CA2239318C - Improved hydrocarbon gelling compositions useful in fracturing formations - Google Patents
Improved hydrocarbon gelling compositions useful in fracturing formations Download PDFInfo
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- CA2239318C CA2239318C CA 2239318 CA2239318A CA2239318C CA 2239318 C CA2239318 C CA 2239318C CA 2239318 CA2239318 CA 2239318 CA 2239318 A CA2239318 A CA 2239318A CA 2239318 C CA2239318 C CA 2239318C
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- amine
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/60—Compositions for stimulating production by acting on the underground formation
- C09K8/62—Compositions for forming crevices or fractures
- C09K8/64—Oil-based compositions
Abstract
The invention relates to compositions and methods for gelling liquid hydrocarbons by the introduction of certain phosphate esters, a crosslinking agent, and an enhancer. The enhancer of the present invention is preferably an oxyalkylated amine or a blend of an oxyalkylated amine with another amine or a non-nitrogen-containing component. Mixed phosphate esters containing an oxyalkylene group are useful in the practice of the invention. Gel-forming compositions for addition to liquid hydrocarbons, as well as methods for forming fracturing fluids, are encompassed. The present compositions and methods are an improvement in the field of hydrocarbon gelling, e.g., in fracturing formations, by providing more rapid gellation and greater viscosities.
Description
IMPROVED HYDROCARBON GELLING COMPOSITIONS USEFUL IN
FRACTURING FORMATIONS
FIELD OF THE INVENTION
The present invention is directed to the improved gellation of hydrocarbons liquids for a variety of applications. The present invention is specifically directed to an enhancer for improving the gelling of hydrocarbon liquids when treated with phosphate esters and crosslinking agents.
BACKGROUND OF THE INVENTION
In order to maximize the amount of oil derived from an oil well a process known as hydraulic pressure stimulation or, more commonly, formation fracturing is often employed. In formation fracturing, fluid is pumped under high pressure down the wellbore through a steel pipe having small perforations in order to create or perpetuate cracks in the adjacent subterranean rock formation. The fluid employed must be able to withstand exceptionally high shear forces. Gelled liquids, and particularly gelled hydrocarbons, are well-suited for this application. The fracturing fluid has entrained therein a particulate material called a proppant (e.g., sand or other particulate matter). The proppant particles become wedged in the cracks of the formation to keep the cracks open once the external pressure is released, thereby enabling continued production stimulation of the well. It is ideal from the vantage points of time economy and cost-savings to have the gelling of the hydrocarbon take place more or less continuously on-site or "on the fly" as the I
components are brought together as they are pumped down the well bore.
Accordingly, it is both desirable and adavatageous that gellation occur as quickly as possible.
The viscosity of the hydrocarbon gel is important for proppant transport. Poor gel viscosity can lead to a phenomenon known as "screening out", whereby the gel is not sufficiently capable of suspending the proppant. Large quantities of proppant material, upwards of 3 to 15 pounds of sand per gallon of pumping fluid, can settle out inside the well bore, as well as in the fracture. If the proppant has dropped, or screened out, part of the created fracture is effectively closed when the external pressure is released. When screening out occurs, the fracturing process must be interupted and the well bore cleaned out, costing both significant time and expense.
Rapid gellation of hydrocarbon liquids is also beneficial when tanks or vessels carrying such liquids are damaged during transport and cause highly hazardous and environmentally damaging spillage. A fast gelling additive composition that can be added to the leaking volume of hydrocarbon liquid would serve to prevent or, at least, reduce or contain the spillage and the resultant damage. A variety of other applications exist which require the rapid gellation of hydrocarbon 1 iquids, and to which the present invention would apply.
Several means for gelling hydrocarbon liquids are disclosed in the prior art.
U.S. Patent No. 5,417,287 to Smith et al. is directed to a method for fracturing a subterranean formation which involves adding to a hydrocarbon liquid (a) an organic phosphate of the formula HP04RR' where R is an alkyl or alkaryl group having from 6 to 18 carbon atoms and R' is hydrogen or an aryl, alkaryl or alkyl group having from 1 to 18 carbon atoms; and (b) a ferric salt.
Smith et al 5,614,010 teaches gelling agents suitable for use in methods of fracturing formations, comprising ferric salts, certain phosphate esters, a low molecular weight amine such as triethanolamine or triethylamine, and an optional surfactant. Smith '010, however, does not achieve, e.g., the impressive hydrocarbon viscosities achievable by the present methods and compositions, and moreover Smith uses twice as much phosphate ester and ferric ion as required herein.
Smith et al US 5,647,900 discloses gelling agents for hydrocarbon gels comprising combinations of certain orthophosphate esters and a composition comprising a source of fernc ions, a C2 - C12 amine, and a polycarboxylic acid or salt thereof. However, the gels formed in the Smith et al inventions demonstrate lower (Marsh funnel) viscosities than those achieved by the gels of the present invention. Moreover, the Smith et al gels are formed using twice as much phosphate ester and ferric ion ( 1 °Io of each relative to the volume of liquid hydrocarbon to be gelled) as compared to the invention as demonstrated, e.g., in the Examples of the invention.
European Patent Application No. 551021A1 to McCabe et al. is directed to gelling a hydrocarbon liquid by adding thereto an at least partially neutralized alkyl orthophosphate acid ester, a C8-C18 surface active amine and C2 - C4 monohydric alcohol. The surface active amine employed includes alkyl and alkanol amines having from about 8 - 18 carbon atoms, N-heterocyclic amines, alkyl substituted derivatives of such heterocyclics and mixtures thereof.
Amines having more than one nitrogen group are preferred and imidazoline, such as that prepared from the reaction of a tall of 1 fatty acid with diethylenetriamine, is most preferred.
U.S. Patent No. 4,316,810 to Burnham is directed to a fracturing composition which is an aluminum salt of an oxaalkyl phosphate in an oil base liquid. Surface active agents are not disclosed.
U.S. Patent No. 4,153,649 to Griffin is directed to the reaction product of a hydroxy ether and a pentavalent phosphorus compound and an alcohol. The hydroxy ether has the formula RORIOH wherein R is a C, to C6 alkyl group, Rl Is a C2 or C3 alkylene group and the total carbon atoms of Rl and R range from 3 to about 8. The disclosed reaction product may be employed in the gelling of hydrocarbon liquids when used with a compound containing a multivalent metal cation.
U. S. Patent No. 5,271,464 to McCabe is directed to a method of plugging or sealing a subterranean formation by introducing a rapidly gelling hydrocarbon thereto.
To the hydrocarbon is added a first component which is an at least partially neutralized alkyl orthophosphate ester and a second component which is the reaction product of an aqueous source of aluminum or ferric ions and a C8 - C18 surface active amine in the presence of a water miscible organic solvent. The surface active amine is as defined above for European Patent Application No.
FRACTURING FORMATIONS
FIELD OF THE INVENTION
The present invention is directed to the improved gellation of hydrocarbons liquids for a variety of applications. The present invention is specifically directed to an enhancer for improving the gelling of hydrocarbon liquids when treated with phosphate esters and crosslinking agents.
BACKGROUND OF THE INVENTION
In order to maximize the amount of oil derived from an oil well a process known as hydraulic pressure stimulation or, more commonly, formation fracturing is often employed. In formation fracturing, fluid is pumped under high pressure down the wellbore through a steel pipe having small perforations in order to create or perpetuate cracks in the adjacent subterranean rock formation. The fluid employed must be able to withstand exceptionally high shear forces. Gelled liquids, and particularly gelled hydrocarbons, are well-suited for this application. The fracturing fluid has entrained therein a particulate material called a proppant (e.g., sand or other particulate matter). The proppant particles become wedged in the cracks of the formation to keep the cracks open once the external pressure is released, thereby enabling continued production stimulation of the well. It is ideal from the vantage points of time economy and cost-savings to have the gelling of the hydrocarbon take place more or less continuously on-site or "on the fly" as the I
components are brought together as they are pumped down the well bore.
Accordingly, it is both desirable and adavatageous that gellation occur as quickly as possible.
The viscosity of the hydrocarbon gel is important for proppant transport. Poor gel viscosity can lead to a phenomenon known as "screening out", whereby the gel is not sufficiently capable of suspending the proppant. Large quantities of proppant material, upwards of 3 to 15 pounds of sand per gallon of pumping fluid, can settle out inside the well bore, as well as in the fracture. If the proppant has dropped, or screened out, part of the created fracture is effectively closed when the external pressure is released. When screening out occurs, the fracturing process must be interupted and the well bore cleaned out, costing both significant time and expense.
Rapid gellation of hydrocarbon liquids is also beneficial when tanks or vessels carrying such liquids are damaged during transport and cause highly hazardous and environmentally damaging spillage. A fast gelling additive composition that can be added to the leaking volume of hydrocarbon liquid would serve to prevent or, at least, reduce or contain the spillage and the resultant damage. A variety of other applications exist which require the rapid gellation of hydrocarbon 1 iquids, and to which the present invention would apply.
Several means for gelling hydrocarbon liquids are disclosed in the prior art.
U.S. Patent No. 5,417,287 to Smith et al. is directed to a method for fracturing a subterranean formation which involves adding to a hydrocarbon liquid (a) an organic phosphate of the formula HP04RR' where R is an alkyl or alkaryl group having from 6 to 18 carbon atoms and R' is hydrogen or an aryl, alkaryl or alkyl group having from 1 to 18 carbon atoms; and (b) a ferric salt.
Smith et al 5,614,010 teaches gelling agents suitable for use in methods of fracturing formations, comprising ferric salts, certain phosphate esters, a low molecular weight amine such as triethanolamine or triethylamine, and an optional surfactant. Smith '010, however, does not achieve, e.g., the impressive hydrocarbon viscosities achievable by the present methods and compositions, and moreover Smith uses twice as much phosphate ester and ferric ion as required herein.
Smith et al US 5,647,900 discloses gelling agents for hydrocarbon gels comprising combinations of certain orthophosphate esters and a composition comprising a source of fernc ions, a C2 - C12 amine, and a polycarboxylic acid or salt thereof. However, the gels formed in the Smith et al inventions demonstrate lower (Marsh funnel) viscosities than those achieved by the gels of the present invention. Moreover, the Smith et al gels are formed using twice as much phosphate ester and ferric ion ( 1 °Io of each relative to the volume of liquid hydrocarbon to be gelled) as compared to the invention as demonstrated, e.g., in the Examples of the invention.
European Patent Application No. 551021A1 to McCabe et al. is directed to gelling a hydrocarbon liquid by adding thereto an at least partially neutralized alkyl orthophosphate acid ester, a C8-C18 surface active amine and C2 - C4 monohydric alcohol. The surface active amine employed includes alkyl and alkanol amines having from about 8 - 18 carbon atoms, N-heterocyclic amines, alkyl substituted derivatives of such heterocyclics and mixtures thereof.
Amines having more than one nitrogen group are preferred and imidazoline, such as that prepared from the reaction of a tall of 1 fatty acid with diethylenetriamine, is most preferred.
U.S. Patent No. 4,316,810 to Burnham is directed to a fracturing composition which is an aluminum salt of an oxaalkyl phosphate in an oil base liquid. Surface active agents are not disclosed.
U.S. Patent No. 4,153,649 to Griffin is directed to the reaction product of a hydroxy ether and a pentavalent phosphorus compound and an alcohol. The hydroxy ether has the formula RORIOH wherein R is a C, to C6 alkyl group, Rl Is a C2 or C3 alkylene group and the total carbon atoms of Rl and R range from 3 to about 8. The disclosed reaction product may be employed in the gelling of hydrocarbon liquids when used with a compound containing a multivalent metal cation.
U. S. Patent No. 5,271,464 to McCabe is directed to a method of plugging or sealing a subterranean formation by introducing a rapidly gelling hydrocarbon thereto.
To the hydrocarbon is added a first component which is an at least partially neutralized alkyl orthophosphate ester and a second component which is the reaction product of an aqueous source of aluminum or ferric ions and a C8 - C18 surface active amine in the presence of a water miscible organic solvent. The surface active amine is as defined above for European Patent Application No.
551021A1, also to McCabe. The water miscible organic solvent is generally a monohydric alcohol.
U.S. Patent No. 3,494,949 to Monroe et al. is directed to an additive for improving the viscosity of motor oils which is generally an aluminum salt of an alkyl orthophosphate.
U.S. Patent No. 2,983,678 to Pellegrini et al. is directed to an additive for lubricating oils which is generally a rare earth metal salt of a diester phosphate.
US Patent Nos. 4,877,894, 5,057,233, 5,110,485, and 5,202,035 to Huddleston are related to phosphate esters as hydrocarbon gelling agents. The gelling agent is generally formed by first reacting phosphorus pentoxide with triethyl phosphate, followed by reaction with a mixed alcohol that may have a substantial hexanol component. The gelling agent may also be in the form of an aluminum salt, by reaction of the phosphate ester with aluminum sulfate in the presence of solvent. None of the gelling agents or systems of the Huddleston patents appreciate the benefit of adding an amine, e.g., oxyalkylated amine, or an amine blend enhancer in the gelling of liquid hydrocarbons. The Huddleston teachings are also. devoid of appreciation of the benefits obtained by using a ferric salt.
US Patent No. 5,190,675 and EP 225,661 to Gross (Dowell Schlumberger) employ metal phosphate diesters in the gelling of liquid hydrocarbons. The metal phosphate diester is prepared by reacting a phosphorus pentoxide with a triethyl phosphate , followed by reaction with an alcohol to form the diester. The metal salt is formed in the presence of the hydrocarbon to be gelled by the addition of a non-aqueous source of aluminum, e.g., aluminum isopropoxide. The gelling agents of Gross are devoid of the presence of an amine enhancer and a crosslinking ferric salt, and accordingly, Gross' methods do not achieve the level of beneficial gelling properties achievable by the present invention.
While a variety of systems are available for gelling hydrocarbon liquids for the application discussed above, there exists a clear need in the art for a means of improving the known systems to achieve decreased gelling times and improved viscosity.
SUMMARY OF THE INVENTION
Therefore, it is one object of the present invention to provide such a means for improving known gellation systems.
It is a further object of the present invention to provide a novel gellation system exhibiting decreased gelling times and improved viscosity.
It is yet another object of the present invention to provide a composition for decreasing gelling time and improving viscosity for use in conventional methods of gelling hydrocarbon liquids.
These as well as other objects are achieved by providing a composition for improving the gelling of hydrocarbon liquids, which composition comprises an enhancer chosen from a specific class of amines, a certain class of phosphate esters, and a crosslinking agent.
Such objects are also achieved by providing a method of gelling hydrocarbon liquids which involves adding to a hydrocarbon liquid the enhancer, the phosphate ester, and the crosslinking agent. -A further object of the invention is to provide synergistic combinations of enhancers, as well as synergistic phosphate ester combinations, useful in improving the gelling of hydrocarbon liquids.
More particularly, the objects of the invention are achieved by providing a method of gelling hydrocarbon liquids which involves adding to a hydrocarbon liquid (a) a phosphate ester or a mixture of phosphate esters; (b) a crosslinking agent; and (c) an amine enhancer which is a CZ - C22 amine, a C2 - C22 oxyalkylated amine, or mixtures thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is drawn, in part, to an enhancer for use in the gelling of hydrocarbon liquids when such a liquid is treated with a phosphate ester and a crosslinking agent.
The invention is also directed to novel compositions comprising the enhancer, a phosphate ester (chosen from a specified class and to be described more fully below), and the crosslinking agent.
The invention relates further still to gel compositions which results from adding to a hydrocarbon liquid the enhancer, the phosphate ester, and the crosslinking agent.
Hydrocarbon liquids which are appropriate for use in accordance with the present invention include kerosene, diesel oil and crude oil, gasoline and other aliphatic and aromatic hydrocarbons such as octane, heptane, paraffinic oils and lubricating oils.
The choice of the liquid for use in accordance with the. present invention will depend o:n the particular industrial or chemical application. In industrial applications, diesel oil is typically gelled, however other liquid hydrocarbons are also well-suited for use in the present invention.
Other factors, such as accessibility and economics(cost) of liquid hydrocarbons at a particular site, dictate to a degree the choice of hydrocarbon to be gelled.
The crosslinking agent or activator employed in the practice of the invention is a salt of a multivalent cation, and is preferably the salt of a multivalent metal cation.
Although a wide variety of metal salts, such as aluminum salts and rare earth metal salts, are within the scope of the present invention, ferric salts are generally preferred. Preferred ferric salts include ferric nitrate and ferric sulfate.
The phosphate ester component of the present invention can be the reaction product of a pentavalent phosphorus compound and an alcohol, and their preparation is according to well-known synthesis procedures (see, for example, Crawford et al UPS 3,757,864, Poklacki US
4,007,128, and Burnham et al US 4,200,539 More preferably, the phosphate esters useful herein are the reaction product of 1) pentavalent phosphorus (e.g., P205) reacted with a trialkylphosphate, and 2) at least one alcohol. The synthesis of these phosphate esters takes place according to well-known procedure, for example, as set forth in Huddleston US 5,202,035,, Alternatively, the phosphate esters useful in the present invention can be prepared by transesterification of orthophosphate ester with triethyl phosphate, for example, Jones et al US
U.S. Patent No. 3,494,949 to Monroe et al. is directed to an additive for improving the viscosity of motor oils which is generally an aluminum salt of an alkyl orthophosphate.
U.S. Patent No. 2,983,678 to Pellegrini et al. is directed to an additive for lubricating oils which is generally a rare earth metal salt of a diester phosphate.
US Patent Nos. 4,877,894, 5,057,233, 5,110,485, and 5,202,035 to Huddleston are related to phosphate esters as hydrocarbon gelling agents. The gelling agent is generally formed by first reacting phosphorus pentoxide with triethyl phosphate, followed by reaction with a mixed alcohol that may have a substantial hexanol component. The gelling agent may also be in the form of an aluminum salt, by reaction of the phosphate ester with aluminum sulfate in the presence of solvent. None of the gelling agents or systems of the Huddleston patents appreciate the benefit of adding an amine, e.g., oxyalkylated amine, or an amine blend enhancer in the gelling of liquid hydrocarbons. The Huddleston teachings are also. devoid of appreciation of the benefits obtained by using a ferric salt.
US Patent No. 5,190,675 and EP 225,661 to Gross (Dowell Schlumberger) employ metal phosphate diesters in the gelling of liquid hydrocarbons. The metal phosphate diester is prepared by reacting a phosphorus pentoxide with a triethyl phosphate , followed by reaction with an alcohol to form the diester. The metal salt is formed in the presence of the hydrocarbon to be gelled by the addition of a non-aqueous source of aluminum, e.g., aluminum isopropoxide. The gelling agents of Gross are devoid of the presence of an amine enhancer and a crosslinking ferric salt, and accordingly, Gross' methods do not achieve the level of beneficial gelling properties achievable by the present invention.
While a variety of systems are available for gelling hydrocarbon liquids for the application discussed above, there exists a clear need in the art for a means of improving the known systems to achieve decreased gelling times and improved viscosity.
SUMMARY OF THE INVENTION
Therefore, it is one object of the present invention to provide such a means for improving known gellation systems.
It is a further object of the present invention to provide a novel gellation system exhibiting decreased gelling times and improved viscosity.
It is yet another object of the present invention to provide a composition for decreasing gelling time and improving viscosity for use in conventional methods of gelling hydrocarbon liquids.
These as well as other objects are achieved by providing a composition for improving the gelling of hydrocarbon liquids, which composition comprises an enhancer chosen from a specific class of amines, a certain class of phosphate esters, and a crosslinking agent.
Such objects are also achieved by providing a method of gelling hydrocarbon liquids which involves adding to a hydrocarbon liquid the enhancer, the phosphate ester, and the crosslinking agent. -A further object of the invention is to provide synergistic combinations of enhancers, as well as synergistic phosphate ester combinations, useful in improving the gelling of hydrocarbon liquids.
More particularly, the objects of the invention are achieved by providing a method of gelling hydrocarbon liquids which involves adding to a hydrocarbon liquid (a) a phosphate ester or a mixture of phosphate esters; (b) a crosslinking agent; and (c) an amine enhancer which is a CZ - C22 amine, a C2 - C22 oxyalkylated amine, or mixtures thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is drawn, in part, to an enhancer for use in the gelling of hydrocarbon liquids when such a liquid is treated with a phosphate ester and a crosslinking agent.
The invention is also directed to novel compositions comprising the enhancer, a phosphate ester (chosen from a specified class and to be described more fully below), and the crosslinking agent.
The invention relates further still to gel compositions which results from adding to a hydrocarbon liquid the enhancer, the phosphate ester, and the crosslinking agent.
Hydrocarbon liquids which are appropriate for use in accordance with the present invention include kerosene, diesel oil and crude oil, gasoline and other aliphatic and aromatic hydrocarbons such as octane, heptane, paraffinic oils and lubricating oils.
The choice of the liquid for use in accordance with the. present invention will depend o:n the particular industrial or chemical application. In industrial applications, diesel oil is typically gelled, however other liquid hydrocarbons are also well-suited for use in the present invention.
Other factors, such as accessibility and economics(cost) of liquid hydrocarbons at a particular site, dictate to a degree the choice of hydrocarbon to be gelled.
The crosslinking agent or activator employed in the practice of the invention is a salt of a multivalent cation, and is preferably the salt of a multivalent metal cation.
Although a wide variety of metal salts, such as aluminum salts and rare earth metal salts, are within the scope of the present invention, ferric salts are generally preferred. Preferred ferric salts include ferric nitrate and ferric sulfate.
The phosphate ester component of the present invention can be the reaction product of a pentavalent phosphorus compound and an alcohol, and their preparation is according to well-known synthesis procedures (see, for example, Crawford et al UPS 3,757,864, Poklacki US
4,007,128, and Burnham et al US 4,200,539 More preferably, the phosphate esters useful herein are the reaction product of 1) pentavalent phosphorus (e.g., P205) reacted with a trialkylphosphate, and 2) at least one alcohol. The synthesis of these phosphate esters takes place according to well-known procedure, for example, as set forth in Huddleston US 5,202,035,, Alternatively, the phosphate esters useful in the present invention can be prepared by transesterification of orthophosphate ester with triethyl phosphate, for example, Jones et al US
5,649,596.
More preferably, the phosphate ester is formed from P205 and a tri-loweralkyl phosphate when reacted with a mixture of alcohols and /or oxyalkylated al.cohols yielding phosphate monoesters, symmetric diesters, asymmetric diesters, symmetric triesters, asymmetric triesters, and mixtures of any of these. "Tri-loweralkyl phosphate" in the present context is to be understood as meaning tri -CI - C6 alkylphosphate. The alcohols suitable for reaction with the phosphate intermediate include alkyl alcohols, aralkyl alcohols, ether-containing alkyl alcohols, and aralkyl ether alcohols (or oxyalkylated aralkyl alcohols), and mixtures thereof. It is to be understood that the term "alkyl" as it applies to the present phosphate esters includes straight and branched alkyl groups. "Aryl" includes C6 to C12 aryl. Therefore, when ether alcohols are employed one or more oxyalkene groups such as oxyethylene, oxypropylene or oxybutylene is present in the "R" group of the alcohol designated as ROH. Accordingly, the phosphate ester that is formed is an ether phosphate ester. Thus, the term "phosphate esters"
as used herein includes ether phosphate esters. The phosphate esters of the present invention will thus be mixtures of esters conforming to the following structures:
RO- P -OH RO- P -ORi RO- P -ORS
OH ~ OH ~ ~d OR2 wherein R, RI , and R2 are independently CI- CI8 alkyl, C6 aryl, C1 - CI8 alkyl or di C1 - CI8 alkyl C6 aryl, C1 - CI8 alkyl ether, C6 aryl ether, or CI - CI8 alkyl or di CI
- CI8 alkyl C6 aryl ether, and where any ether linkage has the following structure: --O(CH2-CHR')-wherein R' is hydrogen, methyl or ethyl.
More preferably, the phosphate ester according to the invention is a mixture of mixed esters such as asymmetric phosphate diesters (i.e., where R ~ RI). The ability to obtain particularly useful phosphate ester mixtures within the scope of the invention hinges upon the specific alkyl, alkaryl, alkyl ether,alkaryl ether, aralkyl, and/or aralkyl ether moieties in the alcohol reactants. For example, a phosphate ester mixture that contains a distribution of C2, C8, CIO, and oxyalkylated C6 aryl groups is particularly useful herein.
The phosphate ester of the present invention is preferably non-neutralized.
However, depending on the particular enhancer employed, it is also within the scope of the invention to at least partially neutralize the phosphate ester.
The enhancer of the present invention is an amine, a mixture of amines, or an amine and another non-amine compound that iunetions as an enhancer. 'I"he following amine structures are within the scope of the enhancer of the present invention:
R~
~,vhere R, R,, and RZ are independently hydrogen, C , - C,H alkyl, CS - C'f;
cycloalkyl, aryl, C i - C, ~ substituted aryl., or -(CH R' -CH20)"
wherein R' is hydrogen, methyl or ethyl. n is an integer from 1 to 10(h and wherein the O atom of the terminal or "n'h" -(CH R' -CH~O)" group is bound to a hydrogen atom, R,~ /
R, R2 where R is hydrogen, C, - Cy~ alkyl, or a group of the structure -(CH R' -CH20)" -wherein R' is hydrogen, methyl or ethyl, n is an integer fiom 1 to 100, and wherein the O atom of the terminal or ''n'h" -(CH R' -CH~O)" group is hound to a hydrogen atom;
R, is hydrogen, C~
alkyl or a group of the structure .(CH R' -CH20)" -wherein R' is hydrogen, methyl or ethyl, n is an integer from 1 to 100. and wherein the O atom of the terminal or "n'~'" -(CH R' -CHZO)" group is hound to a hydrogen atom;
R2 is hydrogen or ..(CH R' -CH20)" -wherein R' is hydrogen, methyl or ethyl, n is an integer from I to 100. and wherein the O atom of the terminal or ''n'h" -(CH R' -Cl l~Ua" group is bound to a hydrogen atom;
and Ri is a C~ or C ,; alkyl; or R~,O -R2__- N
Rr where R is C'~, - C,~ alkyl, R, is hydrogen or a group of the structure -(Cl-1 R'-CHZO)"-wherein R' and n are as defined above with respeca to the diamine; and R~ is a C3 alkyl. With regard to amine structures shown al7ove, the substi.tuent group "alkyl" or "aralkyl" has the meaning of both straight and branched alkyl groups.
More preferably, the amine enhancer an oxyalkylated amine. Thus, preferred oxyalkylated amines include oxyalkylated alkyl amines such as ethoxylated alkyl amines having from 1 to about 100 moles of ethylene oxide per mole of amine and ethoxylated alkyl amines having from about 1 to about 18 carbon atoms in the alkyl group; pulyoxypropylene alkyl amine having from 1 to about 100 moles of propylene oxide per mole of amine; and polyoxybutylene alkyl amine having 1 to about 100 moles of butylene oxide per mole of amine. The term "oxyalkylated alkyl amines" also encompasses oxyalkylated dialkyl amines, such as ethoxylated di C2 - C8 alkyl amines having from 1 to about 100 moles of ethylene oxide per mole of amine;
polyoxypropylene dialkyl amine having from about 1 to about 100 moles of propylene oxide per mole of amine; and polyoxybutylene dialkyl amine having from about 1 to about 100 moles of butylene oxide per mole of amine. More preferably, the term "oxyalkylated amines" means oxyalkylated diamines and oxyalkylated C6 aryl amines. A particularly preferred oxyalkylated amine is N,N-di n-butyl ethanol amine, having the following structure ~aHs The amount of enhancer to be employed in the present compositions and methods is an amount effective to increase the rate of gel formation and to increase the viscosity thereof, relative to known gelling systems that do not incorporate an enhancer of the present invention.
In general, an effective amount of amine enhancer is from 0.01 % to 5.0%
relative to the volume of liquid hydrocarbon to be gelled. More preferably, 0.1 % to 0.5% of amine enhancer is employed.
- Enhancer blends or mixtures are also appropriate for use in the present invention.
Preferred blends include at least one oxyalkylated amine as set forth above with another enhancer component which is either an amine, a non-nitrogen containing compound, a quaternary nitrogen compound or an amide. It should be noted that blends containing more than two components are also within the scope of the present invention.
When a second enhancer component is another amine, this second amine may be chosen from oxyalkylated amines, such as those set forth above, or alkyl amines such as C2 - C22 alkyl amines, C2 - C22 dialkyl amines, C2 - C22 alkyl diamines, C2 - C22 dialkyl diamines, C2 - C22 dialkyl amino C2 - C22 alkylamines, and analogs of these compounds having one or more carbon-carbon double bonds in the alkyl moiety. "Alkyl" within the context of , e.g., alkylamine, is to be understood as meaning straight and branched alkyl groups. The term "C2 -C22 dialkyl" is intended to mean that each alkyl group can be from C2 - C22 . A preferred class of alkyl amines to be used in conjunction with an oxyalkylated amine are fatty amines, and particularly unsaturated fatty amines, such as mono- and di-oleyl amines.
Non-nitrogen containing components which are appropriate in the enhancer blend include oxyalkylated glycerides, oxyalkylated mono- and di-esters and oxyalkylated alcohols and phenols, as well as non-oxyalkylated alcohols and phenols, a fatty acid, or a mixture of a fatty acid and a glyceride.
The specific proportion or ratio of enhancer components varies depending on the nature of the individual enhancer components, as well as on the particular application requiring the gelling of liquid hydrocarbon. However, in general, when the enhancer is a blend comprising at least one oxyalkylated amine and another enhancer component, the components may be mixed at a ratio from about 9 : 1 to 1 : 9 oxyalkylated amine to other enhancer component. When it is advantageous that the enhancer be a mixture or blend of at least one oxyalkylated amine (A) and two other enhancer components (e.g., a second amine enhancer compound (B) and a non-nitrogen-containing enhancer compound (C)), the mixing ratio is from about 1 :
1 : 1 to 6 : 3 : 1 of A : B : C. Further, depending on the particular industrial application, it is within the scope of the invention to employ enhancer blends having, for example, four, five, or more enhancer components. When this is the case, the ratios of the individual components can be determined by the skilled practitioner without resort to undue experimentation.
The invention is further directed to a gel-forming hydrocarbon composition for fracturing formations comprising: 1 ) a hydrocarbon liquid capable of gellation, 2) 0.01 to 10.0% by weight of a phosphate ester which is a reaction product comprising either A) phosphorus pentoxide reacted with a tri-loweralkyl phosphate and subsequently reacted with either an alcohol, an oxyalkylated alcohol or mixtures thereof or B) phosphorous pentoxide reacted with either an alcohol, an oxyalkylated alcohol or mixtures thereof to form a phosphate ester or mixed phosphate ester which is subsequently reacted with a tri-loweralkyl phosphate, 3) a crosslinking agent in an amount effective to gel said hydrocarbon liquid, 4) from about 0.085 molar equivalent to about 0.31 molar equivalent of the phosphate ester of an enhancer comprising an amine selected from the group consisting of alkyl amines, oxyalkylated amines, and mixtures thereof, and 5) optionally a surfactant.
As demonstrated by several of the examples that follow, the invention includes novel synergistic combinations of enhancer components, as well as synergistic phosphate ester combinations. More specifically, the viscosities obtained(as indicated in centipoises and Marsh Funnel time (minutes)) for the present hydrocarbon gel systems using mixtures of enhancer components or mixtures of phosphate esters are greater than the viscosities of the individual components when used at comprable volumes. For example, in Table II below it will be seen that all of the enhancer mixtures have a synergistic effect on production of gels of very high viscosity (in centipoises), relative to the same volume of each of the enhancer components individually.
Particularly preferred synergistic enhancer combinations include, but are not limited to, an ethoxylated di-C4 alkyl amine having one mole of oxyethylene per mole of amine in combination with any of the following oxyalkylated amines: an ethoxylated C16 -C18 alkyl amine having two moles of oxyethylene per mole of amine; an ethoxylated Cg-C16 alkyl amine having two moles of oxyethylene per mole of amine; an ethoxylated C18 alkenyl amine having two moles of oxyethylene per mole of amine; an ethoxylated C16-C18 alkenyl amine having two moles of oxyethylene per mole of amine. Synergistic combinations of any of the following enhancer amines are also preferred: an ethoxylated C16 - C18 alkyl amine having two moles of oxyethylene per mole of amine; an ethoxylated di-C1 alkyl amine having one mole of oxyethylene per mole of amine; an ethoxylated di-C2 alkyl amine having one mole of oxyethylene per mole of amine;
triethanolamine; and an ethoxylated Cg-C16 alkyl amine having two moles of oxyethylene per mole of amine.
Mixtures of phosphate esters in accordance with the invention also have a synergistic effect on gel viscosity. This feature of the invention is exemplified in Table llI
below. Various combinations of the following phosphate esters are effective in this particular aspect of the invention: a C2, C8, CIO alkyl phosphate, having 30.3% C2, 32.1%
C8, and 37.6%
CIO; a C2-CIg alkyl, CI-CI8 alkyl ether phosphate having 30.2% C2, 30.3% C8, 35.6% CIO, and 3.9% CI alkyl ether oxyalkylated with 1 mole of oxypropylene; a C2-CI8 alkyl, CI-CI8 alkyl ether phosphate having 29.7% C2, 26.3% C8, 30.8% CIO, and 13.2% C6 alkyl ether oxyalkylated with 1.5 mole ofoxyethylene; a C2-CI8 alkyl, CI-CI8 alkyl ether phosphate having 30.3%C2, 4.5% C4, 23.8% Cg, 27.9% CIO, and 13.5% C6 alkyl ether oxyalkylated with 1.5 moles of oxyethylene; a C2-CIg alkyl, CI-CI8 alkyl ether phosphate having 27.4%C2, 24.1% C8, 28.4%
CIO, and 20.1% C8 - CIO alkyl ether oxyalkylated with 3 moles of oxyethylene; a C2-CI8 alkyl, CI-CI8 alkyl ether phosphate having 25.7%C2, 22.7% C8, 26.7% CIO, and 24.9% C8 - CIO alkyl ether oxyalkylated with 5 moles of oxyethylene; a C2-CIg alkyl, CI-CIg alkyl ether phosphate having 25.4%C2, 22.1% C8, 26.2% CIO, and 26.3% C16 - CIg alkyl ether oxyalkylated with 3 moles of oxyethylene; a C2-CIg alkyl, C6 aryl ether phosphate having 31 %C2, 25% C8, 30% CIO, and 14%
C6 aryl ether oxyalkylated with 1 mole of oxyethylene; a C2-CIg alkylr C6 aryl ether phosphate having 30.6%C2, 21.6% Cg, 25.4% CIO, and 22.4% C6 aryl ether oxyalkylated with 1 mole of oxyethylene; a C2-CIg alkyl, C6 aryl ether phosphate having 25.9% C2, 22.8%
Cg, 26.8% CIO, and 24.5% C6 aryl ether oxyalkylated with 6 moles of oxyethylene; a C2-CI8 alkyl, C6 aryl ether phosphate having 23.8% C2, 21.0% C8, 24.6% CIO, and 30.6% C6 aryl ether oxyalkylated with 9 moles of oxyethylene; a C2-CIg alkyl, C6 aryl ether phosphate having 26.2% C2, 25.5% C8, 29.9%
Coo, and 18.5% aryl ether oxyalkylated with 10 moles of oxyethylene; a C2-C18 alkyl, C6 aryl ether phosphate having 29.8% C2, 26.3% C8, 30.9% Clo, and 13.0% C6 aryl ether oxyalkylated with 1 mole of oxybutylene; a C2-Clg alkyl, Cl-C12 alkyl or dialkyl C6 aryl ether phosphate having 25.2% C2, 22.3% C8, 26.1% Clo, and 26.4% C9 alkyl C6 aryl ether oxyalkylated with 4 moles of oxyethylene; and a C2-C1g alkyl, C1-Cl8 alkyl ether, C6 aryl ether phosphate having 25.9% C2, 64.7% C8 - Clo alkyl ether oxyalkylated with 1 mole of oxyethylene, and 9.4%
C6 aryl ether oxyalkylated with 1 mole of oxyethylene. Particularly preferred phosphates ester combinations are a C2, Cg, Clo alkyl phosphate, having 30.3% C2, 32.1% C8, and 37.6% Coo with a C2-C~g alkyl, C6 aryl ether phosphate having 30.6%C2, 21.6% C8, 25.4% Cio, and 22.4%
C6 aryl ether oxyalkylated with 1 mole of oxyethylene; a C2-C1g alkyl, C6 aryl ether phosphate having 31%C2, 25% C8, 30% Clo, and 14% C6 aryl ether oxyalkylated with 1 mole of oxyethylene with a C2-C1g alkyl, C6 aryl ether phosphate having 29.8% C2, 26.3% C8, 30.9% Clo, and 13.0%
C6 aryl ether oxyalkylated with 1 mole of oxybutylene; a C2, C8, Clo alkyl phosphate, having 30.3% C2, 32.1 %
C8, and 37.6% Clo with a C2-C1g alkyl, C6 aryl ether phosphate having 31%C2, 25% C8, 30%
Clo, and 14% C6 aryl ether oxyalkylated with 1 mole of oxyethylene. Especially preferred is the combination of a C2, Cg, Clo alkyl phosphate, having 30.3% C2, 32.1% C8, and 37.6% CIO with a C2-C18 alkyl, C6 aryl ether phosphate having 30.6%C2, 21.6% C8, 25.4% Clo, and 22.4% C6 aryl ether oxyalkylated with 1 mole of oxyethylene.
The following examples set forth in Table I are representative of gelling systems in accordance with the present invention. For each of the examples below, 200 milliliters of kerosene was placed in a 500 ml Waring blender having a standard stirring assembly. The blender was plugged into a rheostat set at 30% output. The blender was started. The type and amount of activator and phosphate ester and system enhancer set forth below were added to the kerosene. Where a system enhancer was employed in accordance with the present invention, 0.10 to 0.21 milliliters were added. The blender was stirred until the vortex created from the agitator closed. If the vortex had not closed after 120 seconds, the blender was stopped at that point. The kerosene gel was then poured into a Marsh funnel viscometer. The -time required for 100 milliliters of the gelled kerosene to flow through the viscometer is set forth for each example below. Brookfield viscosity measurements (in centipoises) were also taken for Examples 104 -123d.
The specific components employed in each of the following examples are:
Enhancers:
Am-1: an ethoxylated C~6 - Clg alkyl amine having two moles of oxyethylene per mole of amine;
Am-2: an ethoxylated Cg alkyl amine having two moles of oxyethylene per mole of amine;
Am-3: an ethoxylated di-C4 alkyl amine having one mole of oxyethylene per mole of amine;
Am-4: an ethoxylated C12 - C14 alkyloxy C3 alkyl amine having three moles of oxyethylene per mole of amine;
Am-5: N, N-di-C1 alkyl C16 alkyl amine;
Am-6: N, N-di (C1) alkyl Clg alkyl amine;
Am-7: Ci6 - C18 imidazoline prepared from tall oil fatty acid and diethylenetriamine;
Am-8: an alkoxylated C16 - C18 alkyl amine having six moles of oxypropylene per mole of amine;
Am-9: an ethoxylated di-C4 alkyl amine having ten moles of oxyethylene per mole of amine;
Am-10: an alkoxylated C16 - C18 alkyl diamine having three moles of oxypropylene per mole of diamine;
Am-11: N, N-di-C4 alkyl amine;
Am-12: an alkoxylated C16 - C18 alkyl amine having two moles of oxybutylene per mole of amine;
Am-13: an alkoxylated di-C4 alkyl amine having one mole of oxybutylene per mole of amine;
Am-14: an alkoxylated di-C4 alkyl amine having one mole of oxypropylene per mole of amine;
Am-15: dimethylaminopropylamine;
Am-16: aminomethylpropanol;
Am-17: an ethoxylated aniline having two moles of oxyethylene per mole of benzamine;
Am-18: a C16-Clg alkyl diamine;
Am-19: a C6 alkyl amine;
Am-20: a C8 alkyl amine;
Am-21: an alkoxylated C16-C1g alkyl amine having two moles of_oxypropylene per mole of amine;
Am-22: an ethoxylated di-C~ alkyl amine having one mole of oxyethylene per mole of amine;
Am-23: an ethoxylated di-C4 alkyl amine having four moles of oxyethylene per mole of amine;
Am-24: an ethoxylated di-C2 alkyl amine having one mole of oxyethylene per mole of amine;
Am-25: an ethoxylated C16-C18 alkyl amine having five moles of oxyethylene per mole of amine;
Am-26: amino-bis (hydroxyethyl) C16-C1g alkyl etho-sulfate ( quaternized product of N, N' dihydroxyethyl C16-C18 alkyl amine with diethyl sulfate ) ;
Am-27: triethanolamine;
Am-28: an ethoxylated Cg-C16 alkyl amine having ten moles of oxyethylene per mole of amine;
Am-29: an ethoxylated C8-C16 alkyl amine having two moles of oxyethylene per mole of amine;
Am-30: an ethoxylated C16-Clg alkyl amine having twenty moles of oxyethylene per mole of amine;
Am-31: an ethoxylated C8-C16 alkyl amine having fifteen moles of oxyethylene per mole of amine;
Am-32: an ethoxylated C6 cyclo amine having two moles of oxyethylene per mole of amine;
Am-33: an ethoxylated C16-C1g alkyl amine having thirty two moles of oxyethylene per mole of amine;
Am-34: an ethoxylated tertiary C,~ alkyl amine having two moles of oxyethylene per mole of amine;
Am-35: an ethoxylated C8-C16 alkanol amide having three moles of oxyethylene per mole of amine;
Am-36: a C8-C16 alkyl amine;
Am-37: an ethoxylated C16-C18 alkyl amine having forty moles of oxyethylene per mole of amine;
Am-38: an ethoxylated C16-C18 alkyl amine having fifty moles of oxyethylene per mole of amine;
Am-39: a C16-C1g alkyl amine;
Am-40: dimethylaminopropylamine;
Am-41: C6 cyclohexylamine;
Am-42: a C8-C16 alkyl akanol amide;
Am-43: an ethoxylated C16-C~8 alkyl amine having ten moles of oxyethylene per mole of amine;
Am-44: an ethoxylated C$-C16 alkyl amine having five moles of oxyethylene per mole of amine;
Am-45: tertiary C4 alkyl amine;
Am-46: a C12-C14 alkoxy propyl amine;
Am-47: an ethoxylated N-ethyl toluidine having one mole of oxyethylene per mole of N-ethyl toluidine ;
Am-48: an ethoxylated m-toluidine having two moles of oxyethylene per mole of m-toluidene;
Am-49: morpholine;
Am-50: an ethoxylated aniline having ten moles of oxyethylene per mole of benzamine;
Am-51: m-toluidine;
Am-52: ethylenediamine;
Am-53: an ethoxylated m-toluidine having 100 moles of oxyethylene per mole of m-toluidine;
Am-54: tetraethylene pentamine;
Am-55: an ethoxylated Cl8 alkenyl amine having two moles of oxyethylene per mole of amine;
Am-56: an ethoxylated CI6-C1g alkenyl amine having two moles of oxyethylene per mole of amine;
Am-57: isobutanolamine;
Di-es-1: a polyethylene glycol (200) di-Cg-C16 ester;
Gl-1: an ethoxylated tri-CI8 alkyl glyceride having five moles of oxyethylene per mole of glyceride;
G1-2: castor oil;
Et-1: an ethoxylated C12 - Cia alkyl ether having three moles of oxyethylene per mole of ether;
Et-2: an ethoxylated C16-C1$ alkenyl ether having two moles of oxyethylene per mole of ether;
Es-1: an ethoxylated unsaturated C16-C18 fatty acid having three moles of oxyethylene per mole of fatty acid;
Ph-l: phenol;
Ph-2: CS di-tertiary-alkyl phenol;
Ph-3: an alkoxylated C9 alkyl phenol having three moles of oxypropylene per mole of alkyl phenol;
Ph-4: an alkoxylated phenol having one mole of oxybutylene per mole of phenol;
Ph-5: a tertiary-C5, di-alkyl phenol ;
Ph-6: a C9 alkyl phenol;
Al-l: isodecyl alcohol;
Sol-1: methyl cellosolve;
Fa-1: coconut fatty acid;
B~-l: an alkoxylated bis-phenol-a, having one mole of oxypropylene per equivalent of phenolic; _ Phosphate Esters:
III(1a) (or PE-1): C2, Cg, Clo alkyl phosphate, having 30.3% C2, 32.1% Cg, and 37.6% Clo;
ITI(2a): C2-Ci8 alkyl, Cl-C18 alkyl ether phosphate (having 30.2% C2, 30.3%
Cg, 35.6%
Clo, and 3.9% CI alkyl ether oxyalkylated with 1 mole of oxypropylene);
>II(2b): C2-CI8 alkyl, CI-CI8 alkyl ether phosphate (having 29.7% C2, 26.3%
C8, 30.8%
CIO, and 13.2% C6 alkyl ether oxyalkylated with 1.5 mole of oxyethylene);
)II(2c): C2-CIg alkyl, CI-CI8 alkyl ether phosphate (having 30.3%C2, 4.5% C4, 23.8% C8, 27.9% CIO, and 13.5% C6 alkyl ether oxyalkylated with 1.5 moles of oxyethylene);
)II(2d): C2-CI8 alkyl, CI-CI8 alkyl ether phosphate (having 27.4%C2, 24.1 %
C8, 28.4%
CIO, and 20.1 % C8 - CIO alkyl ether oxyalkylated with 3 moles of oxyethylene);
)II(2e): C2-CI8 alkyl, CI-CI8 alkyl ether phosphate (having 25.7%C2, 22.7% Cg, 26.7%
CIO, and 24.9% Cg - CIO alkyl ether oxyalkylated with 5 moles of oxyethylene);
)II(2f): C2-CI8 alkyl, CI-CI8 alkyl ether phosphate (having 25.4%C2, 22.1 %
C8, 26.2%
CIO, and 26.3% CI6 - CI8 alkyl ether oxyalkylated with 3 moles of oxyethylene);
IZI(3a) (or EP-1): C2-CI8 alkyl, C6 aryl ether phosphate (having 31 %C2, 25%
C8, 30%
CIO, and 14% C6 aryl ether oxyalkylated with 1 mole of oxyethylene);
)II(3b): C2-CI8 alkyl, C6 aryl ether phosphate (having 30.6% C2, 21.6% C8, 25.4% CIO, and 22.4% C6 aryl ether oxyalkylated with 1 mole of oxyethylene);
>II(3c): C2-CI8 alkyl, C6 aryl ether phosphate (having 25.9% C2, 22.8% C8, 26.8% CIO, and 24.5% C6 aryl ether oxyalkylated with 6 moles of oxyethylene);
)II(3d): C2-CI8 alkyl, C6 aryl ether phosphate (having 23.8% C2, 21.0% C8, 24.6% CIO, and 30.6% C6 aryl ether oxyalkylated with 9 moles of oxyethylene);
III(3e): C2-CI8 alkyl, C6 aryl ether phosphate (having 26.2% C2, 25.5% C8, 29.9% CIO, and 18.5% C6 aryl ether oxyalkylated with 10 moles of oxyethylene);
11I(3f): C2-CI8 alkyl, C6 aryl ether phosphate (having 29.8% C2, 26.3% C8, 30.9% CIO, and 13.0% C6 aryl ether oxyalkylated with 1 mole of oxybutylene);
)TI(4a): C2-C18 alkyl, C1-C12 alkyl or dialkyl C6 aryl ether phosphate (having 25.2% C2, 22.3% C8, 26.1% Clo, and 26.4% C9 alkyl C6 aryl ether oxyalkylated with 4 moles of oxyethylene);
)II(Sa): C2-C18 alkyl, Cl-C18 alkyl ether, C6 aryl ether phosphate (having 25.9% C2, 64.7%
C8 - Clo alkyl ether oxyalkylated with 1 mole of oxyethylene, and 9.4% C6 aryl ether oxyalkylated with 1 mole of oxyethylene);
Crosslinking Agents:
Fe3+: a 60% solution of ferric sulfate;
A13+: a solution of an aluminum chloride tall oil imidazoline reaction product, in accordance with US Patent No. 5,271,464.
TABLE I: EXAMPLES
Ex. Enhancer Phosphate Salt Closure Viscosity (total vol. secs. Mins.
) ComparativeNone PE-1 Fe3+ > 120 0.6 (1 ml) (1 ml) Am-l, Am-3 PE-1 Fe3+ 3 32.5 2 (29% / 79%)(1 ml) (0.79 ml) (0.21 ml) Am-1, Am-3 EP-1 Fe3+ 2 150 3 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml 4 none EP-1 Fe3+ > 120 1.30 Com arative (1 ml) (1 ml) 5(*) none PE-1 A13+ 79 2.30 Com arative (0.77 ml) (1 ml) 6(*) Am-1, Am-3 PE-1 Fe3+ 45.7 39 (29% / 71 (0.77 ml) (0.77 ml) %) (0.21 ml) 7(*) none PE-1 Fe3+ > 120 8.5 Com arative (0.77 ml) (1 ml) 8 Am-2, Am-3 PE-1 Fe3+ 30 95 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 9 Am-5, Am-3 PE-1 Fe3+ 9 41.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml Am-3 PE-1 Fe3+ 45 14.5 (0.21 ml) (1 ml) (0.79 ml) 11 Am-3 EP-1 Fe3+ 19 >120 (0.21 ml) (1 ml) (0.79 ml 12 Am-3 III(Sa) Fe3+ >120 4.7 (0.21 ml) (1 ml) (0.79 ml) 13 Am-56, Am-3EP-1 Fe3+ 2.0 _ 140.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 14 Am-1, Am-3 III(2b) Fe3+ 5.8 105.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) Am-1, Am-3 III(2c) Fe3+ 5.5 87.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 16 Am-1, Am-3 III(2e) Fe3+ 7.5 33.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 17 Am-1, Am-3 III(2d) Fe3+ 6.6 64.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) Ex. Enhancer Phosphate Salt Closure Viscosity (total vol. secs. Mins.
18 Am-1, Am-3 III(3c) Fe3+ 21 30.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml 19 Am-1, Am-3 III(3b) Fe3+ 11 60.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 20 Am-1, Am-3 III(4a) Fe3+ 4.7 141.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 21 Am-1, Am-3 III(5a) Fe3+ 2.6 20.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 22 Am-1, Am-3 III(2a) Fe3+ 9.7 18.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 23 Am-1, Am-3 III(2~ Fe3+ >120 2.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 24 Am-1, Am-9 EP-1 Fe3+ > 120 50.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 25 Am-8, Am-9 EP-1 Fe3+ > 120 5.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 26 Am-3, Am-10EP-1 Fe3+ > 120 15.5 (71% / 29%)(1 ml) (0.79 ml) (0.21 ml) 27 Am-1, Am-18EP-1 Fe3+ > 120 15.0 (25% / 75%)(1 ml) (0.79 ml) (0.21 ml) 28 Am-1, Am-19EP-1 Fe3+ 23 197.0 (25% / 75%)(1 ml) (0.79 ml) (0.21 ml) 29 Am-l,Am-11 EP-1 Fe3+ 3.7 > 210 (25% / 75%)(1 ml) (0.79 ml) -(0.21 ml) 30 Am-l,Am-20 EP-1 Fe3+ >120 112.0 (25% / 75%)(1 ml) (0.79 ml) (0.21 ml) 31 Am-2l,Am-3 EP-1 Fe3+ 2.5 31.0 (25% / 75%)(1 ml) (0.79 ml) (0.21 ml) 32 Am-12, Am-3EP-1 Fe3+ > 120 > 150 (25% / 75%)(1 ml) (0.79 ml) (0.21 ml) 33 Am-1, Am-3 III(3c) Fe3+ 27 30.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml Ex. Enhancer Phosphate Salt Closure Viscosity (total vol. sets. Mins.
34 Am-1, Am-3 III(3d) Fe3+ >120 1.6 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml 35 Di-es-1, EP-1 Fe3+ >120 61.0 Am-3 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) Ex. Enhancer Phosphate Salt Closure Viscosity (total vol. sees. Mins.
) 36 Gl-1, Am-3 EP-1 Fe3+ > 120 74 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 37 Et-1, Am-3 EP-1 Fe3+ 90 52 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 38 Et-2, Am-3 EP-1 Fe3+ >120 30.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 39 Am-21, Am- EP-1 Fe3+ 28 >120 22, Sol-1 (1 ml) (0.79 ml) (33%:33%:33 %) (0.21 ml) 40 Am-1, Am-23EP-1 Fe3+ 4 262 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 41 Am-1, Am-13EP-1 Fe3+ 4 52 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 42 Am-1, Am-24EP-1 Fe3+ >120 170.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 43 Am-2, Am-3 EP-1 Fe3+ 9 420.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 44 Am-23 EP-1 Fe3+ >120 - 2.3 (0.21 ml) ( 1 ml) (0.79 ml) 45 Am-3, Am-23EP-1 Fe3+ >120 52.0 (25% / 75%)(1 ml) (0.79 ml) (0.21 ml) 46 Am-21, Am-23EP-1 Fe3+ 3 45.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 47 Am-1, Am-14EP-1 Fe3+ 3 240.0 (29% / 71 (1 ml) (0.79 ml) %) (0.21 ml) 48 Am-1, Am-3 III(3f) Fe3+ 9 15.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) Ex. Enhancer Phosphate Salt Closure Viscosity (total vol. secs. Mins.
49 Am-2, Am-23EP-1 Fe3+ 36 300.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 50 Am-1, Am-3 III(3e) Fe3+ 17 67.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 51 Es-1, Am-3 EP-1 Fe3+ 90 88 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 52 Am-4, Am-3 EP-1 Fe3+ 4.8 360 (29% / 71%)(1 ml) (0.79 ml) -(0.21 ml) 53 Am-5, Am-3 EP-1 Fe3+ 2 900 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 54 Ph-3, Am-3 EP-1 Fe3+ 90 85.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 55 Am-25, Am-3EP-1 Fe3+ >120 7.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 56 Am-26, Am-3EP-1 Fe3+ 3 133.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 57 Am-8, Am-27EP-1 Fe3+ >120 9.0 (50% / 50%)(1 ml) (0.79 ml) (0.21 ml) 58 Am-1, Am-23EP-1 Fe3+ 4 262.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 59 Am-27, Am-3EP-1 Fe3+ 41 86.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 60 Am-1, Am-8,EP-1 Fe3+ >120 9.5 Am-27 (1 ml) (0.79 ml) (33%:33%:33 %) (0.21 ml) 61 Am-21, Am-23EP-1 Fe3+ 3 45.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 62 Am-28, Am-3EP-1 Fe3+ >120 6.3 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 63 Am-29, Am-3EP-1 Fe3+ 2.3 300.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 64 Am-30, Am-3EP-1 Fe3+ >120 1.3 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) Ex. Enhancer Phosphate Salt Closure Viscosity (total vol. sets. Mins.
) 65 Am-31, Am-3EP-1 Fe3+ >120 8.2 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 66 Am-32, Am-3EP-1 Fe3+ 35 66.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 67 Am-33, Am-3EP-1 Fe3+ >120 2.5 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 68* Am-1, Am-34EP-1 Fe3+ 120 35.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml 69 Ph-2, Am-3 EP-1 Fe3+ 90 38.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml 70 Ph-4, Am-3 EP-1 Fe3+ 93 80.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml 71 Ph-1, Am-3 EP-1 Fe3+ > 120 60 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml 72 Am-35, Am-3EP-1 Fe3+ 64 180.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 73 Al-l, Am-3 EP-1 Fe3+ 95 35 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 74 Fa-1, Am-3 EP-1 Fe3+ >120 45.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 75 Am-42, Am-3EP-1 Fe3+ 9 300.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 76 Am-36, Am-3EP-1 Fe3+ >120 75.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 77 Gl-2, Am-3 EP-1 Fe3+ 73 75.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 78 Am-37, Am-3EP-1 Fe3+ >120 7.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 79 Am-38, Am-3EP-1 Fe3+ >120 1.8 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 80 Am-39, Am-3EP-1 Fe3+ 14.4 345.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) Ex. Enhancer Phosphate Salt Closure Viscosity (total secs. Mins.
vol. ) 81 Am-1, Am-40EP-1 Fe3+ 90 300 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 82 Am-1, Am-41EP-1 Fe3+ >120 163.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml 83 Ph-5, Am-3EP-1 Fe3+ > 120 37.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 84 Ph-6, Am-3EP-1 Fe3+ 90 76.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 85 Bp-1, Am-3EP-1 Fe3+ 63 180.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 86* Am-1, Am-34EP-1 Fe3+ >120 53.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 87 Am-1, Am-32EP-1 Fe3+ 9.3 360.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml 88 Am-43, EP-1 Fe3+ >120 3.7 Am-3 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml 89 Am-44, EP-1 Fe3+ 7.5 25.0 Am-3 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 90 Am-1, Am-45EP-1 Fe3+ 12 78.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 91 Am-3, Am-6EP-1 Fe3+ 3 720 (71% / (1 ml) (0.79 ml) 29%) (0.21 ml) 92 Am-46, EP-1 Fe3+ 15 720 Am-3 (25% / (1 ml) (0.90 ml) -75%) (0.10 ml) 93 Am-1, Am-47EP-1 Fe3+ 7.5 180.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 94 Am-1, Am-17EP-1 Fe3+ 10.7 240 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 95 Am-1, Am-48EP-1 Fe3+ 8.1 150.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 96 Am-1, Am-49EP-1 Fe3+ 90 120.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) Ex. Enhancer Phosphate Salt Closure Viscosity (total vol. secs. Mins.
) 97 Am-50, Am-3EP-1 Fe3+ 72 174.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 98 Am-1, Am-51EP-1 Fe3+ >120 150.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 99 Am-1, Am-57EP-1 Fe3+ 81 100.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 100 Am-1, Am-52EP-1 Fe3+ >120 46.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 101 Am-53, Am-3EP-1 Fe3+ >120 24.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 102 Am-1, Am-54EP-1 Fe3+ >120 7.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 103(*) Am-7 EP-1 Fe3+ > 120 0.12 Com arative (1 ml) (0.79 ml) 5(*): utilizes the aluminum system as described in US 5,271,464.
6(*) & 7(*): the phosphate esters of these examples are partially neutralized with 0.23 ml of 45% KOH.
68(*): the enhancer was pre-blended with the ferric salt.
86(*): phosphate ester, enhancer, and ferric salt were each introduced separately.
103(*): the surface active amine is as described in Halliburton, e.g., US
5,271,464 (@Col. 3, lines 1-3).
The gelling systems in accordance with the present invention demonstrate increased gelling speeds as compared to prior art systems. Of the comparative examples set forth hereinabove, only Comparative Example 5 has a gel closure time of less than 120 seconds. The majority (63%) of the examples according to the invention required far less than 120 seconds to achieve gel closure. Some inventive examples are reported as having a closure of >120 seconds.
It is important to clarify that a closure time of greater than 120 seconds is not to be understood as meaning that acceptable gel viscosity was not achieved in those examples.
Rather, a designation of ">120 sec." means only that there was evidence of a vortex extant in the gelled fluid after it had stirred for 120 seconds. The significance of the rapid gel closure times evidenced overall by the gel systems of the invention is that it is an indication to the skilled field worker of the time efficiency, or the rapidity of "on the fly" gelling of the system components.
The more dramatic difference between the examples of the present invention and those of the prior art can be seen in the viscosity of the gels. Increased gel viscosity is necessary for optimal proppant transport. Prior art example, Example 5, did not exceed a viscosity of 10, as measured in minutes required for 100 milliliters of gel to pass through a Marsh funnel. Also, comparative example 103, which utilized the surface active amine of Halliburton '464 as the enhancer component, gave a viscosity of 0.12 minutes. In the numerous examples representative of the invention, 54% of the inventive examples demonstrated a viscosity requiring in excess of 50 minutes, and 34% of the inventive examples demonstrated a viscosity requiring in excess of 100 minutes for 100 milliliters to pass through the funnel. Only 15%
demonstrated a viscosity requiring less than 10 minutes for 100 milliliters of gel to pass through the funnel.
Inventive examples 68 and 86 provide comparative results vis-a-vis each other.
Both examples used the same components for gelling kerosene, the only difference being the manner by which they were introduced to the blender. In example 68, the enhancer was pre-blended with the ferric salt; the blend was introduced to the kerosene, as was the phosphate ester. In example 86, the same enhancer, ferric salt, and phosphate ester were all introduced separately to the kerosene. The separate addition of components gave a gel of higher viscosity (53 mins.) than the method wherein the enhancer and the ferric salt were pre-blended (35 mins).
For the following examples, the same experimental procedure as in Examples 1 -103 was used. Differences in volumes and ratios employed are specified in each of the examples set forth in Table II.
TABLE II. EXAMPLES 104 -119: DEMONSTRATING SYNERGISTIC
EFFECTS OF AMINE MIXTURES
Ex.Enhancer PhosphateSalt ClosureViscosityViscosity Calculated Viscosity Based (vol. Added)(vol. Secs. Mins. Centipoiseson Relative & added) Contribution of mixing (Observed)Each Amine Component ratio, -where applicable in Centipoises (Expected) 104Am-55 EP-1 Fe3+ >120 40.0 4400 (0.21 ml) (1 ml) (0.79m1) 105Am-3 EP-1 Fe3+ 19 215.0 10000 (0.21 ml) (1m1) (0.79m1) 106Am-1 EP-1 Fe3+ >120 23.0 4800 (0.21 ml) (1m1) (0.79m1) 107Am-56 EP-1 Fe3+ 4 23.0 5000 (0.21 ml) (1m1) (0.79m1) 108Am-22 EP-1 Fe3+ >120 5.0 7000 (0.21 ml) (1m1) (0.79m1) 109Am-24 EP-1 Fe3+ >120 1.5 4800 (0.21 ml) (1m1) (0.79m1) 110Am-27 EP-1 Fe3+ >120 1.5 150 (0.21 ml) (1m1) (0.79m1) 111Am-29 EP-1 Fe3+ >120 10.0 250 (0.21 ml) (1m1) (0.79m1) 112Am-55, EP-1 Fe3+ 2 150.0 10600 8376 Am-3 (29:71)(0.21(1m1) (0.79m1) ml) 113Am-1, Am-3EP-1 Fe3+ 2 135.0 11000 8492 (29:71 (1 ml) (0.79m1) -)(0.21 ml) 114Am-56, EP-1 Fe3+ 2 140.0 9600 8550 Am-3 (29:71 (1 ml) (0.79mi) )(0.21 ml) 115Am-29, EP-1 Fe3+ 2 60.0 9200 7173 Am-3 (29:71)(0.21(1m1) (0.79m1) ml) 116Am-1, Am-24EP-1 Fe3+ >120 120.0 7000 6816 (29:71 (1 ml) (0.79m1) )(0.21 ml) 117Am-29, EP-1 Fe3+ 2 600.0 12200 3481 Am-24 (29:71 (1 ml) (0.79m1) )(0.21 ml) 118Am-29, EP-1 Fe3+ 2 345.0 10400 5040 Am-22 (29:71 (1 ml) (0.79m1) )(0.21 ml) 119Am-29, EP-1 Fe3+ 2 260.0 10000 180 Am-27 (29:71)(0.21(1m1) (0.79m1) ml) The results in Table II exemplify the novel synergism, and its effect on viscosity, achieved in combining enhancer components of the invention. All of Examples demonstrate surprising levels of viscosity which are unexpected based on the viscosities of the individual components on a same volume basis. In addition, the viscosities for each of the individual components separately have been calculated to take into account the relative contribution of each amine component in the mixture (see the column on the extreme right). In this way, a theoretical (or expected) value is obtained. The actual viscosities obtained in all of Examples 112 - 119 exceed the calculated viscosities.
For the following examples, the same experimental procedure as in Examples 1 -103 was used. Differences in volumes and ratios employed are specified in each of the examples set forth in Table III.
TABLE III. EXAMPLES 120a -123d: EFFECT OF SYNERGISTIC PHOSPHATE
ESTER MIXTURES ON GEL VISCOSITY
Ex.Enhancer PhosphateSalt ClosureViscosity ViscosityCalculated Mins.
(mixing Secs. CentipoisesViscosity ratio Based on & Relative vol. Added) Contribution of Each Amine Component - in Centipoises Ex acted 120aAm-56, PE-1 Fe3+ 2 1440+ 40000 Am-3 (29:71 (2m1) (1.58m1) (i.e., )(0.42) >24hrs) 120bAm-56, PE-1 Fe3+ 2 70.0 7000 Am-3 (29:71 (1 ml) (0.79m1) )(0.21 ) 120cAm-56, PE-1 Fe3+ 2 15.0 2800 Am-3 (29:71 (0.5m1) (0.40m1) )(0.11 ) 120dAm-56, PE-1 Fe3+ >120 0.8 600 Am-3 (29:71 (0.25m1)(0.20m1) )(0.06) 121aAm-56, (III) Fe3+ 2 1440+ 31000 Am-3 (3b) (29:71)(0.42)(2m1) (1.58m1) 121bAm56, Am-3(III) Fe3+ 2 20.0 5200 (3b) (29:71 (1 ml) (0.79m1) )(0.21 ) 121cAm-56, (III) Fe3+ 3 12.0 2100 Am-3 (3b) (29:71 0.5m1 (0.40m1) )(0.11 ) 121dAm-56, (III) Fe3+ 3 2.5 1200 Am-3 (3b) (29:71 0.25 (0.20m1) )(0.06) ml 122aAm-56, EP-1 Fe3+ 2 1260.0 45000 Am-3 (29:71)(0.42)(2m1) (1.58m1) 122bAm-56, EP-1 Fe3+ 2 150.0 10600 Am-3 (29:71 (1 ml) (0.79m1) )(0.21 ) 122cAm-56, EP-1 Fe3+ 2 10.0 3200 Am-3 (29:71 (0.5m1) (0.40m1) )(0.11 ) 122dAm-56, EP-1 Fe3+ >120 2.0 2000 Am-3 (29:71 (0.25m1)(0.20m1) )(0.06) 123aAm-56, PE-1, Fe3+ 2.0 1440+ 76000 40000 Am-3 (III) (3b) (29:71 (50:50) (1.58m1) )(0.42) 2m1 123bAm-56, PE-1, Fe3+ 2.0 340 15400 7600 Am-3 (III) (3b) (29:71 (50:50) (0.79m1) )(0.21 ) 1 ml 123cAm-56, PE-1, Fe3+ 3.0 30 4000 3300 Am-3 (III) (3b) (29:71 (50:50) (0.40mi) )(0.11 ) 0.5m1 123dAm-56, PE-1, Fe3+ >120 4.0 2400 800 Am-3 (III) (3b) (29:71 (50:50) (0.20m1) )(0.06) 0.25m1 The results in Table )TI exemplify the novel synergism, and its effect on viscosity, achieved in combining phosphate esters according to the invention. All of Examples 123a - 123d demonstrate surprising levels of viscosity which are unexpected based on the viscosities of the individual components on a same volume basis. In addition, the viscosities for each of the individual components separately have been calculated to take into account the relative contribution of each phosphate ester in the mixture (see the column on the extreme right). In this way, a theoretical (or expected) value is obtained. The actual viscosities obtained in all of Examples 123a - 123d are 190%, 202%, 121%, and 300%, respectively, of the calculated values.
The foregoing description of preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated.
It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents.
More preferably, the phosphate ester is formed from P205 and a tri-loweralkyl phosphate when reacted with a mixture of alcohols and /or oxyalkylated al.cohols yielding phosphate monoesters, symmetric diesters, asymmetric diesters, symmetric triesters, asymmetric triesters, and mixtures of any of these. "Tri-loweralkyl phosphate" in the present context is to be understood as meaning tri -CI - C6 alkylphosphate. The alcohols suitable for reaction with the phosphate intermediate include alkyl alcohols, aralkyl alcohols, ether-containing alkyl alcohols, and aralkyl ether alcohols (or oxyalkylated aralkyl alcohols), and mixtures thereof. It is to be understood that the term "alkyl" as it applies to the present phosphate esters includes straight and branched alkyl groups. "Aryl" includes C6 to C12 aryl. Therefore, when ether alcohols are employed one or more oxyalkene groups such as oxyethylene, oxypropylene or oxybutylene is present in the "R" group of the alcohol designated as ROH. Accordingly, the phosphate ester that is formed is an ether phosphate ester. Thus, the term "phosphate esters"
as used herein includes ether phosphate esters. The phosphate esters of the present invention will thus be mixtures of esters conforming to the following structures:
RO- P -OH RO- P -ORi RO- P -ORS
OH ~ OH ~ ~d OR2 wherein R, RI , and R2 are independently CI- CI8 alkyl, C6 aryl, C1 - CI8 alkyl or di C1 - CI8 alkyl C6 aryl, C1 - CI8 alkyl ether, C6 aryl ether, or CI - CI8 alkyl or di CI
- CI8 alkyl C6 aryl ether, and where any ether linkage has the following structure: --O(CH2-CHR')-wherein R' is hydrogen, methyl or ethyl.
More preferably, the phosphate ester according to the invention is a mixture of mixed esters such as asymmetric phosphate diesters (i.e., where R ~ RI). The ability to obtain particularly useful phosphate ester mixtures within the scope of the invention hinges upon the specific alkyl, alkaryl, alkyl ether,alkaryl ether, aralkyl, and/or aralkyl ether moieties in the alcohol reactants. For example, a phosphate ester mixture that contains a distribution of C2, C8, CIO, and oxyalkylated C6 aryl groups is particularly useful herein.
The phosphate ester of the present invention is preferably non-neutralized.
However, depending on the particular enhancer employed, it is also within the scope of the invention to at least partially neutralize the phosphate ester.
The enhancer of the present invention is an amine, a mixture of amines, or an amine and another non-amine compound that iunetions as an enhancer. 'I"he following amine structures are within the scope of the enhancer of the present invention:
R~
~,vhere R, R,, and RZ are independently hydrogen, C , - C,H alkyl, CS - C'f;
cycloalkyl, aryl, C i - C, ~ substituted aryl., or -(CH R' -CH20)"
wherein R' is hydrogen, methyl or ethyl. n is an integer from 1 to 10(h and wherein the O atom of the terminal or "n'h" -(CH R' -CH~O)" group is bound to a hydrogen atom, R,~ /
R, R2 where R is hydrogen, C, - Cy~ alkyl, or a group of the structure -(CH R' -CH20)" -wherein R' is hydrogen, methyl or ethyl, n is an integer fiom 1 to 100, and wherein the O atom of the terminal or ''n'h" -(CH R' -CH~O)" group is hound to a hydrogen atom;
R, is hydrogen, C~
alkyl or a group of the structure .(CH R' -CH20)" -wherein R' is hydrogen, methyl or ethyl, n is an integer from 1 to 100. and wherein the O atom of the terminal or "n'~'" -(CH R' -CHZO)" group is hound to a hydrogen atom;
R2 is hydrogen or ..(CH R' -CH20)" -wherein R' is hydrogen, methyl or ethyl, n is an integer from I to 100. and wherein the O atom of the terminal or ''n'h" -(CH R' -Cl l~Ua" group is bound to a hydrogen atom;
and Ri is a C~ or C ,; alkyl; or R~,O -R2__- N
Rr where R is C'~, - C,~ alkyl, R, is hydrogen or a group of the structure -(Cl-1 R'-CHZO)"-wherein R' and n are as defined above with respeca to the diamine; and R~ is a C3 alkyl. With regard to amine structures shown al7ove, the substi.tuent group "alkyl" or "aralkyl" has the meaning of both straight and branched alkyl groups.
More preferably, the amine enhancer an oxyalkylated amine. Thus, preferred oxyalkylated amines include oxyalkylated alkyl amines such as ethoxylated alkyl amines having from 1 to about 100 moles of ethylene oxide per mole of amine and ethoxylated alkyl amines having from about 1 to about 18 carbon atoms in the alkyl group; pulyoxypropylene alkyl amine having from 1 to about 100 moles of propylene oxide per mole of amine; and polyoxybutylene alkyl amine having 1 to about 100 moles of butylene oxide per mole of amine. The term "oxyalkylated alkyl amines" also encompasses oxyalkylated dialkyl amines, such as ethoxylated di C2 - C8 alkyl amines having from 1 to about 100 moles of ethylene oxide per mole of amine;
polyoxypropylene dialkyl amine having from about 1 to about 100 moles of propylene oxide per mole of amine; and polyoxybutylene dialkyl amine having from about 1 to about 100 moles of butylene oxide per mole of amine. More preferably, the term "oxyalkylated amines" means oxyalkylated diamines and oxyalkylated C6 aryl amines. A particularly preferred oxyalkylated amine is N,N-di n-butyl ethanol amine, having the following structure ~aHs The amount of enhancer to be employed in the present compositions and methods is an amount effective to increase the rate of gel formation and to increase the viscosity thereof, relative to known gelling systems that do not incorporate an enhancer of the present invention.
In general, an effective amount of amine enhancer is from 0.01 % to 5.0%
relative to the volume of liquid hydrocarbon to be gelled. More preferably, 0.1 % to 0.5% of amine enhancer is employed.
- Enhancer blends or mixtures are also appropriate for use in the present invention.
Preferred blends include at least one oxyalkylated amine as set forth above with another enhancer component which is either an amine, a non-nitrogen containing compound, a quaternary nitrogen compound or an amide. It should be noted that blends containing more than two components are also within the scope of the present invention.
When a second enhancer component is another amine, this second amine may be chosen from oxyalkylated amines, such as those set forth above, or alkyl amines such as C2 - C22 alkyl amines, C2 - C22 dialkyl amines, C2 - C22 alkyl diamines, C2 - C22 dialkyl diamines, C2 - C22 dialkyl amino C2 - C22 alkylamines, and analogs of these compounds having one or more carbon-carbon double bonds in the alkyl moiety. "Alkyl" within the context of , e.g., alkylamine, is to be understood as meaning straight and branched alkyl groups. The term "C2 -C22 dialkyl" is intended to mean that each alkyl group can be from C2 - C22 . A preferred class of alkyl amines to be used in conjunction with an oxyalkylated amine are fatty amines, and particularly unsaturated fatty amines, such as mono- and di-oleyl amines.
Non-nitrogen containing components which are appropriate in the enhancer blend include oxyalkylated glycerides, oxyalkylated mono- and di-esters and oxyalkylated alcohols and phenols, as well as non-oxyalkylated alcohols and phenols, a fatty acid, or a mixture of a fatty acid and a glyceride.
The specific proportion or ratio of enhancer components varies depending on the nature of the individual enhancer components, as well as on the particular application requiring the gelling of liquid hydrocarbon. However, in general, when the enhancer is a blend comprising at least one oxyalkylated amine and another enhancer component, the components may be mixed at a ratio from about 9 : 1 to 1 : 9 oxyalkylated amine to other enhancer component. When it is advantageous that the enhancer be a mixture or blend of at least one oxyalkylated amine (A) and two other enhancer components (e.g., a second amine enhancer compound (B) and a non-nitrogen-containing enhancer compound (C)), the mixing ratio is from about 1 :
1 : 1 to 6 : 3 : 1 of A : B : C. Further, depending on the particular industrial application, it is within the scope of the invention to employ enhancer blends having, for example, four, five, or more enhancer components. When this is the case, the ratios of the individual components can be determined by the skilled practitioner without resort to undue experimentation.
The invention is further directed to a gel-forming hydrocarbon composition for fracturing formations comprising: 1 ) a hydrocarbon liquid capable of gellation, 2) 0.01 to 10.0% by weight of a phosphate ester which is a reaction product comprising either A) phosphorus pentoxide reacted with a tri-loweralkyl phosphate and subsequently reacted with either an alcohol, an oxyalkylated alcohol or mixtures thereof or B) phosphorous pentoxide reacted with either an alcohol, an oxyalkylated alcohol or mixtures thereof to form a phosphate ester or mixed phosphate ester which is subsequently reacted with a tri-loweralkyl phosphate, 3) a crosslinking agent in an amount effective to gel said hydrocarbon liquid, 4) from about 0.085 molar equivalent to about 0.31 molar equivalent of the phosphate ester of an enhancer comprising an amine selected from the group consisting of alkyl amines, oxyalkylated amines, and mixtures thereof, and 5) optionally a surfactant.
As demonstrated by several of the examples that follow, the invention includes novel synergistic combinations of enhancer components, as well as synergistic phosphate ester combinations. More specifically, the viscosities obtained(as indicated in centipoises and Marsh Funnel time (minutes)) for the present hydrocarbon gel systems using mixtures of enhancer components or mixtures of phosphate esters are greater than the viscosities of the individual components when used at comprable volumes. For example, in Table II below it will be seen that all of the enhancer mixtures have a synergistic effect on production of gels of very high viscosity (in centipoises), relative to the same volume of each of the enhancer components individually.
Particularly preferred synergistic enhancer combinations include, but are not limited to, an ethoxylated di-C4 alkyl amine having one mole of oxyethylene per mole of amine in combination with any of the following oxyalkylated amines: an ethoxylated C16 -C18 alkyl amine having two moles of oxyethylene per mole of amine; an ethoxylated Cg-C16 alkyl amine having two moles of oxyethylene per mole of amine; an ethoxylated C18 alkenyl amine having two moles of oxyethylene per mole of amine; an ethoxylated C16-C18 alkenyl amine having two moles of oxyethylene per mole of amine. Synergistic combinations of any of the following enhancer amines are also preferred: an ethoxylated C16 - C18 alkyl amine having two moles of oxyethylene per mole of amine; an ethoxylated di-C1 alkyl amine having one mole of oxyethylene per mole of amine; an ethoxylated di-C2 alkyl amine having one mole of oxyethylene per mole of amine;
triethanolamine; and an ethoxylated Cg-C16 alkyl amine having two moles of oxyethylene per mole of amine.
Mixtures of phosphate esters in accordance with the invention also have a synergistic effect on gel viscosity. This feature of the invention is exemplified in Table llI
below. Various combinations of the following phosphate esters are effective in this particular aspect of the invention: a C2, C8, CIO alkyl phosphate, having 30.3% C2, 32.1%
C8, and 37.6%
CIO; a C2-CIg alkyl, CI-CI8 alkyl ether phosphate having 30.2% C2, 30.3% C8, 35.6% CIO, and 3.9% CI alkyl ether oxyalkylated with 1 mole of oxypropylene; a C2-CI8 alkyl, CI-CI8 alkyl ether phosphate having 29.7% C2, 26.3% C8, 30.8% CIO, and 13.2% C6 alkyl ether oxyalkylated with 1.5 mole ofoxyethylene; a C2-CI8 alkyl, CI-CI8 alkyl ether phosphate having 30.3%C2, 4.5% C4, 23.8% Cg, 27.9% CIO, and 13.5% C6 alkyl ether oxyalkylated with 1.5 moles of oxyethylene; a C2-CIg alkyl, CI-CI8 alkyl ether phosphate having 27.4%C2, 24.1% C8, 28.4%
CIO, and 20.1% C8 - CIO alkyl ether oxyalkylated with 3 moles of oxyethylene; a C2-CI8 alkyl, CI-CI8 alkyl ether phosphate having 25.7%C2, 22.7% C8, 26.7% CIO, and 24.9% C8 - CIO alkyl ether oxyalkylated with 5 moles of oxyethylene; a C2-CIg alkyl, CI-CIg alkyl ether phosphate having 25.4%C2, 22.1% C8, 26.2% CIO, and 26.3% C16 - CIg alkyl ether oxyalkylated with 3 moles of oxyethylene; a C2-CIg alkyl, C6 aryl ether phosphate having 31 %C2, 25% C8, 30% CIO, and 14%
C6 aryl ether oxyalkylated with 1 mole of oxyethylene; a C2-CIg alkylr C6 aryl ether phosphate having 30.6%C2, 21.6% Cg, 25.4% CIO, and 22.4% C6 aryl ether oxyalkylated with 1 mole of oxyethylene; a C2-CIg alkyl, C6 aryl ether phosphate having 25.9% C2, 22.8%
Cg, 26.8% CIO, and 24.5% C6 aryl ether oxyalkylated with 6 moles of oxyethylene; a C2-CI8 alkyl, C6 aryl ether phosphate having 23.8% C2, 21.0% C8, 24.6% CIO, and 30.6% C6 aryl ether oxyalkylated with 9 moles of oxyethylene; a C2-CIg alkyl, C6 aryl ether phosphate having 26.2% C2, 25.5% C8, 29.9%
Coo, and 18.5% aryl ether oxyalkylated with 10 moles of oxyethylene; a C2-C18 alkyl, C6 aryl ether phosphate having 29.8% C2, 26.3% C8, 30.9% Clo, and 13.0% C6 aryl ether oxyalkylated with 1 mole of oxybutylene; a C2-Clg alkyl, Cl-C12 alkyl or dialkyl C6 aryl ether phosphate having 25.2% C2, 22.3% C8, 26.1% Clo, and 26.4% C9 alkyl C6 aryl ether oxyalkylated with 4 moles of oxyethylene; and a C2-C1g alkyl, C1-Cl8 alkyl ether, C6 aryl ether phosphate having 25.9% C2, 64.7% C8 - Clo alkyl ether oxyalkylated with 1 mole of oxyethylene, and 9.4%
C6 aryl ether oxyalkylated with 1 mole of oxyethylene. Particularly preferred phosphates ester combinations are a C2, Cg, Clo alkyl phosphate, having 30.3% C2, 32.1% C8, and 37.6% Coo with a C2-C~g alkyl, C6 aryl ether phosphate having 30.6%C2, 21.6% C8, 25.4% Cio, and 22.4%
C6 aryl ether oxyalkylated with 1 mole of oxyethylene; a C2-C1g alkyl, C6 aryl ether phosphate having 31%C2, 25% C8, 30% Clo, and 14% C6 aryl ether oxyalkylated with 1 mole of oxyethylene with a C2-C1g alkyl, C6 aryl ether phosphate having 29.8% C2, 26.3% C8, 30.9% Clo, and 13.0%
C6 aryl ether oxyalkylated with 1 mole of oxybutylene; a C2, C8, Clo alkyl phosphate, having 30.3% C2, 32.1 %
C8, and 37.6% Clo with a C2-C1g alkyl, C6 aryl ether phosphate having 31%C2, 25% C8, 30%
Clo, and 14% C6 aryl ether oxyalkylated with 1 mole of oxyethylene. Especially preferred is the combination of a C2, Cg, Clo alkyl phosphate, having 30.3% C2, 32.1% C8, and 37.6% CIO with a C2-C18 alkyl, C6 aryl ether phosphate having 30.6%C2, 21.6% C8, 25.4% Clo, and 22.4% C6 aryl ether oxyalkylated with 1 mole of oxyethylene.
The following examples set forth in Table I are representative of gelling systems in accordance with the present invention. For each of the examples below, 200 milliliters of kerosene was placed in a 500 ml Waring blender having a standard stirring assembly. The blender was plugged into a rheostat set at 30% output. The blender was started. The type and amount of activator and phosphate ester and system enhancer set forth below were added to the kerosene. Where a system enhancer was employed in accordance with the present invention, 0.10 to 0.21 milliliters were added. The blender was stirred until the vortex created from the agitator closed. If the vortex had not closed after 120 seconds, the blender was stopped at that point. The kerosene gel was then poured into a Marsh funnel viscometer. The -time required for 100 milliliters of the gelled kerosene to flow through the viscometer is set forth for each example below. Brookfield viscosity measurements (in centipoises) were also taken for Examples 104 -123d.
The specific components employed in each of the following examples are:
Enhancers:
Am-1: an ethoxylated C~6 - Clg alkyl amine having two moles of oxyethylene per mole of amine;
Am-2: an ethoxylated Cg alkyl amine having two moles of oxyethylene per mole of amine;
Am-3: an ethoxylated di-C4 alkyl amine having one mole of oxyethylene per mole of amine;
Am-4: an ethoxylated C12 - C14 alkyloxy C3 alkyl amine having three moles of oxyethylene per mole of amine;
Am-5: N, N-di-C1 alkyl C16 alkyl amine;
Am-6: N, N-di (C1) alkyl Clg alkyl amine;
Am-7: Ci6 - C18 imidazoline prepared from tall oil fatty acid and diethylenetriamine;
Am-8: an alkoxylated C16 - C18 alkyl amine having six moles of oxypropylene per mole of amine;
Am-9: an ethoxylated di-C4 alkyl amine having ten moles of oxyethylene per mole of amine;
Am-10: an alkoxylated C16 - C18 alkyl diamine having three moles of oxypropylene per mole of diamine;
Am-11: N, N-di-C4 alkyl amine;
Am-12: an alkoxylated C16 - C18 alkyl amine having two moles of oxybutylene per mole of amine;
Am-13: an alkoxylated di-C4 alkyl amine having one mole of oxybutylene per mole of amine;
Am-14: an alkoxylated di-C4 alkyl amine having one mole of oxypropylene per mole of amine;
Am-15: dimethylaminopropylamine;
Am-16: aminomethylpropanol;
Am-17: an ethoxylated aniline having two moles of oxyethylene per mole of benzamine;
Am-18: a C16-Clg alkyl diamine;
Am-19: a C6 alkyl amine;
Am-20: a C8 alkyl amine;
Am-21: an alkoxylated C16-C1g alkyl amine having two moles of_oxypropylene per mole of amine;
Am-22: an ethoxylated di-C~ alkyl amine having one mole of oxyethylene per mole of amine;
Am-23: an ethoxylated di-C4 alkyl amine having four moles of oxyethylene per mole of amine;
Am-24: an ethoxylated di-C2 alkyl amine having one mole of oxyethylene per mole of amine;
Am-25: an ethoxylated C16-C18 alkyl amine having five moles of oxyethylene per mole of amine;
Am-26: amino-bis (hydroxyethyl) C16-C1g alkyl etho-sulfate ( quaternized product of N, N' dihydroxyethyl C16-C18 alkyl amine with diethyl sulfate ) ;
Am-27: triethanolamine;
Am-28: an ethoxylated Cg-C16 alkyl amine having ten moles of oxyethylene per mole of amine;
Am-29: an ethoxylated C8-C16 alkyl amine having two moles of oxyethylene per mole of amine;
Am-30: an ethoxylated C16-Clg alkyl amine having twenty moles of oxyethylene per mole of amine;
Am-31: an ethoxylated C8-C16 alkyl amine having fifteen moles of oxyethylene per mole of amine;
Am-32: an ethoxylated C6 cyclo amine having two moles of oxyethylene per mole of amine;
Am-33: an ethoxylated C16-C1g alkyl amine having thirty two moles of oxyethylene per mole of amine;
Am-34: an ethoxylated tertiary C,~ alkyl amine having two moles of oxyethylene per mole of amine;
Am-35: an ethoxylated C8-C16 alkanol amide having three moles of oxyethylene per mole of amine;
Am-36: a C8-C16 alkyl amine;
Am-37: an ethoxylated C16-C18 alkyl amine having forty moles of oxyethylene per mole of amine;
Am-38: an ethoxylated C16-C18 alkyl amine having fifty moles of oxyethylene per mole of amine;
Am-39: a C16-C1g alkyl amine;
Am-40: dimethylaminopropylamine;
Am-41: C6 cyclohexylamine;
Am-42: a C8-C16 alkyl akanol amide;
Am-43: an ethoxylated C16-C~8 alkyl amine having ten moles of oxyethylene per mole of amine;
Am-44: an ethoxylated C$-C16 alkyl amine having five moles of oxyethylene per mole of amine;
Am-45: tertiary C4 alkyl amine;
Am-46: a C12-C14 alkoxy propyl amine;
Am-47: an ethoxylated N-ethyl toluidine having one mole of oxyethylene per mole of N-ethyl toluidine ;
Am-48: an ethoxylated m-toluidine having two moles of oxyethylene per mole of m-toluidene;
Am-49: morpholine;
Am-50: an ethoxylated aniline having ten moles of oxyethylene per mole of benzamine;
Am-51: m-toluidine;
Am-52: ethylenediamine;
Am-53: an ethoxylated m-toluidine having 100 moles of oxyethylene per mole of m-toluidine;
Am-54: tetraethylene pentamine;
Am-55: an ethoxylated Cl8 alkenyl amine having two moles of oxyethylene per mole of amine;
Am-56: an ethoxylated CI6-C1g alkenyl amine having two moles of oxyethylene per mole of amine;
Am-57: isobutanolamine;
Di-es-1: a polyethylene glycol (200) di-Cg-C16 ester;
Gl-1: an ethoxylated tri-CI8 alkyl glyceride having five moles of oxyethylene per mole of glyceride;
G1-2: castor oil;
Et-1: an ethoxylated C12 - Cia alkyl ether having three moles of oxyethylene per mole of ether;
Et-2: an ethoxylated C16-C1$ alkenyl ether having two moles of oxyethylene per mole of ether;
Es-1: an ethoxylated unsaturated C16-C18 fatty acid having three moles of oxyethylene per mole of fatty acid;
Ph-l: phenol;
Ph-2: CS di-tertiary-alkyl phenol;
Ph-3: an alkoxylated C9 alkyl phenol having three moles of oxypropylene per mole of alkyl phenol;
Ph-4: an alkoxylated phenol having one mole of oxybutylene per mole of phenol;
Ph-5: a tertiary-C5, di-alkyl phenol ;
Ph-6: a C9 alkyl phenol;
Al-l: isodecyl alcohol;
Sol-1: methyl cellosolve;
Fa-1: coconut fatty acid;
B~-l: an alkoxylated bis-phenol-a, having one mole of oxypropylene per equivalent of phenolic; _ Phosphate Esters:
III(1a) (or PE-1): C2, Cg, Clo alkyl phosphate, having 30.3% C2, 32.1% Cg, and 37.6% Clo;
ITI(2a): C2-Ci8 alkyl, Cl-C18 alkyl ether phosphate (having 30.2% C2, 30.3%
Cg, 35.6%
Clo, and 3.9% CI alkyl ether oxyalkylated with 1 mole of oxypropylene);
>II(2b): C2-CI8 alkyl, CI-CI8 alkyl ether phosphate (having 29.7% C2, 26.3%
C8, 30.8%
CIO, and 13.2% C6 alkyl ether oxyalkylated with 1.5 mole of oxyethylene);
)II(2c): C2-CIg alkyl, CI-CI8 alkyl ether phosphate (having 30.3%C2, 4.5% C4, 23.8% C8, 27.9% CIO, and 13.5% C6 alkyl ether oxyalkylated with 1.5 moles of oxyethylene);
)II(2d): C2-CI8 alkyl, CI-CI8 alkyl ether phosphate (having 27.4%C2, 24.1 %
C8, 28.4%
CIO, and 20.1 % C8 - CIO alkyl ether oxyalkylated with 3 moles of oxyethylene);
)II(2e): C2-CI8 alkyl, CI-CI8 alkyl ether phosphate (having 25.7%C2, 22.7% Cg, 26.7%
CIO, and 24.9% Cg - CIO alkyl ether oxyalkylated with 5 moles of oxyethylene);
)II(2f): C2-CI8 alkyl, CI-CI8 alkyl ether phosphate (having 25.4%C2, 22.1 %
C8, 26.2%
CIO, and 26.3% CI6 - CI8 alkyl ether oxyalkylated with 3 moles of oxyethylene);
IZI(3a) (or EP-1): C2-CI8 alkyl, C6 aryl ether phosphate (having 31 %C2, 25%
C8, 30%
CIO, and 14% C6 aryl ether oxyalkylated with 1 mole of oxyethylene);
)II(3b): C2-CI8 alkyl, C6 aryl ether phosphate (having 30.6% C2, 21.6% C8, 25.4% CIO, and 22.4% C6 aryl ether oxyalkylated with 1 mole of oxyethylene);
>II(3c): C2-CI8 alkyl, C6 aryl ether phosphate (having 25.9% C2, 22.8% C8, 26.8% CIO, and 24.5% C6 aryl ether oxyalkylated with 6 moles of oxyethylene);
)II(3d): C2-CI8 alkyl, C6 aryl ether phosphate (having 23.8% C2, 21.0% C8, 24.6% CIO, and 30.6% C6 aryl ether oxyalkylated with 9 moles of oxyethylene);
III(3e): C2-CI8 alkyl, C6 aryl ether phosphate (having 26.2% C2, 25.5% C8, 29.9% CIO, and 18.5% C6 aryl ether oxyalkylated with 10 moles of oxyethylene);
11I(3f): C2-CI8 alkyl, C6 aryl ether phosphate (having 29.8% C2, 26.3% C8, 30.9% CIO, and 13.0% C6 aryl ether oxyalkylated with 1 mole of oxybutylene);
)TI(4a): C2-C18 alkyl, C1-C12 alkyl or dialkyl C6 aryl ether phosphate (having 25.2% C2, 22.3% C8, 26.1% Clo, and 26.4% C9 alkyl C6 aryl ether oxyalkylated with 4 moles of oxyethylene);
)II(Sa): C2-C18 alkyl, Cl-C18 alkyl ether, C6 aryl ether phosphate (having 25.9% C2, 64.7%
C8 - Clo alkyl ether oxyalkylated with 1 mole of oxyethylene, and 9.4% C6 aryl ether oxyalkylated with 1 mole of oxyethylene);
Crosslinking Agents:
Fe3+: a 60% solution of ferric sulfate;
A13+: a solution of an aluminum chloride tall oil imidazoline reaction product, in accordance with US Patent No. 5,271,464.
TABLE I: EXAMPLES
Ex. Enhancer Phosphate Salt Closure Viscosity (total vol. secs. Mins.
) ComparativeNone PE-1 Fe3+ > 120 0.6 (1 ml) (1 ml) Am-l, Am-3 PE-1 Fe3+ 3 32.5 2 (29% / 79%)(1 ml) (0.79 ml) (0.21 ml) Am-1, Am-3 EP-1 Fe3+ 2 150 3 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml 4 none EP-1 Fe3+ > 120 1.30 Com arative (1 ml) (1 ml) 5(*) none PE-1 A13+ 79 2.30 Com arative (0.77 ml) (1 ml) 6(*) Am-1, Am-3 PE-1 Fe3+ 45.7 39 (29% / 71 (0.77 ml) (0.77 ml) %) (0.21 ml) 7(*) none PE-1 Fe3+ > 120 8.5 Com arative (0.77 ml) (1 ml) 8 Am-2, Am-3 PE-1 Fe3+ 30 95 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 9 Am-5, Am-3 PE-1 Fe3+ 9 41.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml Am-3 PE-1 Fe3+ 45 14.5 (0.21 ml) (1 ml) (0.79 ml) 11 Am-3 EP-1 Fe3+ 19 >120 (0.21 ml) (1 ml) (0.79 ml 12 Am-3 III(Sa) Fe3+ >120 4.7 (0.21 ml) (1 ml) (0.79 ml) 13 Am-56, Am-3EP-1 Fe3+ 2.0 _ 140.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 14 Am-1, Am-3 III(2b) Fe3+ 5.8 105.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) Am-1, Am-3 III(2c) Fe3+ 5.5 87.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 16 Am-1, Am-3 III(2e) Fe3+ 7.5 33.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 17 Am-1, Am-3 III(2d) Fe3+ 6.6 64.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) Ex. Enhancer Phosphate Salt Closure Viscosity (total vol. secs. Mins.
18 Am-1, Am-3 III(3c) Fe3+ 21 30.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml 19 Am-1, Am-3 III(3b) Fe3+ 11 60.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 20 Am-1, Am-3 III(4a) Fe3+ 4.7 141.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 21 Am-1, Am-3 III(5a) Fe3+ 2.6 20.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 22 Am-1, Am-3 III(2a) Fe3+ 9.7 18.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 23 Am-1, Am-3 III(2~ Fe3+ >120 2.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 24 Am-1, Am-9 EP-1 Fe3+ > 120 50.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 25 Am-8, Am-9 EP-1 Fe3+ > 120 5.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 26 Am-3, Am-10EP-1 Fe3+ > 120 15.5 (71% / 29%)(1 ml) (0.79 ml) (0.21 ml) 27 Am-1, Am-18EP-1 Fe3+ > 120 15.0 (25% / 75%)(1 ml) (0.79 ml) (0.21 ml) 28 Am-1, Am-19EP-1 Fe3+ 23 197.0 (25% / 75%)(1 ml) (0.79 ml) (0.21 ml) 29 Am-l,Am-11 EP-1 Fe3+ 3.7 > 210 (25% / 75%)(1 ml) (0.79 ml) -(0.21 ml) 30 Am-l,Am-20 EP-1 Fe3+ >120 112.0 (25% / 75%)(1 ml) (0.79 ml) (0.21 ml) 31 Am-2l,Am-3 EP-1 Fe3+ 2.5 31.0 (25% / 75%)(1 ml) (0.79 ml) (0.21 ml) 32 Am-12, Am-3EP-1 Fe3+ > 120 > 150 (25% / 75%)(1 ml) (0.79 ml) (0.21 ml) 33 Am-1, Am-3 III(3c) Fe3+ 27 30.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml Ex. Enhancer Phosphate Salt Closure Viscosity (total vol. sets. Mins.
34 Am-1, Am-3 III(3d) Fe3+ >120 1.6 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml 35 Di-es-1, EP-1 Fe3+ >120 61.0 Am-3 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) Ex. Enhancer Phosphate Salt Closure Viscosity (total vol. sees. Mins.
) 36 Gl-1, Am-3 EP-1 Fe3+ > 120 74 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 37 Et-1, Am-3 EP-1 Fe3+ 90 52 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 38 Et-2, Am-3 EP-1 Fe3+ >120 30.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 39 Am-21, Am- EP-1 Fe3+ 28 >120 22, Sol-1 (1 ml) (0.79 ml) (33%:33%:33 %) (0.21 ml) 40 Am-1, Am-23EP-1 Fe3+ 4 262 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 41 Am-1, Am-13EP-1 Fe3+ 4 52 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 42 Am-1, Am-24EP-1 Fe3+ >120 170.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 43 Am-2, Am-3 EP-1 Fe3+ 9 420.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 44 Am-23 EP-1 Fe3+ >120 - 2.3 (0.21 ml) ( 1 ml) (0.79 ml) 45 Am-3, Am-23EP-1 Fe3+ >120 52.0 (25% / 75%)(1 ml) (0.79 ml) (0.21 ml) 46 Am-21, Am-23EP-1 Fe3+ 3 45.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 47 Am-1, Am-14EP-1 Fe3+ 3 240.0 (29% / 71 (1 ml) (0.79 ml) %) (0.21 ml) 48 Am-1, Am-3 III(3f) Fe3+ 9 15.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) Ex. Enhancer Phosphate Salt Closure Viscosity (total vol. secs. Mins.
49 Am-2, Am-23EP-1 Fe3+ 36 300.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 50 Am-1, Am-3 III(3e) Fe3+ 17 67.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 51 Es-1, Am-3 EP-1 Fe3+ 90 88 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 52 Am-4, Am-3 EP-1 Fe3+ 4.8 360 (29% / 71%)(1 ml) (0.79 ml) -(0.21 ml) 53 Am-5, Am-3 EP-1 Fe3+ 2 900 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 54 Ph-3, Am-3 EP-1 Fe3+ 90 85.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 55 Am-25, Am-3EP-1 Fe3+ >120 7.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 56 Am-26, Am-3EP-1 Fe3+ 3 133.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 57 Am-8, Am-27EP-1 Fe3+ >120 9.0 (50% / 50%)(1 ml) (0.79 ml) (0.21 ml) 58 Am-1, Am-23EP-1 Fe3+ 4 262.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 59 Am-27, Am-3EP-1 Fe3+ 41 86.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 60 Am-1, Am-8,EP-1 Fe3+ >120 9.5 Am-27 (1 ml) (0.79 ml) (33%:33%:33 %) (0.21 ml) 61 Am-21, Am-23EP-1 Fe3+ 3 45.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 62 Am-28, Am-3EP-1 Fe3+ >120 6.3 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 63 Am-29, Am-3EP-1 Fe3+ 2.3 300.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 64 Am-30, Am-3EP-1 Fe3+ >120 1.3 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) Ex. Enhancer Phosphate Salt Closure Viscosity (total vol. sets. Mins.
) 65 Am-31, Am-3EP-1 Fe3+ >120 8.2 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 66 Am-32, Am-3EP-1 Fe3+ 35 66.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 67 Am-33, Am-3EP-1 Fe3+ >120 2.5 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 68* Am-1, Am-34EP-1 Fe3+ 120 35.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml 69 Ph-2, Am-3 EP-1 Fe3+ 90 38.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml 70 Ph-4, Am-3 EP-1 Fe3+ 93 80.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml 71 Ph-1, Am-3 EP-1 Fe3+ > 120 60 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml 72 Am-35, Am-3EP-1 Fe3+ 64 180.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 73 Al-l, Am-3 EP-1 Fe3+ 95 35 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 74 Fa-1, Am-3 EP-1 Fe3+ >120 45.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 75 Am-42, Am-3EP-1 Fe3+ 9 300.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 76 Am-36, Am-3EP-1 Fe3+ >120 75.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 77 Gl-2, Am-3 EP-1 Fe3+ 73 75.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 78 Am-37, Am-3EP-1 Fe3+ >120 7.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 79 Am-38, Am-3EP-1 Fe3+ >120 1.8 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 80 Am-39, Am-3EP-1 Fe3+ 14.4 345.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) Ex. Enhancer Phosphate Salt Closure Viscosity (total secs. Mins.
vol. ) 81 Am-1, Am-40EP-1 Fe3+ 90 300 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 82 Am-1, Am-41EP-1 Fe3+ >120 163.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml 83 Ph-5, Am-3EP-1 Fe3+ > 120 37.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 84 Ph-6, Am-3EP-1 Fe3+ 90 76.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 85 Bp-1, Am-3EP-1 Fe3+ 63 180.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 86* Am-1, Am-34EP-1 Fe3+ >120 53.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 87 Am-1, Am-32EP-1 Fe3+ 9.3 360.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml 88 Am-43, EP-1 Fe3+ >120 3.7 Am-3 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml 89 Am-44, EP-1 Fe3+ 7.5 25.0 Am-3 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 90 Am-1, Am-45EP-1 Fe3+ 12 78.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 91 Am-3, Am-6EP-1 Fe3+ 3 720 (71% / (1 ml) (0.79 ml) 29%) (0.21 ml) 92 Am-46, EP-1 Fe3+ 15 720 Am-3 (25% / (1 ml) (0.90 ml) -75%) (0.10 ml) 93 Am-1, Am-47EP-1 Fe3+ 7.5 180.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 94 Am-1, Am-17EP-1 Fe3+ 10.7 240 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 95 Am-1, Am-48EP-1 Fe3+ 8.1 150.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) 96 Am-1, Am-49EP-1 Fe3+ 90 120.0 (29% / (1 ml) (0.79 ml) 71%) (0.21 ml) Ex. Enhancer Phosphate Salt Closure Viscosity (total vol. secs. Mins.
) 97 Am-50, Am-3EP-1 Fe3+ 72 174.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 98 Am-1, Am-51EP-1 Fe3+ >120 150.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 99 Am-1, Am-57EP-1 Fe3+ 81 100.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 100 Am-1, Am-52EP-1 Fe3+ >120 46.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 101 Am-53, Am-3EP-1 Fe3+ >120 24.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 102 Am-1, Am-54EP-1 Fe3+ >120 7.0 (29% / 71%)(1 ml) (0.79 ml) (0.21 ml) 103(*) Am-7 EP-1 Fe3+ > 120 0.12 Com arative (1 ml) (0.79 ml) 5(*): utilizes the aluminum system as described in US 5,271,464.
6(*) & 7(*): the phosphate esters of these examples are partially neutralized with 0.23 ml of 45% KOH.
68(*): the enhancer was pre-blended with the ferric salt.
86(*): phosphate ester, enhancer, and ferric salt were each introduced separately.
103(*): the surface active amine is as described in Halliburton, e.g., US
5,271,464 (@Col. 3, lines 1-3).
The gelling systems in accordance with the present invention demonstrate increased gelling speeds as compared to prior art systems. Of the comparative examples set forth hereinabove, only Comparative Example 5 has a gel closure time of less than 120 seconds. The majority (63%) of the examples according to the invention required far less than 120 seconds to achieve gel closure. Some inventive examples are reported as having a closure of >120 seconds.
It is important to clarify that a closure time of greater than 120 seconds is not to be understood as meaning that acceptable gel viscosity was not achieved in those examples.
Rather, a designation of ">120 sec." means only that there was evidence of a vortex extant in the gelled fluid after it had stirred for 120 seconds. The significance of the rapid gel closure times evidenced overall by the gel systems of the invention is that it is an indication to the skilled field worker of the time efficiency, or the rapidity of "on the fly" gelling of the system components.
The more dramatic difference between the examples of the present invention and those of the prior art can be seen in the viscosity of the gels. Increased gel viscosity is necessary for optimal proppant transport. Prior art example, Example 5, did not exceed a viscosity of 10, as measured in minutes required for 100 milliliters of gel to pass through a Marsh funnel. Also, comparative example 103, which utilized the surface active amine of Halliburton '464 as the enhancer component, gave a viscosity of 0.12 minutes. In the numerous examples representative of the invention, 54% of the inventive examples demonstrated a viscosity requiring in excess of 50 minutes, and 34% of the inventive examples demonstrated a viscosity requiring in excess of 100 minutes for 100 milliliters to pass through the funnel. Only 15%
demonstrated a viscosity requiring less than 10 minutes for 100 milliliters of gel to pass through the funnel.
Inventive examples 68 and 86 provide comparative results vis-a-vis each other.
Both examples used the same components for gelling kerosene, the only difference being the manner by which they were introduced to the blender. In example 68, the enhancer was pre-blended with the ferric salt; the blend was introduced to the kerosene, as was the phosphate ester. In example 86, the same enhancer, ferric salt, and phosphate ester were all introduced separately to the kerosene. The separate addition of components gave a gel of higher viscosity (53 mins.) than the method wherein the enhancer and the ferric salt were pre-blended (35 mins).
For the following examples, the same experimental procedure as in Examples 1 -103 was used. Differences in volumes and ratios employed are specified in each of the examples set forth in Table II.
TABLE II. EXAMPLES 104 -119: DEMONSTRATING SYNERGISTIC
EFFECTS OF AMINE MIXTURES
Ex.Enhancer PhosphateSalt ClosureViscosityViscosity Calculated Viscosity Based (vol. Added)(vol. Secs. Mins. Centipoiseson Relative & added) Contribution of mixing (Observed)Each Amine Component ratio, -where applicable in Centipoises (Expected) 104Am-55 EP-1 Fe3+ >120 40.0 4400 (0.21 ml) (1 ml) (0.79m1) 105Am-3 EP-1 Fe3+ 19 215.0 10000 (0.21 ml) (1m1) (0.79m1) 106Am-1 EP-1 Fe3+ >120 23.0 4800 (0.21 ml) (1m1) (0.79m1) 107Am-56 EP-1 Fe3+ 4 23.0 5000 (0.21 ml) (1m1) (0.79m1) 108Am-22 EP-1 Fe3+ >120 5.0 7000 (0.21 ml) (1m1) (0.79m1) 109Am-24 EP-1 Fe3+ >120 1.5 4800 (0.21 ml) (1m1) (0.79m1) 110Am-27 EP-1 Fe3+ >120 1.5 150 (0.21 ml) (1m1) (0.79m1) 111Am-29 EP-1 Fe3+ >120 10.0 250 (0.21 ml) (1m1) (0.79m1) 112Am-55, EP-1 Fe3+ 2 150.0 10600 8376 Am-3 (29:71)(0.21(1m1) (0.79m1) ml) 113Am-1, Am-3EP-1 Fe3+ 2 135.0 11000 8492 (29:71 (1 ml) (0.79m1) -)(0.21 ml) 114Am-56, EP-1 Fe3+ 2 140.0 9600 8550 Am-3 (29:71 (1 ml) (0.79mi) )(0.21 ml) 115Am-29, EP-1 Fe3+ 2 60.0 9200 7173 Am-3 (29:71)(0.21(1m1) (0.79m1) ml) 116Am-1, Am-24EP-1 Fe3+ >120 120.0 7000 6816 (29:71 (1 ml) (0.79m1) )(0.21 ml) 117Am-29, EP-1 Fe3+ 2 600.0 12200 3481 Am-24 (29:71 (1 ml) (0.79m1) )(0.21 ml) 118Am-29, EP-1 Fe3+ 2 345.0 10400 5040 Am-22 (29:71 (1 ml) (0.79m1) )(0.21 ml) 119Am-29, EP-1 Fe3+ 2 260.0 10000 180 Am-27 (29:71)(0.21(1m1) (0.79m1) ml) The results in Table II exemplify the novel synergism, and its effect on viscosity, achieved in combining enhancer components of the invention. All of Examples demonstrate surprising levels of viscosity which are unexpected based on the viscosities of the individual components on a same volume basis. In addition, the viscosities for each of the individual components separately have been calculated to take into account the relative contribution of each amine component in the mixture (see the column on the extreme right). In this way, a theoretical (or expected) value is obtained. The actual viscosities obtained in all of Examples 112 - 119 exceed the calculated viscosities.
For the following examples, the same experimental procedure as in Examples 1 -103 was used. Differences in volumes and ratios employed are specified in each of the examples set forth in Table III.
TABLE III. EXAMPLES 120a -123d: EFFECT OF SYNERGISTIC PHOSPHATE
ESTER MIXTURES ON GEL VISCOSITY
Ex.Enhancer PhosphateSalt ClosureViscosity ViscosityCalculated Mins.
(mixing Secs. CentipoisesViscosity ratio Based on & Relative vol. Added) Contribution of Each Amine Component - in Centipoises Ex acted 120aAm-56, PE-1 Fe3+ 2 1440+ 40000 Am-3 (29:71 (2m1) (1.58m1) (i.e., )(0.42) >24hrs) 120bAm-56, PE-1 Fe3+ 2 70.0 7000 Am-3 (29:71 (1 ml) (0.79m1) )(0.21 ) 120cAm-56, PE-1 Fe3+ 2 15.0 2800 Am-3 (29:71 (0.5m1) (0.40m1) )(0.11 ) 120dAm-56, PE-1 Fe3+ >120 0.8 600 Am-3 (29:71 (0.25m1)(0.20m1) )(0.06) 121aAm-56, (III) Fe3+ 2 1440+ 31000 Am-3 (3b) (29:71)(0.42)(2m1) (1.58m1) 121bAm56, Am-3(III) Fe3+ 2 20.0 5200 (3b) (29:71 (1 ml) (0.79m1) )(0.21 ) 121cAm-56, (III) Fe3+ 3 12.0 2100 Am-3 (3b) (29:71 0.5m1 (0.40m1) )(0.11 ) 121dAm-56, (III) Fe3+ 3 2.5 1200 Am-3 (3b) (29:71 0.25 (0.20m1) )(0.06) ml 122aAm-56, EP-1 Fe3+ 2 1260.0 45000 Am-3 (29:71)(0.42)(2m1) (1.58m1) 122bAm-56, EP-1 Fe3+ 2 150.0 10600 Am-3 (29:71 (1 ml) (0.79m1) )(0.21 ) 122cAm-56, EP-1 Fe3+ 2 10.0 3200 Am-3 (29:71 (0.5m1) (0.40m1) )(0.11 ) 122dAm-56, EP-1 Fe3+ >120 2.0 2000 Am-3 (29:71 (0.25m1)(0.20m1) )(0.06) 123aAm-56, PE-1, Fe3+ 2.0 1440+ 76000 40000 Am-3 (III) (3b) (29:71 (50:50) (1.58m1) )(0.42) 2m1 123bAm-56, PE-1, Fe3+ 2.0 340 15400 7600 Am-3 (III) (3b) (29:71 (50:50) (0.79m1) )(0.21 ) 1 ml 123cAm-56, PE-1, Fe3+ 3.0 30 4000 3300 Am-3 (III) (3b) (29:71 (50:50) (0.40mi) )(0.11 ) 0.5m1 123dAm-56, PE-1, Fe3+ >120 4.0 2400 800 Am-3 (III) (3b) (29:71 (50:50) (0.20m1) )(0.06) 0.25m1 The results in Table )TI exemplify the novel synergism, and its effect on viscosity, achieved in combining phosphate esters according to the invention. All of Examples 123a - 123d demonstrate surprising levels of viscosity which are unexpected based on the viscosities of the individual components on a same volume basis. In addition, the viscosities for each of the individual components separately have been calculated to take into account the relative contribution of each phosphate ester in the mixture (see the column on the extreme right). In this way, a theoretical (or expected) value is obtained. The actual viscosities obtained in all of Examples 123a - 123d are 190%, 202%, 121%, and 300%, respectively, of the calculated values.
The foregoing description of preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated.
It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents.
Claims (38)
1. A gel-forming hydrocarbon composition for fracturing formations comprising: a) a hydrocarbon liquid capable of gellation, b) a crosslinking agent, c) an enhancer comprising an amine selected from the group consisting of alkyl amines, oxyalkylated amines, and mixtures thereof, and d) a phosphate ester comprising a mixture of mono, diesters, and triesters of the formulae wherein R, R1, and R2 are independently C1 -C18 alkyl, C6 aryl, C1 -18 alkyl or di C1 -C18 alkyl C6 aryl, C1 -C18 alkyl ether, C6 aryl ether, or C1 -C18 alkyl or di C1 -C18 alkyl C6 aryl ether, and where any ether linkage has the following structure:
--O(CH2 --CHR')--wherein R' is hydrogen, methyl or ethyl and wherein said phosphate ester is the reaction product comprising either: A) phosphorus pentoxide reacted with a tri-loweralkyl phosphate and subsequently reacted with either an alcohol, an oxyalkylated alcohol or mixtures thereof or B) phosphorous pentoxide reacted with either an alcohol, an oxyalkylated alcohol or mixtures thereof to form a phosphate ester or mixed phosphate ester which is subsequently reacted with a tri-loweralkyl phosphate and wherein said tri-loweralkyl phosphate is selected from the group of triethylphosphate or tributylphosphate with the proviso that said amine enhancer can not be triethylamine ar triethanolamine.
--O(CH2 --CHR')--wherein R' is hydrogen, methyl or ethyl and wherein said phosphate ester is the reaction product comprising either: A) phosphorus pentoxide reacted with a tri-loweralkyl phosphate and subsequently reacted with either an alcohol, an oxyalkylated alcohol or mixtures thereof or B) phosphorous pentoxide reacted with either an alcohol, an oxyalkylated alcohol or mixtures thereof to form a phosphate ester or mixed phosphate ester which is subsequently reacted with a tri-loweralkyl phosphate and wherein said tri-loweralkyl phosphate is selected from the group of triethylphosphate or tributylphosphate with the proviso that said amine enhancer can not be triethylamine ar triethanolamine.
2. The composition according to claim 1 , wherein said phosphate ester is a mixed phosphate ester having C2, C8, and C10 alkyl groups.
3. The composition according to claim 1 wherein said phosphate ester is a mixed phosphate ester having C2, C8, and C10 alkyl groups and oxyalkylated C6 aryl ether groups.
4. The composition according to claim 1 wherein said tri-loweralkyl phosphate is triethylphosphate or tributylphosphate.
5. The composition according to claim 1 wherein said enhancer is an oxyalkylated amine comprising an oxyalkylated alkyl amine, a polyoxyalkylated alkyl amine, an oxyalkylated dialkyl amine, a polyoxyalkylated dialkyl amine, an oxyalkylated diamine, an oxyalkylated aryl amine, or mixtures thereof.
6. The composition according to claim 5 wherein said oxyalkylated amine is an ethoxylated, propoxylated, or butoxylated alkyl amine.
7. The composition according to claim 6 wherein said oxyalkylated amine is an ethoxylated alkyl amine containing from 1 to about 100 moles of ethylene oxide per mole of amine.
8. The composition according to claim 7, wherein the alkyl of said ethoxylated alkyl amine contains from 4 to 18 carbon atoms.
9. The composition according to claim 6 wherein said oxyalkylated amine is a propoxylated alkyl amine containing from 1 to about 50 moles of propylene oxide per mole of amine.
10. The composition according to claim 6 wherein said oxyalkylated amine is a polyoxybutylene alkyl amine.
11. The composition according to claim 5 wherein said oxyalkylated amine is an ethoxylated, propoxylated, or butoxylated dialkyl amine.
12. The composition according to claim 11 wherein said oxyalkylated amine is an ethoxylated dialkyl amine containing from 1 to about 50 moles of ethylene oxide per mole of amine.
13. The composition according to claim 11 wherein said oxyalkylated amine is a polyoxypropylene dialkyl amine.
14. The composition according to claim 11 wherein said oxyalkylated amine is a polyoxybutylene dialkyl amine.
15. The composition according to claim 5 wherein said oxyalkylated amine is an oxyalkylated diamine.
16. The composition according to claim 5 wherein said oxyalkylated amine is an oxyalkylated aryl amine.
17. The composition according to claim 1 wherein said crosslinking agent is a salt of a multivalent cation.
18. The composition according to claim 17 wherein said crosslinking agent is selected from the group consisting of ferric nitrate and ferric sulfate.
19. The composition according to claims wherein said crosslinking agent is a salt of a multivalent cation.
20. The composition according to claim 19 wherein said crosslinking agent is selected from the group consisting of ferric nitrate and ferric sulfate.
21. The composition according to claim 1 wherein said enhancer is a mixture of oxyalkylated amines or a mixture of an oxyalkylated amine and an alkyl amine, and said phosphate ester comprises a C2-C18 alkyl, aryl ether phosphate.
22. The composition according to claim 21 wherein said enhancer is a mixture of N,N-dibutyl ethanol amine and an ethoxylated C18 alkenyl amine having two moles of oxyethylene per mole of amine.
23. The composition according to claim21 wherein said alkyl amines are selected from the group consisting of primary, secondary, and tertiary C1 - C18 alkyl amine.
24. The composition according to claim 21 wherein said alkyl amine is selected from the group consisting of C2 -C22 alkyl amines, C2 -C22 dialkyl amines, C2 -C22 alkyl diamines, C2 -C22 dialkyl diamines, and C2 -C22 dialkyl amino C2 -C22 alkylamines.
25. The composition according to claim21 wherein said enhancer is a mixture selected from the group consisting of N,N-dibutyl ethanolamine and a N,N-dimethyl, C16 alkyl amine;
N,N-dibutyl ethanolamine and a N,N-dimethyl, C18 alkyl amine;
N,N-dibutyl ethanolamine and a C16 - C18 alkyl amine;
N,N-dibutyl ethanolamine and an octylamine ethoxylated with two moles of oxyethylene;
N,N-dibutyl ethanolamine and an ethoxylated C8-C16 alkyl amine ethoxylated with two moles of oxyethylene;
N,N-dibutyl ethanolamine and a C12 - C14 alkoxy propyl amine;
an ethoxylated C16 - C18 alkyl amine ethoxylated with two moles of oxyethylene and an N,N-dibutyl amine alkoxylated with one mole of oxypropylene; and an octylamine ethoxylated with two moles of oxyethylene and N,N-dibutyl amine ethoxylated with four moles of oxyethylene.
N,N-dibutyl ethanolamine and a N,N-dimethyl, C18 alkyl amine;
N,N-dibutyl ethanolamine and a C16 - C18 alkyl amine;
N,N-dibutyl ethanolamine and an octylamine ethoxylated with two moles of oxyethylene;
N,N-dibutyl ethanolamine and an ethoxylated C8-C16 alkyl amine ethoxylated with two moles of oxyethylene;
N,N-dibutyl ethanolamine and a C12 - C14 alkoxy propyl amine;
an ethoxylated C16 - C18 alkyl amine ethoxylated with two moles of oxyethylene and an N,N-dibutyl amine alkoxylated with one mole of oxypropylene; and an octylamine ethoxylated with two moles of oxyethylene and N,N-dibutyl amine ethoxylated with four moles of oxyethylene.
26. The composition according to claim 21 wherein said C2 - C18 alkyl, aryl ether phosphate is selected from the group consisting of C2 - C18 alkyl, aryl ether phosphates having 31%C2, 25% C8, 30% C10, and 14% C6 aryl ether oxyalkylated with 1 mole of oxyethylene and 30.6% C2, 21.6% C8, 25.4% C10, and 22.4% C6 aryl ether oxyalkylated with 1 mole of oxyethylene.
27. The composition according to claim 5 wherein said oxyalkylated amine is a mixture of oxyalkylated amines.
28. An enhancer composition for use in combination with a gellable liquid hydrocarbon, a phosphate ester, and a crosslinking agent, said enhancer composition comprising an oxy-alkylated di C2 -C8 alkyl amine and a second component selected from the group consisting of: N, N-di-C1 alkyl C16 alkyl amine, N, N-di (C1) alkyl C18 alkyl amine, and ethoxylated C16 - C18 alkyl amine having two moles of oxyethylene per mole of amine and mixtures thereof.
29. The enhancer composition according to claim 28, N,N-dibutyl amine ethoxylated with one mole of ethylene oxide and an ethoxylated C18 alkenyl amine having two moles of oxyethylene per mole of amine.
30. The composition according to claim 1 wherein said enhancer further comprises a non-nitrogen containing component.
31. The composition according to claim 30 wherein said non-nitrogen containing component is selected from the group consisting of oxyalkylated glycerides, oxyalkylated mono-and di-esters, oxyalkylated alcohols, oxyalkylated phenols and a fatty acid.
32. The composition according to claim 31 wherein said non-nitrogen containing component is selected from the group consisting of alcohols and phenols.
33. The composition according to claim 1 wherein said phosphate ester is an ether phosphate ester.
34. A composition suitable for gelling hydrocarbon liquids comprising: 1) a phosphate ester which is a reaction product comprising either A) phosphorus pentoxide reacted with a tri-loweralkyl phosphate and subsequently reacted with either an alcohol, an oxyalkylated alcohol or mixtures thereof or B) phosphorous pentoxide reacted with either an alcohol, an oxyalkylated alcohol or mixtures thereof to form a phosphate ester or mixed phosphate ester which is subsequently reacted with a tri-loweralkyl phosphate, 2) a crosslinking agent, and 3) an enhancer comprising an amine selected from the group consisting of alkyl amines, oxyalkylated amines, and mixtures thereof.
35. A gel-forming hydrocarbon composition for fracturing formations comprising: 1) a hydrocarbon liquid capable of gellation, 2) 0.01 to 10.0% by weight of an ether phosphate mixed ester having C2, C8, and C10 alkyl groups and oxyethylated C6 aryl groups which ether phosphate mixed ester is the reaction product comprising either A) phosphorus pentoxide reacted with a tri-loweralkyl phosphate and subsequently reacted with either an alcohol, an oxyalkylated alcohol or mixtures thereof or B) phosphorous pentoxide reacted with either an alcohol, an oxyalkylated alcohol or mixtures thereof to form a phosphate ester or mixed phosphate ester which is subsequently reacted with a tri-loweralkyl phosphate, wherein said tri-loweralkyl phosphate is selected from the group of triethylphosphate or tributylphosphate; 3) a crosslinking agent in an amount effective to gel said hydrocarbon liquid, 4) from about 0.085 molar equivalent to about 0.31 molar equivalent of the phosphate ester of an enhancer comprising an amine selected from the group consisting of alkyl amines, oxyalkylated amines, and mixtures thereof, and 5) optionally a surfactant.
36 . A synergistic amine enhancer composition useful in gelling compositions comprising N,N-dibutyl ethanol amine in combination with a second oxyalkylated amine enhancer comprising an ethoxylated C16 - C18 alkyl amine having two moles of oxyethylene per mole of amine; an ethoxylated C8-C16 alkyl amine having two moles of oxyethylene per mole of amine; an ethoxylated C18 alkenyl amine having two moles of oxyethylene per mole of amine; or an ethoxylated C16-C18 alkenyl amine having two moles of oxyethylene per mole of amine.
37. A synergistic phosphate ester composition useful in gelling compositions comprising mixtures of first and second phosphate esters, wherein said first and second phosphate esters comprise mixtures selected from the group consisiting of a C2, C8, C10 alkyl phosphate, having 30.3% C2, 32.1% C8, and 37.6% C10 with a C2-C18 alkyl, C6 aryl ether phosphate having 30.6%C2, 21.6% C8, 25.4% C10, and 22.4% C6 aryl ether oxyalkylated with 1 mole of oxyethylene; a C2-C18 alkyl, C6 aryl ether phosphate having 31%C2, 25% C8, 30%
C10, and 14%
C6 aryl ether oxyalkylated with 1 mole of oxyethylene with a C2-C18 alkyl, C6 aryl ether phosphate having 29.8% C2, 26.3% C8, 30.9% C10, and 13.0% C6 aryl ether oxyalkylated with 1 mole of oxybutylene; and a C2, C8, C10 alkyl phosphate, having 30.3% C2, 32.1%
C8, and 37.6%
C10 with a C2-C18 alkyl, C6 aryl ether phosphate having 31%C2, 25% C8, 30%
C10, and 14% C6 ary ether oxyalkylated with 1 mole of oxyethylene.
C10, and 14%
C6 aryl ether oxyalkylated with 1 mole of oxyethylene with a C2-C18 alkyl, C6 aryl ether phosphate having 29.8% C2, 26.3% C8, 30.9% C10, and 13.0% C6 aryl ether oxyalkylated with 1 mole of oxybutylene; and a C2, C8, C10 alkyl phosphate, having 30.3% C2, 32.1%
C8, and 37.6%
C10 with a C2-C18 alkyl, C6 aryl ether phosphate having 31%C2, 25% C8, 30%
C10, and 14% C6 ary ether oxyalkylated with 1 mole of oxyethylene.
38. The synergistic phosphate ester composition according to claim 37 wherein said mixture of first and second phosphate esters is a C2, C8, C10 alkyl phosphate, having 30.3% C2, 32.1% C8, and 37.6% C10 with a C2-C18 alkyl, C6 aryl ether phosphate having 30.6%C2, 21.6%
C8, 25.4% C10, and 22.4% C6 aryl ether oxyalkylated with 1 mole of oxyethylene.
C8, 25.4% C10, and 22.4% C6 aryl ether oxyalkylated with 1 mole of oxyethylene.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2239318 CA2239318C (en) | 1998-05-29 | 1998-05-29 | Improved hydrocarbon gelling compositions useful in fracturing formations |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2239318 CA2239318C (en) | 1998-05-29 | 1998-05-29 | Improved hydrocarbon gelling compositions useful in fracturing formations |
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| Publication Number | Publication Date |
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| CA2239318A1 CA2239318A1 (en) | 1999-11-29 |
| CA2239318C true CA2239318C (en) | 2003-09-09 |
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| US10696892B2 (en) | 2016-06-07 | 2020-06-30 | Saudi Arabian Oil Company | Enhancements of gelled hydrocarbon systems |
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