EP2022936A1 - Solvent assisted method to mobilize viscous crude oil - Google Patents
Solvent assisted method to mobilize viscous crude oil Download PDFInfo
- Publication number
- EP2022936A1 EP2022936A1 EP07113850A EP07113850A EP2022936A1 EP 2022936 A1 EP2022936 A1 EP 2022936A1 EP 07113850 A EP07113850 A EP 07113850A EP 07113850 A EP07113850 A EP 07113850A EP 2022936 A1 EP2022936 A1 EP 2022936A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- crude oil
- methane
- solvent
- steam
- bitumen
- Prior art date
- Legal status (The legal status 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 status listed.)
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/16—Enhanced recovery methods for obtaining hydrocarbons
- E21B43/166—Injecting a gaseous medium; Injecting a gaseous medium and a liquid medium
- E21B43/168—Injecting a gaseous medium
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/16—Enhanced recovery methods for obtaining hydrocarbons
- E21B43/24—Enhanced recovery methods for obtaining hydrocarbons using heat, e.g. steam injection
Definitions
- the invention relates to a solvent assisted method to mobilize viscous crude oil in a viscous crude oil containing formation.
- a steam soak method comprises the steps of:
- the method according to the invention is based on the insight that a viscous crude oil generally comprises at least a small fraction methane, which reduces the viscosity of the viscous crude oil and that the injected steam tends to mobilize the methane, thereby stripping the crude oil and leaving an even more viscous methane depleted crude oil in the formation.
- a methane containing solvent is injected into the viscous crude oil to counteract the depletion of methane and/or increase the methane content of the crude oil such that the viscosity of the crude oil is reduced in an optimum manner.
- the solvent comprises at least 75% methane (CH 4 ) on a molar basis.
- the steam stimulation method is a cyclic steam stimulation method, comprising the sequence of steps of:
- the methane containing solvent preferably is injected into the well before step a).
- the viscous crude oil may comprise bitumen, which has a lower viscosity if methane is dissolved in the bitumen.
- the viscosity of bitumen in which methane is dissolved may be less than 55 cp at 8.73 MPa and the viscosity of methane-depleted bitumen may be more than 65 cp at 3.55Mpa.
- Fig.1 illustrates that the viscosity of bitumen in the Peace River formation in Canada can be reduced by adding methane. The higher the saturation pressure the more methane will be dissolved in the bitumen.
- Fig.2 is a forecast based on computer simulations, in which the continuous line 2 depicts the oil to steam ratio improvement of the method according to the invention, wherein methane is injected prior to each steam soaking step such that at least part of the bitumen in the reservoir is saturated with methane, compared to a traditional steam soak method without solvent injection, wherein after a few steam soak cycles the bitumen in the reservoir is substantially methane depleted, which is depicted by the broken line 3.
- Fig.3 is a forecast based on computer simulations, which shows the steam injection and crude oil production rates of a traditional steam soak without solvent injection and a steam soak method with solvent injection in accordance with the invention.
- the broken lines 4 and 5 depict the steam injection and crude oil production rates of a traditional steam soak process, without solvent injection and the continuous lines 6 and 7 depict the steam injection and crude oil production rates of the solvent assisted steam soak method according to the invention.
Abstract
A solvent assisted method to mobilize viscous crude oil comprises the steps of:
- injecting steam and a solvent comprising methane into a viscous crude oil containing formation; and
- producing a heated solvent and crude oil containing fluid mixture from the formation.
The injection of a solvent comprising methane reduces the viscosity of crude oil and counteracts an increase of the viscosity of the crude oil resulting from flashing of methane during the steam injection.
- injecting steam and a solvent comprising methane into a viscous crude oil containing formation; and
- producing a heated solvent and crude oil containing fluid mixture from the formation.
The injection of a solvent comprising methane reduces the viscosity of crude oil and counteracts an increase of the viscosity of the crude oil resulting from flashing of methane during the steam injection.
Description
- The invention relates to a solvent assisted method to mobilize viscous crude oil in a viscous crude oil containing formation.
- Such a method is known from
US patent 5,899,274 . - This prior art reference describes that known steam soak methods have the limitation that steam and heat are lost to the formation. In steam soak methods steam injection and heated crude oil production is cyclically carried out via a single steam injection and production well.
- A steam soak method comprises the steps of:
- a) injecting steam into the formation through a steam injection and production well;
- b) closing the well during a period sufficiently long to allow the heat to soak and reduce the viscosity of the crude oil in the formation surrounding the well;
- c) producing heated crude oil via the steam injection and production well; and
- d) cyclically repeating the steps a) through c).
- In
US patent 5,899,274 it is proposed to substitute steam injection by injection of a partially miscible solvent that will exist predominantly in a vapor phase in the reservoir, without the need for heat input or pressure adjustment. This prior art reference furthermore discloses that the solvent may comprise a mixture of methane, ethane and/or propane, which dissolves in oil and reduces its viscosity. - It is an object of the present invention to provide an improved method solvent assisted method to mobilize viscous crude oil in a viscous crude oil containing formation.
- In accordance with the invention there is provided a solvent assisted method to mobilize viscous crude oil, the method comprising the steps of:
- injecting steam and a solvent comprising methane into a viscous crude oil containing formation; and
- producing a heated solvent and crude oil containing fluid mixture from the formation.
- The method according to the invention is based on the insight that a viscous crude oil generally comprises at least a small fraction methane, which reduces the viscosity of the viscous crude oil and that the injected steam tends to mobilize the methane, thereby stripping the crude oil and leaving an even more viscous methane depleted crude oil in the formation. In the method according to the invention a methane containing solvent is injected into the viscous crude oil to counteract the depletion of methane and/or increase the methane content of the crude oil such that the viscosity of the crude oil is reduced in an optimum manner.
- Preferably the solvent comprises at least 75% methane (CH4) on a molar basis.
- It is furthermore preferred that the steam stimulation method is a cyclic steam stimulation method, comprising the sequence of steps of:
- a) injecting steam via a steam injection and production well into the formation,
- b) closing the well during a period of time; and
- c) producing heated crude oil via the steam injection and production well,
- d) cyclically repeating the sequence steps a) through c); and wherein the method further comprises the step of
- e) injecting during at least one sequence of steps a) through c) the methane containing solvent into the well prior to step b).
- In such case the methane containing solvent preferably is injected into the well before step a).
- The viscous crude oil may comprise bitumen, which has a lower viscosity if methane is dissolved in the bitumen.
- In such case the viscosity of bitumen in which methane is dissolved may be less than 55 cp at 8.73 MPa and the viscosity of methane-depleted bitumen may be more than 65 cp at 3.55Mpa.
- These and other features, embodiments and advantages of the method according to the invention are described in the accompanying claims, abstract and the following detailed description with reference to the accompanying drawings.
-
-
Fig.1 shows a diagram, which illustrates the effect of saturation pressure on the viscosity of CH4 saturated bitumen from the bitumen containing Peace River formation in Canada; -
Fig.2 is a forecast based on computer simulations, which shows the oil to steam ratio improvement of the method according to the invention compared to a traditional steam soak method without solvent injection; and -
Fig.3 is a forecast based on computer simulations, which shows the steam injection and crude oil production rates of a traditional steam soak without solvent injection and a steam soak method with solvent injection in accordance with the invention. - The diagram shown in
Fig.1 illustrates that the viscosity of bitumen in the Peace River formation in Canada can be reduced by adding methane. The higher the saturation pressure the more methane will be dissolved in the bitumen. - Laboratory experiments indicate that at 121 degrees Celsius the viscosity of bitumen from the Peace River reservoir in Alberta, Canada, without a methane fraction is 70 cp at 3.55 MPa and that the viscosity of Peace River bitumen saturated with methane is 50 cp at 8.73 MPa.
-
Fig.2 is a forecast based on computer simulations, in which thecontinuous line 2 depicts the oil to steam ratio improvement of the method according to the invention, wherein methane is injected prior to each steam soaking step such that at least part of the bitumen in the reservoir is saturated with methane, compared to a traditional steam soak method without solvent injection, wherein after a few steam soak cycles the bitumen in the reservoir is substantially methane depleted, which is depicted by thebroken line 3. -
Fig.3 is a forecast based on computer simulations, which shows the steam injection and crude oil production rates of a traditional steam soak without solvent injection and a steam soak method with solvent injection in accordance with the invention. InFig.3 thebroken lines continuous lines
Claims (7)
- A solvent assisted method to mobilize viscous crude oil, the method comprising the steps of:- injecting steam and a solvent comprising methane into a viscous crude oil containing formation; and- producing a heated solvent and crude oil containing fluid mixture from the formation.
- The method of claim 1, wherein the solvent comprises at least 75% methane on a molar basis.
- The method of claim 2, wherein the solvent comprises at least 90% methane on a molar basis.
- The method of claim 1,2 or 3, wherein the steam stimulation method is a cyclic steam stimulation method comprising the sequence of steps of:a) injecting steam via a steam injection and production well into the formation,b) closing the well during a period of time; andc) producing heated crude oil via the steam injection and production well,d) cyclically repeating the sequence steps a) through c) and wherein the method further comprises the step ofe) injecting during at least one sequence of steps a) through c) the methane containing solvent into the well prior to step b).
- The method of claim 4, wherein the methane containing solvent is injected into the well before step a).
- The method of any preceding claim, wherein the viscous crude oil comprises bitumen, which has a lower viscosity if methane is dissolved in the bitumen.
- The method of claim 6, wherein the viscosity of bitumen in which methane is dissolved is less than 55 cp at 8.73 MPa and the viscosity of methane depleted bitumen is more than 65 cp at 3.55Mpa.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP07113850A EP2022936A1 (en) | 2007-08-06 | 2007-08-06 | Solvent assisted method to mobilize viscous crude oil |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP07113850A EP2022936A1 (en) | 2007-08-06 | 2007-08-06 | Solvent assisted method to mobilize viscous crude oil |
Publications (1)
Publication Number | Publication Date |
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EP2022936A1 true EP2022936A1 (en) | 2009-02-11 |
Family
ID=38830976
Family Applications (1)
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EP07113850A Withdrawn EP2022936A1 (en) | 2007-08-06 | 2007-08-06 | Solvent assisted method to mobilize viscous crude oil |
Country Status (1)
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EP (1) | EP2022936A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102080523A (en) * | 2011-01-06 | 2011-06-01 | 中国石油化工股份有限公司 | Compound huff-puff oil recovery method by using steam and oil-soluble viscosity reducer |
US8602098B2 (en) | 2010-02-16 | 2013-12-10 | Exxonmobil Upstream Research Company | Hydrate control in a cyclic solvent-dominated hydrocarbon recovery process |
US8684079B2 (en) | 2010-03-16 | 2014-04-01 | Exxonmobile Upstream Research Company | Use of a solvent and emulsion for in situ oil recovery |
US8752623B2 (en) | 2010-02-17 | 2014-06-17 | Exxonmobil Upstream Research Company | Solvent separation in a solvent-dominated recovery process |
US8899321B2 (en) | 2010-05-26 | 2014-12-02 | Exxonmobil Upstream Research Company | Method of distributing a viscosity reducing solvent to a set of wells |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3908762A (en) * | 1973-09-27 | 1975-09-30 | Texaco Exploration Ca Ltd | Method for establishing communication path in viscous petroleum-containing formations including tar sand deposits for use in oil recovery operations |
US4099568A (en) * | 1974-02-15 | 1978-07-11 | Texaco Inc. | Method for recovering viscous petroleum |
US4121661A (en) * | 1977-09-28 | 1978-10-24 | Texas Exploration Canada, Ltd. | Viscous oil recovery method |
US4141415A (en) * | 1977-07-01 | 1979-02-27 | Texaco Inc. | Method of recovering hydrocarbons by improving the vertical conformance in heavy oil formations |
US4513819A (en) * | 1984-02-27 | 1985-04-30 | Mobil Oil Corporation | Cyclic solvent assisted steam injection process for recovery of viscous oil |
US20030015321A1 (en) * | 2001-05-31 | 2003-01-23 | Lim Git B. | Cyclic solvent process for in-situ bitumen and heavy oil production |
US20070199712A1 (en) * | 2006-02-27 | 2007-08-30 | Grant Hocking | Enhanced hydrocarbon recovery by steam injection of oil sand formations |
-
2007
- 2007-08-06 EP EP07113850A patent/EP2022936A1/en not_active Withdrawn
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3908762A (en) * | 1973-09-27 | 1975-09-30 | Texaco Exploration Ca Ltd | Method for establishing communication path in viscous petroleum-containing formations including tar sand deposits for use in oil recovery operations |
US4099568A (en) * | 1974-02-15 | 1978-07-11 | Texaco Inc. | Method for recovering viscous petroleum |
US4141415A (en) * | 1977-07-01 | 1979-02-27 | Texaco Inc. | Method of recovering hydrocarbons by improving the vertical conformance in heavy oil formations |
US4121661A (en) * | 1977-09-28 | 1978-10-24 | Texas Exploration Canada, Ltd. | Viscous oil recovery method |
US4513819A (en) * | 1984-02-27 | 1985-04-30 | Mobil Oil Corporation | Cyclic solvent assisted steam injection process for recovery of viscous oil |
US20030015321A1 (en) * | 2001-05-31 | 2003-01-23 | Lim Git B. | Cyclic solvent process for in-situ bitumen and heavy oil production |
US20070199712A1 (en) * | 2006-02-27 | 2007-08-30 | Grant Hocking | Enhanced hydrocarbon recovery by steam injection of oil sand formations |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8602098B2 (en) | 2010-02-16 | 2013-12-10 | Exxonmobil Upstream Research Company | Hydrate control in a cyclic solvent-dominated hydrocarbon recovery process |
US8752623B2 (en) | 2010-02-17 | 2014-06-17 | Exxonmobil Upstream Research Company | Solvent separation in a solvent-dominated recovery process |
US8684079B2 (en) | 2010-03-16 | 2014-04-01 | Exxonmobile Upstream Research Company | Use of a solvent and emulsion for in situ oil recovery |
US8899321B2 (en) | 2010-05-26 | 2014-12-02 | Exxonmobil Upstream Research Company | Method of distributing a viscosity reducing solvent to a set of wells |
CN102080523A (en) * | 2011-01-06 | 2011-06-01 | 中国石油化工股份有限公司 | Compound huff-puff oil recovery method by using steam and oil-soluble viscosity reducer |
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