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 numberUS3578080 A
Publication typeGrant
Publication dateMay 11, 1971
Filing dateJun 10, 1968
Priority dateJun 10, 1968
Publication numberUS 3578080 A, US 3578080A, US-A-3578080, US3578080 A, US3578080A
InventorsClosmann Philip J
Original AssigneeShell Oil Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method of producing shale oil from an oil shale formation
US 3578080 A
Abstract  available in
Images(3)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

United States Patent [72] Inventor Philip J- Cl smann 3,322,194 5/1967 Strubhar 166/271X Houston, Tex. 3,342,257 9/1967 Jacobs et al. 166/247 [2]] App]. No. 735,684 3,346,044 10/1967 Slusser 166/259X [22] Flld June 10, 1968 3,352,355 11/1967 Putman l66/271X [3;] 2 9 2: 3,448,801 6/ 1969 Closmann et a1. 166/247 1 Sslgnee York y Primary Examiner-Stephen J. Novosad Att0meysJ H. McCarthy and Louis J. Bovasso [54] SHALE OIL FROM AN ABSTRACT: A method of producing shale oil from a subterranean oil shale formation by exploding a relatively high ener- 4 Claims, 5 Drawing Figs.

- gy explosive device therein thereby forming a chimney of rub- [52] US. Cl 166/248, ble within the formation having fractures extending from the l66/ 166/299 chimney into the formation. A plurality of spaced wells are ex- [51] Int. Cl ..E2lb 43/24, tended into the formation radially outwardly from the chim- E211) E211) 43/29 ney and adjacent to at least some of the fractures. Fluid flow [50] Fleld 0 Search 166/247, paths are formed from the wells through the fractures into the 259, 305, 307 chimney and fluid is circulated from the wells through these fluid flow paths and into the chimney at rates creating a pres- [56] References C'ted sure drop from the wells to the chimney. Oil shale-reactive UNITED STATES PATENTS properties are imparted to the circulating fluid whereby the 1,422,204 7/1922 Hoover et a1. 166/272X fluid reacts with the oil shale thereby moving solid com- 2,630,307 3/1953 Martin 166/259UX ponents thereof into void spaces formed within the chimney 2,795,279 6/ 1957 Sarapuu 166/248 thereby increasing the permeability of the oil shale formation 3,106,244 10/1963 Parker 166/248 relative to the permeability of the chimney in regions sur- 3,316,020 4/1967 Bergstrom 166/259X rounding the chimney.

GAS O|L F HEAT SEPARATOR EXCHANGER g f a r ,1, HEATER .../I/z/ll/: z] 's/ //Z// z z E z ,1 1E ll, 0 //;////zI//= V VII/A711! l6 ,1 g 32 ill? 5 t i i i ill? PATENTEU um 1 1971 3578' 080 sum 1 or s HIS ATTORNEY PATENTEninnm 1 3.578080 f sum 2 or 3 I I h HAT SEPARAT ExcMANGER 5 5/02 I v HEATER III/z 1/11 mvzufom PHILIP J- CLOSMANN FIGA BY:

ms ATTORNEY PATENTEU m I 1 m1 SHEET 3 OF 3 GAS GAS

SEPARATOR SEPARATOR OIL HEAT EXCHANGER OIL HEAT EXCHANGER //////W//fi//////////K//////K/ 1 l FIG.5

INVENTOR:

PHILIP J. CLOSMANN BYz zd HIS ATTORNEY BACKGROUND OF THE INVENTION 1 Field of the Invention The present invention relates to a method of producing shale oil from a subterranean oil shale formation more particularly, it relates to a method for creating a zone of relatively high permeability within an oil shale formation.

2. Description of the Prior Art The use of contained nuclear explosions has been proposed in subterranean oil shale fomtations in an attempt to break up the oil shale formation so that shale oil can be recovered from the rubbled zone by known techniques such as in situ retortmg.

Experience has shown that when a relatively high energy device, such as a nuclear bomb, is exploded within a subterranean earth formation, an almost spherical cavity filled with hot gases is formed. This cavity expands until the pressure within the cavity equals that of the overburden. On cooling, the roof of the cavity collapses since, generally, it cannot support itself, and a so-called chimney" develops. Chimney growth ceases when the rock pile substantially fills the cavity, or a stable arch develops. In both cases, a substantially void space is formed below the overburden and above the rubble contained within the chimney. Surrounding the chimney is a fractured zone which results from the shock of the nuclear explosion.

One of the chief uncertainties with regard to the effects 'of nuclear explosions within a subterranean oil shale formation is the permeability distribution surrounding the cavity andsubsequent chimney produced by a detonation. Evidence from prior explosions suggests that permeability of the fragmented zone may drop very rapidly with distance radially out from the primary rubble zone. A high and uniform permeability is important in order to provide maximum sweep efficiency in any underground hydrocarbon recovery process.

The permeability in the region immediately surrounding the primary rubble zone of an oil shale formation may be increased by surrounding a primary high energy explosive device with a plurality of radially-placed devices of explosive energy, nuclear or nonnuclear. As disclosed in a copending application to Closmann et al..Ser. No. 653,139, filed July 13, 1967, now US. Pat. No. 3,448,801, the radially-placed devices are programmed to be detonated by either the main shock wave from the primary device or exploded by other means after the main shock wave has passed. The explosive energy devices are preferably detonated between-the time the spherical cavity caused by the explosion of the primary device begins to expand radially outwardly and the time at which a chimney is formed by the collapse of the cavity roof. Heated fluids may then be circulated through the chimney and surrounding rubbled areas by known means so as to increase the volume of the permeable zone swept by the circulating fluid.

While a mass of oil shale is being pyrolyzed by the heated fluids, fluid products are removed from surface portions of the kerogen comprising the oil shale as rapidly as they are formed. But, since the mass of oil shale is impermeable, the fluid which is formed within the mass remains in place until its pressure becomes sufficient to fracture and displace the solid components that block its flow. In the oilshale around .a nucleardetonation chimney, the least resistant direction in which solid components may be moved tends to be toward the chimney where solid materials can be squeezed together or pushed towards a void space formed at the top of thechimney.

SUMMARY OF THE INVENTION It is an object of this invention to improve the distribution of the permeability in and around a chimney formed within an oil shale formation while shale oil is being produced.

It is a further object of this invention to increase the rate at which the permeability in the outlying areas from a chimney formed within an oil shale formation is increased relative to that within the chimney.

These objects are accomplished by exploding a relatively high energyexplosive device within an oil shale formation thereby forming a chimney of rubble within the formation having fractures extending from the chimney through the formation. A plurality of spaced wells are extended into the formation radially outwardly from the chimney and adjacent to at least some of the fractures. Fluid flow paths are formed from the wells through the fractures into the chimney and fluid is circulated through these fluid flow paths and into the chimney at rates creating a pressure drop from the wells to the chimney. Oil shale-reactive properties are imparted to the circulating fluid whereby the fluid reacts with the oil shale thereby moving solid components thereof into void spaces formed within the chimney increasing the permeability of the oil shale formation relative to the permeability of the chimney in regions surrounding the chimney.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a vertical cross-sectional view of an oil shale formation prior to detonating a plurality of explosive devices DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows subterranean oil shale formation 11 having a primary explosive device 12 located within the formation 11. Primary explosive device 12 is preferably surrounded by a plurality of explosive devices 13. Devices 13 may be of lesser energy than device 12, if desired. However, optimum results may be obtained by the formation of substantially equal-size chimneys as will be discussed further hereinbelow. The device 12 can be either nuclear or nonnuclear; if a nuclear device is detonated in the subterranean oil shale formation 11, a strong shock wave from the nuclear device begins to move radially outwardly, vaporizing, melting, crushing, cracking and displacing the oil shale formation 11. After the shock wave has passed, the high-pressure vaporized material expands, and a generally spherical cavity (i.e., the central cavity 14 in FIG. 2) is formed which continues to grow until the internal pressure is balanced by the lithostatic pressure. The cavity 14 persists for a variable time depending on the composition of the oil shale formation 11 and then collapses to form a chimney 15 (FIG. 3). Collapse progresses upwardly until the volume initially in the cavity is distributed between the fragments of the oilshale formation 11. The size of the cylindrical rubble zone (i.e., the chimney" 15) formed by the collapse of the cavity 14 can be estimated from the depth and explosive yield of the nuclear device and properties of the earth formations.

A zone of permeability 17 within the fragmented oil shale formation is formed surrounding the chimney" 15 as can be seen in FIG. 3. The permeability of this zone 17 maybe preferably increased by surrounding the primary explosive device which formed the central cavity with a plurality of devices I3. For example, in FIG. I, a primary nuclear explosive device 12 is surrounded by explosive devices 13, equally spaced from each other and radially spaced from the primary explosive device 12. These devices 13 are preferably .on substantially the same horizontal plane as the primary nuclear device (see FIG. 1) and 500 to l,000 feet from the nearest part of the outer wall of the central cavity 14 produced by the explosion of the high energy nuclear device 12. As discussed above, the devices 13 preferably have an energy yield substantially equal to that of the primary high energy nuclear device 12 and can be either nuclear or nonnuclear.

The explosive devices 13 form cavities 18 (FIG. 2) when detonated, surrounded by fractured zones 19 as can be seen in FIG. 2. The devices 13 may be preset with detonating means adjusted to explode upon arrival of the main shock wave from the explosion of the primary explosive device 12. Alternatively, the devices 13 may be suitably delayed to explode after passage of the main shock wave. Of course, another characteristic of the explosion of the primary explosive device 12 can be utilized to detonate the devices 13, as, for example, changes in temperature or pressure as a result of the explosion of the primary explosive device.

Because of this time delay, either detonating the devices 13 upon arrival of the main shock wave or after the main shock wave has passed but before the central cavity 14 becomes filled with rubble due to the chimney collapse from above, the shock waves from the secondary explosions (that is, the explosions of the devices 13) will cause spalling into the central cavity. The movement of rock towards the central cavity 14 due to the satellite explosions will enhance the permeability in the regions between these explosions and the central cavity 14, by allowing development of a greater void space in this region. This void space, indicated as a zone of increased permeability 17 in the drawings, has a high and uniform permeability in the fragmented oil shale formation 11.

Thus, chimney includes a lower rubble zone 21 and an upper void space 22. Similar chimneys formed by the detonation of the devices 13 also include lower rubble zones and upper void spaces. For example, as illustrated in FIG. 3, two such chimneys 23, and 24, formed, for example by devices such as explosive devices 13, form lower rubble zones and 26 and upper void spaces 27 and 28, respectively. A plurality of fractures 29 are formed between the satellite chimneys" and the central chimney 15 as illustrated in FIG. 3. Fractures 29 are generally substantially horizontally extensive through formation 11; however fractures 9 may also be substantially vertically extensive. A more detailed discussion of the formation of chimneys 15, 23 and 24 appears in the aforementioned copending application to Closmann et al., Ser. No. 653,139, filed July 13, I967, now US. Pat. No. 3,448,801. Altematively to forming chimneys 25 and 26 as indicated hereinabove, after chimney 15 is formed, fluid flow paths through fractures 29 may be formed by hydraulically or explosively fracturing wells 32 and 33 by fracturing procedures such as those known in the art, so that the latter fractures communicate with fractures 29.

Referring to FIG. 3, in accordance with the teachings of this invention, a producing well borehole 30 is extended from the earth surface 31 into communication with the lower portion of chimney 15. A plurality of outlying injecting well boreholes, such as well boreholes 32 and 33, shown in FIG. 2, are extended from earth surface 31 into communication with the upperportion of chimneys 25 and 26, respectively. Well boreholes 30, 32, and 33 are preferably cased as is well known in the art. The vertical intervals, that is, the chimneys" or rubbled or fractured regions into which the outlying wells are opened are preferably located at substantially the same depth as the chimney l5.

Fluid flow paths are then formed from the outlying well boreholes 32 and 33 to chimney 30 through the fractures extending out from chimneys 25 and 26 into communication with interconnecting fractures 29. These flow paths are preferably enlarged by circulating acidizing fluids from well boreholes 32 and 33 through fractures 29 and into chimney 30. Another method of forming or enlarging such fluid flow paths from the outlying wells to the central chimney 15 is to fracture the oil shale formation by flowing an electrical current between electrodes that contact the oil shale. A more detailed description of this process for fracturing an oil shale is given in an article by Melton and Cross, Journal of Petroleum Technology, .lan., 1968, pp. 37-41, which is incorporated herein by reference. The electrical energy may be applied prior to or during the initial circulation of fluid from the outlying wells to central chimney 15 as will be explained further hereinbelow.

In operation, fluid is injected into the satellite chimneys 25 and 26 through well boreholes 32 and 33, through fractures 29 and into the rubble zone 21 of chimney 15 as indicated by the arrows in FIG. 3. Fluids are then produced from central chimney 15 through producing well borehole 30.

A preferred method for producing shaleoil from the oil shale formation 11 of FIG. 3 is to inject a combustion-supporting gas, such as air or oxygen, into the satellite well boreholes after the hydrocarbons in the formation have been raised to ignition temperature. This may be accomplished by various means well known in the art, such as by lowering suitable heaters down well boreholes 32 and 33. A combustion zone is thus formed which gradually moves through the intervening rock between chimneys 25, 26, and 15 by means of fractures 29 into central chimney 15. As this rock is heated, it expands, releasing gas and other products and effectively provides additional flow paths for the injected fluid. At the same time, as the rock nearest the satellite chimneys expands, it expands or moves towards the central rubble chimney 15 thus tending to relieve some of the thermal stress generated by the hot fluids. This method makes the porosity distribution of oil shale formation 11 more uniform by developing some porosity adjacent the outside of chimneys 25 and 26 where the rock is first heated and by exerting pressure due to thermal expansion on the central rubble zone (i.e., chimney 15) thus tending to reduce the porosity of central chimney 15.

As an alternative to air or oxygen, the injected fluid may be a heated gas, liquid, or steam. If steam is used, thermal expansion of the rock takes place. After the rock is heated, combustion may again be carried out. The displaced fluids are produced from the bottom of the central chimney 15 to which they drain and out of production well borehole 30. As it becomes desirable to treat more of the upper regions of the rock, the production well borehole 30 may be shut off at the bottom and perforated at progressively higher places within the central chimney. This is illustrated in FIG. 4 where the lower end of the well borehole 30 is packed off, such as by a wireline-set or a tubing-set packer 34, and a perforating device 35 is lowered'into well borehole 30 by means of cable 36. The casing of well borehole 30 is then perforated by device 35 as is well known in the art thus forming a plurality of perforations 37 which may be progressively moved up well borehole 30 as the central chimney 15 is produced.

Alternatively to injecting a fluid such as disclosed hereinabove, acid may be injected from the outlying chimneys through fractures 29 and into central chimney 15. The acid flows through fractures 29, leaching out part of the rock and developing some heating. This acid is produced from the central chimney 15. In some cases, fine suspended material (e.g., produced by decomposition of the oil shale during combustion or acidizing) may be carried from the inlets of this flow system (e.g., chimneys 25 and 26 and/or fractures communicating with wells 32 and 33) and deposited near the central chimney 15. This action makes the overall flow path more uniform. This step may be then followed by hot fluid injection or a combustion process such as previously discussed hereinabove.

In both cases, that is, the circulation of a fluid such as a gas or an acid, when the oil shale-reactive properties of a fluid comprise or include a temperature sufficient to pyrolyze kerogen in the oil shale and the fluid is flowing through interconnected fractures between chimneys at a rate providing a pressure gradient along the flow path, pyrolysis-induced fracturing tends to enhance the movement of solids and fluids in the direction of the lowest pressure. Within a nuclear detonation chimney, such as, for example, chimney 15, the permeability increases with increases in height and becomes substantially infinite in the void at the top. Since the fractures that are formed by a nuclear detonation are initiated by a radially expanded bubble centered in the lower portion of the region that becomes a chimney, the density of radially extending fractures is less at depths near the top of the chimney. Conventional equipment and techniques, such as heaters, pumps, a separator and a heat exchanger, may be used for pressurizing, heating, injecting, producing, and separating components of the fluid circulated through the oil shale formation 11. The production of the fluid may be aided by downhole pumping means, not shown, or restricted to the extent necessary to maintain the selected pressure within the oil shale formation 1 1.

When oil shale pyrolyzing fluid is circulated along a path extending through fractures, from the outlying wells to a nuclear detonation chimney, in the initial stages and at depth near the top of the central chimney, the permeability is the least, the pressure gradient is the highest and the resistance to solidmaterial displacement toward the central chimney is the least. As fractures are formed by the pyrolysis of the oil shale, they tend to form first in the regions which are contacted by the hottest portion of the fluid, and these regions are located near the outlying wells. The largest fractures tend to form at depths near the top of the central chimney where the resistance to the movement of solid material is the least. in addition, the relatively high permeability within the central chimney tends to decrease as solids move into the central chimney. This results in both the creation of additional permeability in regions surrounding the central chimney and an increase in the permeability in the surrounding regions relative to that within the central chimney. The creation of additional permeability in regions surrounding the central chimney increases the amount of permeable oil shale material that is available for depletion and the increase in permeability in the surrounding regions increases the uniformity of the depletion.

The fluid being circulated through central chimney is preferably injected into all the satellite chimneys or intervals into which outlying wells have been opened and, at least initially, produced from near the bottom of central chimney 15. The fluid circulation may advantageously be initiated by circulating air or relatively cool liquid to sweep out any shale oil released by the nuclear detonation. When oil shale-reactive properties imparted to the circulating liquid comprise or include a temperature sufflcient to pyrolyze the oil shale, the method of this invention provides a unique advantage over processes in which production wells are extended through the chimney, or through the immediately adjacent relatively highly fractured zone, to provide conduits arranged for a downward advance of a combustion front. in the process, when the advance of a heat front towards the production well borehole 30 subjects the borehole 30 to a high temperature, the production well borehole conduit or conduits, i.e., the well casing or tubing string, may be shortened to terminate in a relatively cool zone near the top of central chimney 15. After an extended and relatively uniform permeability distribution has been obtained by circulating fluid from the outlying wells to central chimney 15, the flow direction may be reversed, with central chimney 15 now operating as a very large diameter central injection well as illustrated in HG. 5. Such a flow reversal allows the pyrolysis products to be produced from the tops of the intervals (for example, chimneys 23 and 24) into which the outlying wells are opened. This capability of the present process to avoid heat damage to the production well conduits provides material improvement in the economy of the shale oil-production process.

As discussed hereinabove, the oil shale-reactive properties imparted to the circulating fluid may advantageously comprise or include acidizing properties in respect to mineral components, such as the carbonates, in the oil shale. In addition to acids that are commonly used in well acidization treatments, acids suitable for use in the process of this invention comprise those derived from sulfur, such as sulfuric acid; sulfurous acid, etc., and/or their anhydrides, such as oleurn, sulfur trioxide, sulfur dioxide and the like, and nitric acid and acids derived from the oxides of nitrogen and the like. The sulfur-derived acids are not generally used in well acidization treatments because of the tendency of the resultant aqueous solutions of such acids to precipitate polyvalent metal sulfates, sulfltes, etc. In the initial stages of the present process, such precipitates tend to be deposited within the large voids in the central chimney 15, where the flow rate drop relative to those in the smaller void spaces in the fractures 29 leading central chimney 15. Thus, in the process of this invention, such a initial dissolving of solid materials and subsequent precipitation of solid materials is advantageous since it increases the rate at which the permeability in the outlying regions is increased I relative to that within the central chimney l5.

Thus, the specific arrangement of injection and production locations and fluid pressure gradients, together with the fracturing'pattem of a nuclear detonation and the behavior of a mass of oil shale undergoing pyrolysis, improves the distribution of the penneability of the oil shale formation in and around a nuclear detonation-created chimney while shale oil is being produced.

The outlying chimneys may be formed either in the manner disclosed hereinabove as disclosed in the aforementioned copending application to Closmann et al. In either case, it is preferable that the outlying chimneys be located at substantially the same depth as the central chimney. Optimum results are obtained when the outlying chimneys are substantially equal to the height of the central chimney, such as when the outlying chimneys are formed by the use of explosive devices of relatively similar explosive energy as that used to form the central chimney.

1 claim: l. A method of producing shale oil from a subterranean oil shale formation comprising the steps of:

placing a relatively high energy explosive device within the formation; 7

exploding the relatively high energy explosive device within the oil shale formation thereby forming a cavity within the oil shale formation having a roof beneath the overburden which subsequently collapses to form a chimney of rubble within the oil shale formation and extends fractures from the chimney through the oil shale formation;

extending a plurality of spaced wells into said oil shale formation at locations radially outwardly from said chimney and adjacent to at least some of said fractures;

forming fluid flow paths from said wells through said interconnecting fractures to said chimney;

circulating fluid into and them from said wells and through said interconnecting fractures into said chimney and out of said chimney at rates creating a pressure drop from the wells to said chimney;

imparting oil shale-reactive properties to said circulating fluid whereby said fluid reacts with said oil shale thereby moving solid components thereof into void spaces formed within said chimney thereby increasing the permeability of the oil shale formation relative to the permeability of the chimney in regions surrounding said chimney;

forming a plurality of fractured regions adjacent at least some of said fractures from said chimney, said fractured regions being located at substantially the same depth of said first mentioned chimney;

subsequently extending fractures from said plurality of spaced wells into communication with said fractures from said chimney;

said plurality of fractured regions being formed by placing a plurality of devices of substantially lesser explosive energy than said relatively high energy explosive device within the formation; and

spacing the plurality of devices such a distance from the relatively high energy device that the exploding of the plurality of devices causes fractures from said spaced wells to extend into communication with fractures formed by said high energy explosive device.

2. A method of producing shale oil from a subterranean oil shale formation comprising the steps of:

placing a relatively high energy explosive device within the formation;

exploding the relatively high energy explosive device within the oil shale formation thereby forming a cavity within the oil shale formation havinga roof beneath the overburden which subsequently collapses to form a chimney of rubble within the oil shale formation-and extends fractures from the chimney through the oil shale formation;

extending a plurality of spaced wells into said oil shale formation at locations radially outwardly from said chimney and adjacent to at least some of said fractures;

forming fluid flow paths from said wells through said interconnecting fractures to said chimney;

circulating fluid into and then from said wells and through said interconnecting fractures into said chimney and out of said chimney at rates creating a pressure drop from the wells to said chimney;

imparting oil shale-reactive properties to said circulating fluid whereby said fluid reacts with said oil shale thereby moving solid components thereof into void spaced formed within said chimney thereby increasing the permeability of the oil shale formation relative to the permeability of the chimney in regions surrounding said chimney;

extending a well into said chimney adjacent substantially the lower portion thereof;

circulating said fluid from said plurality of wells through said fractures, into said chimney and out of said well; and

producing fluid from said well at progressively higher places within said chimney.

3. A method of producing shale oil from a subterranean oil shale formation comprising the steps of:

placing a relatively high energy explosive device within the formation;

exploding the relatively high energy explosive device within the oil shale formation thereby forming a cavity within the oil shale formation having a roof beneath the overburden which subsequently collapses to form a chimney of rubble within the oil shale formation and and extends fractures from the chimney through the oil shale formation.

extending a plurality of spaced wells into said oil shale formation at locations radially outwardly from said chimney and adjacent to at least some of said fractures;

forming fluid flow paths from said wells through said interconnecting fractures to said chimney by electrically fracturing the portion of the oil shale formation between the chimney and said plurality of spaced wells;

circulating fluid into and then from said wells and through said interconnecting fractures into said chimney and out of said chimney at rates creating a pressure drop from the wells to said chimney; and

imparting oil shale-reactive properties to said circulating fluid whereby said fluid reacts with said oil shale thereby moving solid components thereof into void spacesformed within said chimney thereby increasing the permeability of the oil shale formation relative to the permeability of the chimney in regions surrounding said chimney.

4. A method of producing shale oil from a subterranean oil shale formation comprising the steps of:

placing a relatively high energy explosive devicewithin the formation;

exploding the relatively high energy explosive device within the oil shale formation thereby forming a cavity within the oil shale formation having a roof beneath the overburden which subsequently collapses to form a chimney of rubble within the oil shale formation and extends fractures from the chimney through the oil shale formation;

extending a plurality of spaced wells into said oil shale formation at locations radially outwardly from said chimney and adjacent to at least some of said fractures;

forming fluid flow paths from said wells through said interconnecting fractures to said chimney;

circulating fluid into and then from said wells and through said interconnecting fractures into said chimney and out of said chimney at rates creating a pressure drop from the wells to said chimney;

imparting oil shale-reactive properties to said circulating 'fluid whereby said fluid reacts with said oil shale thereby moving solid components thereof into void spaces formed within said chimney thereby increasing the permeability of the oil shale formation relative to t e permeability of the chimney in regions surrounding said chimney; stopping the circulating of fluid from said wells through said fractures and out of said chimney; and circulating fluid from said chimney through said fractures and out of said wells while imparting oil shale-reactive properties to said fluid circulating from said chimney and out of said wells.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1422204 *Dec 19, 1919Jul 11, 1922Brown Thomas EMethod for working oil shales
US2630307 *Dec 9, 1948Mar 3, 1953Carbonic Products IncMethod of recovering oil from oil shale
US2795279 *Apr 17, 1952Jun 11, 1957Electrotherm Res CorpMethod of underground electrolinking and electrocarbonization of mineral fuels
US3106244 *Jun 20, 1960Oct 8, 1963Phillips Petroleum CoProcess for producing oil shale in situ by electrocarbonization
US3316020 *Nov 23, 1964Apr 25, 1967Mobil Oil CorpIn situ retorting method employed in oil shale
US3322194 *Mar 25, 1965May 30, 1967Mobil Oil CorpIn-place retorting of oil shale
US3342257 *Dec 30, 1963Sep 19, 1967Standard Oil CoIn situ retorting of oil shale using nuclear energy
US3346044 *Sep 8, 1965Oct 10, 1967Mobil Oil CorpMethod and structure for retorting oil shale in situ by cycling fluid flows
US3352355 *Jun 23, 1965Nov 14, 1967Dow Chemical CoMethod of recovery of hydrocarbons from solid hydrocarbonaceous formations
US3448801 *Jul 13, 1967Jun 10, 1969Shell Oil CoMethod for creating a permeable fragmented zone within an oil shale formation
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3730270 *Mar 23, 1971May 1, 1973Marathon Oil CoShale oil recovery from fractured oil shale
US3952801 *Jul 26, 1974Apr 27, 1976Occidental Petroleum CorporationMethod for igniting oil shale retort
US4015664 *Apr 14, 1976Apr 5, 1977Gulf Research & Development CompanyShale oil recovery process
US4025115 *Apr 14, 1975May 24, 1977Occidental Petroleum CorporationMethod of enhancing recovery of oil from pillars adjacent in situ oil shaft retort
US4045085 *Apr 14, 1975Aug 30, 1977Occidental Oil Shale, Inc.Fracturing of pillars for enhancing recovery of oil from in situ oil shale retort
US4082146 *Mar 24, 1977Apr 4, 1978Occidental Oil Shale, Inc.Low temperature oxidation of hydrogen sulfide in the presence of oil shale
US4086962 *Mar 24, 1977May 2, 1978Occidental Oil Shale, Inc.Decreasing hydrogen sulfide concentration of a gas
US4086963 *Mar 24, 1977May 2, 1978Occidental Oil Shale, Inc.Method of oxidizing hydrogen sulfide
US4093026 *Apr 15, 1977Jun 6, 1978Occidental Oil Shale, Inc.Removal of sulfur dioxide from process gas using treated oil shale and water
US4121663 *Mar 24, 1977Oct 24, 1978Occidental Oil Shale, Inc.Removing hydrogen sulfide from a gas
US4125157 *Jul 12, 1977Nov 14, 1978Occidental Oil Shale, Inc.Removing sulfur dioxide from gas streams with retorted oil shale
US4135579 *Sep 30, 1977Jan 23, 1979Raytheon CompanyIn situ processing of organic ore bodies
US4140181 *Dec 9, 1977Feb 20, 1979Occidental Oil Shale, Inc.Two-stage removal of sulfur dioxide from process gas using treated oil shale
US4151877 *May 13, 1977May 1, 1979Occidental Oil Shale, Inc.Determining the locus of a processing zone in a retort through channels
US4239283 *Mar 5, 1979Dec 16, 1980Occidental Oil Shale, Inc.In situ oil shale retort with intermediate gas control
US4243100 *May 4, 1979Jan 6, 1981Occidental Oil Shale, Inc.Operation of in situ oil shale retort with void at the top
US6874580 *Oct 25, 2002Apr 5, 2005Conocophillips CompanyMethod for enhancing well productivity
US7357180 *Apr 22, 2005Apr 15, 2008Shell Oil CompanyInhibiting effects of sloughing in wellbores
US7644765Oct 19, 2007Jan 12, 2010Shell Oil CompanyHeating tar sands formations while controlling pressure
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
US7681647Oct 19, 2007Mar 23, 2010Shell Oil CompanyMethod of producing drive fluid in situ in tar sands formations
US7683296Apr 20, 2007Mar 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
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
US7798221May 31, 2007Sep 21, 2010Shell Oil CompanyIn situ recovery from a hydrocarbon containing formation
US7831133Apr 21, 2006Nov 9, 2010Shell Oil CompanyInsulated conductor temperature limited heater for subsurface heating coupled in a three-phase WYE configuration
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
US7836949Mar 27, 2007Nov 23, 2010Halliburton Energy Services, Inc.Method and apparatus for controlling the manufacture of well treatment fluid
US7841394Dec 1, 2005Nov 30, 2010Halliburton Energy Services Inc.Method and apparatus for centralized well treatment
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
US7841425Apr 18, 2008Nov 30, 2010Shell Oil CompanyDrilling subsurface wellbores with cutting structures
US7845411Oct 19, 2007Dec 7, 2010Shell Oil CompanyIn situ heat treatment process utilizing a closed loop heating system
US7849922Apr 18, 2008Dec 14, 2010Shell Oil CompanyIn situ recovery from residually heated sections in a hydrocarbon containing formation
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
US7866388Oct 13, 2008Jan 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
US7931082 *Oct 16, 2007Apr 26, 2011Halliburton Energy Services Inc.,Method and system for centralized well treatment
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
US7942203Jan 4, 2010May 17, 2011Shell Oil CompanyThermal processes for subsurface formations
US7946340Oct 16, 2007May 24, 2011Halliburton Energy Services, Inc.Method and apparatus for orchestration of fracture placement from a centralized well fluid treatment center
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
US8011451Oct 13, 2008Sep 6, 2011Shell Oil CompanyRanging methods for developing wellbores in subsurface formations
US8027571Apr 21, 2006Sep 27, 2011Shell Oil CompanyIn situ conversion process systems utilizing wellbores in at least two regions of a formation
US8042610Apr 18, 2008Oct 25, 2011Shell Oil CompanyParallel heater system for subsurface formations
US8070840Apr 21, 2006Dec 6, 2011Shell Oil CompanyTreatment of gas from an in situ conversion process
US8083813Apr 20, 2007Dec 27, 2011Shell Oil CompanyMethods of producing transportation fuel
US8113272Oct 13, 2008Feb 14, 2012Shell Oil CompanyThree-phase heaters with common overburden sections for heating subsurface formations
US8146661Oct 13, 2008Apr 3, 2012Shell Oil CompanyCryogenic treatment of gas
US8146669Oct 13, 2008Apr 3, 2012Shell Oil CompanyMulti-step heater deployment in a subsurface formation
US8151880Dec 9, 2010Apr 10, 2012Shell Oil CompanyMethods of making transportation fuel
US8151907Apr 10, 2009Apr 10, 2012Shell Oil CompanyDual motor systems and non-rotating sensors for use in developing wellbores in subsurface formations
US8162059Oct 13, 2008Apr 24, 2012Shell Oil CompanyInduction heaters used to heat subsurface formations
US8162405Apr 10, 2009Apr 24, 2012Shell Oil CompanyUsing tunnels for treating subsurface hydrocarbon containing formations
US8172335Apr 10, 2009May 8, 2012Shell Oil CompanyElectrical current flow between tunnels for use in heating subsurface hydrocarbon containing formations
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
US8196658Oct 13, 2008Jun 12, 2012Shell Oil CompanyIrregular spacing of heat sources for treating hydrocarbon containing formations
US8200072Oct 24, 2003Jun 12, 2012Shell Oil CompanyTemperature limited heaters for heating subsurface formations or wellbores
US8220539Oct 9, 2009Jul 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
US8224165Apr 21, 2006Jul 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
US8233782Sep 29, 2010Jul 31, 2012Shell Oil CompanyGrouped exposed metal heaters
US8238730Oct 24, 2003Aug 7, 2012Shell Oil CompanyHigh voltage temperature limited heaters
US8240774Oct 13, 2008Aug 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
US8261832Oct 9, 2009Sep 11, 2012Shell Oil CompanyHeating subsurface formations with fluids
US8267170Oct 9, 2009Sep 18, 2012Shell Oil CompanyOffset barrier wells in subsurface formations
US8267185Oct 9, 2009Sep 18, 2012Shell Oil CompanyCirculated heated transfer fluid systems used to treat a subsurface formation
US8272455Oct 13, 2008Sep 25, 2012Shell Oil CompanyMethods for forming wellbores in heated formations
US8276661Oct 13, 2008Oct 2, 2012Shell Oil CompanyHeating subsurface formations by oxidizing fuel on a fuel carrier
US8281861Oct 9, 2009Oct 9, 2012Shell Oil CompanyCirculated heated transfer fluid heating of subsurface hydrocarbon formations
US8327681Apr 18, 2008Dec 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
US8355623Apr 22, 2005Jan 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
US8448707Apr 9, 2010May 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
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
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
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
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
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
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
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
US9399905May 4, 2015Jul 26, 2016Shell Oil CompanyLeak detection in circulated fluid systems for heating subsurface formations
US20040206506 *Oct 25, 2002Oct 21, 2004Montgomery Carl T.Method for enhancing well productivity
US20050269088 *Apr 22, 2005Dec 8, 2005Vinegar Harold JInhibiting effects of sloughing in wellbores
US20070121649 *Nov 30, 2005May 31, 2007Cicchetti Christopher JHigh density optical network access switch
US20070137857 *Apr 21, 2006Jun 21, 2007Vinegar Harold JLow temperature monitoring system for subsurface barriers
US20080236818 *Mar 27, 2007Oct 2, 2008Dykstra Jason DMethod and Apparatus for Controlling the Manufacture of Well Treatment Fluid
US20090071647 *Apr 7, 2008Mar 19, 2009Vinegar Harold JThermal processes for subsurface formations
US20090095482 *Oct 16, 2007Apr 16, 2009Surjaatmadja Jim BMethod and System for Centralized Well Treatment
US20090194273 *Oct 16, 2007Aug 6, 2009Surjaatmadja Jim BMethod and Apparatus for Orchestration of Fracture Placement From a Centralized Well Fluid Treatment Center
US20110170843 *Sep 29, 2010Jul 14, 2011Shell Oil CompanyGrouped exposed metal heaters
Classifications
U.S. Classification166/248, 166/299, 166/247, 166/259
International ClassificationE21B43/24, E21B43/25, E21B43/16, E21B43/263
Cooperative ClassificationE21B43/2403, E21B43/2635
European ClassificationE21B43/24F, E21B43/263F