Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3882941 A
Publication typeGrant
Publication dateMay 13, 1975
Filing dateDec 17, 1973
Priority dateDec 17, 1973
Publication numberUS 3882941 A, US 3882941A, US-A-3882941, US3882941 A, US3882941A
InventorsPelofsky Arnold H
Original AssigneeCities Service Res & Dev Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
In situ production of bitumen from oil shale
US 3882941 A
Abstract
Hydrocarbons are recovered from oil shale deposits by introducing hot fluids into the deposits through wells and then shutting in the wells to allow kerogen in the deposits to be converted to bitumen which is then recovered through the wells after an extended period of soaking.
Images(1)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

United States Patent [191 Pelofsky [451 May 13, 1975 1 IN SlTU PRODUCTION OF BITUMEN FROM OIL SHALE [75] Inventor: Arnold H. Pelofsky, East Brunswick,

[73] Assignee: Cities Service Research &

Development Co., Cranbury, NJ.

[22] Filed: Dec. 17, 1973 [21] Appl. No.: 425,449

[52] US. Cl 166/303; 166/263 [51] Int. Cl E211) 43/24 [58] Field of Search 166/302, 303, 272, 263

[56] References Cited UNlTED STATES PATENTS 11/1966 Thomas 166/303 X 5/1967 Strubhar 166/303 X 3,358,762 12/1967 Closmann 166/303 3,382,922 5/1968 Needham..... 166/303 X 3,480,082 11/1969 Gilliland 166/303 X 3,515,213 6/1970 Prats 166/303 X 3,550,685 12/1970 Parker 166/303 3,618,663 11/1971 Needham 166/303 X Primary ExaminerStephen J. Novosad Attorney, Agent, or Firm-Joshua J. Ward; George L. Rushton [57] ABSTRACT Hydrocarbons are recovered from oil shale deposits by introducing hot fluids into the deposits through wells and then shutting in the wells to allow kerogen in the deposits to be converted to bitumen which is then recovered through the wells after an extended period of soaking.

6 Claims, 2 Drawing Figures IN SITU PRODUCTION OF BITUMEN FROM OIL SHALE BACKGROUND OF THE INVENTION This invention relates to the recovery of bitumen from oil shale and more particularly to an in situ process for conversion of kerogen to bitumen and recovery of the resulting bitumen.

Oil shale deposits are found in many locations throughout the world and are a potential source of extremely large quantities of hydrocarbon products. Oil shale is generally a laminated, nonporous, impermeable, fine-grained dolomitic marlstone containing variable but relatively large amounts of organic matter known as kerogen. Kerogen is a high molecular weight substance largely insoluble in benzene and which is dispersed throughout an inorganic matric composed-principally of carbonates along with other minor constituents. The kerogen in oil shale is relatively rich in hydrogen and will yield a benzene soluble material (bitumen) on heating.

Many proposals have been made for recovering usuable hydrocarbons from oil shales, most of which involve the use of heat in one form or another to soften or liquefy the kerogen for conversion to bitumen or for further conversion to produce both liquid and gaseous products. The heat may be applied in situ or the shale may be mined by conventional mining methods with subsequent heating or retorting of the mined shale. In conventional in situ retorting, a heating agent is injected into one or more wells extending into the shale deposit and product is produced through the same or separate wells. It is also known to inject air into the formation to ignite the kerogen and form a combustion front which is then moved through the formation in a conventional manner to liquefy and partially gasify the kerogen and carry the liquid and gaseous product through the formation to wells from which it may be recovered. In situ processes frequently involve fracturing the shale deposit to facilitate contact between heating agents and kerogen.

In all of the previously known in situ processes for recovery of bitumen from shale deposits, thermal efficiency has been extremely low because, once formed from the kerogen, bitumen has been recovered at relatively high temperatures. Also a significant amount of the bitumen that has been formed migrates through the formation and is not recovered. It is therefore an object of the present invention to recover bitumen from shale deposits by means of a novel in situ recovery process which involves recovery of substantial quantities of bitumen with a high degree of thermal efficiency and to reduce the migration of the bitumen out of the formation.

SUMMARY OF THE INVENTION Hydrocarbon product is recovered from a subterranean deposit of oil-shale by introducing heat energy into the deposit through one or more wells extending into the deposit. Heat energy is introduced in quantities sufficient to heat the deposit in the vicinity of the wells to more than 50F (Fahrenheit Degrees) above its transition temperature (the temperature at which exfoliation of the shale structure commences).The wells are then shut in until the temperature in the vicinity of the wells drops to less than 50 above transition temperature, at which time the wells are again opened and bitumen is produced therefrom.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a vertical cross-sectional view illustrating use of the present invention in recovery of hydrocarbons from an oil shale deposit.

FIG. 2 is a horizontal cross-sectional view further illustrating use of the invention in recovering hydrocarbons from oil shale deposits.

DETAILED DESCRIPTION OF THE INVENTION those at which bitumen is normally recovered from such deposits while achieving at the same time recovcry of substantial quantities of the total possible recoverable hydrocarbons. As mentioned above, this is accomplished by introducing heat energy into the deposit through one or more wells extending into the deposit with the heat energy being introduced in quantities sufficient to heat the deposit in the vicinity of the wells to more than 50F above its transition temperature. The transition temperature is considered to be that temperature at which exfoliation (swelling) of the shale structure begins to take place. The wells are then shut in until the temperature of the deposit in the vicinity of the wells drops to less than 50F above the transition temperature of the deposit at which point the wells may be opened and bitumen produced therefromor additional heat energy may be introduced for conversion of additional kerogen to bitumen. If the bitumen is not removed, it will act as a solvent and tend to solubilize more of the kerogen.

The exfoliation temperature for a particular shale deposit varies depending on the amount of kerogen contained in the shale between about 600 and about 700F. with the lower transition temperatures occuring in connection with relatively richer shale deposits. When an oil shale deposit is heated to above its transition temperature in the absence of oxygen, exfoliation is accompanied by a marked increase in permeability. If the shale is allowed to remain above the transition temperature for a few hours, the permeability decreases again to the original value, usually essentially zero. If,'however, the shale deposit is maintained above its transition temperature for a substantial length of time, such as weeks or months, significant portions of the kerogen are converted to bitumen which has substantially lower viscosity than the kerogen and can flow freely through the inorganic matrix of the shale deposit. In accordance with this invention, the shale deposit is heated to more than 5OF and preferably at least about F above its transition temperature and then allowed to cool to less than 50F, preferably to about 25F or less above its transition temperature before recovery of any bitumen therefrom. This allows ample time for substantial quantities of kerogen to convert to bitumen and allows heat to be transferred to further portions of the formation to avoid loss of thermal efficiency in recovery of bitumen from the deposit. It also allows the bitumen to act as a solubilizing agent on the undissolved or unconverted kerogen.

Introduction of heat energy to a shale deposit in accordance with the invention can be by any suitable means with use of hot fluids at temperatures between about 700 and about 2,000F. being preferred. Preferred fluids include steam and hot water although other fluids not containing free oxygen, such as liquid or vaporous hydrocarbons, flue gas, etc. may be used.

Because of the extremely low permeability of oil shale deposits, it is usually not possible to inject hot fluids at normal injection rates without increasing pressure in the injection well to an undesirable degree before the desired rise in temperature has taken place in significant portions of the surrounding shale deposit. It is therefore preferred that the initial step of heating the deposit in the vicinity of the wellbores to more than 5OF- above its transition temperature be done in stages. In this preferred embodiment of the invention, hot fluid is injected through the wells until the pressure is raised to between about 200 and about 1,000 psi above normal formation pressure of the deposit. The wells are then shut in for a period of time necessary to allow the pressure to drop to less than about 50 psi above the formation pressure of the deposit. This frequently takes between about 2 weeks and about six months. Additional hot fluid is then injected until the pressure again rises more than 200 psi above formation pressure. Similar cycles of injection and shut in are continued until the temperature in the vicinity of the injection wells reaches the desired range of more than 50F above the transition temperature of the deposit. The injection wells'are then shut in until the temperature in the vicinityof the wells drops to less than 5OF above the transition temperature of the deposit at which time bitumen may be produced from the wells or, preferably, injection of hot fluids as described above is again resumed. By so resuming injection of hot fluids, the affected area of the shale deposit may be extended beyond that possible by merely raising the temperature in the immediate vicinity of the wells. This is possible because of the increased permeability of the formation in the vicinity of the wells due to conversion of kerogen to lower viscosity bitumen during the injection and shut in cycles mentioned above and also because the bitumen tends to so]- ubilize additional kerogen.

Once the deposit in the immediate vicinity of the injection wells has been heated to more than 50F above its transition temperature, it is preferred that the wells be shut in for between about 6 months and about 1 year to allow the temperature to drop to less than 50F and more preferably to less than 25F above transition temperature. Bitumen may then be produced from the wells or more preferably injection of hot fluids may be resumed to extend the affected area of the deposit before production of any bitumen therefrom. Such expansion of the effected area of the deposit preferably is carried out in the same manner as the original heating of the deposit described above, i.e., hot fluids are injected into the deposit until the well pressures rise to between about 200 and about 1,000 psi above normal formation pressures, the wells are shut in for between about 2 weeks and about 6 months to allow pressure to return to less than 50 psi above formation pressure and injection of hot fluids is then resumed on the same basis until temperatures in the previously unaffected portions of the shale deposit surrounding the wells have been raised to more than 50F. above their transition temperatures. The increase in temperature of previously unaffected shale deposit may in part. or in whole be achieved by indirect transfer of the heat from the injected hot fluids through previously formed bitumen.

It is preferred that the introduction of heat energy into the shale deposit as described above be'continued until the deposit has been heated to more thanv 5OF above its transition temperature throughout a sphere having a radius of at least about 50 feet from the injection point of each well through whichhot fluid has been injected. Each portion of the deposit so heated should then be allowed to soak with the wells shut in until the temperature again drops to less than 50F above the transition temperature (usually for a period of at least about 6 months) to allow time for conversion of kerogen to bitumen. For maximum efficiency of recovery, it is preferred that no bitumen be produced from the deposit until all of the above heating and soaking cycles have been completed at least once for each portion of the deposit contained within the spheres mentioned above.

ln practicing the invention, it is important to avoid fracturing the shale deposit since any fractures .formed beyond the area of the deposit in which kerogen is transformed to bitumen will result in excessive loss of bitumen into other portions of the deposit-or surrounding formations. For the same reason, it is not desirable to allow the portions of the deposit in which kerogen is converted to bitumen to extend to the boundaries of the shale deposit if the surrounding or underlying formations or overburden are permeable. For this reason, it is preferred that theinvention be practiced in shale deposits having a thickness of at least about 200 feet and that the periphery of each of the spheres of affected area in which kerogen is converted to bitumen remain a minimum of at least about 50 feet fromthe boundary of the deposit. Overlapping of affected spheres is, of course, permissible and frequently desirable to ensure maximum recovery of hydrocarbons but it is preferred that overlapping be kept to the minimum necessary to obtain desired recovery of hydrocarbons. Otherwise, excessive temperatures may build up in portions of the deposit thereby resulting in thermal inefficiency of undesirably long periods of time being required for heat to be transferred to other portions of the deposit. For this reason, it is preferred that the average temperature of affected portions of the shale deposits not rise above about 900F. and that, to the extent practical, temperatures above about 1200F. be avoided completely.

In practicing the invention, the temperature of the shale deposit may be determined by temperature sensing means introduced into the deposit such as through the wells used to inject hot fluids or by means such as infrared aerial photography which allows reasonably accurate determination of temperatures throughout the deposit. Most accurate temperature information is usually obtained by a combination of these or other temperature measuring means. g

If the invention is carried out using the preferred embodiments described above, it is normally feasible to convert at least about percent and; frequently at least about percent of the kerogen inthe af ected areas of the deposit intobitumen-and to recover at least about 65 percent of such bitumen from the deposit. Recovery initially is by merely opening the injection wells as described above but it should be understood that in addition, other conventional primary, secondary and even tertiary recovery processes may be used as desired to recover bitumen.

Referring to the drawings, FIG. 1 shows a well 12 extending from the surface of the earth 14 through overburden formation 16 into a shale oil deposit 18. An underlying formation 20 is also indicated. The well 12 may be suitably lined and equipped with tubing, etc. in a conventional manner. A conduit 22 communicates at one end thereof to the top of the well l2. The other end of conduit 22 may be connected to a source of hot injection fluids (not shown) or may be connected to means for recovering bitumen produced from the shale deposit 18. Means (not shown) are also provided for closing off the conduit 22 completely to shut in the well 12.

As an example of recovery of hydrocarbons from oil shale in accordance with a preferred embodiment of the invention, superheated steam at a temperature of about 1,000F. may be introduced through the conduit 22 and well 12 into the shale deposit 18. The shale deposit 18 for this example begins about 2,000 feet below the surface and has a thickness of 200 feet from top to bottom and a normal formation pressure of about 1,000 psi. Injection of steam at the rate of 4,000 pounds per hour through the well 12 for up to 8 hours will increase the well pressure to 2000 psi at which time the well is shut in for 4 weeks to allow the pressure to return to less than 50 psi above the formation pressure. Three subsequent similar cycles of injection and shutting in are required to raise the temperature of the shale deposit in the vicinity of the well (within a sphere 24 as represented in FIG. 1) to a temperature 100F. above the formation transition temperature of 562F. The well 12 is then shut in for 6 months during which time the temperature within the sphere 24 diminishes to 587F. (25 above formation transitions temperature). At this time at least about 20 percent of the kerogen contained within the sphere 24 has been converted to bitumen. A series of injections and shut ins similar to that described immediately above is then used to extend the affected area of the shale deposit to encompass all the material within a sphere 26 (FIG. 1). Also during this period of time more of the kerogen is converted to bitumen by the action of not only the heat energy but also the solubilizing effect of the bitumen itself until about 90% of the kerogen is converted. Another complete series of injections and shut ins as described above is used to extend the effected area of the shale deposit in which kerogen is converted to bitumen to encompass material within the sphere 28 as shown in FIG. 1. At this time (a total of years after the start of the injections) bitumen is produced from theshale deposit through the well 12. A total of 65 percent of the bitumen contained within the deposit is produced by primary recovery and an additional 25 percent is available for production by conventional secondary and tertiary methods.

To recover the maximum amount of hydrocarbons from a shale formation it is generally desirable to use more than one well as is depicted in FIG. 2 which shows an oil shale deposit 32 with a number of wells such as 34 and 40 completed within the shale deposit. By injecvert kerogen to bitumen throughout the maximum possible volume of the deposit and that none of the spheres reaches the boundary of the deposit. By keeping the spheres from reaching the boundary of the shale deposit and avoiding fracturing of the shale, it is possible to take advantage of the extremely low permeability of the natural shale deposit to prevent loss of bitumen be fore it can be produced from the deposit.

While the invention has been described above with respect to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit or scope of the invention.

What is claimed is:

l. A process for recovering hydrocarbon product from a subterranean deposit of oil shale which comprises the steps of:

a. introducing heat energy in the form of hot fluids not containing oxygen into said deposit through one or more wells extending into the deposit, said heat energy being introduced in quantities sufficient to heat the deposit in the vicinity of the wells to more than about 50F above its transition temperature and until the pressure at the bottom of the wells is from at least 200 to about 1,000 psi about the formation pressure of the deposit;

b. then shutting in said wells until the temperature in the vicinity of the wells drops to less than about 50F above the transition temperature of the deposit until the pressure at the bottom thereof drops to less than about 50 psi above formation pressure, with the shutting in period lasting from about two weeks to about 6 months;

c. repeating steps (a) and (b) for a period of from about I to about 10 years; and

d. producing bitumen through said wells.

2. The process of claim 1 in which steps (a) and (b) are repeated until the deposit has been heated to more than 50F above its transition temperature and then allowed to drop to less than 5OF above its transition temperature throughout a sphere having a radius of at least about 50 feet from the bottom of each of said wells.

3. The process of claim 2 in which at least about percent of the kerogen in the spheres is converted to bitumen before bitumen is produced through the wells.

4. The process of claim 2 in which the deposit of oil shale is at least about 200 feet thick, the radius of each of the spheres is between about 50 and about 500 feet and the periphery of each sphere is at least 50 feet from the boundary of the deposit.

5. The process of claim 1 in which heat energy is injected in the form of hot fluids at a temperature of bet-ween about 500and about 2,000F.

6. The process of claim 1 in which step (b) takes at least about 6 months.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3284281 *Aug 31, 1964Nov 8, 1966Phillips Petroleum CoProduction of oil from oil shale through fractures
US3322194 *Mar 25, 1965May 30, 1967Mobil Oil CorpIn-place retorting of oil shale
US3358762 *Dec 6, 1965Dec 19, 1967Shell Oil CoThermoaugmentation of oil-producing reservoirs
US3382922 *Aug 31, 1966May 14, 1968Phillips Petroleum CoProduction of oil shale by in situ pyrolysis
US3480082 *Sep 25, 1967Nov 25, 1969Continental Oil CoIn situ retorting of oil shale using co2 as heat carrier
US3515213 *Apr 19, 1967Jun 2, 1970Shell Oil CoShale oil recovery process using heated oil-miscible fluids
US3550685 *Dec 20, 1967Dec 29, 1970Phillips Petroleum CoShale oil production
US3618663 *May 1, 1969Nov 9, 1971Phillips Petroleum CoShale oil production
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4091869 *Sep 7, 1976May 30, 1978Exxon Production Research CompanyIn situ process for recovery of carbonaceous materials from subterranean deposits
US4105072 *Jan 27, 1977Aug 8, 1978Occidental Oil ShaleProcess for recovering carbonaceous values from post in situ oil shale retorting
US4160481 *Feb 7, 1977Jul 10, 1979The Hop CorporationMethod for recovering subsurface earth substances
US4257650 *Sep 7, 1978Mar 24, 1981Barber Heavy Oil Process, Inc.Method for recovering subsurface earth substances
US4263970 *Jul 31, 1978Apr 28, 1981Occidental Oil Shale, Inc.Method for assuring uniform combustion in an in situ oil shale retort
US4667739 *Mar 10, 1986May 26, 1987Shell Oil CompanyThermal drainage process for recovering hot water-swollen oil from a thick tar sand
US4753293 *Jan 18, 1982Jun 28, 1988Trw Inc.Process for recovering petroleum from formations containing viscous crude or tar
US5025863 *Jun 11, 1990Jun 25, 1991Marathon Oil CompanyEnhanced liquid hydrocarbon recovery process
US5036917 *Dec 6, 1989Aug 6, 1991Mobil Oil CorporationMethod for providing solids-free production from heavy oil reservoirs
US5036918 *Dec 6, 1989Aug 6, 1991Mobil Oil CorporationMethod for improving sustained solids-free production from heavy oil reservoirs
US6581684Apr 24, 2001Jun 24, 2003Shell Oil CompanyIn Situ thermal processing of a hydrocarbon containing formation to produce sulfur containing formation fluids
US6588503Apr 24, 2001Jul 8, 2003Shell Oil CompanyIn Situ thermal processing of a coal formation to control product composition
US6588504Apr 24, 2001Jul 8, 2003Shell Oil CompanyIn situ thermal processing of a coal formation to produce nitrogen and/or sulfur containing formation fluids
US6591906Apr 24, 2001Jul 15, 2003Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation with a selected oxygen content
US6591907Apr 24, 2001Jul 15, 2003Shell Oil CompanyIn situ thermal processing of a coal formation with a selected vitrinite reflectance
US6607033Apr 24, 2001Aug 19, 2003Shell Oil CompanyIn Situ thermal processing of a coal formation to produce a condensate
US6609570Apr 24, 2001Aug 26, 2003Shell Oil CompanyIn situ thermal processing of a coal formation and ammonia production
US6688387Apr 24, 2001Feb 10, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation to produce a hydrocarbon condensate
US6698515Apr 24, 2001Mar 2, 2004Shell Oil CompanyIn situ thermal processing of a coal formation using a relatively slow heating rate
US6702016 *Apr 24, 2001Mar 9, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation with heat sources located at an edge of a formation layer
US6708758Apr 24, 2001Mar 23, 2004Shell Oil CompanyIn situ thermal processing of a coal formation leaving one or more selected unprocessed areas
US6712135Apr 24, 2001Mar 30, 2004Shell Oil CompanyIn situ thermal processing of a coal formation in reducing environment
US6712136Apr 24, 2001Mar 30, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation using a selected production well spacing
US6712137Apr 24, 2001Mar 30, 2004Shell Oil CompanyIn situ thermal processing of a coal formation to pyrolyze a selected percentage of hydrocarbon material
US6715546Apr 24, 2001Apr 6, 2004Shell Oil CompanyIn situ production of synthesis gas from a hydrocarbon containing formation through a heat source wellbore
US6715547Apr 24, 2001Apr 6, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation to form a substantially uniform, high permeability formation
US6715548Apr 24, 2001Apr 6, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation to produce nitrogen containing formation fluids
US6715549Apr 24, 2001Apr 6, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation with a selected atomic oxygen to carbon ratio
US6719047Apr 24, 2001Apr 13, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation in a hydrogen-rich environment
US6722429Apr 24, 2001Apr 20, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation leaving one or more selected unprocessed areas
US6722430Apr 24, 2001Apr 20, 2004Shell Oil CompanyIn situ thermal processing of a coal formation with a selected oxygen content and/or selected O/C ratio
US6722431Apr 24, 2001Apr 20, 2004Shell Oil CompanyIn situ thermal processing of hydrocarbons within a relatively permeable formation
US6722436Jan 25, 2002Apr 20, 2004Precision Drilling Technology Services Group Inc.Apparatus and method for operating an internal combustion engine to reduce free oxygen contained within engine exhaust gas
US6725920 *Apr 24, 2001Apr 27, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation to convert a selected amount of total organic carbon into hydrocarbon products
US6725921Apr 24, 2001Apr 27, 2004Shell Oil CompanyIn situ thermal processing of a coal formation by controlling a pressure of the formation
US6725928Apr 24, 2001Apr 27, 2004Shell Oil CompanyIn situ thermal processing of a coal formation using a distributed combustor
US6729395Apr 24, 2001May 4, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation with a selected ratio of heat sources to production wells
US6729396Apr 24, 2001May 4, 2004Shell Oil CompanyIn situ thermal processing of a coal formation to produce hydrocarbons having a selected carbon number range
US6729397Apr 24, 2001May 4, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation with a selected vitrinite reflectance
US6729401Apr 24, 2001May 4, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation and ammonia production
US6732794Apr 24, 2001May 11, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation to produce a mixture with a selected hydrogen content
US6732795Apr 24, 2001May 11, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation to pyrolyze a selected percentage of hydrocarbon material
US6732796Apr 24, 2001May 11, 2004Shell Oil CompanyIn situ production of synthesis gas from a hydrocarbon containing formation, the synthesis gas having a selected H2 to CO ratio
US6736215Apr 24, 2001May 18, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation, in situ production of synthesis gas, and carbon dioxide sequestration
US6739393Apr 24, 2001May 25, 2004Shell Oil CompanyIn situ thermal processing of a coal formation and tuning production
US6739394Apr 24, 2001May 25, 2004Shell Oil CompanyProduction of synthesis gas from a hydrocarbon containing formation
US6742587Apr 24, 2001Jun 1, 2004Shell Oil CompanyIn situ thermal processing of a coal formation to form a substantially uniform, relatively high permeable formation
US6742588Apr 24, 2001Jun 1, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation to produce formation fluids having a relatively low olefin content
US6742589Apr 24, 2001Jun 1, 2004Shell Oil CompanyIn situ thermal processing of a coal formation using repeating triangular patterns of heat sources
US6742593Apr 24, 2001Jun 1, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation using heat transfer from a heat transfer fluid to heat the formation
US6745831Apr 24, 2001Jun 8, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation by controlling a pressure of the formation
US6745832Apr 24, 2001Jun 8, 2004Shell Oil CompanySitu thermal processing of a hydrocarbon containing formation to control product composition
US6745837Apr 24, 2001Jun 8, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation using a controlled heating rate
US6749021Apr 24, 2001Jun 15, 2004Shell Oil CompanyIn situ thermal processing of a coal formation using a controlled heating rate
US6752210Apr 24, 2001Jun 22, 2004Shell Oil CompanyIn situ thermal processing of a coal formation using heat sources positioned within open wellbores
US6758268Apr 24, 2001Jul 6, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation using a relatively slow heating rate
US6761216Apr 24, 2001Jul 13, 2004Shell Oil CompanyIn situ thermal processing of a coal formation to produce hydrocarbon fluids and synthesis gas
US6763886Apr 24, 2001Jul 20, 2004Shell Oil CompanyIn situ thermal processing of a coal formation with carbon dioxide sequestration
US6769483Apr 24, 2001Aug 3, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation using conductor in conduit heat sources
US6769485Apr 24, 2001Aug 3, 2004Shell Oil CompanyIn situ production of synthesis gas from a coal formation through a heat source wellbore
US6789625Apr 24, 2001Sep 14, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation using exposed metal heat sources
US6805195Apr 24, 2001Oct 19, 2004Shell Oil CompanyIn situ thermal processing of a hydrocarbon containing formation to produce hydrocarbon fluids and synthesis gas
US6820688Apr 24, 2001Nov 23, 2004Shell Oil CompanyIn situ thermal processing of coal formation with a selected hydrogen content and/or selected H/C ratio
US7441603Jul 30, 2004Oct 28, 2008Exxonmobil Upstream Research CompanyHydrocarbon recovery from impermeable oil shales
US7644765Oct 19, 2007Jan 12, 2010Shell Oil CompanyHeating tar sands formations while controlling pressure
US7644769Jan 12, 2010Osum Oil Sands Corp.Method of collecting hydrocarbons using a barrier tunnel
US7673681Oct 19, 2007Mar 9, 2010Shell Oil CompanyTreating tar sands formations with karsted zones
US7673786Apr 20, 2007Mar 9, 2010Shell Oil CompanyWelding shield for coupling heaters
US7677310Oct 19, 2007Mar 16, 2010Shell Oil CompanyCreating and maintaining a gas cap in tar sands formations
US7677314Oct 19, 2007Mar 16, 2010Shell Oil CompanyMethod of condensing vaporized water in situ to treat tar sands formations
US7677673Mar 5, 2007Mar 16, 2010Hw Advanced Technologies, Inc.Stimulation and recovery of heavy hydrocarbon fluids
US7681647Mar 23, 2010Shell Oil CompanyMethod of producing drive fluid in situ in tar sands formations
US7683296Mar 23, 2010Shell Oil CompanyAdjusting alloy compositions for selected properties in temperature limited heaters
US7703513Oct 19, 2007Apr 27, 2010Shell Oil CompanyWax barrier for use with in situ processes for treating formations
US7717171Oct 19, 2007May 18, 2010Shell Oil CompanyMoving hydrocarbons through portions of tar sands formations with a fluid
US7730945Oct 19, 2007Jun 8, 2010Shell Oil CompanyUsing geothermal energy to heat a portion of a formation for an in situ heat treatment process
US7730946Oct 19, 2007Jun 8, 2010Shell Oil CompanyTreating tar sands formations with dolomite
US7730947Oct 19, 2007Jun 8, 2010Shell Oil CompanyCreating fluid injectivity in tar sands formations
US7735935Jun 1, 2007Jun 15, 2010Shell Oil CompanyIn situ thermal processing of an oil shale formation containing carbonate minerals
US7785427Apr 20, 2007Aug 31, 2010Shell Oil CompanyHigh strength alloys
US7793722Apr 20, 2007Sep 14, 2010Shell Oil CompanyNon-ferromagnetic overburden casing
US7798220Apr 18, 2008Sep 21, 2010Shell Oil CompanyIn situ heat treatment of a tar sands formation after drive process treatment
US7798221Sep 21, 2010Shell Oil CompanyIn situ recovery from a hydrocarbon containing formation
US7831134Apr 21, 2006Nov 9, 2010Shell Oil CompanyGrouped exposed metal heaters
US7832484Apr 18, 2008Nov 16, 2010Shell Oil CompanyMolten salt as a heat transfer fluid for heating a subsurface formation
US7841401Oct 19, 2007Nov 30, 2010Shell Oil CompanyGas injection to inhibit migration during an in situ heat treatment process
US7841408Apr 18, 2008Nov 30, 2010Shell Oil CompanyIn situ heat treatment from multiple layers of a tar sands formation
US7841425Nov 30, 2010Shell Oil CompanyDrilling subsurface wellbores with cutting structures
US7845411Dec 7, 2010Shell Oil CompanyIn situ heat treatment process utilizing a closed loop heating system
US7849922Dec 14, 2010Shell Oil CompanyIn situ recovery from residually heated sections in a hydrocarbon containing formation
US7857056Oct 15, 2008Dec 28, 2010Exxonmobil Upstream Research CompanyHydrocarbon recovery from impermeable oil shales using sets of fluid-heated fractures
US7860377Apr 21, 2006Dec 28, 2010Shell Oil CompanySubsurface connection methods for subsurface heaters
US7866385Apr 20, 2007Jan 11, 2011Shell Oil CompanyPower systems utilizing the heat of produced formation fluid
US7866386Oct 13, 2008Jan 11, 2011Shell Oil CompanyIn situ oxidation of subsurface formations
US7866388Jan 11, 2011Shell Oil CompanyHigh temperature methods for forming oxidizer fuel
US7912358Apr 20, 2007Mar 22, 2011Shell Oil CompanyAlternate energy source usage for in situ heat treatment processes
US7931086Apr 18, 2008Apr 26, 2011Shell Oil CompanyHeating systems for heating subsurface formations
US7942197Apr 21, 2006May 17, 2011Shell Oil CompanyMethods and systems for producing fluid from an in situ conversion process
US7942203May 17, 2011Shell Oil CompanyThermal processes for subsurface formations
US7950453Apr 18, 2008May 31, 2011Shell Oil CompanyDownhole burner systems and methods for heating subsurface formations
US7986869 *Apr 21, 2006Jul 26, 2011Shell Oil CompanyVarying properties along lengths of temperature limited heaters
US8011451Sep 6, 2011Shell Oil CompanyRanging methods for developing wellbores in subsurface formations
US8027571Sep 27, 2011Shell Oil CompanyIn situ conversion process systems utilizing wellbores in at least two regions of a formation
US8042610Oct 25, 2011Shell Oil CompanyParallel heater system for subsurface formations
US8070840Apr 21, 2006Dec 6, 2011Shell Oil CompanyTreatment of gas from an in situ conversion process
US8082995Dec 27, 2011Exxonmobil Upstream Research CompanyOptimization of untreated oil shale geometry to control subsidence
US8083813Dec 27, 2011Shell Oil CompanyMethods of producing transportation fuel
US8087460Jan 3, 2012Exxonmobil Upstream Research CompanyGranular electrical connections for in situ formation heating
US8104537Jan 31, 2012Exxonmobil Upstream Research CompanyMethod of developing subsurface freeze zone
US8113272Oct 13, 2008Feb 14, 2012Shell Oil CompanyThree-phase heaters with common overburden sections for heating subsurface formations
US8122955Apr 18, 2008Feb 28, 2012Exxonmobil Upstream Research CompanyDownhole burners for in situ conversion of organic-rich rock formations
US8127865Apr 19, 2007Mar 6, 2012Osum Oil Sands Corp.Method of drilling from a shaft for underground recovery of hydrocarbons
US8146661Oct 13, 2008Apr 3, 2012Shell Oil CompanyCryogenic treatment of gas
US8146664May 21, 2008Apr 3, 2012Exxonmobil Upstream Research CompanyUtilization of low BTU gas generated during in situ heating of organic-rich rock
US8146669Oct 13, 2008Apr 3, 2012Shell Oil CompanyMulti-step heater deployment in a subsurface formation
US8151877Apr 18, 2008Apr 10, 2012Exxonmobil Upstream Research CompanyDownhole burner wells for in situ conversion of organic-rich rock formations
US8151880Dec 9, 2010Apr 10, 2012Shell Oil CompanyMethods of making transportation fuel
US8151884Oct 10, 2007Apr 10, 2012Exxonmobil Upstream Research CompanyCombined development of oil shale by in situ heating with a deeper hydrocarbon resource
US8151907Apr 10, 2009Apr 10, 2012Shell Oil CompanyDual motor systems and non-rotating sensors for use in developing wellbores in subsurface formations
US8162059Apr 24, 2012Shell Oil CompanyInduction heaters used to heat subsurface formations
US8162405Apr 24, 2012Shell Oil CompanyUsing tunnels for treating subsurface hydrocarbon containing formations
US8167960Oct 21, 2008May 1, 2012Osum Oil Sands Corp.Method of removing carbon dioxide emissions from in-situ recovery of bitumen and heavy oil
US8172335May 8, 2012Shell Oil CompanyElectrical current flow between tunnels for use in heating subsurface hydrocarbon containing formations
US8176982May 15, 2012Osum Oil Sands Corp.Method of controlling a recovery and upgrading operation in a reservoir
US8177305Apr 10, 2009May 15, 2012Shell Oil CompanyHeater connections in mines and tunnels for use in treating subsurface hydrocarbon containing formations
US8191630Apr 28, 2010Jun 5, 2012Shell Oil CompanyCreating fluid injectivity in tar sands formations
US8192682Apr 26, 2010Jun 5, 2012Shell Oil CompanyHigh strength alloys
US8196658Jun 12, 2012Shell Oil CompanyIrregular spacing of heat sources for treating hydrocarbon containing formations
US8209192Jun 26, 2012Osum Oil Sands Corp.Method of managing carbon reduction for hydrocarbon producers
US8220539Jul 17, 2012Shell Oil CompanyControlling hydrogen pressure in self-regulating nuclear reactors used to treat a subsurface formation
US8224163Oct 24, 2003Jul 17, 2012Shell Oil CompanyVariable frequency temperature limited heaters
US8224164Oct 24, 2003Jul 17, 2012Shell Oil CompanyInsulated conductor temperature limited heaters
US8224165Jul 17, 2012Shell Oil CompanyTemperature limited heater utilizing non-ferromagnetic conductor
US8225866Jul 21, 2010Jul 24, 2012Shell Oil CompanyIn situ recovery from a hydrocarbon containing formation
US8230927May 16, 2011Jul 31, 2012Shell Oil CompanyMethods and systems for producing fluid from an in situ conversion process
US8230929Jul 31, 2012Exxonmobil Upstream Research CompanyMethods of producing hydrocarbons for substantially constant composition gas generation
US8233782Jul 31, 2012Shell Oil CompanyGrouped exposed metal heaters
US8238730Aug 7, 2012Shell Oil CompanyHigh voltage temperature limited heaters
US8240774Aug 14, 2012Shell Oil CompanySolution mining and in situ treatment of nahcolite beds
US8256512Oct 9, 2009Sep 4, 2012Shell Oil CompanyMovable heaters for treating subsurface hydrocarbon containing formations
US8261832Sep 11, 2012Shell Oil CompanyHeating subsurface formations with fluids
US8267170Sep 18, 2012Shell Oil CompanyOffset barrier wells in subsurface formations
US8267185Sep 18, 2012Shell Oil CompanyCirculated heated transfer fluid systems used to treat a subsurface formation
US8272455Sep 25, 2012Shell Oil CompanyMethods for forming wellbores in heated formations
US8276661Oct 2, 2012Shell Oil CompanyHeating subsurface formations by oxidizing fuel on a fuel carrier
US8281861Oct 9, 2012Shell Oil CompanyCirculated heated transfer fluid heating of subsurface hydrocarbon formations
US8287050Jul 17, 2006Oct 16, 2012Osum Oil Sands Corp.Method of increasing reservoir permeability
US8313152Nov 21, 2007Nov 20, 2012Osum Oil Sands Corp.Recovery of bitumen by hydraulic excavation
US8327681Dec 11, 2012Shell Oil CompanyWellbore manufacturing processes for in situ heat treatment processes
US8327932Apr 9, 2010Dec 11, 2012Shell Oil CompanyRecovering energy from a subsurface formation
US8353347Oct 9, 2009Jan 15, 2013Shell Oil CompanyDeployment of insulated conductors for treating subsurface formations
US8355623Jan 15, 2013Shell Oil CompanyTemperature limited heaters with high power factors
US8381815Apr 18, 2008Feb 26, 2013Shell Oil CompanyProduction from multiple zones of a tar sands formation
US8434555Apr 9, 2010May 7, 2013Shell Oil CompanyIrregular pattern treatment of a subsurface formation
US8448707May 28, 2013Shell Oil CompanyNon-conducting heater casings
US8459359Apr 18, 2008Jun 11, 2013Shell Oil CompanyTreating nahcolite containing formations and saline zones
US8485252Jul 11, 2012Jul 16, 2013Shell Oil CompanyIn situ recovery from a hydrocarbon containing formation
US8536497Oct 13, 2008Sep 17, 2013Shell Oil CompanyMethods for forming long subsurface heaters
US8540020Apr 21, 2010Sep 24, 2013Exxonmobil Upstream Research CompanyConverting organic matter from a subterranean formation into producible hydrocarbons by controlling production operations based on availability of one or more production resources
US8555971May 31, 2012Oct 15, 2013Shell Oil CompanyTreating tar sands formations with dolomite
US8562078Nov 25, 2009Oct 22, 2013Shell Oil CompanyHydrocarbon production from mines and tunnels used in treating subsurface hydrocarbon containing formations
US8579031May 17, 2011Nov 12, 2013Shell Oil CompanyThermal processes for subsurface formations
US8596355Dec 10, 2010Dec 3, 2013Exxonmobil Upstream Research CompanyOptimized well spacing for in situ shale oil development
US8606091Oct 20, 2006Dec 10, 2013Shell Oil CompanySubsurface heaters with low sulfidation rates
US8608249Apr 26, 2010Dec 17, 2013Shell Oil CompanyIn situ thermal processing of an oil shale formation
US8616279Jan 7, 2010Dec 31, 2013Exxonmobil Upstream Research CompanyWater treatment following shale oil production by in situ heating
US8616280Jun 17, 2011Dec 31, 2013Exxonmobil Upstream Research CompanyWellbore mechanical integrity for in situ pyrolysis
US8622127Jun 17, 2011Jan 7, 2014Exxonmobil Upstream Research CompanyOlefin reduction for in situ pyrolysis oil generation
US8622133Mar 7, 2008Jan 7, 2014Exxonmobil Upstream Research CompanyResistive heater for in situ formation heating
US8627887Dec 8, 2008Jan 14, 2014Shell Oil CompanyIn situ recovery from a hydrocarbon containing formation
US8631866Apr 8, 2011Jan 21, 2014Shell Oil CompanyLeak detection in circulated fluid systems for heating subsurface formations
US8636323Nov 25, 2009Jan 28, 2014Shell Oil CompanyMines and tunnels for use in treating subsurface hydrocarbon containing formations
US8641150Dec 11, 2009Feb 4, 2014Exxonmobil Upstream Research CompanyIn situ co-development of oil shale with mineral recovery
US8662175Apr 18, 2008Mar 4, 2014Shell Oil CompanyVarying properties of in situ heat treatment of a tar sands formation based on assessed viscosities
US8701768Apr 8, 2011Apr 22, 2014Shell Oil CompanyMethods for treating hydrocarbon formations
US8701769Apr 8, 2011Apr 22, 2014Shell Oil CompanyMethods for treating hydrocarbon formations based on geology
US8701788Dec 22, 2011Apr 22, 2014Chevron U.S.A. Inc.Preconditioning a subsurface shale formation by removing extractible organics
US8739874Apr 8, 2011Jun 3, 2014Shell Oil CompanyMethods for heating with slots in hydrocarbon formations
US8752904Apr 10, 2009Jun 17, 2014Shell Oil CompanyHeated fluid flow in mines and tunnels used in heating subsurface hydrocarbon containing formations
US8770284Apr 19, 2013Jul 8, 2014Exxonmobil Upstream Research CompanySystems and methods of detecting an intersection between a wellbore and a subterranean structure that includes a marker material
US8789586Jul 12, 2013Jul 29, 2014Shell Oil CompanyIn situ recovery from a hydrocarbon containing formation
US8791396Apr 18, 2008Jul 29, 2014Shell Oil CompanyFloating insulated conductors for heating subsurface formations
US8820406Apr 8, 2011Sep 2, 2014Shell Oil CompanyElectrodes for electrical current flow heating of subsurface formations with conductive material in wellbore
US8833453Apr 8, 2011Sep 16, 2014Shell Oil CompanyElectrodes for electrical current flow heating of subsurface formations with tapered copper thickness
US8839860Dec 22, 2011Sep 23, 2014Chevron U.S.A. Inc.In-situ Kerogen conversion and product isolation
US8851170Apr 9, 2010Oct 7, 2014Shell Oil CompanyHeater assisted fluid treatment of a subsurface formation
US8851177Dec 22, 2011Oct 7, 2014Chevron U.S.A. Inc.In-situ kerogen conversion and oxidant regeneration
US8857506May 24, 2013Oct 14, 2014Shell Oil CompanyAlternate energy source usage methods for in situ heat treatment processes
US8863839Nov 15, 2010Oct 21, 2014Exxonmobil Upstream Research CompanyEnhanced convection for in situ pyrolysis of organic-rich rock formations
US8875789Aug 8, 2011Nov 4, 2014Exxonmobil Upstream Research CompanyProcess for producing hydrocarbon fluids combining in situ heating, a power plant and a gas plant
US8881806Oct 9, 2009Nov 11, 2014Shell Oil CompanySystems and methods for treating a subsurface formation with electrical conductors
US8936089Dec 22, 2011Jan 20, 2015Chevron U.S.A. Inc.In-situ kerogen conversion and recovery
US8992771May 25, 2012Mar 31, 2015Chevron U.S.A. Inc.Isolating lubricating oils from subsurface shale formations
US8997869Dec 22, 2011Apr 7, 2015Chevron U.S.A. Inc.In-situ kerogen conversion and product upgrading
US9016370Apr 6, 2012Apr 28, 2015Shell Oil CompanyPartial solution mining of hydrocarbon containing layers prior to in situ heat treatment
US9022109Jan 21, 2014May 5, 2015Shell Oil CompanyLeak detection in circulated fluid systems for heating subsurface formations
US9022118Oct 9, 2009May 5, 2015Shell Oil CompanyDouble insulated heaters for treating subsurface formations
US9033033Dec 22, 2011May 19, 2015Chevron U.S.A. Inc.Electrokinetic enhanced hydrocarbon recovery from oil shale
US9033042Apr 8, 2011May 19, 2015Shell Oil CompanyForming bitumen barriers in subsurface hydrocarbon formations
US9051829Oct 9, 2009Jun 9, 2015Shell Oil CompanyPerforated electrical conductors for treating subsurface formations
US9080441Oct 26, 2012Jul 14, 2015Exxonmobil Upstream Research CompanyMultiple electrical connections to optimize heating for in situ pyrolysis
US9127523Apr 8, 2011Sep 8, 2015Shell Oil CompanyBarrier methods for use in subsurface hydrocarbon formations
US9127538Apr 8, 2011Sep 8, 2015Shell Oil CompanyMethodologies for treatment of hydrocarbon formations using staged pyrolyzation
US9129728Oct 9, 2009Sep 8, 2015Shell Oil CompanySystems and methods of forming subsurface wellbores
US9133398Dec 22, 2011Sep 15, 2015Chevron U.S.A. Inc.In-situ kerogen conversion and recycling
US9181467Dec 22, 2011Nov 10, 2015Uchicago Argonne, LlcPreparation and use of nano-catalysts for in-situ reaction with kerogen
US9181780Apr 18, 2008Nov 10, 2015Shell Oil CompanyControlling and assessing pressure conditions during treatment of tar sands formations
US9309755Oct 4, 2012Apr 12, 2016Shell Oil CompanyThermal expansion accommodation for circulated fluid systems used to heat subsurface formations
US9347302Nov 12, 2013May 24, 2016Exxonmobil Upstream Research CompanyResistive heater for in situ formation heating
US9394772Sep 17, 2014Jul 19, 2016Exxonmobil Upstream Research CompanySystems and methods for in situ resistive heating of organic matter in a subterranean formation
US9399905May 4, 2015Jul 26, 2016Shell Oil CompanyLeak detection in circulated fluid systems for heating subsurface formations
US20030066642 *Apr 24, 2001Apr 10, 2003Wellington Scott LeeIn situ thermal processing of a coal formation producing a mixture with oxygenated hydrocarbons
US20070023186 *Jul 30, 2004Feb 1, 2007Kaminsky Robert DHydrocarbon recovery from impermeable oil shales
US20070039729 *Jul 17, 2006Feb 22, 2007Oil Sands Underground Mining CorporationMethod of increasing reservoir permeability
US20070044957 *May 25, 2006Mar 1, 2007Oil Sands Underground Mining, Inc.Method for underground recovery of hydrocarbons
US20070137857 *Apr 21, 2006Jun 21, 2007Vinegar Harold JLow temperature monitoring system for subsurface barriers
US20080017416 *Apr 19, 2007Jan 24, 2008Oil Sands Underground Mining, Inc.Method of drilling from a shaft for underground recovery of hydrocarbons
US20080073079 *Mar 5, 2007Mar 27, 2008Hw Advanced Technologies, Inc.Stimulation and recovery of heavy hydrocarbon fluids
US20080078552 *Sep 28, 2007Apr 3, 2008Osum Oil Sands Corp.Method of heating hydrocarbons
US20080087422 *Oct 16, 2007Apr 17, 2008Osum Oil Sands Corp.Method of collecting hydrocarbons using a barrier tunnel
US20090038795 *Oct 15, 2008Feb 12, 2009Kaminsky Robert DHydrocarbon Recovery From Impermeable Oil Shales Using Sets of Fluid-Heated Fractures
US20090084707 *Sep 24, 2008Apr 2, 2009Osum Oil Sands Corp.Method of upgrading bitumen and heavy oil
US20090100754 *Oct 21, 2008Apr 23, 2009Osum Oil Sands Corp.Method of removing carbon dioxide emissions from in-situ recovery of bitumen and heavy oil
US20090139716 *Dec 3, 2008Jun 4, 2009Osum Oil Sands Corp.Method of recovering bitumen from a tunnel or shaft with heating elements and recovery wells
US20090194280 *Feb 6, 2009Aug 6, 2009Osum Oil Sands Corp.Method of controlling a recovery and upgrading operation in a reservoir
US20090308608 *Mar 17, 2009Dec 17, 2009Kaminsky Robert DField Managment For Substantially Constant Composition Gas Generation
US20100147521 *Oct 9, 2009Jun 17, 2010Xueying XiePerforated electrical conductors for treating subsurface formations
US20100163227 *Mar 11, 2010Jul 1, 2010Hw Advanced Technologies, Inc.Stimulation and recovery of heavy hydrocarbon fluids
US20100224370 *May 18, 2010Sep 9, 2010Osum Oil Sands CorpMethod of heating hydrocarbons
WO2001081239A2 *Apr 24, 2001Nov 1, 2001Shell Internationale Research Maatschappij B.V.In situ recovery from a hydrocarbon containing formation
WO2001081239A3 *Apr 24, 2001May 23, 2002Shell Oil CoIn situ recovery from a hydrocarbon containing formation
WO2003062619A1 *Jan 10, 2003Jul 31, 2003Precision Drilling Technology Services Group Inc.Apparatus and method for operating an internal combustion engine to reduce free oxygen contained within engine exhaust gas
Classifications
U.S. Classification166/303, 166/263
International ClassificationE21B43/24, E21B43/18, E21B43/16
Cooperative ClassificationE21B43/18, E21B43/24
European ClassificationE21B43/18, E21B43/24