WO2014015892A1 - Abaissement du point de congélation en traitement de gaz ou de pétrole à l'aide de solvants mélangés - Google Patents

Abaissement du point de congélation en traitement de gaz ou de pétrole à l'aide de solvants mélangés Download PDF

Info

Publication number
WO2014015892A1
WO2014015892A1 PCT/EP2012/064444 EP2012064444W WO2014015892A1 WO 2014015892 A1 WO2014015892 A1 WO 2014015892A1 EP 2012064444 W EP2012064444 W EP 2012064444W WO 2014015892 A1 WO2014015892 A1 WO 2014015892A1
Authority
WO
WIPO (PCT)
Prior art keywords
glycol
gas
mixture
freezing point
monothylene
Prior art date
Application number
PCT/EP2012/064444
Other languages
English (en)
Inventor
Lars Henrik Gjertsen
Baard Kaasa
Gry Pedersen KOJEN
Even SOLBRAA
Kjersti Omdahl CHRISTENSEN
Georgios FOLAS
Original Assignee
Statoil Petroleum As
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Statoil Petroleum As filed Critical Statoil Petroleum As
Priority to PCT/EP2012/064444 priority Critical patent/WO2014015892A1/fr
Publication of WO2014015892A1 publication Critical patent/WO2014015892A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L3/00—Gaseous fuels; Natural gas; Synthetic natural gas obtained by processes not covered by subclass C10G, C10K; Liquefied petroleum gas
    • C10L3/06—Natural gas; Synthetic natural gas obtained by processes not covered by C10G, C10K3/02 or C10K3/04
    • C10L3/10—Working-up natural gas or synthetic natural gas
    • 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
    • C09K8/52—Compositions for preventing, limiting or eliminating depositions, e.g. for cleaning
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L1/00—Liquid carbonaceous fuels
    • C10L1/02—Liquid carbonaceous fuels essentially based on components consisting of carbon, hydrogen, and oxygen only
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L3/00—Gaseous fuels; Natural gas; Synthetic natural gas obtained by processes not covered by subclass C10G, C10K; Liquefied petroleum gas
    • C10L3/06—Natural gas; Synthetic natural gas obtained by processes not covered by C10G, C10K3/02 or C10K3/04
    • C10L3/10—Working-up natural gas or synthetic natural gas
    • C10L3/101—Removal of contaminants
    • C10L3/106—Removal of contaminants of water
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L3/00—Gaseous fuels; Natural gas; Synthetic natural gas obtained by processes not covered by subclass C10G, C10K; Liquefied petroleum gas
    • C10L3/06—Natural gas; Synthetic natural gas obtained by processes not covered by C10G, C10K3/02 or C10K3/04
    • C10L3/10—Working-up natural gas or synthetic natural gas
    • C10L3/107—Limiting or prohibiting hydrate formation
    • 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
    • C09K2208/00—Aspects relating to compositions of drilling or well treatment fluids
    • C09K2208/22—Hydrates inhibition by using well treatment fluids containing inhibitors of hydrate formers
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
    • C10G2300/20—Characteristics of the feedstock or the products
    • C10G2300/30—Physical properties of feedstocks or products
    • C10G2300/304—Pour point, cloud point, cold flow properties

Definitions

  • the present invention relates to the use of mixed solvents in gas or oil processing systems to depress the freezing point of said systems.
  • Freezing the formation of ice or solid solvent
  • hydrate formation is a major problem in oil and gas production and processing systems such as dew point control in the transport of gas, various oil and gas processing systems in which a cooling medium is used and contacting units for drying gas.
  • freezing will be used to describe the formation of ice, the formation of pure solid solvents at low temperature such as solid alcohol or glycol or the formation of mixed solid complexes, for example the solid monoethylene glycol - water complex at low temperatures.
  • the most common method to help prevent freezing is by the addition of a thermodynamic inhibitor (a freezing point inhibitor) such as an alcohol (e.g. methanol or ethanol) or a glycol (e.g. monothylene glycol or triethylene glycol).
  • a freezing point inhibitor such as an alcohol (e.g. methanol or ethanol) or a glycol (e.g. monothylene glycol or triethylene glycol).
  • the injected monothylene glycol has a concentration of 80 wt% monothylene glycol and 20 wt% water, and after the process it is 78 wt% monothylene glycol and 22 wt% water. Outside this narrow concentration range water or monoethylene glycol can form solid.
  • glycols such as monoethylene glycol or triethylene glycol used to prevent freezing during gas processing have high freezing points and if the concentration of the inhibitor is too high, solid inhibitor may form and plug the equipment.
  • thermodynamic background If two different components A and B have different freezing points Ta, Tb, a mixture of them will in general have a lower freezing point than the pure components.
  • Component A might have, for example, a freezing point of -5°C while component B might have a freezing point of -15°C. If one starts with pure A, and then starts to mix in B, the freezing temperature is reduced. The same happens if we start with B and mix in some A. At some specific ratio of A and B, the two freezing curves meet. Below this point, only solid is present.
  • the reason why the freezing point is reduced is mainly because the components are diluted, i.e. the mole fraction is reduced.
  • the slope of the freezing curve is determined by the enthalpy of freezing for the various solids.
  • the phase diagram can be more complex if A and B can form new components, for example AB, A 2 B, or AB 2 .
  • An example of this is the use of monothylene glycol as an antifreeze agent in water.
  • the phase diagram for this is even more complex because an intermediate solid complex phase is being formed. The formation of these intermediate solid complex phases together with the limitations generated by the hydrate lines and the formation of solid inhibitor once the specific ratio of
  • the present inventors have addressed the problem of freezing in gas or oil processing systems through the discovery that mixed solvents can be used to depress the freezing point much further in said gas or oil processing systems, compared to the use of a single inhibitor.
  • a method for the depression of the freezing point in a gas or oil processing system by the use of a freezing point inhibitor characterised in that said freezing point inhibitor consists solely of a mixture of two different glycols.
  • a pure glycol acting as a freezing point inhibitor e.g. monothylene glycol
  • a mixture of glycols e.g. monothylene glycol and triethylene glycol
  • the freezing temperature of the inhibitor itself is reduced compared to either of the inhibitors alone, it is possible to operate at a higher inhibitor concentration without solid inhibitor being formed.
  • the inhibitor concentration is increased, the ice formation temperature and hydrate formation temperature is reduced.
  • the safe operational area for natural gas-water-inhibitor systems can be extended to lower temperatures and higher inhibitor concentrations by use of a mixed solvent inhibitor compared to the use of single inhibitors, giving a much wider safe operational window.
  • Lower temperatures because we avoid the formation of solid complexes and higher inhibitor concentrations because we are depressing the inhibitor solidus line.
  • a freezing point inhibitor that consists solely of a mixture of two different glycols in accordance with the present invention will work more or less identically as a pure inhibitor consisting of just one glycol with respect to hydrate inhibition for the same total amount of inhibitor, with the freezing temperature of hydrate being practically unaffected.
  • a freezing point inhibitor that consists solely of a mixture of two different glycols in accordance with the present invention has a lower freezing point and it is therefore possible to increase the inhibitor concentration without it freezing out as a pure solid (monoethylene- or triethylene glycol) or intermediate solid phase in the presence of water and hence operate at lower temperatures.
  • Preferred methods of the present invention include the method according to the present invention as defined above, wherein said freezing point inhibitor consists solely of a mixture of two different glycols selected from the group consisting of monothylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol and tetraethylene glycol; more preferably it is selected from monothylene glycol, diethylene glycol and triethylene glycol; and most preferably the freezing point inhibitor consists of a mixture of monothylene glycol and triethylene glycol.
  • said freezing point inhibitor consists solely of a mixture of two different glycols selected from the group consisting of monothylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol and tetraethylene glycol; more preferably it is selected from monothylene glycol, diethylene glycol and triethylene glycol; and most preferably the freezing point inhibitor consists of a mixture of monothylene glycol and triethylene glycol.
  • said gas or oil production system is a system for low temperature gas processing.
  • said freezing point inhibitor that consists solely of a mixture of two different glycols inhibits the formation of ice and hydrates in said system for the low temperature processing of gas.
  • low temperature gas processing is the processing of natural gas at low temperatures to remove water or liquid hydrocarbon (so-called dew point control), e.g. at temperatures of -20 °C to -30 °C under the application of pressure.
  • dew point control e.g. at temperatures of -20 °C to -30 °C under the application of pressure.
  • the composition of the gas must be adjusted so that the condensation of water or a liquid hydrocarbon phase does not occur, even if the gas is exposed to very low temperatures.
  • a typical requirement for export gas is be that its dew point is below -10°C at 5,000 kPa.
  • One option to obtain this is to cool the gas to -10°C at 5,000 kPa and remove whatever condenses at this temperature. At -10°C freezing is easy to avoid by, for example, the addition of monothylene glycol.
  • the dew point control is done at a much higher pressure to save energy, and it is then necessary to go to much lower temperatures.
  • the gas is cooled to -26°C at 6,700 kPa.
  • This operational temperature is very close to the limits of hydrate formation (too little monothylene glycol) or solid monothylene glycol formation (too high monothylene glycol concentration).
  • the monothylene glycol concentration is only allowed to vary between 78-80 wt%. This means that 80 wt% monothylene glycol -water mixture is injected before cooling, and due to water condensation, the monothylene glycol concentration is reduced to 78 wt%.
  • a single freezing point inhibitor such as monoethylene glycol is replaced with a freezing point inhibitor that consists solely of a mixture of two different glycols such as a mixture that consists of monoethylene glycol and triethylene glycol.
  • a monoethylene glycol-triethylene glycol mixture consisting of approximately 75 mole% monoethylene glycol and 25 mole% triethylene glycol has a freezing point of around -30 °C. As this freezing temperature is below the
  • this mixture can therefore be used during gas processing in accordance with the first preferred aspect of the present invention without any danger of the mixture of glycols freezing out. Adjustment of the relative amounts of the two glycols allows mixtures with different freezing points to be obtained which are suitable for the desired temperature to which the gas is cooled. Furthermore, when the mixture of glycols in accordance with the present invention mixes with condensed water, the freezing point of the ternary system will be further reduced.
  • Particularly preferred embodiments of this first particularly preferred aspect of the method of the present invention include the following.
  • said freezing point inhibitor that consists solely of a mixture of two different glycols which inhibits the formation of ice and hydrates in said system is selected from the group consisting of monothylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol and tetraethylene glycol; more preferably it is selected from monothylene glycol, diethylene glycol and triethylene glycol; and most preferably the freezing point inhibitor is a mixture of monothylene glycol and triethylene glycol.
  • a method according to the above second particularly preferred embodiment of the first particularly preferred aspect of the present invention wherein the mole ratio of monothylene glycohtriethylene glycol is from 80:20 to 20:80, more preferably from 50:50 to 70:30, and most preferably from 65:35.
  • a method according to the above first particularly preferred aspect of the present invention wherein the use of said mixture of two different glycols prevents the formation of a solid intermediate comprising water and one or both of said glycols.
  • said gas or oil processing system is a low temperature gas or oil processing system operating at temperatures of at least -50 ' ⁇ in which a cooling medium is used, said cooling medium comprising a mixture of water and said freezing point inhibitor that consists solely of a mixture of two different glycols.
  • the gas or oil production system is a gas system.
  • the water- monothylene glycol system has a minimum liquid temperature of approximately - 50 ' ⁇ and a water-triethylene glycol system has a minimum liquid temperature of approximately -65 °C.
  • these low temperatures can only be obtained in a narrow concentration range.
  • the present inventors have found that if a single glycol in accordance with the prior art is replaced by a mixture consisting solely of a mixture of two different glycols, the freezing point is reduced significantly and the concentration range is significantly wider. If, for example, a mixture of glycols is used consisting of monothylene glycol and triethylene glycol in which the monothylene glycol/triethylene glycol mixture contains 50-75 mole% monothylene glycol, the present inventors have found that the temperature of the resulting cooling medium can be reduced to as low as -70 to -85 ' ⁇ .
  • the cooling medium can be used to significantly lower temperatures in the system.
  • a mixture of glycols such as a mixture consisting solely of a mixture of monothylene glycol/triethylene glycol
  • the cooling medium can be used to significantly lower temperatures in the system.
  • said freezing point inhibitor that consists solely of a mixture of two different glycols is selected from the group consisting of monothylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol and tetraethylene glycol; more preferably it is selected from monothylene glycol, diethylene glycol and triethylene glycol; and most preferably the freezing point inhibitor consists of a mixture of monothylene glycol and triethylene glycol.
  • mol ratio of monothylene glycohtriethylene glycol is from 80:20 to 20:80, more preferably from 50:50 to 70:30, and most preferably from 65:35.
  • the above second particularly preferred aspect wherein the mol ratios of water:monothylene glycohtriethylene glycol in said cooling medium are in the range 60-40:25-35:15-25 respectively, preferably in the range 55:30:15 to 45:35:20 and most preferably the mol ratio is 50:32.5:17.5.
  • said gas or oil processing system is a contacting unit for drying gas, wherein said freezing point inhibitor that consists solely of a mixture of two different glycols is used to remove water from said gas.
  • Gas is dried before it is exported.
  • a common method to dry gas is to use what is a contacting unit.
  • a particularly common example of this in the art is called a triethylene glycol contactor.
  • Gas is mixed with triethylene glycol, normally in a counter flowing column. Close to pure triethylene glycol is added at the top of the column and as it comes into contact with the gas it extracts water out of the gas.
  • the triethylene glycol is then taken out at the bottom of the column and regenerated by heating so that the water evaporates. This is possible because the boiling point of triethylene glycol is 285 °C while that of water is 100°C.
  • the dry regenerated triethylene glycol is then reused and circulated back to the contactor.
  • Typical operation conditions for a contactor are 30 ' ⁇ .
  • Typical requirements for a triethylene glycol drying process are that the water content of the gas is so low that water will not start to condense before below -18 ⁇ € at 6,900 kPa.
  • a limitation relating to lowering the temperature limit for operation of a triethylene glycol contacting unit would be the freezing point of triethylene glycol. If the triethylene glycol is replaced by the said freezing point inhibitor being a mixture of triethylene glycol and monoethylene glycol, the contacting unit can be operated at lower temperatures and thereby obtain a more efficient removal of water.
  • the gas In cases where the natural gas to be treated is at low temperature, the gas has to be heated before entering the triethylene glycol contactor unit.
  • the energy requirement for heating the gas can be high, and it will be positive if the contacting temperature can be reduced.
  • the use of a mixture of monoethylene- and triethylene glycol will enable the operation of the counter flow contacting unit at very low temperatures.
  • Particularly preferred embodiments of this third particularly preferred aspect of the method of the invention which may be used in combination as well as individually, include the following.
  • said freezing point inhibitor that consists solely of a mixture of two different glycols is selected from the group consisting of monothylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol and tetraethylene glycol; more preferably it is selected from monothylene glycol, diethylene glycol and triethylene glycol; and most preferably the freezing point inhibitor consists of a mixture of monothylene glycol and triethylene glycol.
  • a method according to the above third particularly preferred aspect wherein the use of a freezing point inhibitor that consists solely of a mixture of two different glycols to remove water from said gas in said contacting unit enables the water to be removed at a lower temperature than is possible with either of the glycols alone when used as the freezing point inhibitor for this purpose.
  • Figure 1 is a solid-liquid diagram for a binary system of two components A and B (plot of temperature v. mol%);
  • Figure 2 is a solid-liquid diagram for monoethylene glycol-water binary mixtures (plot of temperature v. wt%);
  • Figure 3 is the same diagram as Figure 2, but this time including typical natural gashydrate line;
  • Figure 4 is a solid-liquid diagram for triethylene glycol-water binary mixtures (plot of temperature v. mol%);
  • Figure 5 is a solid liquid diagram for triethylene glycol-monoethylene glycol binary mixtures (plot of temperature v. mol fraction);
  • Figure 6 is a theoretical phase diagram for hydrate inhibitor-water, wherein the hydrate inhibitors are triethylene glycol, monoethylene glycol (alone and in combination) (plot of temperature v. water mol. fraction);
  • Figure 7 is a theoretical calculated phase diagram of the solid-liquid diagram for hydrate inhibitor-water, wherein the hydrate inhibitors are triethylene glycol, monoethylene glycol (alone and in combination) (plot of temperature v. water mol. fraction); and
  • Figure 8 is a theoretical calculated phase diagram for hydrate inhibitor-water, wherein the hydrate inhibitors are triethylene glycol, monoethylene glycol (alone and in combination) (plot of temperature v. water mol. fraction).
  • Figure 9 is a simplified process diagram for a dew point control unit.
  • Figure 10 is a simplified drawing of a counter flowing absorber column.
  • Freezing is a major problem during oil and gas production and processing.
  • the most common method to date to avoid freezing is to add an antifreeze agent such as an alcohol (e.g. methanol or ethanol) or a glycol
  • FIG. 1 A typical application of a mixture of water and one antifreeze agent is for example the cooling system in a car engine. This is illustrated in Figure 1 , where the lines with square dots show the freezing curves (i.e. solid liquid equilibrium of Solid A with the liquid mixture, or solid B with the liquid mixture). Pure A freezes out at -5°C while component B has a freezing point of - ⁇ ⁇ ' ⁇ . If one starts with pure A, and then starts to mix in B, the freezing temperature is reduced, e.g.
  • the phase diagram can be more complex if A and B can form new components, for example AB, A 2 B, or AB 2 .
  • a and B can form new components, for example AB, A 2 B, or AB 2 .
  • One example where this can occur is with the use of monothylene glycol as an antifreeze agent.
  • the phase diagram is even more complex compared to that shown in Figure 1 , because an intermediate solid complex phase is being formed. This is illustrated in Figure 2, which shows the freezing diagram of the binary monothylene glycol - water system.
  • the solid complex phase with a temperature maximum at approximately 50% monothylene glycol
  • an antifreeze agent such as monothylene glycol or triethylene glycol
  • gas and oil processing such as offshore processing platforms where gas temperature is reduced to sub-zero values, e.g. in order to condense and separate heavy hydrocarbons and meet the dew point specification (the process commonly known as dew point control, see Figure 9).
  • dew point control see Figure 9
  • natural gas (1 ) is transported via a pipeline and arrives to the processing facilities at 100 bar and 10°C.
  • a glycol-water mixture (2) e.g. an 80 wt. %
  • the injected monothylene glycol has a concentration of 80 wt% monothylene glycol, 20 wt% water, and after the process it is 78 wt% monothylene glycol, 22 wt% water.
  • the narrow operating range results in unplanned shutdowns due to solid formation.
  • the narrow operating widows are further illustrated in Figure 3.
  • the line on the right hand side of the diagram (solid black line with open squares) is the freezing curve of pure monothylene glycol solid.
  • the dashed line with closed black squares on the left hand side is the hydrate formation curve of a typical natural gas system. That forms a triangle between those lines which provides the safe operating window (see densely spotted area). This illustrates how tightly the safe operational area is limited by the relatively low freezing points, the hydrate formation lines and the formation of the intermediate solid complex.
  • a mixture of 50-50% mole monoethylene glycol and triethylene glycol enables trouble-free operation at much lower temperatures compared to the case that only one antifreeze agent is used, as the dashed (short and long dashes) black lines for pure monoethylene glycol or pure triethylene glycol freezing have been shifted to much lower temperatures (reference thick solid line on the left hand side of the figure).
  • the optimum concentration is a mixture of 65-35% mol monoethylene glycol— triethylene glycol respectively, which starts freezing at around -35°C.
  • the long-dashed line shows the phase diagram for water-monoethylene glycol, which is the same as in Figure 6.
  • the densely spotted triangle is the same as in Figure 3 which shows the safe operating area for a water-monoethylene glycol- hydrate system.
  • the triangle is expanded to the broader rhombus by the addition of the area marked out with the area that is more sparsely dotted.
  • the hydrate line is indicated as the thick solid line.
  • Figure 10 shows a simplified drawing of a counter flowing absorber column. This is used to dry the gas before it is exported.
  • natural gas (7) is fed via an inlet into the bottom of the counter current absorber column (8).
  • a typical prior art example of such an absorber column is a so-called triethylene glycol contactor, in which the gas is mixed with triethylene glycol which is fed into the counter current absorber column via inlet (9) at the top of the column. Close to pure triethylene glycol is added at the top of the column and as it comes into contact with the gas it extracts water out of the gas.
  • the triethylene glycol is then taken out at the bottom of the column via outlet (1 1 ) and regenerated by heating so that the water evaporates, while the dehydrated natural gas is removed via outlet (10) at the top of the absorber column. This is possible because the boiling point of triethylene glycol is 285 °C while that of water is 100 °C.
  • the dry regenerated triethylene glycol is then reused and circulated back to the contactor.
  • Typical operation conditions for a contactor are 30 ' ⁇ .
  • Typical requirements for a triethylene glycol drying process are that the water content of the gas is so low that water will not start to condense before below -18°C at 6,900 kPa. Being able to obtain the required dew point of - ⁇ ⁇ ' ⁇ at 6,900 kPa requires that the triethylene glycol has very high purity when the contactor is operated at a
  • a limitation relating to lowering the temperature limit for operation of a triethylene glycol contacting unit would be the freezing point of triethylene glycol. If the triethylene glycol is replaced by a freezing point inhibitor comprising a mixture of glycols such as a mixture of triethylene glycol and monoethylene glycol in accordance with the invention, the contacting unit can be operated at lower temperatures and thereby obtain a more efficient removal of water.
  • the gas In cases where the natural gas to be treated is at low temperature, the gas has to be heated before entering the triethylene glycol contactor unit.
  • the energy requirement for heating the gas can be high, and it will be positive if the contacting temperature can be reduced.
  • the use of a mixture of monoethylene- and triethylene glycol will enable the operation of the counter flow contacting unit at very low temperatures.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Materials Engineering (AREA)
  • Fuel Cell (AREA)

Abstract

L'invention porte sur un procédé pour l'abaissement du point de congélation dans un système de traitement de gaz ou de pétrole à l'aide d'un inhibiteur de congélation, caractérisé en ce que ledit inhibiteur de congélation est constitué uniquement d'un mélange de deux glycols différents. Ceci est particulièrement utile quand la congélation est un problème majeur dans des systèmes de production et de traitement de pétrole et de gaz tels que des systèmes de réglage du point de rosée dans le transport de gaz, divers systèmes de traitement de pétrole et de gaz dans lesquels un fluide frigorigène est utilisé et des unités de mise en contact pour le séchage de gaz.
PCT/EP2012/064444 2012-07-23 2012-07-23 Abaissement du point de congélation en traitement de gaz ou de pétrole à l'aide de solvants mélangés WO2014015892A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/EP2012/064444 WO2014015892A1 (fr) 2012-07-23 2012-07-23 Abaissement du point de congélation en traitement de gaz ou de pétrole à l'aide de solvants mélangés

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/EP2012/064444 WO2014015892A1 (fr) 2012-07-23 2012-07-23 Abaissement du point de congélation en traitement de gaz ou de pétrole à l'aide de solvants mélangés

Publications (1)

Publication Number Publication Date
WO2014015892A1 true WO2014015892A1 (fr) 2014-01-30

Family

ID=46545813

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2012/064444 WO2014015892A1 (fr) 2012-07-23 2012-07-23 Abaissement du point de congélation en traitement de gaz ou de pétrole à l'aide de solvants mélangés

Country Status (1)

Country Link
WO (1) WO2014015892A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105623767A (zh) * 2016-01-11 2016-06-01 天津大学 油包水乳液相变换热的气体水合物制备方法
US10563496B2 (en) 2014-05-29 2020-02-18 Equinor Energy As Compact hydrocarbon wellstream processing

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3857686A (en) 1971-02-08 1974-12-31 Dow Chemical Co Glycol-butyrolactone mixtures
US5084074A (en) * 1990-12-31 1992-01-28 Atlantic Richfield Company Method and apparatus for separating and recovering water and light aromatic hydrocarbons from a gaseous stream
US6955705B1 (en) * 2004-06-02 2005-10-18 Rdc Research Llc Method and system for compressing and dehydrating wet natural gas produced from low-pressure wells
WO2012141824A1 (fr) * 2011-04-15 2012-10-18 Exxonmobil Chemical Patents Inc. Procédé et appareil de gestion de la formation d'hydrates dans le traitement d'un courant d'hydrocarbures

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3857686A (en) 1971-02-08 1974-12-31 Dow Chemical Co Glycol-butyrolactone mixtures
US5084074A (en) * 1990-12-31 1992-01-28 Atlantic Richfield Company Method and apparatus for separating and recovering water and light aromatic hydrocarbons from a gaseous stream
US6955705B1 (en) * 2004-06-02 2005-10-18 Rdc Research Llc Method and system for compressing and dehydrating wet natural gas produced from low-pressure wells
WO2012141824A1 (fr) * 2011-04-15 2012-10-18 Exxonmobil Chemical Patents Inc. Procédé et appareil de gestion de la formation d'hydrates dans le traitement d'un courant d'hydrocarbures

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
CAMPBELL J M: "Chapter 18 : Absorbtion dehydration", 1 January 1974, GAS CONDITIONING AND PROCESSING 3RD ED, PETRO TECH LTD, US, PAGE(S) 293 - 302, XP008161619 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10563496B2 (en) 2014-05-29 2020-02-18 Equinor Energy As Compact hydrocarbon wellstream processing
CN105623767A (zh) * 2016-01-11 2016-06-01 天津大学 油包水乳液相变换热的气体水合物制备方法
CN105623767B (zh) * 2016-01-11 2018-05-25 天津大学 油包水乳液相变换热的气体水合物制备方法

Similar Documents

Publication Publication Date Title
AU2006234825B2 (en) Recovery of kinetic hydrate inhibitor
US10786780B2 (en) Method and system for lowering the water dew point of a hydrocarbon fluid stream subsea
US10184090B2 (en) Combined dehydration of gas and inhibition of liquid from a well stream
CN105121986A (zh) 使受污染的含烃气流液化的方法
CA2962274C (fr) Methodes et appareils permettant d'obtenir un produit de petrole lourd a partir d'un melange
NO20180242A1 (en) System and method for processing natural gas produced from a subsea well
WO2014015892A1 (fr) Abaissement du point de congélation en traitement de gaz ou de pétrole à l'aide de solvants mélangés
Gandomkar et al. CO2 mobility control by small molecule thickeners during secondary and tertiary enhanced oil recovery
WO2009094285A1 (fr) Extraction des huiles à l'aide de carbonates d'alkylène
Xu et al. Recovery of monoethylene glycol combined with kinetic hydrate inhibitor
US20150053401A1 (en) Systems and Methods for Enhancing Production of Viscous Hydrocarbons From a Subterranean Formation
US20190225891A1 (en) System for recovering natural gas liquid from low pressure source
AU2015330970B2 (en) System and method for subsea cooling a wellhead gas to produce a single phase dew-pointed gas
Igboanusi et al. The advancement from thermodynamic inhibitors to kinetic inhibitors and anti-agglomerants in natural gas flow assurance
US20050187421A1 (en) Method for extracting an antihydrate contained in condensed hydrocarbons
RU2179177C2 (ru) Способ обработки газа, содержащего метан, по меньшей мере один высший углеводород и воду
WO2016054695A1 (fr) Système et procédé de refroidissement sous-marin de gaz de tête de puits en vue de produire un gaz au point de rosée monophasé
Olabisi et al. LPG hydrate formation and prevention using ethanol and methanol
US20220154080A1 (en) System for recovering natural gas liquid from low pressure source at low temperatures
CA3026716C (fr) Traitement de fluides produits d'une formation souterraine dans un procede d'injection proche azeotropique
RU2629845C2 (ru) Способ подготовки углеводородного газа к транспорту
Wu et al. Study on Process Calculation Methods of Pipeline Transportation of CO2
Kontogeorgis Association models for petroleum applications
BR102017015092A2 (pt) processo para recuperar inibidores termodinâmicos de hidratos de gás de cargas de gás natural utilizando separador supersônico simultaneamente ajustando ponto de orvalho de hidrocarbonetos e ponto de orvalho de água do gás final
Behar et al. Hydrates Inhibition by Physical Solvents in the Treatment of Natural Gas From Offshore Reservoirs

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12737577

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12737577

Country of ref document: EP

Kind code of ref document: A1