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Publication numberUS3233670 A
Publication typeGrant
Publication dateFeb 8, 1966
Filing dateJul 18, 1960
Priority dateJul 18, 1960
Publication numberUS 3233670 A, US 3233670A, US-A-3233670, US3233670 A, US3233670A
InventorsCorneil Hampton G, Suttle Jr Andrew D, Thompson Gene D
Original AssigneeExxon Production Research Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Additional recovery of hydrocarbons from a petroliferous formation
US 3233670 A
Abstract  available in
Images(4)
Previous page
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Claims  available in
Description  (OCR text may contain errors)

1966 e. D. THOMPSON ETAL 3,233,670

ADDITIONAL RECOVERY OF HYDROCARBONS FROM A PETROLIFEROUS FORMATION Filed July 18, 1960 4 Sheets-Sheet 1 PRODUCING WELL OVERBURDEN CAPROCK FORMATION I4 POROUS OIL FORMATION ENTRY Io .WELL 20 PREDOMINATELY CALCIUM CARBONATE ROCK FORMATION FIG. I.

R J I ....L 1 MNEH I E OL N N T R EPTO O WMU T 1M M TD N DWO ET ERP NDM ENA GAH Y B 1966 s. D. THOMPSON ETAL 3,233,670

ADDITIONAL RECOVERY OF HYDROCARBONS FROM A PETROLIFEROUS FORMATION Filed July 18, 1960 4 Sheets-Sheet 2 R I C P F A N OS T m K N EG NW V D m n E NH 0 .Z

FLOWING OIL REA OF COOLED GAS ZONE WATER POROUS OIL FORMATION G N ML Ul- DE OW R P x, m w n R U w; R E V L O L E W m 0 2 E O 4 I W I T E Jw m PREDOMINATELY CALCIUM CARBONATE ROCK FORMATION INVENTORS. THOMPSON,

o. SUTTLE,JR., N s. CORNEIL,

ATTORNEY.

Feb. 8, 1966 s. D. THOMPSON ETAL 3,233,670

ADDITIONAL RECOVERY OF HYDROCARBONS FROM A PETROLIFEROUS FORMATION Filed July 18, 1960 4 Sheets-Sheet 5 ENTRY WATER WELL INJECTION WELL OVERBURDEN CAPROCK FORMATION POROUS OIL FORMATION CAPROOK FORMATION CONSOLIDATED FORMATION PREDOMINATELY CALCIUM CAREONATE ROCK FORMATION INVENTORS GENE D. THOMPSON, ANDREW D. SUTTLE,JR. 4 HAMPTON G. CORNEIL,

ATTORNEY.

1966 e. D. THOMPSON ETAL 3,233,670

ADDITIONAL RECOVERY OF HYDROCARBONS FROM A PETROLIFEROUS FORMATION Flled July 18, 1960 4 Sheets-Sheet 4 ACCESS WELL PRODUCING WE L INJECTION WELL PLANT IIG OVERBURDEN CAPROOK FORMATION POROUS OIL FORMATION INTERMEDIATE FORMATIONS CONSOLIDATED FORMATION PREDOMINATELY CALCIUM CARBONATE ROCK FORMATION D. THOMPSON,

TON G. CORNEIL,

FIG.5. an/(gla ATTORNEY.

GENE ANDREW D. SUTTLE,JR. HAMP United States Patent 7 3,233,670 ADDITIONAL RECOVERY OF HYDROCARBONS FROM A PETROLIFEROUS FORMATION Gene D. Thompson, Houston, Tex., Andrew Suttle, Jr., Jackson, Miss, and Hampton G. Cornell, Baytown, Texz, assignoi's, by mesne assignments, to Esso Production Research Company, Houston, Tex., a corporation of Delaware Filed July 18, 1960, Ser. No. 43,586 Claims. (Cl. 16611) This invention relates to a method for generating gases. More particularly, the present invention relates to a method for generating a subsurface high temperature gas deposit for the additional recovery of oil or gas from a porous Subsurface hydrocarbon bearing formation, the generation of power, etc.

.It is known that an enhanced recovery of oil can be obtained from subsurface porous petroliferous. formations by additional recovery techniques wherein a gas such as carbon dioxide, normally gaseous hydrocarbons, steam, etc. or a mixture thereof are injected into the formation in order to provide a driving mechanism to cause hydrocarbons in place to flow from an injection well toward a producing well (see, for example, W'horton et al., US. Patent No. 2,623,596). l

A serious problem is encountered with additional recovery operations with respect to the acquisition and injcction of the large quantities of the inert gases or hot gases or both that are required for the increased recovery operations. The cost of generating such gases above ground are significant and, likewise, tl 1e cost of pumping equipment and injection wells for in ecting the gases into the petroliferous formation 18 significant.

The present invention is directed to a method for the subsurface generation of large quantities of inert gases and to the utilization of such gases for the increased recovery of hydrocarbons from a petroliferous subsurface formation. The present invention is particularly useful for increased recovery operations wherein the subsurface 'petroliferous formation is associated with a geological formation containing a predominant amount of a carbonate rock.

Briefly, an access well is drilled from the surface of the earth into the carbonate rock formation. After suitable prefracturing of the petroliferous formation "(If necessary) a nuclear fusion device or a nuclear fission device is spotted in the access well in the carbonate rock formation. The access well is closed and the nuclear device is actuated, whereby a number of events occur.

During the actuation step, a substantial void 18 formed which is surfaced with a shell of molten rock containing a predominant amount of the radioactive entities formed by the actuation. Collapse of the roof will form a chimney above the spherical void to thereby provide a rubble filled cavity. The high temperatures generated by the actuation will decompose large and significant quantities of the carbonate rock into metal oxides such as calcium oxide, magnesium oxide, etc. and carbon dioxide, and may also cause reactions to occur with respect to such water and organic matter as may be present.

Alkaline earth metal oxides such as magnesium or calcium oxide form a magmatic type of eutectic with alkaline earth metal carbonates at temperatures in excess of about 1200 C. and this magma seals off voids or cracks or other permeations in the carbonate rock formation. As a consequence, high temperature carbon dioxide is provided for any desired purpose (e.g., a gas type of drive) together with a body of confined high temperature magma. As will be hereinafter described, the carbon dioxide that is formed in this manner may be used for an increased oil recovery operation and simultaneously or subsequently, the thermal energy of the magma may be utilized to generate gases for useful purposes such as power generation, supplemental additional hydrocarbon recovery operation, etc. The resulting gases which contact oil or condensate will also swell the fluids and improve mobility.

The invention will be further described in the accompanying drawings herein.

FIGURE 1 is a schematic evaluation view in section illustrating the one mode of increased recovery which may be practiced in accordance with the present invention;

FIGURE 2 is an evaluational fragmentary view of a portion of a petroliferous formation illustrating the manner in which the multi-type gas drive is accomplished in accordance with the present invention; and

FIGURES 3 to 5 are schematic evaluational views in section illustrating modified methods of practicing the present invention.

Turning now to FIGURE 1, there is shown a sectional view of a geologic sequence extending from the surface of the earth 10 through an overburdened formation or formations 12 and through an oil impervious caip rock formation 14 such as shale, compacted sandstone, etc. overlying a porous dil formation 16. Formation 16 is representative of the various type of petroliferous oil formations which are encountered below the ground such as porous sandstone formations, porous carbonate rock, limestone (e.g., submerged coral reefs), etc.

There is also shown a carbonate rock formation 18 as a host formation for the nuclear device and it may be characterized as a formation which contains a significant amount (e.g., 30 to weight percent) of a carbonate rock. Representative formations of this nature include dolomite formations, limestone formations, chalk formations, etc. and related formations containing significant quantities of carbonate minerals (e.g., calcite, dolomite, magnesite, aragonite, etc.).

' In order to initiate the additional recovery operation of the present invention, an access well 20 and a recovery well 22 are drilled from the surface of the earth. It will be understood that it will normally be preferred to utilize a plurality of existing or newly drilled producing wells 22 which are spaced about the access well 2th in any normal injecting-producing pattern (e.g., a 5-spot pattern surrounded With multiple rows of recovery Wells).

The present invention finds particular utility with respect to highly compacted petroliferous formations which are comparatively impermeable to injected fluids, since the permeability of such formations can be improved by prefracturing, by seismic fracturing caused by actuation of the nuclear device or by post-fracturing with the hot, high pressure gases formed by the actuation.

Accordingly, if the porous oil formation 16 is a coniparatively impermeable formation of this character, the access Well 20 is initially drilled from the surface into the porous oil formation 16. Next, the formation is fractured by any suitable fracturing technique, such as the method disclosed in Brown et al. U.S. Patent No. 2,779,735 if a prefracturing technique is to be employed. The prefracturing step will result in the opening of fractures (e.g., sand propped fractures) in the formation.

After completion of the. preliminary fracturing step, if such a step is necessary, the access well 20 is further drilled into the underlying carbonate rock formation, which in the embodiment of FIG. 1, directly underlies the porous oil formation.

The extent to which the access well 20 is drilled into the carbonate rock formation 18 will be dependent upon a number of factors.

Firstly, the size of the nuclear device is predetermined.

The size of a nuclear device is normally expressed in terms of the energy release which is obtained by actuation of the nuclear device. Thus, a nuclear device liberating an amount of energy equal to the amount of energy obtained by turning 1000 tons (1 kiloton) of TNT (trinitrotoluene) it is conventionally defined as a 1 kiloton device and is defined as ore which releases 10 cal.

It is desirable to confine the explosive force of the nuclear device below the surface of the ground and, therefore, the device should be actuated at a depth from the surface of the earth 10 which is at least sufiicient to satisfy the equation:

D=KE

wherein D is the depth in feet;

K is a constant having a value within the range of 1000 E is the energy of the nuclear device in terms of megaton equivalents of TNT; and

n is an exponent having a value between 0.1 and 0.5.

Preferably, K is about 3000, and n is about 0.3.

The size of the cavern that initially will be formed upon actuation of the nuclear device is dependent upon a number of factors including the porosity of the formation and the resistance of the formation to rupture or fracture. Generally speaking, the radius of the cavern may be estimated from the formula:

R=Radius in Meters E :Energy of device in kilotons P=Pressure, atmospheres Also, it is desirable that the chimney formed by collapse of the roof of the initial spherical cavern be of a height such that the cap rock formation 14 above the petroliferous formation 16 is not completely pierced. The height and shape of the chimney will be determined, of course, by the nature of the carbonate rock formation and the formations overlying such carbonate rock formations.

As has been indicated, the nuclear device to be utilized is a nuclear fission device or a nuclear fusion device.

The nuclear device to be utilized in accordance with the present invention may be defined as a nuclear device which will release substantially all its available energy within not more than about 60 minutes after the establishment of criticality by changes involving exoergic transformation. Normally, the energy will be released within less than 1 second.

The fuel components of the nuclear device will include nuclear fission components, nuclear fusion components, or both. The fuel component should preferably consume comparatively low cost and abundant isotopes. A table of useful fusion fuel reactants, the fusion products resulting therefrom and the energy release obtainable are listed in the following table:

TABLE I Useful nuclear reactions Reaction: Q, mev. (1) D (d,n)l-le 3.25 (2) D (d,p)T 4.08 (3) T (d,n)He 17.6 (4) He (d,p)He 18.3 (5) Li (d,a)He 22.4 (6) Li"(p, x)He 17.3

Further examples of suitable nuclear reactions which may be employed, together with the energy obtainable therefrom, are set forth in Table II.

' 4 TABLE II Selected exoergic reactions of low Z isotope Reaction: Q, mev. (1) p (I1,'y)D 223010.005 (2) D (I1,'y)T 6.2510008 (3) D (p,'y)He 55010.03 (4) D (d,p)T 403010.006 (5) D (d,n)He 326510009 (6) T (p,'y)He 2 19.710.04 (7) T (d,n)He 2 1757810030 (8) He (t,p)He 11.181007 (9) He (n,p)T 0.76610.010 (10) He (d,p)He 18.451017 (11) He (d,'-, )Li 16310.2 (12) He (He ,p)Li 10.861015 (13) Li (n,a)T 4.80410.022 (14) Ll (P,oc)H 402310003 (15) Li (d,ot)I-Ie 2239610012. (16) Li (d,p)Li 502810003 (17) Li (d,n)Be" 3.401005 (18) Li (t,d)Li' 0.98210.007 (19) Li (He ,p)Be 16.601? (20) Li (p,a)He 1734610010 (21) Li"'(p;y)l3e 17.1102 (22) Li' (d,a)He 14210.1 (23) Li (d,n)Be 15.0101 24) Li"(t,a)I-Ie 91910.03 (25) B6 2oc 009410.001

1 Preferred reactions.

2 Reactions giving the most favorable results.

The fusion reaction is normally triggered. by a critical mass of a fissile material such as U U Pu which is initially of a non-critical configuration and which is brought into a condition of critically when the device is to be fired in order to initiate the exoergic transformation.

In some situations it is desirable to obtain the desired amount of energy solely from nuclear fission reactions. However, for the greatest economy, it is preferable to employ nuclear fusion reactions. Preferably, the nuclear device to be utilized is a nuclear fusion device having energy equivalent within the range of about to kilotons of TNT.

The general sequence of events that will transpire on actuation of the nuclear device is similar to that described in U.C.R.L., publication 5124 of the University of California Laurence Radiation Laboratory entitled The Underground Detonation of September 19, 1957-Ranier Operation Plumb Bob dated February 4, 1958.

Thus, a cavern will be formed initially due to expansion of the fire ball. The surface of the cavity will be defined by a zone of heated rock and extending outwardly from this zone will be a spherical zone of crushed rock. Thereafter, collapse of part of the surface of the upper part of the cavern will occur whereby a chimney will be formed extending upwardly from the zone of actuation. Thus, in FIG. 1, there is shown at the end of the actuation step, a lower zone A of crushed rock, an intermediate zone B of fused rock derived from the surface of the initial cavity. This zone will contain a major portion of the bomb debris. Extending upwardly of zone B is a zone C of crushed rock and rubble derived from the chimney 21 extending upwardly into the porous oil formation 16.

Since temperatures in excess of 3000 C. are generated by actuation, large quantities of the carbonate rock will be decomposed into carbon dioxide and metal oxides including a substantial amount of calcium and magnesium oxide. Calcium oxides melt at a temperature of about 2570 C. and form a magmatic eutectic with solid calcium oxide at a temperature of about 1200 C. In similar fashion, magma is formed from the other alkaline earth metal carbonates. This highly viscose magma is therefore formed in the zone by high temperature contact of the molten alkaline earth metal oxide (e.g., magnesium or surface 30.

calcium oxide) with solid alkaline earth metal oxides (e.g., calcium or magnesium oxide). As a consequence, any fissures or fractures or other voids about the cavern which are not self-sealing are effectively sealed by this magma. The same effect occurs in the portion of the chimney 21 extending through the carbonate rock formation because hot high pressure carbon dioxide and gases associated therewith will cause melting and magmatic jeutectic formation to occur about the surface of the chimney.

As a consequence, the high temperature, high pressure carbonfdioxide is maintained within the void caused by actuation of the nuclear device, and it is not difused throughout the carbonate rock formation through fissures and cracks. As a further consequence, the thermal energy released by the nuclear device is retained adjacent the situs of actuation because the magmatic eutectic prevents the entry of formation fluids such as water, which would otherwise tend to. rapidly dissipate the heat.

The thermal energy that is retained in this fashion may be used for a'number of purposes, as hereinafter described.

- In FIG. la chimney 21 is shown'as extending upwardly into the porous formation16. A magmatic eutectic lwill coat the, fractures of the porous oil formation 16 and, as a consequence, the hot carbon dioxide will intrude into the formation 16 through natural fissures, fissures caused by .the detonation, fissures formed by prefracturing or combinations thereof to initiate additional recovery operations. In addition, the pressure and heat of the hot carbon dioxide may. be suflicient to cause post-fracturing of the formation, or the extension or further development of existing fraction patterns.

, Turning now to. FIG. 2, there is schematically shown a fractured, exposedsurface 30 of the petroliferous forma- -tiou.16.into which hot carbondioxide flows. The hot 'carbon. dioxide will react with petroliferous materials immediately adjacent the surface 30 to decompose the same .int0;.hot gases including hydrogen, carbon monoxide, etc. .As a consequence of this reaction, and of the need for heating the formation, the initially introduced carbon dioxide will be formed into a bank of relatively cool gases comprising carbon dioxide, carbon monoxide, hydrogen, etc.1 As further; quantities of carbon. dioxide intrude the Iformation the cool gases will flow further. into the formation to thereby provide a driving bank for displacing flowable petroliferous fluids in the zone 16 whereby such caused'to flow by a bank of cool gas as defined above, which is shown in FIG. 2 as zone II. Adjacent zone II is'a zone III which may be characterized as a heat reac- Rtionzone. Within this zone, nonflowable petroliferous fluids are heated to temperatures in excess of about 400 1 C. by the hot carbon dioxide, and, as a result, chemical 'interrea-ctions occur between the residual petroliferous fluids and the hot carbon dioxide whereby the driving bank Qfrelatively cool gasis formed. Hot gas is introduced into the formation zone 16 in zone IV, adjacent exposed A Stated differently, zone IV is a heated zone substantially free from petroliferous fluids containing predominantly thehot gas introduced i n the surface 30. s

Zone IIIcomprises, as indicated, a reaction zone wherein the hotgas reacts with the residual hydrocarbons present in the formation. As aconsequence, additional gases are formed which have a lowertemperature, whereby a bank of cooled gas is formed which drives the flowable petroliferous fluids of,zone I toward producing wells.

After the passage of a suitable period of time, pressure equilibrium will be reached due to the flow of carbon dioxide into the porous formation 16. Prior to or subsemay terminate at its quent to this time, additional quantities of hot gas or steam may be provided, as shown schematically in FIG. 3.

Turning now to FIG. 3, an injection well 40 is drilled from the surface to a point in the cavern formed by the actuation of the nuclear device and entry into the cavern is established either by drilling the well thereinto or by stopping the well a short distance from the surface and then fracturing the formation in order to provide entrance.

A liquid which is capable of reacting with the hot magma in the cavern is then injected in the well 40.

For example, the liquid may be a low quality, heavy residual crude oil fraction which will be decomposed in the cavern into hydrogen and light hydrocarbon gases such as methane, etc. and residual carbon. Decomposition of the low quality hydrocarbon will cause additional quantities of gas to be generated which will flow into the porous oil fraction 16 in the manner indicated above.

As an alternate or supplementary measure, water may be injected through the well 40. The thus injected water will slake the lime in the cavern and significant quantities a predominantly carbonate rock formation 50 underlying an impervious consolidated formation 52 which, in turn underlies a porous oil formation 54. Porous oil formation 54 will, in turn underlie a cap rock formation 56 which, in turn, will underlie overburden 58.

In this situation, an entry well 60 may be drilled from the surface into the carbonate rock formation 52 in the manner described above with respect to FIG. 1 and a nuclear device may be spotted in the carbonate rock formation 50 and actuated therein in the manner described above with respect to FIG. 1 whereby there is formed a subsurface'cavern 62 containing high temperature, high pressure carbon dioxide and surfaced with a glass such as a magmatic eutectic of calcium oxide. The cavern 62 may thus contain a lower zone A of crushed rock, an intermediate zone B of fused rock derived from the surface of the initial cavity and a zone C composed of crushed rock and rubble formed from a chimney 64 extending upwardly from the zone of actuation. The chimney 64 may extend upwardly from the host rock formation 50 into consolidated formation 52 or, alternately,

upper end within the host rock formation (not shown). I

In order to produce oil from porous oil formation 54 overlying the host rockformation 50, there is provided ,a producing well 66 or a plurality of such producing Wells chimney 64 of the cavern 62 and the well is closed at the surface with a suitable high pressure packing Christmas tree schematically shown by the reference numeral 70. 'As a consequence, hot carbon dioxide will flow from the chimney 64 thorugh the well 68 up to porous formation 54 and will thereafter enter into formation 54 to promote additional recovery operations in the manner described above with reference to FIGURE 2.

When the supply of carbon dioxide is substantially exhausted or at any otherdesired time, an additional in jection well 72 may be drilled from the surface into the chimney 64. Water may be injected thereinto for the production of steam within the cavern, such steam flowing upwardly through access Well 68 into producing formation 54-; to further assist in additional recovery operations. Alternately, a liquid which is capable of reacting with the hot magma in the cavern is injected through injection well 72 such as a petroleumhydrocarbon (e.g., heavy residual crude oil) which is decomposed thermally into hydrogen, light hydrocarbon gases and residual carbon. The hot gases in this situation will flow upwardly through the access well 68 and into porous oil formation 54 to promote additional recovery operations. I

It will be understood that in the practice of the present invention it will normally be desirable to utilize wellhead equipment which is capable of preventing blowouts due to the high pressure of the carbon dioxide or other gases generated in the subsurface cavern. Suitable wellhead equipment for this purpose is disclosed, for example on page 4155 of the Composite Catalog of Oil Field and Pipe Line Equipment for the Year 1957.

An alternate method, as shown in FIG. 5, is to produce gases from the cavern to the surface and to utilize and inject the gases into injection wells in a hydrocarbon bearing formation adjacent to but not directly communicating with the cavern.

Turning now to FIG. 5, there is shown a predominantly carbonate rock formation 100 underlying an impervious consolidated formation 102 which, in turn, underlies intermediate formation 104 and a porous oil formation 106. A caprock formation 1118 overlies oil formation 106 which formation 108, in turn, is overlain by overburden 110.

In FIG. 5, there is shown a cavern in the carbonate rock formation 100 formed, for example, in the manner described above with respect to FIG. 1 and comprising a lower zone A" of crushed rock, an intermediate zone B of fused rock derived from the surface of the initial cavity which Zone contains a major portion of the bomb debris. Extending upward of zone B" is a zone C" of crushed rock and rubble derived from the chimney 21" extending upwardly (e.g., into consolidated formation 102). In FIG. there is also schematically shown the initial entry well 60' used for spotting of a nuclear device in the carbonate rock formation 100, as described in connection with FIG. 1.

In accordance with the embodiment of the present invention shown in FIG. 5, an access well 112 containing suitable surface control equipment 114 is drilled from the surface into the carbonate rock formation. Communication between the cavern and the entry well 112 is established in any suitable manner. For example, the well 112 may be terminated at a point adjacent to the cavern and, through the use of suitable fractioning techniques, such as those conventionally employed for the fracturing of hydrocarbon formations, fissures and cracks may be opened from the cavern through the carbonated rock formation and into the access well 112.

In addition, an injection well 115 is drilled into porous oil formation 106 and at least one producing well 116 is also drilled in the oil formation 106. The access well 112 is interconnected with the injection well 115 by suitable means such as how line 118 leading from access well 112 to a plant 120 which may be a simple manifolding station or a plant for at least partial utilization of the gases from the cavern for purposes such as electricity generation, heating, etc. From plant 120 a line 122 is provide which leads to injection well 115.

As a consequence, carbon dioxide from the cavern may be withdrawn from the well 112 and transported by way of surface line 118, plant 120 and surface line 122 to injection well 115. The carbon dioxide may be introduced into the porous oil formation 106 to initiate or further the progress of additional recovery operation being conducted in porous oil formation 106. In this case, of course, the additional production is achieved by way of a producing well 116, or, more preferably, a plurality of such producing wells spotted around the injection well 115.

As in the previous embodiments, additional quantities of gas may be provided by drilling an injection well 124 to a point adjacent the cavern, by communicating the injection well 124 with the cavern in any suitable manner (e.g., by fracturing step for the purpose of opening fissures and cracks to formation 102 intermediate the cavern and well 104). After this has been done, a liquid such as water or a hydrocarbon may be introduced into the cavern by way of an injection well 124 to provide additional quantities of gas such as steam or mixtures of hydrogen or light hydrocarbons. The additional gases may then be withdrawn from the cavern by way of well 112 and charged to porous oil formation 106 through the injection well in the described manner.

Having thus described our invention, what is claimed 1. A method for the additional recovery of petroliferous hydrocarbons from a petroliferous formation containing at producing Well and lying adjacent a predominantly calcium carbonate formation which comprises the steps of spotting a nuclear explosive device in said calcium carbonate rock formation and actuating said device to thereby provide a cavern containing hot magma and high temperature carbon dioxide and introducing said carbon dioxide into said porous oil formation to drive petroliferous hydrocarbons in said porous oil formation toward said producing well and producing said petroliferous hydrocarbons and generating additional gases in said ca'v'ern for said additional recovery operations by contacting the hot magma in said cavern with water to produce steam and by introducing said steam intosaid petroliferous formation.

2. A method for the additional recovery of petroliferous hydrocarbons from a petroliferous formation containing a producing well and lying adjacent a predominantly calcium carbonate formation which comprises the steps of spotting a nuclear explosive device in said calcium carbonate rock formation and actuating said device to thereby provide a cavern containing hot magma and high temperature carbon dioxide and introducing said carbon dioxide into said porous oil formation to drive petroliferous hydrocarbons in said porous oil formation toward said producing well and producing said petroliferous hydrocarbons and generating additional gases in said cavern by contacting the hot magma with a heavy residual crude oil fraction to produce hydrogen and light hydrocarbon gases.

3. A method which comprises drilling a first well from the surface of the earth through a petroliferous formation into an underlying formation containing a predominant amount of calcium carbonate and drilling a second Well from the surface of the earth into said petroliferous formation and laterally spaced from said first well, spotting a nuclear explosive device in said first well in the portion thereof penetrating said calcium rock formation .and activating said device to thereby provide a cavern containing high temperature carbon dioxide and hot magma, said nuclear explosive device 'being spotted with respect to said calcium carbonate rock formation and said petroliferous formation in a manner such that said cavern extends upwardly from said calcium carbonate rock formation into said petroliferous formation whereby said high temperature carbon dioxide will spontaneously flow into said petroliferous formation to drive petroliferous hydrocarbons therein to said second well and producing said petroliferous hydrocarbons and introducing water into said cavern after pressure equilibrium between said cavern and said petroliferous formation has been established in order to generate high temperature steam under pressure suflicient to permit said steam to spontaneously penetrate said petroliferous formation to drive additional quantities of petroliferous hydrocarbons contained therein toward said producing well and wherein said additional petroliferous hydrocarbons are produced.

4. A method which comprises drilling a first well from the surface of the earth through a petroliferous formation into an underlying formation containing a predominant amount of calcium carbonate and drilling a second well from the surface of the earth into said petroliferous formation and laterally spaced from said first well, spotting a nuclear explosive device in said first well in the portion thereof penetrating said calcium rock formation and activating said device to thereby provide a cavern containing high temperature carbon dioxide and hot magma, said nuclear explosive device being spotted with respect to said calcium carbonate rock formation and said petroliferous formation in a manner such that said cavern extends upwardly from said calcium carbonate rock formation into said petroliferous formation whereby said high temperature carbon dioxide will spontaneously flow into said petroliferous format-ion to drive petroliferous hydrocarbons therein to said second well and producing said petroliferous hydrocarbons and introducing residual oil into said cavern after pressure equilibrium between said cavern and said petroliferous formation has been established in order to generate high temperature hydrogen and light hydrocarbon gases under pressure sufficient to permit said hydrogen and light hydrocarbon gases to spontaneously penetrate said petroliferous formation to drive additional quantities of petroliferous hydrocarbons contained therein toward said producing Well and wherein said additional petroliferous hydrocarbons are produced.

5. A method for the additional recovery of petroliferous fluids from a porous oil formation (underlying or overlying and) remotely spaced from a predominantly calcium carbonate rock formation which comprises the steps of activating a nuclear explosive device in a calcium carbonate rock formation to thereby provide a cavern containing hot magma and high temperature carbon dioxide, drilling a well through said petroliferous formation, establishing fluid communication between said cavern and said well and flowing said hot carbon dioxide from said cavern through said well into said petroliferous formation to drive petroliferous hydrocarbons contained therein toward a producing well and producing said petroliferous hydrocarbons and introducing Water into said cavern after pressure equilibrium between said cavern and said petroliferous formation has been established in order to generate high temperature steam under pressure suflicient to permit said steam to be flared through said well to penetrate said petroliferous formation to drive additional quantities of petroliferous hydrocarbons contained therein toward said producing well and herein said additional petroliferous hydrocarbons are produced.

References Cited by the Examiner Uren, Lesterz' Petroleum Production Engineering, 4th edition, McGraW-Hill Book Co., 1956, pp. 14-25.

UCRL-S 124, Feb. 4, 1958, pp. 3, 27.

UCRL-5026, University of California Radiation Laboratory, Non Military Uses of Atomic Energy, June 12, 1958, pp. 7-9.

The Washington Post and Times Herald, Nov. 12, 1958, p. B12.

Non-Military Uses of Nuclear Explosives. American, pp. 199, 29-35 (1958) Dec.

UCRL-5458, University of California Radiation laboratory Mineral Resources Development by the Use of Nuclear Explosives, Feb. 5, 1959, pp. 13-15.

UCRL-5678, Plowshare Series, Water Resources, Mining, Chemical, Petroleum, May 15, 1959, pp. 74-101.

UCRL-S 840, University of California Radiation Laboratory, industrial and Scientific, Applications of Nuclear Weapons, January 19, 1960, pp. 9, 10, 11, 28.

Scientific REUBEN EPSTEIN, Primary Examiner.

CARL D. QUARFORTH, LEON D. ROSDOL, ROGER L. CAMPBELL, Examiners.

Non-Patent Citations
Reference
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US20090044943 *Oct 13, 2008Feb 19, 2009O'brien Thomas BMethod and system for extraction of hydrocarbons from oil shale
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US20090236092 *Feb 23, 2006Sep 24, 2009O'brien Thomas BMethod and system for extraction of hydrocarbons from oil sands
US20110198085 *Apr 20, 2011Aug 18, 2011O'brien Thomas BMethod and system for extraction of hydrocarbons from oil sands
Classifications
U.S. Classification166/247, 376/325, 166/401, 376/275
International ClassificationE21B43/16, E21B43/24
Cooperative ClassificationE21B43/2403
European ClassificationE21B43/24F