CA1142114A - Method of inhibiting precipitation of asphaltenes - Google Patents
Method of inhibiting precipitation of asphaltenesInfo
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- CA1142114A CA1142114A CA000358195A CA358195A CA1142114A CA 1142114 A CA1142114 A CA 1142114A CA 000358195 A CA000358195 A CA 000358195A CA 358195 A CA358195 A CA 358195A CA 1142114 A CA1142114 A CA 1142114A
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- phosphoric acid
- petroleum
- asphaltenes
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- per million
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Abstract
METHOD OF INHIBITING PRECIPITATION
OF ASPHALTENES
Abstract of the Disclosure Precipitation of asphaltenes in bituminous liquids, e.g., petroleum and petroleum derived products, is inhibited by the addition of alkyl phosphoric acids derived from aliphatic alcohols having from 10 to 20 carbon atoms.
OF ASPHALTENES
Abstract of the Disclosure Precipitation of asphaltenes in bituminous liquids, e.g., petroleum and petroleum derived products, is inhibited by the addition of alkyl phosphoric acids derived from aliphatic alcohols having from 10 to 20 carbon atoms.
Description
METEIOD OF INHIsITIN~ PRECIPITATION
OF ASPHALTENES
Background of the Invention Asphaltenes are components of the bitumen in petroleums, petroleum products, and other bituminous materials which are soluble in carbon disulfide but insoluble in paraffin naphtha. The physical and chemical characteristics of asphaltenes have been the subject of considerable investigation for at least a century. (2, 3).
The asphaltene molecule appears to carry a core of 10 approximately five stacked flat sheets of condensed aromatic rings, one above the other giving an overall height of 16-20 angstroms. The average sheet diameter appears to be about 8.5 to 15 angstroms. The molecular weight of petroleum 15 asphaltenes ranges from about 1,000 to 10,000. Shale oil asphaltenes appear to have a lower molecular weight.
Qualitative and semiquantitative detection of asphaltenes and bituminous liquids, e.g. petroleum and petroleum derived liquids, is conventionally carried out by 20 observing the precipitation of asphaltenes by naphtha addition. (3).
The presence of asphaltenes in bituminous liquid, e.g. petroleum crude, refinery streams, and other natural and processed bituminous liquids, is well known as are the 25 problems resolving from the presence and precipitation of the asphaltenes. In petroleum production, for example, it has long been known that asphaltenes may, under some circumstancesl precipitate to form a sludge which plugs up the oil bearing formation and prevents the recovery of l~Zll.~
additional petroleum. Sludge in such compositions is known to form in petroleum bearing formations, on valves, pump impellers, in conduits, and in other bituminous liquid handling equipment.
Generally, it is regarded as an advantage to keep the asphaltenes in a stable suspension in the bituminous liquid until well into the refining process. This not only increases the ultimate yield but prevents or reduces maintenance problems and also improves productivity from 10 bituminous liquid bearing formations.
This invention constitutes a method for stabilizing asphaltenes in petroleum, shale oil, refinery streams, and other bituminous liquids.
Disclosure of the Invention f ~ha /c It has been discovered that certain ~lphati~
alcohol-phosphoric acid derivatives, when added to petroleum or other bituminous liquids, stabilizes asphaltenes against precipitation. According to this invention C-10 through C-20 aliphatic alcohol partial esters of phosphoric acid 20 improve the stability of asphaltenes in bituminous liquids.
These phosphoric acid derivatives, or mixtures of such derivatives, are added to the bituminous liquid in an effective amount of at least about 50 parts per million and may be added up to as high as 15,000 parts per million, or 25 even higher, although higher addition levels do not significantly increase the effectiveness of the alkyl phosphoric acid derivatives stabilizing materials.
~ lkyl phosphoric acid derivatives having aliphatic alcohol substituents of less than about 9 or 10 carbon atoms 30 generally are ineffective and are actually detrimental in most cases, tending to reduce the stability of asphaltenes in the bituminous liquid. The utility of alkyl phosphoric acid derivatives having aliphatic chains of more than 20 carbon atoms is limited primarily by the availability and 35 solubility of these compounds. Such compounds may be considered to be technically equivalent insofar as stabilizing the asphaltenes but the practical application of such compounds is extremely limited because of the high cost of these compounds and the difficulty in solubilizing these
OF ASPHALTENES
Background of the Invention Asphaltenes are components of the bitumen in petroleums, petroleum products, and other bituminous materials which are soluble in carbon disulfide but insoluble in paraffin naphtha. The physical and chemical characteristics of asphaltenes have been the subject of considerable investigation for at least a century. (2, 3).
The asphaltene molecule appears to carry a core of 10 approximately five stacked flat sheets of condensed aromatic rings, one above the other giving an overall height of 16-20 angstroms. The average sheet diameter appears to be about 8.5 to 15 angstroms. The molecular weight of petroleum 15 asphaltenes ranges from about 1,000 to 10,000. Shale oil asphaltenes appear to have a lower molecular weight.
Qualitative and semiquantitative detection of asphaltenes and bituminous liquids, e.g. petroleum and petroleum derived liquids, is conventionally carried out by 20 observing the precipitation of asphaltenes by naphtha addition. (3).
The presence of asphaltenes in bituminous liquid, e.g. petroleum crude, refinery streams, and other natural and processed bituminous liquids, is well known as are the 25 problems resolving from the presence and precipitation of the asphaltenes. In petroleum production, for example, it has long been known that asphaltenes may, under some circumstancesl precipitate to form a sludge which plugs up the oil bearing formation and prevents the recovery of l~Zll.~
additional petroleum. Sludge in such compositions is known to form in petroleum bearing formations, on valves, pump impellers, in conduits, and in other bituminous liquid handling equipment.
Generally, it is regarded as an advantage to keep the asphaltenes in a stable suspension in the bituminous liquid until well into the refining process. This not only increases the ultimate yield but prevents or reduces maintenance problems and also improves productivity from 10 bituminous liquid bearing formations.
This invention constitutes a method for stabilizing asphaltenes in petroleum, shale oil, refinery streams, and other bituminous liquids.
Disclosure of the Invention f ~ha /c It has been discovered that certain ~lphati~
alcohol-phosphoric acid derivatives, when added to petroleum or other bituminous liquids, stabilizes asphaltenes against precipitation. According to this invention C-10 through C-20 aliphatic alcohol partial esters of phosphoric acid 20 improve the stability of asphaltenes in bituminous liquids.
These phosphoric acid derivatives, or mixtures of such derivatives, are added to the bituminous liquid in an effective amount of at least about 50 parts per million and may be added up to as high as 15,000 parts per million, or 25 even higher, although higher addition levels do not significantly increase the effectiveness of the alkyl phosphoric acid derivatives stabilizing materials.
~ lkyl phosphoric acid derivatives having aliphatic alcohol substituents of less than about 9 or 10 carbon atoms 30 generally are ineffective and are actually detrimental in most cases, tending to reduce the stability of asphaltenes in the bituminous liquid. The utility of alkyl phosphoric acid derivatives having aliphatic chains of more than 20 carbon atoms is limited primarily by the availability and 35 solubility of these compounds. Such compounds may be considered to be technically equivalent insofar as stabilizing the asphaltenes but the practical application of such compounds is extremely limited because of the high cost of these compounds and the difficulty in solubilizing these
2:114 compounds in bituminous liquids. This invention, therefore, is directed to the method of stabilizing asphaltenes in bituminous li~uids to inhibit the formation of sludge and other precipitation products of asphaltenes and comprises 5 the addition to such bituminous liquids of an effective amount of at least about 50 parts per million enough to about 15,000 parts per million of 1 or more C-10 to C-20 aliphatic alcohol partial esters of phosphoric acid. These compositions, which are referred to for purposes of this 10 disclosure and the claims appended hereto as C-10 to C-20 aliphatic alcohol partial esters of phosphoric acid, are mixtures of mono- and di-substituted phosphoric acid of the formulas (RO)2PO2H and ROPO3H2 15 wherein R is selected from the group consisting of Clo to C20 aliphatic hydrocarbon chains and hydrogen, the compound including at least one such C-10 to C-20 hydrocarbon substituent and not more than two hydrogen substitutents.
These esters have a general formula (CnH2n+2O)x PO(OH~y wherein n, x and y are positive integers, n = 10 to 20, x = 1 or 2, y = 1 or 2, and x + y = 3.
Best Mode For Carrying Out the Invention The method of this invention is practiced by 25 adding to the bituminous liquid to be treated, e.g.
petroleum in the bearing formation or in a process stream, an effective amount of the C-10 to C-20 aliphatic alcohol partial esters of phosphoric acid. In oil bearing formations this addition would typically be made by forcing 30 such phosphoric acid partial esters downhole and into the petroleum bearing formation. This may be done either directly from the producing hole or from an adjacent injection hole. This treatment may be carried out in petroleum bearing formations where it is known that the 35 petroleum includes relatively unstable asphaltenes as a preventive measure. Similarly, the treatment is effective to stabilize and in some cases to improve production in formations in which some degree of plugging has occurred by the precipitation of asphaltenes.
In a process stream, addition may be made by combining the C-10 to C-20 aliphatic alcohol partial esters of phosphoric acid in an effective amount by injection into the stream by any convenient means. For example, the 5 injection can be accomplished through a Venturi port, by pumping the phosphoric acid partial ester into the stream, by mixing it in a vessel, etc. It is desirable to obtain complete mixing of the phosphoric acid partial ester into the bituminous liquid to obtain optimum stabilizing effect.
10 To this end, any convenient mixing mechanism or injection mechanism may be used. Incomplete mixing results in less efficient stabilization but may still give effective stabilization.
The compounds which are most suitable for use in 15 this invention are the C-10 to C-20 mono- and di-substituted phosphoric acid partial esters. In practice, mixtures of mono- and di-substituted partial esters are usually employed because it is impractical to drive the esterification reaction fully to completion. Decyl, undecyl, dodecyl, 20 tridecyl, tetradecyl, pentadecyl, hexadecyl, hep~adecyl, octadecyl, monadecyl and eicosanyl partial esters of phosphoric acid, and mixtures of these partial esters, mono-or di-substituted, are effectively employed in this invention. Higher aliphatic alcohol partial esters of 25 phosphoric acid may be equivalently employed but are not currently practically or economically employed because of the cost and lack of availability.
Mixtures of phosphoric acid partial esters may advantageously be employed in this invention. For example, 30 mixtures or hexadecyl phosphoric acid, mono- and di-substituted, and octadecyl phosphoric acid, mono- and di-substituted, or the mixed partial ester of hexadecyl and octadecyl alcohol and phosphoric acid are believed to exhibit optimum stabilizing effect.
In practice, it has been found that the reaction product of decyl alcohol, of tridecyl alcohol, of hexadecyl alcohol, and of octadecyl alcohol with phosphoric anhydride (4) have been established as effective stabilizers o asphaltenes in bituminous liquids. These results were ~L~4;~
established initially in the laboratory and have been confirmed in preliminary field tests. Laboratory testing of the procedures carried on by a spot test adapted from Oliensis t3).
In the spot test, a solvent which precipitates asphaltenes from oil is added in finite increments to a small sample of the oil until the asphaltenes precipitate.
The precipitation is detected by removing a drop of the mixture periodically from the bulk of the bituminous liquid 10 and placing it on a sheet of filter paper. When the paper is bakeA in an oven, the oil diffuses radially from the point of addition to give a uniform brown circle. Any asphaltenes which have precipitated by the added solvent will not move, however, and will appear a ring of darker 15 material, usually with a sharp outer boundary and a size roughly equal to the initial size of the drop. The volume of solvent needed to produce this "spot" is called the spot test number and is given in units of milliliters.
In carrying out the spot test, 5 grams of crude 20 oil, or other bituminous liquid, is weighed into a 50 ml.
beaker with a 0.05 g accuracy. This is titrated with hexadecane with stirrings. The hexadecane is added in 1 ml. increments for the first run of a new crude. The drop sample to be put on the filter paper is taken 30 seconds 25 after the addition of the solvent. Addition in this fashion is continued until an asphaltene spot is evident without baking. The paper is then placed in a 100C oven for 10 minutes. This preliminary run brackets the spot test to the nearest 1 ml. A second run is then made on a new sample 30 with 0.1 ml. additions of hexadecane, allowing the spot test number to be determined to the nearest 0.1 ml. For this reason, solvent may be added continuously up to 1.5 ml.
below the spot test volume which gave precipitation in the first run. Additional hexadecane is added in 0.1 ml.
35 increments.
When testing the phosphoric acid partial esters as stabilizing additives, the additive to be tested is weighed into a 50 ml. beaker before the oil is weighed in. The chemical is weighed to 0.1 mg. accuracy. The oil and the chemical are stirred for at lest 2 minutes before the spot test titration is commenced. In the case of solid treating agents, the mixture of bituminous liquid, e.g. petroleum, and the partial ester are warmed for 1 minute on a hot plate 5 just at the boiling point of water. The hot oil and melted chemical are then stirred 5 minutes as they cool. The spot test titration is then commenced in the usual fashion.
The following data show comparative results with the phosphoric acid derivatives of ethyl, decyl, tridecyl, 10 hexadecyl and octadecyl alcohol. The ethyl phosphoric acid and the tridecyl phosphoric acid were obtained commercially. The decyl, hexadecyl and octadecyl alcohol partial esters of phosphoric acid were prepared by reacting the respective alcohols with phosphorous pentoxide in a 15 ratio of 3 formula weights of alcohol to 1 formula weight of phosphorous pentoxide in each case.
The following tables demonstrate the effectiveness of these C-10 to C-20 aliphatic alcohol phosphoric acid partial esters in stabilizing asphaltenes. The first column 20 identifies the additive, the second column states the ratio of the additive to the bituminous liquid in parts per million, the third column indictes whether or not the oil was warmed to dissolve the additive, and the fourth test is numerically in milliliters and indicates the quantity of 25 precipitating solvent, hexadecane, require to initiate precipitation of asphaltenes in the bituminous liquid. The higher the number in the fourth column, the more stable the asphaltenes are, as indicated by the higher concentration of precipitating solvent required to bring about precipiration.
Table 1 Spot Test Results Crude No. 1 Untreated Warmed 3.2 *EPA 5120 ppm room temp 0.9 DPA 7500 ppm warmed 4.0 TDPA 8220 ppm warmed 4.4 IIDPA 6640 ppm warmed 5.6 HDPA 6388 ppm warmed 5.6 ODPA 7060 ppm warmed 6.3 ODPA 5993 ppm warmed 7.4 Untreated room temp 3.0 ~ot Table 2 {~g~ Test Results - Crude No. 2 Untreated room temp 4.2 EPA 9120 ppm room temp 1.5 Untreated warmed 3.8 DPA10 420 ppm warmed 4.2 MDPA9422 ppm warmed 5.8 TDPA7280 ppm warmed 4.4 ODPA5665 ppm warmed 6.4 Table 3 Spot Test Results - Crude No. 3 Untreated room temp 5.1 EPA10480 ppm room temp 2.1 TDPA7300 ppm room temp 6.2 15 Untreated warmed 5.0 DPA11320 ppm warmed 5.4 HDPA8020 ppm warmed 6.8 ODPA7595 ppm warmed 8.5 Table 4 Spot Test Results - Crude No. 4 Untreated room temp 3.4 EPA 5580 ppm room temp 1.8 TDPA14680 ppm room temp 4.3 DP~ 7260 ppm warmed 3.9 25 HDPA9504 ppm warmed 5.8 ODPA9254 ppm warmed 7.5 * EPA = ethyl phosphoric acid DPA = decyl phosphoric acid TDPA = tridecyl phosphoric acid HDPA = hexadecyl phosphoric acid ODPA = octadecyl phosphoric acid As the foregoing data demonstrates, the addition of lower aliphatic alcohol partial es~ers of phosphoric acid is 35 actually detrimental and tends to ~-stabilize the asphaltenes. When C-10 aliphatic alcohol phosphoric acid partial esters are added, there is a slight improvement in stability of the asphaltenes in the bituminous liquid. The most significant improvement in stability occurs in the 2~1~
hexadecyl (C-16) and octadecyl (C-18) aliphatic alcohol partial esters of phosphoric acid.
The phenomena observed with this range of phosphoric acid partial esters is not observed with other 5 classes of esters. For example, esters of sulEuric acid do not exhibit a comparable phenomena.
While the micelle theory of asphaltenes is fairly well established and is generally accepted, the exact physical and chemical structure of asphaltenes and the great 10 variability in chemical and physical characteristics of asphaltenes makes it impossible to define exactly why the C-10, or longer chain, aliphatic alcohol partial esters of phosphoric acid are uniquely and surprisingly effective in stabilizing asphaltenes. It is postulated that this 15 stability results from the formation of a stable peptizing layer around the asphaltene micelle. This is produced by partial protonation of the asphaltene by the alkyl phosphoric acid, followed by electrostatic attachment of the negatively charged alkyl phosphoric acid residue. In any 20 event, data establish that this unique result occurs only from the addition of the particular class of phosphoric acid partial esters described herein.
Industrial Application This invention finds application in petroleum 25 production, in petroleum refining, and in the production and refining of shale oils, and other bituminous liquids from whatever source derived, which include asphaltenes. The addition of C-10 to C-20 aliphatic alcohol phosphoric acid partial esters tends to stabilize asphaltenes in petroleum 30 and other bituminous liquids thereby increasing production and decreasing handling difficuties associated with these materials.
References The following works and the publications cited 35 therein are cited and incorporatcd hercin as background to the subject matter of the foregoing disclosure:
l. MODERN PETROLEUM TEC~INOLOGY, Hobson, ~.D., and Pohl! W., Eds., Applied Science Publishers, Ltd. (1973).
Z.~l~
_9_ 2. BITUMENS, ASPHALTS and TAR SANDS, Chilingarian, G.V. and Yen, T.F., Eds., Elsevier, New York 1978 Chapter 7, "Properties and Structure of Bitumens", Wen, C.S., Chilingarian, G.V., and Yen, T.F.
These esters have a general formula (CnH2n+2O)x PO(OH~y wherein n, x and y are positive integers, n = 10 to 20, x = 1 or 2, y = 1 or 2, and x + y = 3.
Best Mode For Carrying Out the Invention The method of this invention is practiced by 25 adding to the bituminous liquid to be treated, e.g.
petroleum in the bearing formation or in a process stream, an effective amount of the C-10 to C-20 aliphatic alcohol partial esters of phosphoric acid. In oil bearing formations this addition would typically be made by forcing 30 such phosphoric acid partial esters downhole and into the petroleum bearing formation. This may be done either directly from the producing hole or from an adjacent injection hole. This treatment may be carried out in petroleum bearing formations where it is known that the 35 petroleum includes relatively unstable asphaltenes as a preventive measure. Similarly, the treatment is effective to stabilize and in some cases to improve production in formations in which some degree of plugging has occurred by the precipitation of asphaltenes.
In a process stream, addition may be made by combining the C-10 to C-20 aliphatic alcohol partial esters of phosphoric acid in an effective amount by injection into the stream by any convenient means. For example, the 5 injection can be accomplished through a Venturi port, by pumping the phosphoric acid partial ester into the stream, by mixing it in a vessel, etc. It is desirable to obtain complete mixing of the phosphoric acid partial ester into the bituminous liquid to obtain optimum stabilizing effect.
10 To this end, any convenient mixing mechanism or injection mechanism may be used. Incomplete mixing results in less efficient stabilization but may still give effective stabilization.
The compounds which are most suitable for use in 15 this invention are the C-10 to C-20 mono- and di-substituted phosphoric acid partial esters. In practice, mixtures of mono- and di-substituted partial esters are usually employed because it is impractical to drive the esterification reaction fully to completion. Decyl, undecyl, dodecyl, 20 tridecyl, tetradecyl, pentadecyl, hexadecyl, hep~adecyl, octadecyl, monadecyl and eicosanyl partial esters of phosphoric acid, and mixtures of these partial esters, mono-or di-substituted, are effectively employed in this invention. Higher aliphatic alcohol partial esters of 25 phosphoric acid may be equivalently employed but are not currently practically or economically employed because of the cost and lack of availability.
Mixtures of phosphoric acid partial esters may advantageously be employed in this invention. For example, 30 mixtures or hexadecyl phosphoric acid, mono- and di-substituted, and octadecyl phosphoric acid, mono- and di-substituted, or the mixed partial ester of hexadecyl and octadecyl alcohol and phosphoric acid are believed to exhibit optimum stabilizing effect.
In practice, it has been found that the reaction product of decyl alcohol, of tridecyl alcohol, of hexadecyl alcohol, and of octadecyl alcohol with phosphoric anhydride (4) have been established as effective stabilizers o asphaltenes in bituminous liquids. These results were ~L~4;~
established initially in the laboratory and have been confirmed in preliminary field tests. Laboratory testing of the procedures carried on by a spot test adapted from Oliensis t3).
In the spot test, a solvent which precipitates asphaltenes from oil is added in finite increments to a small sample of the oil until the asphaltenes precipitate.
The precipitation is detected by removing a drop of the mixture periodically from the bulk of the bituminous liquid 10 and placing it on a sheet of filter paper. When the paper is bakeA in an oven, the oil diffuses radially from the point of addition to give a uniform brown circle. Any asphaltenes which have precipitated by the added solvent will not move, however, and will appear a ring of darker 15 material, usually with a sharp outer boundary and a size roughly equal to the initial size of the drop. The volume of solvent needed to produce this "spot" is called the spot test number and is given in units of milliliters.
In carrying out the spot test, 5 grams of crude 20 oil, or other bituminous liquid, is weighed into a 50 ml.
beaker with a 0.05 g accuracy. This is titrated with hexadecane with stirrings. The hexadecane is added in 1 ml. increments for the first run of a new crude. The drop sample to be put on the filter paper is taken 30 seconds 25 after the addition of the solvent. Addition in this fashion is continued until an asphaltene spot is evident without baking. The paper is then placed in a 100C oven for 10 minutes. This preliminary run brackets the spot test to the nearest 1 ml. A second run is then made on a new sample 30 with 0.1 ml. additions of hexadecane, allowing the spot test number to be determined to the nearest 0.1 ml. For this reason, solvent may be added continuously up to 1.5 ml.
below the spot test volume which gave precipitation in the first run. Additional hexadecane is added in 0.1 ml.
35 increments.
When testing the phosphoric acid partial esters as stabilizing additives, the additive to be tested is weighed into a 50 ml. beaker before the oil is weighed in. The chemical is weighed to 0.1 mg. accuracy. The oil and the chemical are stirred for at lest 2 minutes before the spot test titration is commenced. In the case of solid treating agents, the mixture of bituminous liquid, e.g. petroleum, and the partial ester are warmed for 1 minute on a hot plate 5 just at the boiling point of water. The hot oil and melted chemical are then stirred 5 minutes as they cool. The spot test titration is then commenced in the usual fashion.
The following data show comparative results with the phosphoric acid derivatives of ethyl, decyl, tridecyl, 10 hexadecyl and octadecyl alcohol. The ethyl phosphoric acid and the tridecyl phosphoric acid were obtained commercially. The decyl, hexadecyl and octadecyl alcohol partial esters of phosphoric acid were prepared by reacting the respective alcohols with phosphorous pentoxide in a 15 ratio of 3 formula weights of alcohol to 1 formula weight of phosphorous pentoxide in each case.
The following tables demonstrate the effectiveness of these C-10 to C-20 aliphatic alcohol phosphoric acid partial esters in stabilizing asphaltenes. The first column 20 identifies the additive, the second column states the ratio of the additive to the bituminous liquid in parts per million, the third column indictes whether or not the oil was warmed to dissolve the additive, and the fourth test is numerically in milliliters and indicates the quantity of 25 precipitating solvent, hexadecane, require to initiate precipitation of asphaltenes in the bituminous liquid. The higher the number in the fourth column, the more stable the asphaltenes are, as indicated by the higher concentration of precipitating solvent required to bring about precipiration.
Table 1 Spot Test Results Crude No. 1 Untreated Warmed 3.2 *EPA 5120 ppm room temp 0.9 DPA 7500 ppm warmed 4.0 TDPA 8220 ppm warmed 4.4 IIDPA 6640 ppm warmed 5.6 HDPA 6388 ppm warmed 5.6 ODPA 7060 ppm warmed 6.3 ODPA 5993 ppm warmed 7.4 Untreated room temp 3.0 ~ot Table 2 {~g~ Test Results - Crude No. 2 Untreated room temp 4.2 EPA 9120 ppm room temp 1.5 Untreated warmed 3.8 DPA10 420 ppm warmed 4.2 MDPA9422 ppm warmed 5.8 TDPA7280 ppm warmed 4.4 ODPA5665 ppm warmed 6.4 Table 3 Spot Test Results - Crude No. 3 Untreated room temp 5.1 EPA10480 ppm room temp 2.1 TDPA7300 ppm room temp 6.2 15 Untreated warmed 5.0 DPA11320 ppm warmed 5.4 HDPA8020 ppm warmed 6.8 ODPA7595 ppm warmed 8.5 Table 4 Spot Test Results - Crude No. 4 Untreated room temp 3.4 EPA 5580 ppm room temp 1.8 TDPA14680 ppm room temp 4.3 DP~ 7260 ppm warmed 3.9 25 HDPA9504 ppm warmed 5.8 ODPA9254 ppm warmed 7.5 * EPA = ethyl phosphoric acid DPA = decyl phosphoric acid TDPA = tridecyl phosphoric acid HDPA = hexadecyl phosphoric acid ODPA = octadecyl phosphoric acid As the foregoing data demonstrates, the addition of lower aliphatic alcohol partial es~ers of phosphoric acid is 35 actually detrimental and tends to ~-stabilize the asphaltenes. When C-10 aliphatic alcohol phosphoric acid partial esters are added, there is a slight improvement in stability of the asphaltenes in the bituminous liquid. The most significant improvement in stability occurs in the 2~1~
hexadecyl (C-16) and octadecyl (C-18) aliphatic alcohol partial esters of phosphoric acid.
The phenomena observed with this range of phosphoric acid partial esters is not observed with other 5 classes of esters. For example, esters of sulEuric acid do not exhibit a comparable phenomena.
While the micelle theory of asphaltenes is fairly well established and is generally accepted, the exact physical and chemical structure of asphaltenes and the great 10 variability in chemical and physical characteristics of asphaltenes makes it impossible to define exactly why the C-10, or longer chain, aliphatic alcohol partial esters of phosphoric acid are uniquely and surprisingly effective in stabilizing asphaltenes. It is postulated that this 15 stability results from the formation of a stable peptizing layer around the asphaltene micelle. This is produced by partial protonation of the asphaltene by the alkyl phosphoric acid, followed by electrostatic attachment of the negatively charged alkyl phosphoric acid residue. In any 20 event, data establish that this unique result occurs only from the addition of the particular class of phosphoric acid partial esters described herein.
Industrial Application This invention finds application in petroleum 25 production, in petroleum refining, and in the production and refining of shale oils, and other bituminous liquids from whatever source derived, which include asphaltenes. The addition of C-10 to C-20 aliphatic alcohol phosphoric acid partial esters tends to stabilize asphaltenes in petroleum 30 and other bituminous liquids thereby increasing production and decreasing handling difficuties associated with these materials.
References The following works and the publications cited 35 therein are cited and incorporatcd hercin as background to the subject matter of the foregoing disclosure:
l. MODERN PETROLEUM TEC~INOLOGY, Hobson, ~.D., and Pohl! W., Eds., Applied Science Publishers, Ltd. (1973).
Z.~l~
_9_ 2. BITUMENS, ASPHALTS and TAR SANDS, Chilingarian, G.V. and Yen, T.F., Eds., Elsevier, New York 1978 Chapter 7, "Properties and Structure of Bitumens", Wen, C.S., Chilingarian, G.V., and Yen, T.F.
3. "A Qualitative Test for Determining the Degree of Heterogeneity of Asphalts", Oliensis, G.L., American Socity for Testing Materials Proceedings, V. 33, Part II
(1933) pp. 715-728.
(1933) pp. 715-728.
4. ADVANCED INORGANIC CHEMISTRY, Cotton, F.A., and 10 Wilkinson, G., Interscience, John Wiley & Sons, New York, 1972, see e.g. p. 382.
Claims (12)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. The method of stabilizing asphaltenes in bitu-minous liquids to inhibit formation of sludge and other preci-pitation products of asphaltenes comprising the addition to such bituminous liquids of an effective amount of from about 50 to about 15,000 parts per million of one or more C-10 to C-20 aliphatic alcohol partial esters of phosphoric acid.
2. The method of stabilizing asphaltenes in bitu-minous liquids to inhibit formation of sludge and other preci-pitation products of asphaltene comprising the combination with such bituminous liquid of an effective amount of at least about 50 parts per million of phosphoric acid partial ester of the type resulting from the reaction of one or more C-10 to C-20 aliphatic alcohols with phosphoric acid anhydride.
3. The method of stabilizing asphaltenes in bitu-minous liquids to inhibit formation of sludge and other preci-pitation products of asphaltene comprising the combination with such bituminous liquid of an effective amount of from about 50 to about 15,000 parts per million of phosphoric acid partial ester of the type resulting from the reaction of one or more C-10 to C-20 aliphatic alcohols with phosphoric acid anhydride, having the general formula (CnH2n+2)xPO(OH)y wherein n, x and y are positive integers, n = 10 to 20, x = 1 or 2, and y = 1 to 2, and x plus y = 3.
4. The method of stabilizing asphaltenes in bituminous liquids to inhibit formation of sludge and other precipitation products of asphaltenes comprising the addition to such bituminous liquids of an effective amount of from about SO to about 15,000 parts per million of one or more C-16 to C-18 aliphatic alcohol partial esters of phosphoric acid.
5. The method of stabilizing asphaltenes in bituminous liquids to inhibit formation of sludge and other precipitation products of asphaltene comprising the com-bination with such bituminous liquid of an effective amount of at least about 50 parts per million of phosphoric acid partial ester of the type resulting from the reaction of one or more C-16 to C-18 aliphatic alcohols with phos-phoric acid anhydride.
6. The method of stabilizing asphaltenes in bituminous liquids to inhibit formation of sludge and other precipitation products of asphaltene comprising the com-bination with such bituminous liquid of an effective amount of from about 50 to about 15,000 parts per million of phosphoric acid partial ester of the type resulting from the reaction of one or more C-16 to C-18 aliphatic alcohols with phosphoric acid anhydride, having the general formula (CnH2n+2O)xPO(OH)y wherein n, x and y are positive integers, n = 16 to 18, x = 1 to 2, and y = 1 to 2, and x plus y = 3.
7. In the oil field production of petroleum from oil bearing formation, the improvement of stabilizing asphaltenes in bituminous liquids comprising injecting into the petroleum in the oil bearing formation an effective amount of from about 50 to about 15,000 parts per million of one or more C-10 to C-20 aliphatic alcohol partial esters of phosphoric acid.
8. In the oil field production of petroleum from oil bearing formation, the improvement of stabilizing asphaltenes in bituminous liquids comprising injecting in-to the petroleum in the oil bearing formation an effective amount of from about 50 to about 15,000 parts per million of phosphoric acid partial ester of the type resulting from the reaction of one or more C-10 to C-20 aliphatic alcohols with phosphoric acid anhydride, having the general formula (CnH2n+2O)xPO(OH)y wherein n, x and y are positive integers, n = 10 to 20, x = 1 or 2, and y = 1 or 2, and x plus y = 3.
9. In the oil field production of petroleum from oil bearing formation, the improvement of stabilizing asphaltenes in bituminous liquids comprising injecting into the petroleum in the oil bearing formation an effec-tive amount of from about 50 to about 15,000 parts per million of phosphoric acid partial ester of the type re-sulting from the reaction of one or more C-16 to C-18 aliphatic alcohols with phosphoric acid anhydride, having the general formula (CnH2n+2O)xPO(OH)y wherein n, x and y are positive integers, n = 16 to 18, x = 1 or 2, and y = 1 or 2, and x plus y = 3.
10. In the production of petroleum, the improve-ment comprising preventing deposition of asphaltenes on production valves, pump impellers and conduits used in petroleum production by mixing with said petroleum an effective amount of from about 50 to about 15,000 parts per million of one or more C-10 to C-20 aliphatic alcohol partial esters of phosphoric acid.
11. In the production of petroleum, the improve-ment comprising preventing deposition of asphaltenes on production valves, pump impellers and conduits used in petroleum production by mixing with said petroleum an effective amount of from about 50 to about 15,000 parts per million of phosphoric acid partial ester of the type re-sulting from the reaction of one or more C-10 to C-20 aliphatic alcohols with phosphoric acid anhydride, having the general formula (CnH2n+2O)xPO(OH)y wherein n, x, and y are positive integers, n = 10 to 20, x = 1 or 2, and y = 1 or 2, and x plus y = 3.
12. In the production of petroleum, the improve-ment comprising preventing deposition of asphaltenes on production valves, pump impellers and conduits used in petroleum production by mixing with said petroleum an effective amount of from about 50 to about 15,000 parts per million of phosphoric acid partial ester of the type resulting from the reaction of one or more C-16 to C-18 aliphatic alcohols with phosphoric acid anhydride, having the general formula (CnH2n+2O)xPO (OH)y wherein n, x, and y are positive integers, n = 16 to 18, x = 1 or 2, and y = 1 or 2, and x plus y = 3.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US7016379A | 1979-08-27 | 1979-08-27 | |
| US070,163 | 1979-08-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1142114A true CA1142114A (en) | 1983-03-01 |
Family
ID=22093540
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000358195A Expired CA1142114A (en) | 1979-08-27 | 1980-08-13 | Method of inhibiting precipitation of asphaltenes |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1142114A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3511760A1 (en) * | 1985-03-30 | 1986-10-02 | Akzo Gmbh, 5600 Wuppertal | AGENT AGAINST FELLING AND DEPOSITING ASPHALTED AND THE LIKE |
| US5133781A (en) * | 1990-12-21 | 1992-07-28 | Texaco Inc. | Compatibilization of asphaltenes in bituminous liquids using bulk phosphoalkoxylation |
| US6204420B1 (en) | 1998-06-25 | 2001-03-20 | Clariant Gmbh | Synergistic mixtures of phosphoric esters with carboxylic acids or carboxylic acid derivatives as asphaltene dispersants |
-
1980
- 1980-08-13 CA CA000358195A patent/CA1142114A/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3511760A1 (en) * | 1985-03-30 | 1986-10-02 | Akzo Gmbh, 5600 Wuppertal | AGENT AGAINST FELLING AND DEPOSITING ASPHALTED AND THE LIKE |
| US5133781A (en) * | 1990-12-21 | 1992-07-28 | Texaco Inc. | Compatibilization of asphaltenes in bituminous liquids using bulk phosphoalkoxylation |
| US6204420B1 (en) | 1998-06-25 | 2001-03-20 | Clariant Gmbh | Synergistic mixtures of phosphoric esters with carboxylic acids or carboxylic acid derivatives as asphaltene dispersants |
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