Technical Field

The present invention generally relates to a composition with foaming properties. The present invention also relates to the use of said composition in enhanced oil recovery techniques, such as foam-assisted water-alternating-gas processes.

Background Art

Crude oil is a vital source of energy for the world and makes a major contribution to the world economy.

Conventional oil production strategies have followed primary depletion, secondary recovery and tertiary recovery processes. During the primary depletion stage, reservoir drive uses a number of natural mechanisms to displace oil from porous rocks. Recovery factor during the primary recovery stage may average 5-20%. At some point, there will be insufficient underground pressure to force oil to the surface. Secondary recovery methods are then applied wherein the oil is subjected to immiscible displacement with injected fluids such as water or gas. Typical recovery factor after primary and secondary oil recovery operations may be between 30-50%. Much of the remaining oil is trapped in porous media. Tertiary, or enhanced oil recovery (EOR) methods, increase the mobility of oil in order to increase extraction.

There are currently several different methods for EOR, including steam flood and water flood injection and hydraulic fracturing. One method is through a water alternating-gas (WAG) process. WAG injection consists of injection of intermittent slugs of water and gas to improve gas sweep efficiency in the reservoir.

Conventional WAG methods to improve oil recovery is often marred with gas mobility issues due to density and gravity difference between gas and water. Gas has the tendency to move to upper section in a reservoir while water tends to move to the bottom of reservoir, leaving behind regions of unswept oil. To address this issue, foam can be used to control gas mobility, gas front and early gas breakthrough - ultimately to improve gas sweep efficiency. The use of foams to enhance the WAG process is termed as “Foam-Assisted WAG” or FAWAG, referring to the addition of foaming chemicals into the injection water in the WAG cycle. Foams have an apparent viscosity greater than the displacing medium (e.g. water alone), thus lowering gas mobility in high permeability parts of the formation to recover additional oil.

While foam has been used in EOR processes before, most developed formulations for FAWAG have not been assessed for their environmental-friendliness for offshore applications as such formulations have mainly concentrated on foam performance.

This poses a problem as there are some countries which do not have any regulations governing the use and discharge of oil recovery chemicals in offshore environments. Overboard discharge of potentially toxic and non-readily biodegradable formulations can be costly to the environment and marine creatures. Further, fluid management of such formulations for disposal into the sea after use is challenging.

Additionally, conventional foam formulations for FAWAG may be costly due to the components and their respective concentrations which make up the formulation.

Hence, there is a need to provide foam compositions useful in FAWAG processes that overcome, or at least ameliorate, one or more of the disadvantages described above.

Summary

According to a first aspect, there is provided a composition with foaming properties comprising an exopolysaccharide, and at least one compound selected from the group consisting of olefin sulfonate, sulfo-betaine and betaine.

According to a second aspect, there is provided a composition with foaming properties as defined herein, when used as a foam.

Advantageously, the disclosed composition with foaming properties may be useful to generate stable foams at high temperature and salinity. Also advantageously, the disclosed composition with foaming properties may be non toxic and biodegradable. Hence, the disclosed composition with foaming properties may be disposed directly into the sea with minimal or no negative effects to marine creatures.

According to a third aspect, there is provided a composition with foaming properties as defined herein, when used in an oil recovery process.

According to a fourth aspect, there is provided a method for recovering oil from a subterranean oil-containing formation comprising:

(a) introducing a composition with foaming properties as defined herein into the subterranean oil-containing formation;

(b) introducing a gas into the subterranean oil-containing formation, wherein the presence of the composition with foaming properties lowers the gas mobility within said formation; and

(c) recovering oil from the formation.

According to a fifth aspect, there is provided a method for recovering oil from a subterranean oil-containing formation comprising:

(a) injecting a composition with foaming properties as defined herein into the subterranean oil-containing formation through one or more injection wells;

(b) introducing a gas into the subterranean oil-containing formation, wherein the presence of the composition with foaming properties lowers the gas mobility within said formation; and

(c) extracting oil from the formation through one or more production wells.

According to a sixth aspect, there is provided a composition with foaming properties as defined herein, when used in offshore direct discharge after use.

Advantageously, the composition with foaming properties may be used to generate a foam that exhibits good foam generation and stability under severe reservoir conditions of high temperatures (>95°C), high salinity (>35,000 ppm) and in the presence of crude oil and a foaming gas.

Further advantageously, the composition with foaming properties may be used to generate foam that has a low adsorption rate on reservoir rock.

Advantageously, the composition with foaming properties may be used to generate a foam that displays a high Mobility Reduction Factor (MRF) within a reservoir. The MRF may be >10. The lowered gas mobility advantageously results in improved sweep efficiency.

Further advantageously, the composition with foaming properties may display regeneration capability and may be used to generate foam even after multiple contacts with a foaming gas.

Advantageously, the composition with foaming properties may display biodegradability and non-toxicity and thus safe to be discharged overboard after use. Hence, the composition with foaming properties may eliminate the use of end- of-pipe solutions and facilities (such as Advance Oxidation Processes), which may translate to substantial cost savings due to less manpower requirement and energy consumption.

Also advantageously, the composition with foaming properties may require a lower application concentration and minimal components in the composition. The components in the composition may be of lower concentrations. These may translate to cost-effectiveness and substantial cost savings.

Definitions

Unless otherwise defined herein, scientific and technical terms used in this application shall have the meanings that are commonly understood by those of ordinary skill in the art. Generally, nomenclature used in connection with, and techniques of, chemistry described herein, are those well-known and commonly used in the art. Unless the context requires otherwise or specifically stated to the contrary, integers, steps, or elements of the invention recited herein as singular integers, steps or elements clearly encompass both singular and plural forms of the recited integers, steps or elements.

As used herein, unless otherwise specified, the following terms have the following meanings, and unless otherwise specified, the definitions of each term (i.e. moiety or substituent) apply when that term is used individually or as a component of another term (e.g., the definition of aryl is the same for aryl and for the aryl portion of arylalkyl, alkylaryl, arylalkynyl, and the like).

As used herein, the term“exopolysaccharide” refers to a polysaccharide secreted by a microorganism.

As used herein, the term "alkyl" includes within its meaning monovalent (“alkyl”) and divalent (“alkylene”) straight chain or branched chain saturated aliphatic groups having from 1 to 20 carbon atoms, eg, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,

15, 16, 17, 18, 19, or 20 carbon atoms. For example, the term alkyl includes, but is not limited to, methyl, ethyl, 1 -propyl, isopropyl, 1 -butyl, 2-butyl, isobutyl, tert-butyl, amyl,

1.2-dimethylpropyl, 1,1-dimethylpropyl, pentyl, isopentyl, hexyl, 4-methylpentyl, 1- methylpentyl, 2-methylpentyl, 3-methylpentyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl,

1.2-dimethylbutyl, 1,3-dimethylbutyl, 1,2,2-trimethylpropyl, 1,1,2-trimethylpropyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicodecyl and the like. Alkyl groups may be optionally substituted.

As used herein, the term "alkenyl" refers to divalent straight chain or branched chain unsaturated aliphatic groups containing at least one carbon-carbon double bond and having from 2 to 20 carbon atoms, eg, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,

16, 17, 18, 19, or 20 carbon atoms. For example, the term alkenyl includes, but is not limited to, ethenyl, propenyl, butenyl, 1-butenyl, 2-butenyl, 2-methylpropenyl, 1- pentenyl, 2-pentenyl, 2-methylbut-l-enyl, 3-methylbut-l-enyl, 2-methylbut-2-enyl, 1- hexenyl, 2-hexenyl, 3-hexenyl, 2, 2-dimethyl-2 -butenyl, 2-methyl-2-hexenyl, 3-methyl- 1-pentenyl, 1,5-hexadienyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, octadecenyl, nonadecenyl, eicodecenyl and the like. Alkenyl groups may be optionally substituted. As used herein, the term“olefin” refers to alkenyl with one carbon-carbon double bond. An “alpha-olefin” refers to an olefin having a double bond at the primary or alpha position.

As used herein, the term "alkynyl" refers to divalent straight chain or branched chain unsaturated aliphatic groups containing at least one carbon-carbon triple bond and having from 2 to 20 carbon atoms, eg, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 carbon atoms. For example, the term alkynyl includes, but is not limited to, ethynyl, propynyl, butynyl, 1-butynyl, 2-butynyl, 2-methylpropynyl, 1-pentynyl, 2- pentynyl, 2-methylbut-l-ynyl, 3-methylbut-l-ynyl, 2-methylbut-2-ynyl, 1-hexynyl, 2- hexynyl, 3-hexynyl, 2,2-dimethyl-2-butynyl, 2-methyl-2-hexynyl, 3 -methyl- 1-pentynyl, 1,5-hexadiynyl, heptynyl, octynyl, nonynyl, decynyl, undecynyl, dodecynyl, tridecynyl, tetradecynyl, pentadecynyl, hexadecynyl, heptadecynyl, octadecynyl, nonadecynyl, eicodecynyl and the like. Alkynyl groups may be optionally substituted.

The term“carbocycle”, or variants such as“carbocyclic ring” as used herein, includes within its meaning any stable 3, 4, 5, 6, or 7~membered monocyclic or bicyclic or 7, 8, 9, 10, 1 1 , 12, or 13-membered bicyclic or tricyclic, any of which may be saturated, partially unsaturated, or aromatic. The term“carbocycle” includes within its meaning cycloalkyl, cycloalkenyl and aryl groups. Examples of such carbocycles include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, adarnantyl, cyclooctyl, [3.3.0]bicyclooctane, [4 3.0]bicyc!ononane, [4.4.0]bicyciodecane (decalin), [2.2.2]bicyclooctane, fluorenyl, phenyl, naphthyl, indanyl, adarnantyl, or tetrahydronaphthyl (tetra!in). Preferred carbocycles, unless otherwise specified, are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, naphthyl, and indanyl. Carbocycles may be optionally substituted.

The term "cycloalkyl" as used herein refers to a non-aromatic mono- or multi cyclic ring system comprising about 3 to about 10 carbon atoms. The cycloalkyl can be optionally substituted with one or more "ring system substituents" which may be the same or different, and are as defined herein. Non-limiting examples of suitable monocyclic cycloalkyls include cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl and the like. Non-limiting examples of suitable multicyclic cycloalkyls include 1 -decalinyl, norbornyl, adarnantyl and the like. Further non-limiting examples of cycloalkyl include the following: The term "cycloalkenyl" as used herein refers to a non-aromatic mono or multi cyclic ring system comprising about 3 to about 10 carbon atoms which contains at least one carbon-carbon double bond. Non-limiting examples of suitable monocyclic cycloalkenyls include cyclopentenyl, cyclohexenyl, cyclohepta-l,3-dienyl, and the like. Non-limiting example of a suitable multicyclic cycloalkenyl is norbomylenyl, as well as unsaturated moieties of the examples shown above for cycloalkyl. Cycloalkenyl groups may be optionally substituted.

The term“aryl”, or variants such as“aromatic group” or“arylene” as used herein refers to monovalent (“aryl”) and divalent (“arylene”) single, polynuclear, conjugated or fused residues of aromatic hydrocarbons having from 6 to 10 carbon atoms. Such groups include, for example, phenyl, biphenyl, naphthyl, phenanthrenyl, and the like. Aryl groups may be optionally substituted.

The term“halogen”, or variants such as“halide” or“halo” as used herein, includes within its meaning fluorine, chlorine, bromine and iodine.

The term "heteroaryl" as used herein refers to an aromatic monocyclic or multicyclic ring system comprising about 5 to about 14 ring atoms, preferably about 5 to about 10 ring atoms, in which one or more of the ring atoms is an element other than carbon, for example nitrogen, oxygen or sulfur, alone or in combination. "Heteroaryl" may also include a heteroaryl as defined above fused to an aryl as defined above. Non limiting examples of suitable heteroaryls include pyridyl, pyrazinyl, furanyl, thienyl, pyrimidinyl, pyridone (including N-substituted pyridones), isoxazolyl, isothiazolyl, oxazolyl, thiazolyl, pyrazoiyl, furazany!, pyrroiyl, pyrazoly!, triazolyl, 1 ,2,4- thiadiazolyf, pyrazinyl, pyridaziny!, quinoxalinyl, phthalazinyl, oxindolyl, imidazojd ,2- ajpyridinyl, imidazo[2,l -bjthiazoiyl, benzofurazanyl, indolyi, azaindolyl, benzimidazolyl, benzothienyl, quino!myl, imidazolyl, thienopyridyl, quinazolinyl, thienopyrimidyl, pyrrolopyridyi, imidazopyridyl, isoquinolinyl, benzoazaindoiyl, 1 ,2,4- triazinyl, benzothiazolyl and the like. The term "heteroaryl" also refers to partially saturated heteroaryl moieties such as, for example, tetrahydroisoquinoiyl, tetrahydroquino!yl and the like. Heteroaryl groups may be optionally substituted.

The term "heterocycle" as used herein refers to a group comprising a covalently closed ring herein at least one atom forming the ring is a carbon atom and at least one atom forming the ring is a heteroatom. Heterocyclic rings may be formed by three, four, five, six, seven, eight, nine, or more than nine atoms, any of which may be saturated, partially unsaturated, or aromatic. Any number of those atoms may be heteroatoms (i.e., a heterocyclic ring may comprise one, two, three, four, five, six, seven, eight, nine, or more than nine heteroatoms). Herein, whenever the number of carbon atoms in a heterocycle is indicated (e.g., C1-C6 heterocycle), at least one other atom (the heteroatom) must be present in the ring. Designations such as "C1-C6 heterocycle" refer only to the number of carbon atoms in the ring and do not refer to the total number of atoms in the ring. It is understood that the heterocylic ring will have additional heteroatoms in the ring. In heterocycles comprising two or more heteroatoms, those two or more heteroatoms may be the same or different from one another. Heterocycles may be optionally substituted. Binding to a heterocycle can be at a heteroatom or via a carbon atom. Examples of heterocycles include heterocycloalkyls (where the ring contains fully saturated bonds) and heterocycloalkenyls (where the ring contains one or more unsaturated bonds) such as, but are not limited to the following: wherein D, E, F, and G independently represent a heteroatom. Each of D, E, F, and G may be the same or different from one another.

The term“optionally substituted” as used herein means the group to which this term refers may be unsubstituted, or may be substituted with one, two, three or more groups other than hydrogen provided that the indicated atom’s normal valency is not exceeded, and that the substitution results in a stable compound. Such groups may be, for example, halogen, hydroxy, oxo, cyano, nitro, alkyl, alkoxy, haloalkyl, haloa!koxy, aryl alkoxy, alkylthio, hydroxya!ky!, alkoxyalkyl, cycloalkyl, cycloaikylalkoxy, alkanoyl, alkoxy carbonyl, alkyl sulfonyl, a!ky!sulfonyloxy, alkylsulfonyl alkyl, arylsulfonyl, arylsulfonyloxy, arylsulfonylalkyl, alkylsuifonamido, alkylamido, alkylsulfonamidoalkyl, alkylamidoalkyl, arylsulfonamido, arylcarboxamido, arylsulfonamidoaikyi, arylcarboxamidoaikyi, aroyl, aroyl4alkyl, arylaikanoyi, acyl, and, arylalkyl, alkylaminoalkyl, a group R ^x R ^y N~, R ^K CQN(R ^y )(CFI ₂ ) _m , R ^x R ^y NCO(CH ₂ ) _m , R ^x R ^y N S 0 ₂ (CFI ₂ ) _m or R ^x S0 ₂ NR ^y (CH ₂ ) _m (where each of W and R ^y is independently selected from hydrogen or alkyl , or where appropriate R ^x R ^y forms part of carbocylic or heterocyclic ring and m is 0, 1 , 2, 3 or 4), a group R ^x R ^y N(CH ₂ ) _P~ or R ^X R N(CH ₂ ) _P O- (wherein p is 1 , 2, 3 or 4); wherein when the substituent is R ^X R'N(CH ) _P~ or R¾ ^> N(CH ) _p O, R ^x with at least one C¾ of the (CFEj _p portion of the group may also form a earbocyeiyl or heterocyclyl group and R may be hydrogen, alkyl.

The word“substantially” does not exclude“completely” e.g. a composition which is“substantially free” from Y may be completely free from Y. Where necessary, the word“substantially” may be omitted from the definition of the invention.

Unless specified otherwise, the terms "comprising" and "comprise", and grammatical variants thereof, are intended to represent "open" or "inclusive" language such that they include recited elements but also permit inclusion of additional, unrecited elements.

As used herein, the term "about", in the context of concentrations of components of the formulations, typically means +/- 5% of the stated value, more typically +/- 4% of the stated value, more typically +/- 3% of the stated value, more typically, +/- 2% of the stated value, even more typically +/- 1% of the stated value, and even more typically +/- 0.5% of the stated value.

Throughout this disclosure, certain embodiments may be disclosed in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the disclosed ranges. Accordingly, the description of a range should be considered to have specifically disclosed all the possible sub-ranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

Certain embodiments may also be described broadly and genetically herein. Each of the narrower species and subgeneric groupings falling within the generic disclosure also form part of the disclosure. This includes the generic description of the embodiments with a proviso or negative limitation removing any subject matter from the genus, regardless of whether or not the excised material is specifically recited herein.

Detailed Description

This present invention seeks to provide a foam composition that has high enhanced oil recovery (EOR) performance and is environmentally-friendly, to reduce the burden of fluid management. The invention also seeks to confidently discharge the foam composition overboard without extra intervention.

The present invention relates to a composition which can alleviate problems related to conventional water alternating-gas (WAG), and yet having the additional benefit of being environmentally friendly.

The present invention also relates to foam-surfactant formulations that may generate stable foams in subterranean environments of high temperatures (for example, above 90 °C), and tolerant to crude oil (which is known to be deterious to foams).

In one aspect, there is provided a composition with foaming properties comprising an exopolysaccharide, and at least one compound selected from the group consisting of olefin sulfonate, sulfo-betaine and betaine.

The composition with foaming properties may comprise an olefin sulfonate and an exopolysaccharide. The composition with foaming properties may comprise a sulfo- betaine and an exopolysaccharide. The composition with foaming properties may comprise a betaine and an exopolysaccharide. The composition with foaming properties may comprise an olefin sulfonate, a sulfo-betaine, and an exopolysaccharide. The composition with foaming properties may comprise an olefin sulfonate, a betaine, and an exopolysaccharide. The composition with foaming properties may comprise olefin sulfonate, sulfo-betaine, betaine, and an exopolysaccharide. The composition with foaming properties may consist of olefin sulfonate, sulfo-betaine, betaine, and an exopolysaccharide.

The olefin sulfonate of the disclosed composition may provide the composition with high temperature tolerance (for example, above 90 °C) and may reduce adsorption to reservoir walls. The olefin sulfonate may also provide the composition with foam generation capabilities, and may provide negative charges to the composition, thus providing electrical repulsion between two opposite faces of foam lamella to prevent foam thinning and making it less sensitive to adsorption on clayey reservoirs.

The olefin sulfonate of the disclosed composition may be sodium alpha-olefin sulfonate. The alpha-olefin group may be selected from C ₃ to Cix alpha olefin, such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 1-heptenyl, 1-octenyl, 1-nonenyl or 1- decenyl, 1-undecenyl, 1-dodecenyl, 1-tridecenyl, 1-tetradecenyl, 1-pentadecenyl, 1- hexadecenyl, 1-heptadecenyl, 1-octadecenyl, 1-nonadecenyl or 1-eicosenyl. The alpha- olefin group may be a C _i to Ci ₆ alpha olefin. The olefin sulfonate may be of the formula C _n FF _n -iSChM, wherein n is an integer of 14, 15, or 16, and M is a counterion, such as Na ⁺ .

The olefin sulfonate may be a compound of Formula (I):

Formula (I) wherein R ¹ is an optionally substituted alkyl, alkenyl or alkynyl and M ⁺ is sodium. R ¹ may be optionally substituted C ₁₀ to C ₁₂ alkyl, alkenyl or alkynyl.

In a compound of Formula (I), R ¹ may be selected from optionally substituted alkyl, alkenyl or alkynyl. R ¹ may be selected from an optionally substituted alkyl group selected from optionally substituted methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, or eicodecyl. R ¹ may be substituted or unsubstituted. The optional substituents on R ¹ may be Ci- ₆ alkyl, C _2-6 alkenyl, C _2-6 alkynyl, Ci- ₆ alkoxy, amino, sulfmyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyciyl, hydroxyl, carboxylic acid, cyano or halogen. R ¹ may be Cho to C ₁₂ alkyl R ¹ may be C ₁₀ or C ₁₂ alkyl.

The olefin sulfonate may be selected from the group consisting of the following compounds: The sulfo-betaine of the disclosed composition may be a foam booster. The betaine group may provide a synergistic effect to the olefin sulfonate surfactant to increase its foaminess.

The sulfo-betaine of the disclosed composition may be any neutral compound with a positively charged cationic group and a negatively charged functional group which is a sulfo- group. The sulfo-betaine may be of the formula (C _n H _2n+i )- C0NH(CH ₂ )3N ⁺ (CH3)2CH2CH(0H)CH ₂ S03 , wherein n is an integer of 11, 12 or 13.

The sulfo-betaine may be a compound of Formula (II):

Formula (II) wherein R ² is optionally substituted alkylene, alkenylene or alkynylene;

R ³ is optionally substituted alkyl, alkenyl or alkynyl; and

R ⁵ and R ⁶ each are independently optionally substituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, carbocyclyl, heterocyclyl. In a compound of Formula (II), R ² may be selected from optionally substituted alkylene, alkenylene or alkynylene. R ² may be selected from an optionally substituted alkylene group selected from optionally substituted methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, tridecylene, tetradecylene, pentadecylene, hexadecylene, heptadecylene, octadecylene, nonadecylene, or eicodecylene. R ² may be substituted or unsubstituted. The optional substituents on R ² may be Ci- ₆ alkyl, C _2-6 alkenyl, C _2-6 alkynyl, Ci- ₆ a!koxy, amino, sulfmyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyciyl, hydroxyl, carboxylic acid, cyano or halogen. R ² may be an optionally substituted alkylene. R ² may be an alkylene group substituted with a hydroxygroup. R ² may be a methylene, ethylene, propylene or butylene substituted with hydroxy. R ² may be - (CH ₂ ) ₂ -CH(OH)-, -CH ₂ -CH(OH)-CH ₂ - or -CH(OH)-(CH ₂ ) ₂ -.

In a compound of Formula (II), R ³ may be selected from optionally substituted alkyl, alkenyl or alkynyl. R ³ may be selected from an optionally substituted alkyl group selected from optionally substituted methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, or eicodecyl. R ³ may be substituted or unsubstituted. The optional substituents on R ³ may be Ci- ₆ alkyl, C _2-6 alkenyl, C _2-6 alkynyl, Ci- ₆ alkoxy, amino, sulfmyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyciyl, hydroxyl, carboxylic acid, cyano, halogen or alkylamido. R may be an optionally substituted alkyl. R ^' may be an alkyl substituted with alkylamido. R ^' may be [Cn- ₁₃ aikv! ! -C ({) >X! MCI f }:··. R ³ may be [Cn _{or j 3} a!kv! I-( (0}CI !··{( ! I _{2 ; ;}

In a compound of Formula (II), R ⁵ and R ⁶ may each be selected from optionally substituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, carbocyclyl, heterocyciyl. R ⁵ and R ⁶ may each be alkyl selected from methyl, ethyl, propyl, butyl, pentyl or hexyl. R ⁵ and R ⁶ may each be alkenyl selected from ethenyl, propenyl, butenyl, pentenyl or hexenyl. R ⁵ and R ⁶ may each be alkynyl selected from ethynyl, propynyl, 1-butynyl, 2-butynyl, 1- pentynyl, 2-pentynyl, 1-hexynyl, 2-hexynyl, 3-hexynyl or 3 -methyl- 1-pentynyl. R ⁵ and R ⁶ may each be aryl selected from phenyl or naphthyl. R ⁵ and R ⁶ may each be heteroaryl selected from pyrroline, pyrrolidine, imidazoline, imidazolidine, pyrazoline, pyrazolidine, pyrane, piperidine, morpholine, thiomorpholine, piperazine or hydrofuran. R ⁵ and R ⁶ may each be substituted or unsubstituted. The optional substituents on R ⁵ or R ⁶ may be Ci. ₆ alkyl, C _2-6 alkenyl, C _2-6 alkynyl, Ci. ₆ alkoxy, amino, sulfmyl, sulfonyl, carbonyl, and, heteroaryl, carbocyclyl, or heterocyciyl, hydroxyl, carboxylic acid, cyano or halogen. R ⁵ and R ⁶ may each independently be optionally substituted alkyl. R ⁵ and R ⁶ may each independently be methyl, ethyl or propyl. The sulfo-betaine of the disclosed composition may be an alkyl amidopropyl hydroxy sulfo-betaine of formula (IIA):

CH ₃ Formula (IIA) wherein R ⁴ is an optionally substituted alkyl, alkenyl or alkynyl.

In a compound of Formula (IIA), R ⁴ may be selected from optionally substituted alkyl, alkenyl or alkynyl. R ⁴ may be selected from an optionally substituted alkyl group selected from optionally substituted methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, or eicodecyl. R ⁴ may be substituted or unsubstituted. The optional substituents on R ⁴ may be Ci-6 alkyl, C _2-6 alkenyl, C _2-6 alkynyl, Ci-6 a!koxy, amino, sulfmyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyciyl, hydroxyl, carboxylic acid, cyano or halogen. R ⁴ may be an optionally substituted alkyl group. R ⁴ may be optionally substituted Cn to C13 alkyl. R ⁴ may be optionally substituted Cn or C ₁₃ alkyl.

The sulfo-betaine of the disclosed composition may be a compound selected from the group consisting of the following compounds:

The betaine of the disclosed composition may a foam booster. The betaine group may provide a synergistic effect to the olefin sulfonate surfactant to increase its foaminess.

The betaine of the disclosed composition may be of Formula (III):

Formula (III) wherein R ⁷ is optionally substituted alkylene, alkenylene or alkynylene;

R ¹⁰ is optionally substituted alkyl, alkenyl or alkynyl; and

R ⁸ and R ⁹ each are independently optionally substituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, carbocyclyl, heterocyclyl.

In a compound of Formula (III), R ⁷ may be selected from optionally substituted alkylene, alkenylene or alkynylene. R ⁷ may be selected from an optionally substituted alkylene group selected from optionally substituted methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, tridecylene, tetradecylene, pentadecylene, hexadecylene, heptadecylene, octadecylene, nonadecylene, or eicodecylene. R ⁷ may be substituted or unsubstituted. The optional substituents on R ⁷ may be Ci. ₆ alkyl, C _2.6 alkenyl, C _2-6 alkynyl, Ci. ₆ alkoxy, amino, sulfmyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl, hydroxyl, carboxylic acid, cyano or halogen. R ⁷ may be an optionally substituted alkylene. R ⁷ may be optionally substituted methylene, ethylene, propylene or butylene. In a compound of Formula (III), R ¹⁰ may be selected from optionally substituted alkyl, alkenyl or alkynyl. R ¹⁰ may be selected from an optionally substituted alkyl group selected from optionally substituted methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, or eicodecyl. R ¹⁰ may be substituted or unsubstituted. The optional substituents on R ¹⁰ may be Ci- ₆ alkyl, C2-6 alkenyl, C2-6 alkynyl, Ci- ₆ a!koxy, amino, suffinyl, sulfonyl, carbonyl, aryl, heteroaryl, carhocyc!yl, or heterocyclyl, hydroxyl, carboxylic acid, cyano, halogen or alkylamido. R ¹⁰ may be an optionally substituted alkyl. R ¹⁰ may be an alkyl substituted with alkylamido. R ¹⁰ may be [Cii. ₁₃ alkyl]-C(0)NH-(CH ₂ ) ₃ -. R ⁱ⁰ may be [C _{U or i3} alkyl]-C(0)NH-(CH ₂ ) ₃ -.

In a compound of Formula (III), R ⁸ and R ⁹ may each be selected from optionally substituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, carbocyclyl, heterocyclyl. R ⁸ and R ⁹ may each be alkyl selected from methyl, ethyl, propyl, butyl, pentyl or hexyl. R ⁸ and R ⁹ may each be alkenyl selected from ethenyl, propenyl, butenyl, pentenyl or hexenyl. R ⁸ and R ⁹ may each be alkynyl selected from ethynyl, propynyl, 1-butynyl, 2-butynyl, 1- pentynyl, 2-pentynyl, 1-hexynyl, 2-hexynyl, 3-hexynyl or 3 -methyl- 1-pentynyl. R ⁸ and R ⁹ may each be aryl selected from phenyl or naphthyl. R ⁸ and R ⁹ may each be heteroaryl selected from pyrroline, pyrrolidine, imidazoline, imidazolidine, pyrazoline, pyrazolidine, pyrane, piperidine, morpholine, thiomorpholine, piperazine or hydrofuran. R ⁸ and R ⁹ may each be substituted or unssubstituted. The optional substituents on R ⁸ or R ⁹ may be Ci- ₆ alkyl, C2-6 alkenyl, C2-6 alkynyl, Ci- ₆ aikoxy, amino, sulfmyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl, hydroxyl, carboxylic acid, cyano or halogen. R ⁸ and R ⁹ may each independently be optionally substituted alkyl. R ⁸ and R ⁹ may each independently be methyl, ethyl or propyl.

The betaine of the disclosed composition may be of formula (IIIA):

Formula (IIIA) wherein R ¹¹ is an optionally substituted alkyl, alkenyl or alkynyl. In a compound of Formula (IIIA), R ¹¹ may be selected from optionally substituted alkyl, alkenyl or alkynyl. R ¹¹ may be selected from an optionally substituted alkyl group selected from optionally substituted methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, or eicodecyl. R ¹¹ may be substituted or unsubstituted. The optional substituents on R ¹¹ may be Ci- ₆ alkyl, C2-6 alkenyl, C2-6 alkynyl, Ci- ₆ alkoxy, amino, sulfmyl, sulfonyi, carbonyl, aryl, heteroaryl, carbocyclyl, or heteiOcyclyi, hydroxyl, carboxylic acid, cyano or halogen. R ¹¹ may be an optionally substituted alkyl group. R ¹¹ may be optionally substituted Cn to C 13 alkyl. R ¹¹ may be optionally substituted Cn or C _i3 alkyl.

The betaine of the disclosed composition may be selected from the group consisting of the following compounds:

The exopolysaccharide of the disclosed composition may be a foam stabilizer.

The exopolysaccharide may be a biological-based polymer (=biopolymer) which may provide bulk viscosity, thus keeping foams thicker and reducing the drainage rate of liquid from foam lamellae. This increase in viscosity may provide the lamellae with “self-healing” or re-generation capabilities - a key feature that eliminates the need for constant re-injection of surfactant(s) which may allow for a minimal surfactant concentration during application. The exopolysaccharide may a PLONOR (=Pose Little or No Risk)-listed compound by the OSPAR Commission whereby chemicals under this category are considered to be readily biodegradable and non-toxic.

The exopolysaccharide of the disclosed composition may be acetan, alginate, cellulose, chitosan, curdlan, a cyclosophoran, dextran, emulsan, a galactoglucopolysaccbaride, gellan, glucuronan, N-acetyl-glucosamine, N-acetyl- heparosan, hyaluronic acid, indicant, kefiran, lent! nan, levan, mauran, pul!ufan, scleroglucan, schizophyllan, stewartan, succinoglycan, xanthan, or welan, preferably scleroglucan.

The exopolysaccharide of the disclosed composition may be secreted by a microorganism.

The microorganism may be a microorganism from a family or genus selected from the group consisting of Acetohacter, Acinetohacter, Aeropyrum, Agrobacterium, Alcaligenes, Alteromonas, Aquifex, Archaeoglobus, Aureomonas, Azotobacter, Bacillus, Beijerinckia, Chrotnohalobacter, Colwellia, Escherichia, Exiguobacterium, Geobacillus, Geothermobacterium, Hahella, Haloarcula, Halohacterium, Halobiforma, Halococcus, Haloferax, Halomonas, Halopiger, Haloterrigena, Lactobacillus, Lentinus, Leuconostoc, Meikanococcus, Natronobacterium, Pallewnia, Pantoea, Phoma, Pseudoalteromonas, Pseudomonas, Pywcoccus, Pyrolobus, Salipiger, Sclerotium, Schizophyllum, Sinorhizobium, Sphingomonas, Staphylococcus, Streptococcus, Sulfolobus , Tetragenococcus, Thermococcus, Thermotoga, Thermus, Vibrio, Xanthotnonas, and Zymomonas.

The microorganism may be selected from the group consisting of Acetohacter xylinum, Acinetohacter calcoaceticus, Aeropyrum pernix, Agrobacterium radiobacter, Alcaligenes faecalis var. myxogenes, Alcaligenes viscosus, Alteromonas hispanica, Alteromonas infernus, Alteromonas macleodii subsp. Fijiensis, Aquifex aeolicus, Archaeoglobus fidgidus, Aureomonas elodea, Azotobacter vinelandii, Bacillus licheniformis, Bacillus rnegaterium, Bacillus subtil is. Bacillus ihermodenitrificans, Beijerinckia indica, Chrotnohalobacter beijerinckii, Colwellia psychrerythraea, Escherichia coli, Exiguobacterium acetylicum, Exiguobacterium aestuarii, Exiguobacterium antarticum, Exiguobacterium artmeiae, Exiguobacterium aurantiacum, Exiguobacterium marinum, Exiguobacterium mexicanum, Exiguobacterium oxidotolerans, Exiguobacterium profumsum, Exiguobacterium sibiricum, Exiguobacterium undae, Geobacillus tepidamans, Geothermobacterium ferrireducens, Hahella chejuensis, Haloarcula hispanica, Haloarcula japonica, Haloarcula marismortui, Halobacterium noricense, Halobiforma haloterrestris, Halococcus dombrowskii, Halococcus salifodinae, Haloferax denitrificans, Haloferax gibbonsii, Haloferax mediterranei, Haloferax volcanii, Halomonas alkaliantarctica , Halomonas eurihalina, Halomonas rnaura, Halomonas solaria , Halopiger aswanensis , Haloterrigena hispanica. , Lactobacillus hilgardii, Lentinus elodes, Leuconostoc dextranicurn, Leuconostoc mesentewides, Methanococcus jannaschii, Natronobacterium gregoryi, Pallewnia marisminoris, Panioea stewartii subsp. Stewartii, Phoma herbarum, Pseudoalteromonas antarctica, Pseudomonas aeruginosa, Pseudomonas marginalis, Pywcoccus furiosus, Pyrolobus fumarii, Salipiger mucosus, Sclerotium delfinii, Sclerotium glucanicum, Sclerotium rolfsii, Schizophyllum commune, Schizophyllum arnplum, Schizophyllum fas datum, Schizophyllum murrayi, Schizophyllum radiatum, Schizophyllum variabile, Sinorhizobium meliloti, Sphingomonas paucimobilis, Staphylococcus epidermidis, Streptococcus equi, Sulfolobus solfataricus, Tetragenococcus halophilus, Thermococcus litoralis, Therrnoioga maritima, Therrnus aquaticus, Vibrio Diabolicus, Xanthomonas campestris, or Zymomonas mobilis, preferably Sclerotium rolfsii.

The exopolysaccharide of the disclosed composition may comprise at least one of glucose, dextrose, mannose, fructose, galactose, ribose, deoxyribose or glucoronic acid.

The exopolysaccharide of the disclosed composition may be of formula (IV):

wherein n is an integer of 700 to 20,000. The exopolysaccharide of the disclosed composition may be Schleroglucan. Schleroglucan may be secreted by the basidiomycete Sclerotium rolfsii. Schleroglucan may advantageously be a PLONOR (=Pose Little or No Risk)-listed compound by the OSPAR Commission whereby chemicals under this category are considered readily biodegradable and not toxic.

The Schleroglucan polysaccharide may consist of glucose, mannose and glucoronic acid units.

In a compound of Formula (IV), n may be an integer of about 700 to about 20,000, about 700 to about 18,000, about 700 to about 16,000, about 700 to about 14,000, about 700 to about 12,000, about 700 to about 10,000, about 700 to about 8,000, about 700 to about 6,000, about 700 to about 4,000, about 700 to about 2,000, about

2.700 to about 20,000, about 4,700 to about 20,000, about 6,700 to about 20,000, about

8.700 to about 20,000, about 10,700 to about 20,000, about 12,700 to about 20,000, about 14,700 to about 20,000, about 16,700 to about 20,000, about 18,700 to about 20,000, about 700, about 1,000, about 2,000, about 3,000, about 4,000, about 5,000, about 6,000, about 7000, about 8,000, about 9,000, about 10,000, about 11,000, about 12,000, about 13,000, about 14,000, about 15,000, about 16,000, about 17,000, about 18,000, about 19,000, about 20,000, or any range or integer falling within about 700 to about 20,000.

The disclosed exopolysaccharide may have a molecular weight of between about 1,000,000 to about 5,000,000 Da, between about 1,500,000 to about 5,000,000 Da, between about 2,000,000 to about 5,000,000 Da, between about 2,500,000 to about 5,000,000 Da, between about 3,000,000 to about 5,000,000 Da, between about 3,500,000 to about 5,000,000 Da, between about 4,000,000 to about 5,000,000 Da, between about 4,500,000 to about 5,000,000 Da, between about 1,000,000 to about 4,500,000 Da, between about 1,000,000 to about 4,000,000 Da, between about 1,000,000 to about 3,500,000 Da, between about 1,000,000 to about 3,000,000 Da, between about 1,000,000 to about 2,500,000 Da, between about 1,000,000 to about 2,000,000 Da, between about 1,000,000 to about 1,500,000 Da, about 1,000,000 Da, about 1,500,000 Da, about 2,000,000 Da, about 2,500,000 Da, about 3,000,000 Da, about 3,500,000 Da, about 4,000,000 Da, about 4,500,000 Da, about 5,000,000 Da, or any range or integer falling within about 1,000,000 to about 5,000,000 Da. The active concentration of exopolysaccharide in the disclosed composition may range from about 0.01 to about 0.1% by weight, about 0.01 to about 0.09% by weight, about 0.01 to about 0.08% by weight, about 0.01 to about 0.07% by weight, about 0.01 to about 0.06% by weight, about 0.01 to about 0.05% by weight, about 0.01 to about 0.04% by weight, about 0.01 to about 0.03% by weight, about 0.01 to about 0.02% by weight, about 0.02 to about 0.1% by weight, about 0.03 to about 0.1% by weight, about 0.04 to about 0.1% by weight, about 0.05 to about 0.1% by weight, about 0.06 to about 0.1% by weight, about 0.07 to about 0.1% by weight, about 0.08 to about 0.1% by weight, about 0.09 to about 0.1% by weight, about 0.01% by weight, about 0.02% by weight, about 0.03% by weight, about 0.04% by weight, about 0.05% by weight, about 0.06% by weight, about 0.07% by weight, about 0.08% by weight, about 0.09% by weight, about 0.1% by weight, or any range or integer falling within about 0.01 to about 0.1 wt%.

The quantity of active olefin sulfonate in the disclosed composition may range from about 7.0 to about 15.0 wt%, about 7.0 to about 14.0 wt%, about 7.0 to about 13.0 wt%, about 7.0 to about 12.0 wt%, about 7.0 to about 11.0 wt%, about 7.0 to about 10.0 wt%, about 7.0 to about 9.0 wt%, about 7.0 to about 8.0 wt%, about 8.0 to about 15.0 wt%, about 9.0 to about 15.0 wt%, about 10.0 to about 15.0 wt%, about 11.0 to about 15.0 wt%, about 12.0 to about 15.0 wt%, about 13.0 to about 15.0 wt%, about 14.0 to about 15.0 wt%, about 7.0 wt%, about 8.0 wt%, about 9.0 wt%, about 10.0 wt%, about 11.0 wt%, about 12.0 wt%, about 13.0 wt%, about 14.0 wt%, about 15.0 wt%, or any range or integer falling within about 7.0 to about 15.0 wt%. The quantity of active olefin sulfonate in the disclosed composition may range from about 7.12 to about 8.44 wt%, about 7.22 to about 8.44 wt%, about 7.32 to about 8.44 wt%, about 7.42 to about 8.44 wt%, about 7.52 to about 8.44 wt%, about 7.62 to about 8.44 wt%, about 7.72 to about 8.44 wt%, about 7.82 to about 8.44 wt%, about 7.92 to about 8.44 wt%, about 8.02 to about 8.44 wt%, about 8.12 to about 8.44 wt%, about 8.22 to about 8.44 wt%, about 8.32 to about 8.44 wt%, about 8.42 to about 8.44 wt%, about 7.12 to about 8.34 wt%, about 7.12 to about 8.24 wt%, about 7.12 to about 8.14 wt%, about 7.12 to about 8.04 wt%, about 7.12 to about 7.94 wt%, about 7.12 to about 7.84 wt%, about 7.12 to about 7.74 wt%, about 7.12 to about 7.64 wt%, about 7.12 to about 7.54 wt%, about 7.12 to about 7.44 wt%, about 7.12 to about 7.34 wt%, about 7.12 to about 7.24 wt%, about 7.12 to about 7.14 wt%, about 7.2 wt%, about 7.3 wt%, about 7.4 wt%, about 7.5 wt%, about 7.6 wt%, about 7.7 wt%, about 7.8 wt%, about 7.9 wt%, about 8.0 wt%, about 8.1 wt%, about 8.2 wt%, about 8.3 wt%, about 8.4 wt%, or any range of integer falling within about 7.12 to about 8.44 wt%.

The quantity of active sulfo-betaine in the disclosed composition may range from about 3.0 to about 5.0 wt%, about 3.5 to about 5.0 wt%, about 4.0 to about 5.0 wt%, about 4.5 to about 5.0 wt%, about 3.0 to about 4.5 wt%, about 3.0 to about 4.0 wt%, about 3.0 to about 3.5 wt%, about 3.0 wt%, about 3.5 wt%, about 4.0 wt%, about 4.5 wt%, about 5.0 wt%, or any range or integer falling within about 3.0 to about 5.0 wt%. The quantity of active sulfo-betaine in the disclosed composition may range from about 3.94 to about 4.41 wt%, about 3.94 to about 4.31 wt%, about 3.94 to about 4.21 wt%, about 3.94 to about 4.11 wt%, about 3.94 to about 4.01 wt%, about 4.04 to about 4.41 wt%, about 4.14 to about 4.41 wt%, about 4.24 to about 4.41 wt%, about 4.34 to about 4.41 wt%, about 3.94 wt%, about 4.03 wt%, about 4.12 wt%, about 4.20 wt%, about 4.21 wt%, about 4.30 wt%, about 4.39 wt%, or any range or integer falling within about 3.94 to about 4.41 wt%.

The quantity of active betaine may range from about 1.5 to about 11.0 wt%, about 2.5 to about 11.0 wt%, about 3.5 to about 11.0 wt%, about 4.5 to about 11.0 wt%, about 5.5 to about 11.0 wt%, about 6.5 to about 11.0 wt%, about 7.5 to about 11.0 wt%, about 8.5 to about 11.0 wt%, about 9.5 to about 11.0 wt%, about 10.5 to about 11.0 wt%, about 1.5 to about 10.5 wt%, about 1.5 to about 10.0 wt%, about 1.5 to about 9.5 wt%, about 1.5 to about 9.0 wt%, about 1.5 to about 8.5 wt%, about 1.5 to about 8.0 wt%, about 1.5 to about 7.5 wt%, about 1.5 to about 7.0 wt%, about 1.5 to about 6.5 wt%, about 1.5 to about 6.0 wt%, about 1.5 to about 5.5 wt%, about 1.5 to about 5.0 wt%, about 1.5 to about 4.5 wt%, about 1.5 to about 4.0 wt%, about 1.5 to about 3.5 wt%, about 1.5 to about 3.0 wt%, about 1.5 to about 2.5 wt%, about 1.5 to about 2.0 wt%, about 1.5 wt%, about 2.0 wt%, about 2.5 wt%, about 3.0 wt%, about 3.5 wt%, about 4.0 wt%, about 4.5 wt%, about 5.0 wt%, about 5.5 wt%, about 6.0 wt%, about 6.5 wt%, about 7.0 wt%, about 7.5 wt%, about 8.0 wt%, about 8.5 wt%, about 9.0 wt%, about 9.5 wt%, about 10.0 wt%, about 10.5 wt%, about 11.0 wt%, or any range or integer falling within about 1.5 to about 11.0 wt%. The quantity of active betaine may range from about 4.12 to about 4.59 wt%, about 4.12 to about 4.49 wt%, about 4.12 to about 4.39 wt%, about 4.12 to about 4.29 wt%, about 4.12 to about 4.19 wt%, about 4.22 to about 4.59 wt%, about 4.32 to about 4.59 wt%, about 4.42 to about 4.59 wt%, about 4.52 to about 4.59 wt%, about 4.21 wt%, about 4.31 wt%, about 4.40 wt%, about 4.41 wt%, about 4.51 wt%, or any range or integer falling within about 4.12 to about 4.59 wt%.

The composition with foaming properties may be a four-component foam- surfactant formulation whereby each component consists of different functional groups to tackle challenging conditions of the reservoir. The olefin sulfonate of the composition may provide the composition with high temperature tolerance (for example, above 90 °C) and may reduce adsorption to reservoir walls. The olefin sulfonate may also provide the composition with foam generation capabilities, and may provide negative charges to the composition, thus providing electrical repulsion between two opposite faces of foam lamella to prevent foam thinning and making it less sensitive to adsorption on clayey reservoirs. The betaine and sulfo-betaine of the composition may be foam boosters. The betaine and sulfo-betaine groups may provide a synergistic effect to the olefin sulfonate surfactant to increase its foaminess. The exopolysaccharide of the composition may be a foam stabilizer. The exopolysaccharide may be a biological-based polymer (=biopolymer) which may provide bulk viscosity, thus keeping foams thicker and reducing the drainage rate of liquid from foam lamellae. This increase in viscosity may provide the lamellae with“self-healing” or re-generation capabilities - a key feature that eliminates the need for constant re-injection of surfactant(s) which may allow for a minimal surfactant concentration during application. The exopolysaccharide may a PLONOR (=Pose Little or No Risk)-listed compound by the OSPAR Commission whereby chemicals under this category are considered to be readily biodegradable and non-toxic.

The ratio of the four components to each other may be tailored such that a synergistic‘golden’ ratio is obtained. This ratio gives the composition a superior foam performance at high temperature with low adsorption at subterranean, biodegradability and environmentally-friendliness.

The composition with foaming properties may advantageously not comprise a buffer. This advantageously provides cost savings as one less component is needed. The composition with foaming properties may comprise cocaamido propyl hydroxy sulfo-betaine of Formula (II) or Formula (IIA), cocaamido propyl betaine of Formula (III) or Formula (IIIA), C14-C16 alpha olefin sulfonate of Formula (I); and exopolysaccharide. The composition with foaming properties may comprise cocaamido propyl hydroxy sulfo-betaine of Formula (II) or Formula (IIA) with an active concentration of about 3.94 wt% to about 4.41 wt%, cocaamido propyl betaine of Formula (III) or Formula (IIIA) with an active concentration of about 4.12 wt% to about 4.59 wt%, C14-C16 alpha olefin sulfonate of Formula (I) with an active concentration of about 7.12 wt% to about 8 44 wt%; and exopolysaccharide with an active concentration of about 0.01 wt% to about 0.1 wt%. The composition with foaming properties may comprise cocaamido propyl hydroxy sulfo-betaine of Formula (II) or Formula (IIA) with an active concentration of about 4.20 wt%, cocaamido propyl betaine of Formula (III) or Formula (IIIA) with an active concentration of about 4.40 wt%, C14-C16 alpha olefin sulfonate of Formula (I) with an active concentration of about 7.60 wt%; and exopolysaccharide with an active concentration of about 0.02 wt%.

The composition with foaming properties may comprise cocaamido propyl hydroxy sulfo-betaine of Formula (II) or Formula (IIA), cocaamido propyl betaine of Formula (III) or Formula (IIIA), C14-C16 alpha olefin sulfonate of Formula (I); and exopolysaccharide secreted by a microorganism. The composition with foaming properties may comprise cocaamido propyl hydroxy sulfo-betaine of Formula (II) or Formula (IIA) with an active concentration of about 3.94 wt% to about 4.41 wt% _a cocaamido propyl betaine of Formula (III) or Formula (IIIA) with an active concentration of about 4.12 wt% to about 4.59 wt%, C14-C16 alpha olefin sulfonate of Formula (I) with an active concentration of about 7.12 wt% to about 8.44 wt%; and exopolysaccharide secreted by a microorganism with an active concentration of about 0.01 wt% to about 0.1 wt%. The composition with foaming properties may comprise cocaamido propyl hydroxy sulfo-betaine of Formula (II) or Formula (IIA) with an active concentration of about 4.20 wt% _a cocaamido propyl betaine of Formula (III) or Formula (IIIA) with an active concentration of about 4.40 wt%, C14-C16 alpha olefin sulfonate of Formula (I) with an active concentration of about 7.60 wt%; and exopolysaccharide secreted by a microorganism with an active concentration of about 0.02 wt%. The composition with foaming properties may comprise cocaamido propyl hydroxy sulfo-betaine of Formula (II) or Formula (IIA), cocaamido propyl betaine of Formula (III) or Formula (IIIA), C14-C16 alpha olefin sulfonate of Formula (I); and exopolysaccharide secreted by Sclerotium rolfsii. The composition with foaming properties may comprise cocaamido propyl hydroxy sulfo-betaine of Formula (II) or Formula (IIA) with an active concentration of about 3.94 wt% to about 4.41 wt% _a cocaamido propyl betaine of Formula (III) or Formula (IIIA) with an active concentration of about 4.12 wt% to about 4.59 wt%, C14-C16 alpha olefin sulfonate of Formula (I) with an active concentration of about 7.12 wt% to about 8.44 wt%; and exopolysaccharide secreted by Sclerotium rolfsii with an active concentration of about 0.01 wt% to about 0.1 wt%. The composition with foaming properties may comprise cocaamido propyl hydroxy sulfo-betaine of Formula (II) or Formula (IIA) with an active concentration of about 4.20 wt%, cocaamido propyl betaine of Formula (III) or Formula (IIIA) with an active concentration of about 4.40 wt%, C14-C16 alpha olefin sulfonate of Formula (I) with an active concentration of about 7.60 wt%; and exopolysaccharide secreted by Sclerotium rolfsii with an active concentration of about 0.02 wt%.

The composition with foaming properties may comprise cocaamido propyl hydroxy sulfo-betaine of Formula (II) or Formula (IIA), cocaamido propyl betaine of Formula (III) or Formula (IIIA), C14-C16 alpha olefin sulfonate of Formula (I); and exopolysaccharide of Formula (IV). The composition with foaming properties may comprise cocaamido propyl hydroxy sulfo-betaine of Formula (II) or Formula (IIA) with an active concentration of about 3.94 wt% to about 4.41 wt% _a cocaamido propyl betaine of Formula (III) or Formula (IIIA) with an active concentration of about 4.12 wt% to about 4.59 wt%, Ci -Ci ₆ alpha olefin sulfonate of Formula (I) with an active concentration of about 7.12 wt% to about 8.44 wt%; and exopolysaccharide of Formula (IV) with an active concentration of about 0.01 wt% to about 0.1 wt%. The composition with foaming properties may comprise cocaamido propyl hydroxy sulfo-betaine of Formula (II) or Formula (IIA) with an active concentration of about 4.20 wt% _a cocaamido propyl betaine of Formula (III) or Formula (IIIA) with an active concentration of about 4.40 wt%, C14-C16 alpha olefin sulfonate of Formula (I) with an active concentration of about 7.60 wt%; and exopolysaccharide of Formula (IV) with an active concentration of about 0.02 wt%. The composition with foaming properties may comprise olefin sulfonate; sulfo- betaine; betaine; and exopolysaccharide, wherein the active concentration of olefin sulfonate ranges from about 7.12 to about 8.44% by weight of said composition, the active concentration of sulfo-betaine ranges from about 3 94 to about 4.41% by weight of said composition, the active concentration of betaine ranges from about 4.12 to about 4.59% by weight of said composition, and the active concentration of exopolysaccharide ranges from about 0 01 to about 0.1% by weight of said composition. The composition with foaming properties may comprise olefin sulfonate; sulfo-betaine; betaine; and exopolysaccharide, wherein the active concentration of olefin sulfonate is about 7.60% by weight of said composition, the active concentration of sulfo-betaine is about 4.20% by weight of said composition, the active concentration of betaine is about 4.40% by weight of said composition, and the active concentration of exopolysaccharide is about 0.02% by weight of said composition.

The disclosed composition with foaming properties may be useful to generate stable foams at high temperature and salinity.

The disclosed composition with foaming properties may be useful to generate stable foams at a temperature of about 90°C to about 98°C, about 90°C to about 97°C, about 90°C to about 96°C, about 90°C to about 95°C, about 90°C to about 94°C, about

90°C to about 93 °C, about 90°C to about 92°C, about 90°C to about 91°C, about 91°C to about 98°C, about 92°C to about 98°C, about 93 °C to about 98°C, about 94°C to about 98°C, about 95°C to about 98°C, about 96°C to about 98°C, about 97°C to about 98°C, about 90°C, about 91°C, about 92°C, about 93°C, about 94°C, about 95°C, about 96°C, about 97°C, about 98°C, or any range or integer falling within about 90°C to about 98°C.

The disclosed composition with foaming properties may be useful to generate stable foams at salinity of more than about 30,000 ppm, more than about 35,000 ppm, more than about 40,000 ppm, more than about 45,000ppm, more than about 50,000 ppm, more than about 60,000 ppm, more than about 70,000 ppm, more than about 80,000 ppm, more than about 90,000 ppm, up to about 100,000 ppm, or any range or integer falling within about 30,000 to about 100,000 ppm. The disclosed composition with foaming properties may be able to generate stable foams at about 5 to about 25% oil saturation, about 5 to about 20%, about 5 to about 15%, about 5 to about 10%, about 10 to about 25%, about 15 to about 25%, about 20 to about 25%, about 10 to about 20%, about 15 to about 20%, about 5%, about 10%, about 15%, about 20%, about 25%, or any range or integer falling within about 5 to about 25% of oil saturation.

The composition with foaming properties may be used as a foam.

The composition with foaming properties further comprises water and a foaming gas. The water may be distilled water, double distilled water or sea water. The foaming gas may be any gas that imparts foaming properties to the composition such as nitrogen, oxygen, carbon dioxide, natural gas, methane, propane, butane, and mixtures thereof. The foaming gas may generate a stable foam with said composition upon contact. The stability of the generated foam may be sustained after multiple contacts with a foaming gas.

The composition with foaming properties may further comprise an aqueous medium. The aqueous medium may be water or seawater.

The amount of aqueous medium in a composition with foaming properties may be present in about 50.0 to about 90.0 wt%, about 50.0 to about 85.0 wt%, about 50.0 to about 80.0 wt%, about 50.0 to about 75.0 wt%, about 50.0 to about 70.0 wt%, about 50.0 to about 65.0 wt%, about 50.0 to about 60.0 wt%, about 50.0 to about 55.0 wt%, about 55.0 to about 90.0 wt%, about 60.0 to about 90.0 wt%, about 65.0 to about 90.0 wt%, about 70.0 to about 90.0 wt%, about 75.0 to about 90.0 wt%, about 80.0 to about 90.0 wt%, about 85.0 to about 90.0 wt%, about 50.0 wt%, about 60.0 wt%, about 70.0 wt%, about 80.0 wt%, about 90.0 wt%, or any range or integer falling within about 50.0 to about 90.0 wt% of the composition with foaming properties.

The corresponding amount of active ingredients in said composition may be present in about 10.0 to about 50.0 wt%, about 15.0 to about 50.0 wt%, about 20.0 to about 50.0 wt%, about 25.0 to about 50.0 wt%, about 30.0 to about 50.0 wt%, about 35.0 to about 50.0 wt%, about 40.0 to about 50.0 wt%, about 45.0 to about 50.0 wt%, about 10.0 to about 45.0 wt%, about 10.0 to about 40.0 wt%, about 10.0 to about 35.0 wt%, about 10.0 to about 30.0 wt%, about 10.0 to about 25.0 wt%, about 10.0 to about 20.0 wt%, about 10.0 to about 15.0 wt%, about 10.0 wt%, about 15.0 wt%, about 20.0 wt%, about 25.0 wt%, about 30.0 wt%, about 35.0 wt%, about 40.0 wt%, about 45.0 wt%, about 50 wt%, or any range or integer falling within about 10.0 to about 50 wt% of the composition with foaming properties.

The amount of aqueous medium in a composition with foaming properties may be present in about 82.5 to about 84.8 wt%, about 82.5 to about 84.5 wt%, about 82.5 to about 84.2 wt%, about 82.5 to about 83.9 wt%, about 82.5 to about 83.6 wt%, about

82.5 to about 83.3 wt%, about 82.5 to about 83.0 wt%, about 82.5 to about 82.7 wt%, about 82.8 to about 84.8 wt%, about 83.1 to about 84.8 wt%, about 83.4 to about 84.8 wt%, about 83.7 to about 84.8 wt%, about 84.0 to about 84.8 wt%, about 84.3 to about 84.8 wt%, about 84.6 to about 84.8 wt%, about 82.5 wt%, about 83.0 wt%, about 83.5 wt%, about 84.0 wt%, about 84.5 wt%, or any range or integer falling within scope of about 82.5 to about 84.8 wt% of the composition with foaming properties.

The corresponding amount of active ingredients in said composition may be present in about 15.2 to about 17.5 wt%, about 15.2 to about 17.2 wt%, about 15.2 to about 16.9 wt%, about 15.2 to about 16.6 wt%, about 15.2 to about 16.3 wt%, about 15.2 to about 16.0 wt%, about 15.2 to about 15.7 wt%, about 15.2 to about 15.4 wt%, about 15.5 to about 17.5 wt%, about 15.8 to about 17.5 wt%, about 16.1 to about 17.5 wt%, about 16.4 to about 17.5 wt%, about 16.7 to about 17.5 wt%, about 17.0 to about

17.5 wt%, about 17.3 to about 17.5 wt%, about 15.5 wt%, about 16.0 wt%, about 16.5 wt%, about 17.0 wt%, about 17.5 wt%, or any range or integer falling within about 15.2 to about 17.5 wt% of the composition with foaming properties. In one embodiment, the amount of aqueous medium in a composition with foaming properties may be present in about 84 wt%, and the amount of active ingredients may be present in about 16 wt% of the composition with foaming properties.

In another aspect, there is provided a composition with foaming properties according to the present disclosure, when used in offshore direct discharge after use.

In yet another aspect, there is provided a composition with foaming properties according to the present disclosure, when used as a foam.

In a further aspect, there is provided a composition with foaming properties according to the present disclosure, when used in oil recovery processes. In another aspect, there is provided a method to enhance the recovery of oil from a subterranean oil-containing formation comprising the use of a composition with foaming properties according to the present disclosure, comprising:

(a) introducing a composition with foaming properties according to the present disclosure into the subterranean oil-containing formation;

(b) introducing a gas into the subterranean oil-containing formation, wherein the presence of the composition with foaming properties lowers the gas mobility within said formation; and recovering oil from the formation. In yet another aspect, there is provided a method to enhance the recovery of oil from a subterranean oil-containing formation comprising the use of a composition with foaming properties according to the present disclosure, comprising:

(a) injecting a composition with foaming properties according to the present disclosure into the subterranean oil-containing formation through one or more injection wells;

(b) introducing a gas into the subterranean oil-containing formation, wherein the presence of the composition with foaming properties lowers the gas mobility within said formation;

(c) extracting oil from the formation through one or more production wells.

The composition with foaming properties may be part of a package introduced into a subterranean oil-containing formation by itself or with another fluid.

The disclosed composition with foaming properties may be used as a fire fighting foam, foam cleaner, industrial foam, agricultural foam or foam used in home and personal care products. Description of Drawings

The accompanying drawings illustrate a disclosed embodiment and serves to explain the principles of the disclosed embodiment. It is to be understood, however, that the drawings are designed for purposes of illustration only, and not as a definition of the limits of the invention.

Figure 1

Fig. 1 shows a schematic representation of the CHARM dilution modelling.

Figure 2 Fig. 2 shows a biodegradability comparison study of a foam composition of

Table 2B compared to other known biodegradable compounds.

Figure 3

Fig. 3 shows a comparative foam stability and static adsorption study between a foam composition of Table 2B and four other comparative foam compositions.

Figure 4

Fig. 4A and Fig. 4B show a foam stability comparison study between a foam composition of Table 2B and the comparative foam composition of Table 5 under reservoir conditions.

Examples

Non-limiting examples of the invention and a comparative example will be further described in greater detail by reference to specific Examples, which should not be construed as in any way limiting the scope of the invention. Example 1: Preparation of a foam composition

75 g of Witconate AOS was weighed into a 500 mL beaker. Within the same beaker, 37.50 g of Betadet SHR, and 37.50 g of Betadet HR-50K were weighed. By using laboratory stand mixer, the three chemicals were mixed together at 400 rpm until the mixture was observed to be homogenous. 66.67 g of Schleroglucan liquid from its original bottle (supplied as 0.15%) was then weighed into a separate beaker. Under stirring condition, 33.33 g of distilled water was added slowly to dilute Schleroglucan to 0.10 %. Thereafter, the diluted Schleroglucan was mixed with the previous surfactant mixture of Witconate AOS, Betadet SHR and Betadet HR-50K to form a homogenous solution.

Subsequently, 150 g of distilled water was added into the above solution and stirred at 200 rpm until homogeneous. The solution was then left to stand overnight or until the bubbles have disappeared.

Example 2: Composition with foaming properties

The following is an example of a composition with foaming properties of the present disclosure. A foam composition of the present invention is consisted of a synergistic‘golden’ ratio of the four components as shown in Table 1. This ratio gives the composition a superior foam performance at high temperature with low adsorption at subterranean. With the combination of the four components in the concentrations defined below in Tables 2A and 2B, the composition has proven to perform exceptionally well at reservoir conditions (e.g. 94°C) with a reduction in gas mobility by 10 times, or relatively, a reduction of gas-oil-ratio (GOR) of nearly 50%. The Schleroglucan exopolysaccharide as part of the composition makes the total composition readily biodegradable and environmentally-friendly. The foam composition of the present invention exhibits no incompatibilities and total solubilisation in seawater while meeting environmentally friendly criteria (i.e. Gold or Silver colour banding) set by OSPAR Commission. [Table 1] Synergistic‘golden’ ratio of the four components in a foam composition.

[Table 2A] Concentration ranges of components in a foam composition.

[Table 2B] Embodiment of foam composition

Tables 2 A and 2B show the exemplary active concentration ranges and active concentrations of the four components in a foam composition of the present invention which has exceptional performance at reservoir conditions with a reduction in gas mobility by 10 times, or relatively, a reduction of gas-oil-ratio (GOR) of nearly 50%. The composition is also readily biodegradable and environmentally-friendly, exhibiting no incompatibilities and total solubilisation in seawater while meeting environmentally friendly criteria (i.e. Gold or Silver colour banding) set by OSPAR Commission.

Example 3: Chemical Hazard Assessment and Risk Management (CHARM) dilution modelling of a foam composition

The following example reveals the CHARM dilution modelling performed on a foam composition of the present invention. CHARM dilution modelling under the OSPAR Convention is conducted to determine the risk and extent of chemical movement in the ocean. This is a vital decision-making tool to determine if the chemicals are safe to be discharged overboard. To be determined safe to discharge overboard, the chemicals should at least rank GOLD or SILVER band, indicating a low hazard quotient (HQ). Fig. 1 shows a schematic of the CHARM dilution modelling.

Extensive ecotoxicology evaluations on the degree of toxicity, biodegradability and persistency of a foam composition of the present invention were performed using recognised standard methods for eco-toxicity evaluation from the Organisation for Economic Co-operation and Development (OECD). A foam composition of the present invention has the following eco-toxicological values:

Persistency (Bioaccumulation) for each component:

All components of a foam composition of the present invention are non-persistent. All components meet the persistency criteria of either: Log Pow >3 or BCF<100, MW >700)

Biodegradabilitv of formulation:

A foam composition of the present invention is readily biodegradable = 89% degradation after 28 days

Toxicity of organisms from three trophic levels:

• Acute toxicity on fish, 1 50= 2.55 mg/L • Acute toxicity on invertebrate ( Daphnia magna ), EC5o= 9.4 mg/L

• Acute algae, EC50 = 7.79 mg/L

Based on the above, the foam composition of the present invention has met the Persistency and Biodegradation criteria set by OSPAR. The next step is to evaluate/calculate the extent of toxicity over time through a risk assessment known as the hazard quotient (HQ) using the CHARM dilution model as shown in Fig. 1.

The PNEC (predicted no effect concentration) is derived on the basis of the results obtained in the ecotoxicology studies with algae, invertebrate and fish, by dividing the lowest observed effect concentration by an appropriate assessment factor which is found in the ECHA Guidance Document R.10. Here, the lowest toxicity value is LC50 = 2.55 mg/L from acute fish. According to the ECHA Guidance R.10, an assessment of 10,000 for the derivation of PNEC should be applied, i.e.:

PNFC / /T 1 = ^{Lowest Toxicit} y ^{Value (} ug L ⁾

& ' Assessment Factor

= 2.55 mg/L /10, 000

= 0.000255 mg/L

= 0.255 pg/L

Then, the PEC (predicted environmental concentration) for the on-going discharge is calculated using the following equation:

f _r - F squeezing treatment C squeezing treatment

PEC At

water, on-going D

F distances

¹ pw

In which:

• fr = fraction released (=0.33)

• C squeezing treatment = initial concentration of chemical in the chemical solution

• F squeezing treatment ⁼ the total amount in mg/L of chemical solution pumped into the well in the squeezing treatment

• Dΐ is the duration in days of the on-going release. This was set to 90 days • F _pw is the volume of produced water discharged per day (m ³ /d). A value of 14,964 m ³ /d is the CHARM default value.

• Di _{stance, x} is the dilution factor at distance x from the platform. The dilution factor is set to 0.001 at distance of 500 m according to CHARM, i.e. Di _stance , soo _m = 0.001

• Calculations of the on-going PECs were carried out by assuming different ratios between F _S q _UCC/m g treatment and F _pw .

The Hazard Quotient (HQ) is then calculated by dividing the PEC with the PNEC, or HQ = PEC/PNEC.

[Table 3] Hazard Quotient (HQ) and Colour Banding of the foam composition of

Table 2B.

[Table 4] Colour banding indicating hazard rating from CHARM dilution model.

The foam composition of the present invention achieves Silver when the dilution ratio is 1/2 or the volume of produced water is twice the amount of chemical solution injected i.e. F _sq /F _pw. The foam composition of the present invention has the potential to achieve the Gold colour band when the minimum dilution of the formulation is 50 times the initial squeeze amount, but this dilution scenario is unlikely typical oil and gas affair. Therefore, the foam composition of the present invention is considered a Silver ranked chemical if this chemical was to be listed against other chemicals used at North Sea under OSPAR system. A Silver ranked chemical is considered to pose a low hazard to the environment.

Comparative Examples

Comparative Example 1: CHARM dilution modelling of a foam composition compared with a comparative composition

The composition of the comparative composition is shown in Table 5.

[Table 5] Composition of a comparative composition.

The following is a comparison between the foam composition of Table 2Band the comparative composition of Table 5 using the CHARM dilution modelling.

[Table 6] Hazard Quotient (HQ) and Colour Banding of the foam composition of Table 2B versus the comparative composition of Table 5.

[Table 7] Biodegradation, bioaccumulation and toxicity of the foam composition of Table 2B versus the comparative composition of Table 5.

Although the comparative composition of Table 5 achieves the gold band, the polymeric amphiphilic surfactant component in it has poor biodegradability and is therefore not safe to be discharged overboard as stated in the OSPAR Regulations. Additionally, the comparative composition of Table 5 is also hard to be treated in water treatment and may cause hazards to the environment.

The extent of environmental friendliness depends on all three factors - toxicity, biodegradability, and bioaccumulation. While the comparative composition of Table 5 achieves the gold band while the foam composition of Table 2B achieves the silver band, it should be noted that the foam composition of Table 2B has met all 3 factors (toxicity, biodegradability and bioaccumulation) while the comparative composition of Table 5 has only met 2 factors (bioaccumulation and toxicity). Hence, the foam composition of Table 2B (and Table 2A) is considered to be more environmentally friendly than the comparative composition of Table 5.

Comparative Example 2: Biodegradability comparison study

The biodegradability of the foam composition of Table 2B in a marine environment was assessed by comparing against 6 other compounds. OECD TG 301C (Modified MITI) defines a positive result of readily biodegradability as: the chemical will undergo rapid and ultimate biodegradation to their natural state when subjected to sunlight, water and microbial. Fig. 2 shows the results of the comparison study. Results show that the foam composition of the present invention underwent 60-100% biodegradation in 28 days.

Comparative Example 3: Foam stability and static adsorption comparison study

The foam stability and static adsorption comparison between the foam composition of Table 2B and four other comparative foam compositions are shown in Fig. 3 and the comparison results are summarized in Table 8.

The foaming test was performed at 94°C, with Baronia crude oil and using nitrogen gas. Static adsorption of each foam composition was determined using Hyamine titration method to measure the concentration before and after exposure to crushed core for 7 days at 25°C. [Table 8] Summary of foam stability and static adsorption comparison results.

As shown in Table 8, the foam half-life of a foam composition of the present invention is comparatively higher than the four other comparative foam compositions. Furthermore, a foam composition of the present invention also exhibits the lowest extent of static adsorption. Comparative Example 4: Foam stability comparison study under reservoir conditions

The foam stability comparison study between a foam composition of the present invention (Table 2B) and a comparative foam composition (Table 5) under reservoir conditions is shown.

[Table 9] Compositions of the comparative composition of Table 5 and the foam composition of Table 2B.

The foam stability test was performed at a temperature of 94°C, with and without Baronia (BN65) crude oil, and spurged with nitrogen gas.

Fig. 4A and Fig. 4B show the results of the foam stability comparison study under reservoir conditions. Fig. 4A shows that although a lower application concentration of a foam composition of the present invention i.e. at 0.3 wt% was used, as compared to 0.5 wt% of the comparative composition, similar foam stability performance with and without oil was achieved. Furthermore, it should be noted that the concentration of each component in the foam composition of the present invention is comparatively lower. Fig. 4B shows the results of the foam stability comparison study when a foam composition of the present invention and the comparative composition were applied at the same concentration (0.3 wt%). The results show that similar foam stability performance was achieved.

Comparative Example 5: Cost comparison study

The following is a cost comparison between a foam composition of Table 2B and the comparative foam composition of Table 5.

[Table 10] Cost comparison study of the foam composition of Table 2B and the comparative composition of Table 5.

*Unit Development Cost (UDC) + Unit Production Cost (UPC) = Unit Technical Cost (UTC) The foam composition of the present invention (Table 2A and 2B) has an appreciable cost advantage over the comparative composition (Table 5) in terms of Unit Production Cost (UPC) due to the lower application concentration required (0.3 wt% compared to 0.5 wt%). This translates to overall lower UTC and hence more economical.

The lower application concentration required for the foam composition of the present invention (Table 2A and 2B) also resulted in lower OPEX when CAPEX and ABEX (abandonment Expenditure) are assumed to be the same for both foam compositions. [Table 11] Cost comparison study with a commercial composition.

As shown in Table 11, the foam composition of the present invention (Table 2A and 2B) requires a lower application concentration (0.3 wt%) and this translates to an appreciable cost advantage over the comparative composition (Table 5), and a significant cost advantage over the comparative commercial composition.

As the foam composition of the present invention displays biodegradability and non-toxicity, and thus safe to be discharged overboard after use, it eliminates the use of end-of-pipe solution and facilities and translates to substantial cost savings. Furthermore, as the foam composition of the present invention requires a lower application concentration, lesser components in its composition and lower concentration of each component, it translates to cost-effectiveness and further cost savings.

Applications

The disclosed composition with foaming properties advantageously comprises an exopolysaccharide that may be an efficient foam stabilizer, and is readily biodegradable and non-toxic.

Advantageously, the composition with foaming properties may be used to generate a foam that exhibits good foam generation and stability under severe reservoir conditions of high temperatures, high salinity and in the presence of crude oil.

Therefore advantageously, the disclosed composition with foaming properties may be used in improved oil recovery methods and may be directly discharged offshore after use.

There is therefore also provided a method for recovering oil from a subterranean oil-containing formation.

The composition with foaming properties advantageously may be used to generate foam which exhibits a low adsorption rate on reservoir rock and high Mobility Reduction Factor. The lowered gas mobility advantageously results in improved sweep efficiency.

Further advantageously, the composition with foaming properties may be used to generate a stable foam even after repeated contacts with a foaming gas.

It will be apparent that various other modifications and adaptations of the invention will be apparent to the person skilled in the art after reading the foregoing disclosure without departing from the spirit and scope of the invention and it is intended that all such modifications and adaptations come within the scope of the appended claims.