|Publication number||US3618663 A|
|Publication date||9 Nov 1971|
|Filing date||1 May 1969|
|Priority date||1 May 1969|
|Publication number||US 3618663 A, US 3618663A, US-A-3618663, US3618663 A, US3618663A|
|Inventors||Needham Riley B|
|Original Assignee||Phillips Petroleum Co|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (2), Referenced by (120), Classifications (6)|
|External Links: USPTO, USPTO Assignment, Espacenet|
United States Patent inventor Riley B. Needham Bartlesvllle, Okla. Appl. No. 820,777 Filed May 1, 1969 Patented Nov. 9, 1971 Assignee Phillip Petroleum Company SHALE OlL PRODUCTION 5 Claims, 2 Drawing Figs.
US. Cl 166/247, 166/254. 166/272, 166/303 Int. Cl E2lh43/24, 1521b 43/26 Field of Search 166/247. 272. 303, 271, 254
 References Cited UNITED STATES PATENTS 3,342,257 9/1967 Jacobs etal. 1 166/247 3.465.819 9/1969 Dixon 166/247 Primary Examiner-Stephen J. Novosad V Auorney-Young & Quigg 2-1 3= 40 4a SHALE RICHNES$,GA1
i ON FR 'ON PATENTEDuuv 9 I971 SHEET 1 0F 2 50 z CL I l l l I l l l J l 8 I6 24 32 40 48 SHALERICHNESS, GALLON PER TON F G INVENTOR.
RB. NEEDHAM BY A T TORNE VS P ATENTEDuuv 9 an SHEET 2 OF 2 modmntwmzmh wizm TIME,DAYS
N EEDHAM A TTORNEYS SHALE OIL PRODUCTION BACKGROUND OF THE INVENTION This invention relates to improvements inrecovery of oil from subsurface oil shale and similar formations. In accordance with one aspect, this invention relates to an improvement for fracturing an oil shale formation with a nuclear device to form a chimney and retorting of the mass of fractured oil shale in the chimney with a heated gas. In accordance with another aspect, thisinvention relates to a method for strategically locating a nuclear device in an oil shale formation in order to produce a usable nuclear chimney which can be heated at a lower temperature in order to maintain more permeability without compaction of the shale causing plugging. In accordance with a further aspect, this invention relates to the determining of where to locate a nuclear device in order to produce a nuclear chimney comprising a mass of fractured oil shale with lean shale at the bottom and rich shale near the top of the chimney, followed by producing shale oil from the chimney by heating stepwise at different temperatures.
Despite the widespread occurrence of oil shale throughout much'of the world, the large scale recovery of shale oil from such deposits has not been widely practiced. The barriers of geology, technology and economics have heretofore effectively prevented more than token use of this source of oil. Geologically, many of the potentially most productive shales are covered by deep overburdens of earth and rock and, except in a few instances of outcroppings or surface valleys, are inaccessible for commercial recovery. Technologically, oil shale occurs as a relatively compact, impermeable rock which by present practice must be crushed or fractured by mechanical means before oil can be recovered by retorting the fragments;
because of this imperrneability, in situ retorting of oil shale has not met with success. From the economic standpoint, shale mining by open pit methods involves problems of overburden disposal, transportation to the refinery, crushing and grinding and disposal of spent shale. Similarly, underground mining by gallery techniques and subsequent crushing and heating in special retorts is hardly suitable when considering current day liquid fuel requirements.
Control of the tremendous energy of nuclear devices for peacetime uses has of late become a subject of considerable interest. Withthe knowledge that such energy in the form of thermal nuclear explosives should be available for a fraction of a mil per kilowatt hour equivalent, numerous applications involving underground explosions have been proposed. Further, it has now been realized that ultrahigh energy explosions can be used in mining operations to break up formations in the oil industry to increase or stimulate productivity by heating or raising the pressure of a reservoir and in landscaping or earth moving techniques such as digging canals, making harbors or removing troublesome obstacles.
The present invention is primarily directed to the production of oil utilizing an underground explosion chamber in a bituminous deposit suitable for the explosion of a high energy explosive charge. A nuclear explosion within a bed of shale deep in the earth produces a huge chimney containing a mass of shale rubble which has high permeability and is amenable to production by contacting the shale with hot gases. The nuclear chimney may have a diameter of 600 feet and a height of about 1,400 feet. In heating oil shale with hot gases, one of the problems encountered is that of plastic flow which greatly reduces or completely eliminates permeability, thereby hindering or terminating the pyrolysis operation. This invention is concerned with the strategic location of a nuclear device prior to detonation to form a chimney with lean shale near the bottom and rich shale near the top and subsequent heating with hot gases with the reduction or prevention of plastic flow during the heating of the oil shale, with such gases.
Accordingly, it is an object of this invention to provide a method for producing a usable nuclear chimney in a bituminous formation.
Another object of this invention is to provide a process for producing oil from an oil shale by pyrolysis with hot gases which avoids or substantially diminishes plastic flow of the shale.
Another object is to provide a process for producing oil from shale rubble in a nuclear chimney by effecting pyrolysis with hot gas while avoiding substantial plastic flow of the shale.
A further object of this invention is to provide a process for heating a nuclear chimney at a lower temperature in order to maintain more permeability without'compaction of the shale causing plugging.
Other objects and aspects as well as the several advantages of the invention will become apparent to those skilled in the art upon consideration of the accompanying disclosure and the appended claims.
SUMMARY OF THE INVENTION manner that upon detonation of the nuclear device-a nuclear chimney comprising a mass of fractured oil shale is produced wherein the crumbled shale is lean shale at the bottom and rich near the top of the chimney.
' In accordance with another embodiment of the invention, a mass of fractured or broken oil shale in a nuclear chimney having lean shale at the bottom and rich shale near the top is produced by being preheated with a heating gas at a temperature not in excess of 650 F. for a prolonged period of time so as to maintain permeability of the shale without compaction of the shale and causing plugging, followed by heating at a retorting temperature in excess of 700 F.
In accordance with a preferred embodiment of the inven tion, the nuclear chimney comprising a mass of fractured oil shale with lean shale at the bottom and rich shale nearthe top of the chimney is produced by passing a heating gas through the mass of fractured oil shale at a temperature so as to preheatthe shale at a temperature in the range of 500-575 F. for a period of time of at least 30 days, and then increasing the temperature of the fractured shale at a rate of l /2 to 2 F. per day to a temperature in the range of 600-650 F., and continuing the heating within this range for a period of 3 to 70 days and then rapidly heating the formation to a temperature of 700-800 F., the final retorting temperature to produce the BRIEF DESCRIPTION OF THE DRAWING FIG. 1 graphically illustrates shale richness distribution as a function of formation depth in an oil shale formation treated according to the present invention; and
FIG. 2 graphically shows the temperature history of a fragmented oil shale bed treated in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS As discussed above, one of the major technical operability uncertainties regarding in situ retorting of oil shale contained in a nuclear chimney is shale compaction during heating and the resulting reduction in permeability. in accordance to the invention, this reduction of permeability is controlled by selection of the chimney location so that the bottom of the fragmented shale is lean and the thick sections of the rich shale are near the top, and producing of the shale oil is preferably effected by prolonged heating of the shale at temperatures below the rapid retorting temperature and then sub sequent recovery of the remaining oil by heating to a higher temperature.
Bituminous deposits containing oil shale can be produced in accordance with the method of the present invention. The process is suitable for rock formations known as oil shale" which contain a combination of organic and inorganic sediments which have become hardened into impermeable rock. Suitable shales have a compressive strength in the range of 5,000 to 30,000 p.s.i. The organic portion laid down in layers is a solid amorphous material generally known as kerogen which can be converted to oil under the application of heat. The oil recovered is a black, viscous, waxy substance which will not flow below about 85 or 90 F.
The method of the present invention is employed with bituminous deposits lying in the range of from I to 20,000 feet below the surface of the earth. The minimum ground cover required is that necessary to insure complete containment of the explosion. This depends upon the energy yield of the explosive utilized. For nuclear devices, the minimum depth in feet is approximately equal to in the range of 250-450 times the cube root of the size of the device in kilotons. Thus, the ex plosion from a l-kiloton nuclear bomb is completely contained if the device is exploded 250450 feet below the nearest surface point. The maximum depth is limited only by the economic considerations involved in penetrating very deep-lying formations with conventional drilling equipment.
The method of the present invention is carried out utilizing a thermal nuclear device such as the hydrogen or atomic bomb. Suitable thermal nuclear devices are now available for underground explosion; therefore, it is to be understood that the present discovery involves merely the use of a nuclear device in a novel and useful method of exploding oil deposits and that the fabrication and manufacture of hydrogen and atomic bombs form no part of this invention.
To employ the invention, it is preferable to drill an access well into the formation and then performing a geological survey of the oil shale along the length of said access well to determine the location of a rich shale section and an underlying lean shale section. In the Green River shale in the Piceance Creek basin there is excellent lateral continuity of the shale strata therefore some definition of the shale beds already exists. In addition the richness of the shale can be obtained by two methods, (a) core drilling of the entire shale section and analysis of the recovered core, and (b) logging of the drilled hole.
Upon determining location of a rich shale section and an underlying lean shale section, a nuclear explosive device is then placed into the formation in such a manner that upon detonation a nuclear chimney is produced with lean shale at the bottom and rich shale near the top of the chimney.
In a specific embodiment of the process, oil is retorted from a shale seam which is 900 feet in thickness and carries an overburden of 1,650 feet of rock. The shale seam contains an average of 27.3 gallons of oil per ton (Fischer assay) in the top half of the seam and 23.1 gallons of oil per ton (Fischer assay) in the bottom half of the seam. A I00 kiloton nuclear device is disposed in a well near the lower innerface of the shale seam and the underlying rock. Upon detonation of the device, a chimney having a radius of 180 feet and 900 feet height is formed. The crumbled shale formation is provided with inlet means for introducing hot retorting gas into the upper portion of the cavity and recovering means for recovery from the bottom of the mass of crumbled shale and bringing to the earth's surface gases and liquids. An inert gas such as nitrogen or combustion gases or hot recycle produced gases are introduced through the inlet means into the cavity and heat the formation as described above to produce shale oil. Gases and condensed liquids are withdrawn and transported to the surface via the recovery means.
The mass of fractured or broken oil shale ordinarily will have a Fischer assay value in the range of -50 gallons per ton.
The fractured shale in a preferred embodiment is first preheated to a temperature of 500-575 F. for a period of time of at least 30 days. Generally the heating will be continued at this temperature for a period of time ranging from 100 to 1,000 days.
The temperature of the preheated fractured shale is then preferably increased to a temperature in the range of 600-65 0 F. at a rate of 1/2 to 2 F. per day, and the heating in this temperature range is continued for a period of 3 to 70 days. Maintaining the shale temperature in these low temperature ranges hardens the shale, retaining more of the fragmented shale bed permeability.
After the formation is heated to 600-650 F. for a prolonged period of time, it is heated rapidly to 700-800 F., the final retorting temperature. The heating during the final retorting temperature is continued generally until the formation is substantially depleted of shale oil.
In heating the oil shale rubble with hot gases, it is feasible to utilize combustion gases, inert gases and/or hot recycle produced gases. It is preferred to inject a hot gas into the top of the chimney and move the heat front downwardly through the rubble.
EXAMPLE In order to illustrate the operation of the invention, the effective permeability at 800 F. has been calculated for four specific cases. These calculations were perfonned using data which are summarized in table 1. The average particle size in the 900-foot high nuclear chimney used in each case was assumed to be one foot. In all four cases the shale represented in FIG. 1 was used. The four cases calculated are stated below.
Case I-A fragmented shale column 900 feet high located between 1,400 and 2,300 feet below the surface in the well shown in FIG. 1. FIG. I shows the position of the shale column as position number I. The shale richness distribution is also shown in FIG. 1. This fragmented shale column is heated to 800 F. by the injection of hot gases into the top of the chimney to recover the shale oil. The resulting retorted fragmented shale bed permeability is estimated to be 20 Darcy.
II-ll-A fragmented shale column 900 feet high located between 1,650 and 2,550 feet below the surface in the well shown in FIG. 1. FIG. 1 shows this position of the shale column as position number 2. Again the shale richness distribution is shown in FIG. I. This fragmented shale column is heated to 800 F. by the injection of hot gases into the top of the chimney to recover the shale oil. The resulting permeability of the retorted fragmented shale bed is estimated to be I20 Darcy.
Case lII-This case is identical to case I except that the shale is heated to 600 F. for 350 hours before the shale temperature is increased to 800" F. This low temperature heating results in a permeability of the retorted fragmented shale bed of 150 Darcy.
Case IV-This case is identical to case II except that the shale is heated to 600 F. for 350 hours before the shale temperature is increased to 800 F. This low temperature heating results in a permeability of the retorted fragmented shale bed of 540 Darcy.
It can be seen that by placing the fragmented shale column in such a position that the richer shale I) are nearer the top (case II compared with case I) that the permeability of the retorted shale bed was increased from 30 to I20 Darcy. It can also be seen that by preheating the shale to 600 F. for 350 hours the retorted shale bed permeability was increased from 30 to I50 Darcy (comparison of case III with case I) and from to 540 Darcy (comparison of case IV to case II) for chimney positions numbers 1 and 2, respectively.
It should especially be noted that a combination of chimney placement and preheating increased the retorted shale bed permeability from 30 to 540 Darcy (comparison of case IV to case I).
Although in the above example the shale was preheated at 600 F. to increase the retorted shale bed permeability, other preheat temperatures and other times can be used. The low temperature (500 to 650 F.) history of the shale is a determining factor in maintaining a high bed permeability. There are several methods that can be used to heat the shale to a low temperature and then continue the retorting at a temperature in excess of 700 and in general about 800 F. One method which uses the injection of hot inert gases and recycle produced gases is outlined below:
A typical operation to achieve the required low temperature heating of the shale would be to inject hot gases into the top of the nuclear chimney and withdraw the gases and generated oil from the chimney bottom. The temperature of the injected gases is increased over a several-day span to a temperature in the 500-575 F. range. Thereafter, the temperature is increased very slowly (perhaps, for example, l/2 to 2 F. per day) to a temperature in the range of 600-650 F. Then the temperature is raised relatively rapidly to the final retorting temperature of at least 700' and generally to about 800 F. This temperature history is represented graphically in FIG. -2. The result of a temperature history such as the above is that the shale throughout the chimney is subjected to a low temperature history without the necessity of an accurate knowledge of the magnitude of the heat losses to the chimney wall. As the heat is carried down the chimney by the injected and created gases, the shale will be heated at a lower rate, thus subjecting the lower shales to a longer effective low temperature history.
it appears that the critical temperature span for subjecting the shale to an effective low temperature history is from about 500 to 650 F. The data in table 1 illustrate that prolonged low temperature heating of the shale at 650 F. had only a minor influence upon the retorted shale bed permeability. The time required to achieve an appreciable permeability benefit at a temperature of 500 F. would be too long for practical application; therefore, temperatures below 500 F. are thus excluded. indeed, the critical temperature range is probable within 550 to 625 F. However, in practice the shale could be heated slowly over a broader temperature range (such as 500 to 650 F.) to insure a sufficient low temperature history even in the presence of natural variations in heating rates due to the heat lost to the chimney wall and variations in the gas flow due to variations in the shale bed permeability.
TABLE I Compaction of a bed of fragmented green river oil shale Average particle size of Shale iregrichness Permea- Time Lithomented by bility of held static shale, Fischer shale bed at "1" pressure diameter assay at 800 F. (hrs.) (p.s.i.) (in.) (gaL/ton) (Darcy) 550 0. 23 26. 9 0. 91 0 450 0. 23 26. 9 2. 0 300 0. 23 26. 9 8. 5 0 150 0. 23 26. 9 74. 7 B 350 550 0. 23 26. 9 5. 7 0 900 0. 23 18. 3 6. 3 0 460 0. 23 18. 3 79. 4 0 450 0. 046 17. 6 10. 7 0 450 0. 046 26. 6 0. 93 0 560 0. 054 23. 7 O. 69 0 450 0. 054 23. 7 1. 9 0 450 0. 054 23. 7 1. 4 B 340 450 0. 054 23. 7 5. 4 b 150 460 0. 064 23. 7 l. 6 0 300 0. 23 37. 4 4. 4
e "T" in these runs was 600 F. b "'I in this run was 650 F.
rapid pyrolysis temperature range) is effective in maintaining a higher permeability. A comparison of runs 12 and 14 shows that a temperature 650 F. had little effect upon the final permeability at 800 F. Heating preferably is achieved by the use of hot inert gases and the use of recycle produced gases.
1. An improved process of recovering shale oil from a subsurface oil shale formation containing hydrocarbonsnot n aturally flowable into a well bore traversing said formation with a nuclear explosive device which comprises:
a. forming a nuclear chimney in said formation by detonating a strategically located nuclear explosive device so that the nuclear chimney formed following detonation contains a mass of fractured and broken oil shale with lean shale at the bottom of the chimney and rich shale near the top of the chimney,
b. passing a heated gas through said mass of fractured and broken oil shale at a temperature such that said mass is preheated to a temperature not in excess of 650 F. and maintaining the heating of said mass for a prolonged period of time of at least 30 days sufficient to bake the oil shale to reduce or substantially prevent plastic flow during heating of the oil shale and thereby maintain permeability of the shale without compaction of the shale causing P g.
c. retorting said preheated fractured shale by elevating the temperature of same to above 700 F., the retort temperature of said fractured shale, so as to pyrolyze and produce oil therefrom, and
d. recovering produced oil from said formation.
2. A process according to claim 1 for forming said nuclear chimney in step (a) which comprises the additional steps of:
l. drilling an access well into the formation,
2. performing a geological survey of the oil shale along the length of said access well to determine the location of a rich shale section and an underlying lean shale section,
3. Disposing a nuclear device in said formation and positioning same in said formation so that upon subsequent detonation of said device the fragmented shale forming the nuclear produced chimney is lean at the bottom and the thick sections of rich shale are near the top of the chimney, and
4. detonating the nuclear device to create a cavity in said formation, which cavity at least partially fills with collapsing oil shale to form said chimney of fractured and crumbled shale with lean shale at the bottom and rich shale near the top of said chimney.
3. A process according to claim 1 wherein i. said fractured shale is produced by first preheating same to a temperature of 500-575 F. for a period of time of at least 30 days,
2. the temperature of the preheated fractured shale is increased to 600-650 F. at a rate of l/2 to 2 F. per day and said heating is continued within the latter temperature range for 3 to 70 days, and
3. said preheated fractured shale is then rapidly heated to 700-800 F., the final retorting temperature, and continued within this temperature range until said fractured shale is essentially produced.
4. A process according to claim 1 wherein said heating gas is introduced into the top of the chimney and said oil is recovered principally from the bottom thereof.
5. A process according to claim 1 wherein said gas comprises essentially combustion gases.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US3342257 *||30 Dec 1963||19 Sep 1967||Standard Oil Co||In situ retorting of oil shale using nuclear energy|
|US3465819 *||13 Feb 1967||9 Sep 1969||American Oil Shale Corp||Use of nuclear detonations in producing hydrocarbons from an underground formation|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3882941 *||17 Dec 1973||13 May 1975||Cities Service Res & Dev Co||In situ production of bitumen from oil shale|
|US4047760 *||28 Nov 1975||13 Sep 1977||Occidental Oil Shale, Inc.||In situ recovery of shale oil|
|US4149595 *||27 Dec 1977||17 Apr 1979||Occidental Oil Shale, Inc.||In situ oil shale retort with variations in surface area corresponding to kerogen content of formation within retort site|
|US4227574 *||8 Jan 1979||14 Oct 1980||Occidental Oil Shale, Inc.||Locating the top of an in situ oil shale retort for ease of ignition|
|US4577908 *||19 Sep 1984||25 Mar 1986||Phillips Petroleum Company||Method for in situ shale oil recovery|
|US7011154 *||24 Oct 2002||14 Mar 2006||Shell Oil Company||In situ recovery from a kerogen and liquid hydrocarbon containing formation|
|US7040397||24 Apr 2002||9 May 2006||Shell Oil Company||Thermal processing of an oil shale formation to increase permeability of the formation|
|US7644765||19 Oct 2007||12 Jan 2010||Shell Oil Company||Heating tar sands formations while controlling pressure|
|US7673681||19 Oct 2007||9 Mar 2010||Shell Oil Company||Treating tar sands formations with karsted zones|
|US7673786||20 Apr 2007||9 Mar 2010||Shell Oil Company||Welding shield for coupling heaters|
|US7677310||19 Oct 2007||16 Mar 2010||Shell Oil Company||Creating and maintaining a gas cap in tar sands formations|
|US7677314||19 Oct 2007||16 Mar 2010||Shell Oil Company||Method of condensing vaporized water in situ to treat tar sands formations|
|US7681647||19 Oct 2007||23 Mar 2010||Shell Oil Company||Method of producing drive fluid in situ in tar sands formations|
|US7683296||20 Apr 2007||23 Mar 2010||Shell Oil Company||Adjusting alloy compositions for selected properties in temperature limited heaters|
|US7703513||19 Oct 2007||27 Apr 2010||Shell Oil Company||Wax barrier for use with in situ processes for treating formations|
|US7717171||19 Oct 2007||18 May 2010||Shell Oil Company||Moving hydrocarbons through portions of tar sands formations with a fluid|
|US7730945||19 Oct 2007||8 Jun 2010||Shell Oil Company||Using geothermal energy to heat a portion of a formation for an in situ heat treatment process|
|US7730946||19 Oct 2007||8 Jun 2010||Shell Oil Company||Treating tar sands formations with dolomite|
|US7730947||19 Oct 2007||8 Jun 2010||Shell Oil Company||Creating fluid injectivity in tar sands formations|
|US7735935||1 Jun 2007||15 Jun 2010||Shell Oil Company||In situ thermal processing of an oil shale formation containing carbonate minerals|
|US7785427||20 Apr 2007||31 Aug 2010||Shell Oil Company||High strength alloys|
|US7793722||20 Apr 2007||14 Sep 2010||Shell Oil Company||Non-ferromagnetic overburden casing|
|US7798220||18 Apr 2008||21 Sep 2010||Shell Oil Company||In situ heat treatment of a tar sands formation after drive process treatment|
|US7798221||31 May 2007||21 Sep 2010||Shell Oil Company||In situ recovery from a hydrocarbon containing formation|
|US7831134||21 Apr 2006||9 Nov 2010||Shell Oil Company||Grouped exposed metal heaters|
|US7832484||18 Apr 2008||16 Nov 2010||Shell Oil Company||Molten salt as a heat transfer fluid for heating a subsurface formation|
|US7841401||19 Oct 2007||30 Nov 2010||Shell Oil Company||Gas injection to inhibit migration during an in situ heat treatment process|
|US7841408||18 Apr 2008||30 Nov 2010||Shell Oil Company||In situ heat treatment from multiple layers of a tar sands formation|
|US7841425||18 Apr 2008||30 Nov 2010||Shell Oil Company||Drilling subsurface wellbores with cutting structures|
|US7845411||19 Oct 2007||7 Dec 2010||Shell Oil Company||In situ heat treatment process utilizing a closed loop heating system|
|US7849922||18 Apr 2008||14 Dec 2010||Shell Oil Company||In situ recovery from residually heated sections in a hydrocarbon containing formation|
|US7860377||21 Apr 2006||28 Dec 2010||Shell Oil Company||Subsurface connection methods for subsurface heaters|
|US7866385||20 Apr 2007||11 Jan 2011||Shell Oil Company||Power systems utilizing the heat of produced formation fluid|
|US7866386||13 Oct 2008||11 Jan 2011||Shell Oil Company||In situ oxidation of subsurface formations|
|US7866388||13 Oct 2008||11 Jan 2011||Shell Oil Company||High temperature methods for forming oxidizer fuel|
|US7912358||20 Apr 2007||22 Mar 2011||Shell Oil Company||Alternate energy source usage for in situ heat treatment processes|
|US7931086||18 Apr 2008||26 Apr 2011||Shell Oil Company||Heating systems for heating subsurface formations|
|US7942197||21 Apr 2006||17 May 2011||Shell Oil Company||Methods and systems for producing fluid from an in situ conversion process|
|US7942203||4 Jan 2010||17 May 2011||Shell Oil Company||Thermal processes for subsurface formations|
|US7950453||18 Apr 2008||31 May 2011||Shell Oil Company||Downhole burner systems and methods for heating subsurface formations|
|US7986869||21 Apr 2006||26 Jul 2011||Shell Oil Company||Varying properties along lengths of temperature limited heaters|
|US8011451||13 Oct 2008||6 Sep 2011||Shell Oil Company||Ranging methods for developing wellbores in subsurface formations|
|US8027571||21 Apr 2006||27 Sep 2011||Shell Oil Company||In situ conversion process systems utilizing wellbores in at least two regions of a formation|
|US8042610||18 Apr 2008||25 Oct 2011||Shell Oil Company||Parallel heater system for subsurface formations|
|US8070840||21 Apr 2006||6 Dec 2011||Shell Oil Company||Treatment of gas from an in situ conversion process|
|US8083813||20 Apr 2007||27 Dec 2011||Shell Oil Company||Methods of producing transportation fuel|
|US8113272||13 Oct 2008||14 Feb 2012||Shell Oil Company||Three-phase heaters with common overburden sections for heating subsurface formations|
|US8146661||13 Oct 2008||3 Apr 2012||Shell Oil Company||Cryogenic treatment of gas|
|US8146669||13 Oct 2008||3 Apr 2012||Shell Oil Company||Multi-step heater deployment in a subsurface formation|
|US8151880||9 Dec 2010||10 Apr 2012||Shell Oil Company||Methods of making transportation fuel|
|US8151907||10 Apr 2009||10 Apr 2012||Shell Oil Company||Dual motor systems and non-rotating sensors for use in developing wellbores in subsurface formations|
|US8162059||13 Oct 2008||24 Apr 2012||Shell Oil Company||Induction heaters used to heat subsurface formations|
|US8162405||10 Apr 2009||24 Apr 2012||Shell Oil Company||Using tunnels for treating subsurface hydrocarbon containing formations|
|US8172335||10 Apr 2009||8 May 2012||Shell Oil Company||Electrical current flow between tunnels for use in heating subsurface hydrocarbon containing formations|
|US8177305||10 Apr 2009||15 May 2012||Shell Oil Company||Heater connections in mines and tunnels for use in treating subsurface hydrocarbon containing formations|
|US8191630||28 Apr 2010||5 Jun 2012||Shell Oil Company||Creating fluid injectivity in tar sands formations|
|US8192682||26 Apr 2010||5 Jun 2012||Shell Oil Company||High strength alloys|
|US8196658||13 Oct 2008||12 Jun 2012||Shell Oil Company||Irregular spacing of heat sources for treating hydrocarbon containing formations|
|US8200072||24 Oct 2003||12 Jun 2012||Shell Oil Company||Temperature limited heaters for heating subsurface formations or wellbores|
|US8220539||9 Oct 2009||17 Jul 2012||Shell Oil Company||Controlling hydrogen pressure in self-regulating nuclear reactors used to treat a subsurface formation|
|US8224163||24 Oct 2003||17 Jul 2012||Shell Oil Company||Variable frequency temperature limited heaters|
|US8224164||24 Oct 2003||17 Jul 2012||Shell Oil Company||Insulated conductor temperature limited heaters|
|US8224165||21 Apr 2006||17 Jul 2012||Shell Oil Company||Temperature limited heater utilizing non-ferromagnetic conductor|
|US8230927||16 May 2011||31 Jul 2012||Shell Oil Company||Methods and systems for producing fluid from an in situ conversion process|
|US8233782||29 Sep 2010||31 Jul 2012||Shell Oil Company||Grouped exposed metal heaters|
|US8238730||24 Oct 2003||7 Aug 2012||Shell Oil Company||High voltage temperature limited heaters|
|US8240774||13 Oct 2008||14 Aug 2012||Shell Oil Company||Solution mining and in situ treatment of nahcolite beds|
|US8256512||9 Oct 2009||4 Sep 2012||Shell Oil Company||Movable heaters for treating subsurface hydrocarbon containing formations|
|US8261832||9 Oct 2009||11 Sep 2012||Shell Oil Company||Heating subsurface formations with fluids|
|US8267170||9 Oct 2009||18 Sep 2012||Shell Oil Company||Offset barrier wells in subsurface formations|
|US8267185||9 Oct 2009||18 Sep 2012||Shell Oil Company||Circulated heated transfer fluid systems used to treat a subsurface formation|
|US8272455||13 Oct 2008||25 Sep 2012||Shell Oil Company||Methods for forming wellbores in heated formations|
|US8276661||13 Oct 2008||2 Oct 2012||Shell Oil Company||Heating subsurface formations by oxidizing fuel on a fuel carrier|
|US8281861||9 Oct 2009||9 Oct 2012||Shell Oil Company||Circulated heated transfer fluid heating of subsurface hydrocarbon formations|
|US8327681||18 Apr 2008||11 Dec 2012||Shell Oil Company||Wellbore manufacturing processes for in situ heat treatment processes|
|US8327932||9 Apr 2010||11 Dec 2012||Shell Oil Company||Recovering energy from a subsurface formation|
|US8353347||9 Oct 2009||15 Jan 2013||Shell Oil Company||Deployment of insulated conductors for treating subsurface formations|
|US8355623||22 Apr 2005||15 Jan 2013||Shell Oil Company||Temperature limited heaters with high power factors|
|US8381815||18 Apr 2008||26 Feb 2013||Shell Oil Company||Production from multiple zones of a tar sands formation|
|US8434555||9 Apr 2010||7 May 2013||Shell Oil Company||Irregular pattern treatment of a subsurface formation|
|US8448707||28 May 2013||Shell Oil Company||Non-conducting heater casings|
|US8459359||18 Apr 2008||11 Jun 2013||Shell Oil Company||Treating nahcolite containing formations and saline zones|
|US8485252||11 Jul 2012||16 Jul 2013||Shell Oil Company||In situ recovery from a hydrocarbon containing formation|
|US8536497||13 Oct 2008||17 Sep 2013||Shell Oil Company||Methods for forming long subsurface heaters|
|US8555971||31 May 2012||15 Oct 2013||Shell Oil Company||Treating tar sands formations with dolomite|
|US8562078||25 Nov 2009||22 Oct 2013||Shell Oil Company||Hydrocarbon production from mines and tunnels used in treating subsurface hydrocarbon containing formations|
|US8579031||17 May 2011||12 Nov 2013||Shell Oil Company||Thermal processes for subsurface formations|
|US8606091||20 Oct 2006||10 Dec 2013||Shell Oil Company||Subsurface heaters with low sulfidation rates|
|US8608249||26 Apr 2010||17 Dec 2013||Shell Oil Company||In situ thermal processing of an oil shale formation|
|US8627887||8 Dec 2008||14 Jan 2014||Shell Oil Company||In situ recovery from a hydrocarbon containing formation|
|US8631866||8 Apr 2011||21 Jan 2014||Shell Oil Company||Leak detection in circulated fluid systems for heating subsurface formations|
|US8636323||25 Nov 2009||28 Jan 2014||Shell Oil Company||Mines and tunnels for use in treating subsurface hydrocarbon containing formations|
|US8662175||18 Apr 2008||4 Mar 2014||Shell Oil Company||Varying properties of in situ heat treatment of a tar sands formation based on assessed viscosities|
|US8701768||8 Apr 2011||22 Apr 2014||Shell Oil Company||Methods for treating hydrocarbon formations|
|US8701769||8 Apr 2011||22 Apr 2014||Shell Oil Company||Methods for treating hydrocarbon formations based on geology|
|US8739874||8 Apr 2011||3 Jun 2014||Shell Oil Company||Methods for heating with slots in hydrocarbon formations|
|US8752904||10 Apr 2009||17 Jun 2014||Shell Oil Company||Heated fluid flow in mines and tunnels used in heating subsurface hydrocarbon containing formations|
|US8789586||12 Jul 2013||29 Jul 2014||Shell Oil Company||In situ recovery from a hydrocarbon containing formation|
|US8791396||18 Apr 2008||29 Jul 2014||Shell Oil Company||Floating insulated conductors for heating subsurface formations|
|US8820406||8 Apr 2011||2 Sep 2014||Shell Oil Company||Electrodes for electrical current flow heating of subsurface formations with conductive material in wellbore|
|US8833453||8 Apr 2011||16 Sep 2014||Shell Oil Company||Electrodes for electrical current flow heating of subsurface formations with tapered copper thickness|
|US8851170||9 Apr 2010||7 Oct 2014||Shell Oil Company||Heater assisted fluid treatment of a subsurface formation|
|US8857506||24 May 2013||14 Oct 2014||Shell Oil Company||Alternate energy source usage methods for in situ heat treatment processes|
|US8881806||9 Oct 2009||11 Nov 2014||Shell Oil Company||Systems and methods for treating a subsurface formation with electrical conductors|
|US9016370||6 Apr 2012||28 Apr 2015||Shell Oil Company||Partial solution mining of hydrocarbon containing layers prior to in situ heat treatment|
|US9022109||21 Jan 2014||5 May 2015||Shell Oil Company||Leak detection in circulated fluid systems for heating subsurface formations|
|US9022118||9 Oct 2009||5 May 2015||Shell Oil Company||Double insulated heaters for treating subsurface formations|
|US9033042||8 Apr 2011||19 May 2015||Shell Oil Company||Forming bitumen barriers in subsurface hydrocarbon formations|
|US9051829||9 Oct 2009||9 Jun 2015||Shell Oil Company||Perforated electrical conductors for treating subsurface formations|
|US9127523||8 Apr 2011||8 Sep 2015||Shell Oil Company||Barrier methods for use in subsurface hydrocarbon formations|
|US9127538||8 Apr 2011||8 Sep 2015||Shell Oil Company||Methodologies for treatment of hydrocarbon formations using staged pyrolyzation|
|US9129728||9 Oct 2009||8 Sep 2015||Shell Oil Company||Systems and methods of forming subsurface wellbores|
|US20020053429 *||24 Apr 2001||9 May 2002||Stegemeier George Leo||In situ thermal processing of a hydrocarbon containing formation using pressure and/or temperature control|
|US20020053432 *||24 Apr 2001||9 May 2002||Berchenko Ilya Emil||In situ thermal processing of a hydrocarbon containing formation using repeating triangular patterns of heat sources|
|US20020056551 *||24 Apr 2001||16 May 2002||Wellington Scott Lee||In situ thermal processing of a hydrocarbon containing formation in a reducing environment|
|US20020057905 *||24 Apr 2001||16 May 2002||Wellington Scott Lee||In situ thermal processing of a hydrocarbon containing formation to produce oxygen containing formation fluids|
|US20020077515 *||24 Apr 2001||20 Jun 2002||Wellington Scott Lee||In situ thermal processing of a hydrocarbon containing formation to produce hydrocarbons having a selected carbon number range|
|US20040108111 *||24 Apr 2001||10 Jun 2004||Vinegar Harold J.||In situ thermal processing of a coal formation to increase a permeability/porosity of the formation|
|US20040140096 *||24 Oct 2003||22 Jul 2004||Sandberg Chester Ledlie||Insulated conductor temperature limited heaters|
|US20040177966 *||24 Oct 2003||16 Sep 2004||Vinegar Harold J.||Conductor-in-conduit temperature limited heaters|
|U.S. Classification||166/247, 166/254.2|
|International Classification||E21B43/24, E21B43/16|