydroxyl groups; n is the numeral 1, 2 or 3; and S032; is the typical sulfonic acid radical in which Z represents an ionizable hydrogen atom equivalent.

2. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demuisifying agent comprising a compound of the formula in w.ich RG00 a carboxy acid radical derived ircm a rosin acid; ITOHM is a residue tierived from a polyhydric alcohol of the kind which in unaltered form contains at least three hydroxyl groups; n is the numeral 1, 2 or 3; and S032 is the typical sulfonic acid radical in which Z represents an ionizable hydrogen atom equivalent.

3. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsilying agent comprising a compound oi. the formula type:

RCOQIJKOH) 1&(3032) in which H.600 is a carboxy acid radical derived from a petroleum acid; T OH n is a residue derived from a polyhydric alcohol of the kind which in unaltered form contains at least three hydroxyl groups; n is the numeral 1, 2 or 3; and S032 is the typical. sulfonic acid radical in which Z represents an ionizable hydrogen atom equivalent.

4. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting temulsion to the action of a demulsifying agent ccunprising a compound of the formula type:

HJFJOO.T(OH) 12(8032) in which 13.000 is a carboxy acid radical derived from a higherfatty acid; T(OH)n is a residue, free from an ether linkage, and derived from a polyhydric alcohol of the kind which in unaltered form contains at least three hydroxyl groups: n is the numeral 1, 2 or 3; and S032 is the typical in which R.COO is a carboxyacid radical derived from a higher fatty acid; T(-H)n is the bivalent radical CaHOH; and SOaZ is the typical sulfonic acid radical in which Z represents an ionizable hydrogen atom equivalent.

7. A process for breaking petroleum emulsions oi the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent comprising a compound of the formula type:

R.COO.T(OH)1.(SO3Z) in which R.COO is a carboxy acid radical de-' J rived from a hydroxylated higher fatty acid;

ing agent comprising a compound of the formula type:

R.CO0.T (OH) MSOaZ) in which R.COO is a carboxy acid radical derived from a hydroxylated higher fatty acid; T(O.H)n is the bivalent radical CaHsOH; and SOaZ is the typical sulfonic acid radical in which Z represents a metallic atom.

9. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsiiying agent of the water-soluble type comprising a compound of the formula type:

in which R.COO is a carboxy acid radical derived from a hydroxylated higher fatty acid; T(OH)11 is the bivalent radical CsHsOH; and S032 is the typical sulfonic acid radical in which Z represents a metallic atom.

10. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent comprising a compound of the formula type:

OH.C3H5.CmHrizOI-IQOOSOaNa MELVIN DE GROO'I'E.