METHOD FOR THE IN SITU RECOVERY OF HEAVY OIL FROM A SUBTERRANEAN DEPOSIT

A method for extracting bitumen from a subterranean oil sand deposit including: drilling a portion of the deposit; fragmenting the drilled deposit; drilling of the fragmented deposit to allow for flooding, wherein one or more wells are drilled to provide access to the deposit and retrieval of extracted bitumen, to form a drilled fragmented deposit; flooding the drilled fragmented deposit with a first flood volume of fluid to permit the first flood volume of fluid to admix with the fragmented first portion, to re lease heavy oil from any inert material so that the heavy oil floats within the first flood volume of fluid in the drilled fragmented deposit to form a flooded first portion; recovering the heavy oil; and repeating the above for each additional portions.

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Description

TECHNICAL FIELD

This invention relates to the field of mining. More particularly, to recovering heavy oil from a subterranean oil sand deposit.

BACKGROUND

U.S. Pat. No. Pat. No. 4,037,657 to Lekas describes a process for recovering carbonaceous material from a deposit by retorting. Lekas teaches that the deposit must be sealed and that a deposit should be blasted in a graded fashion so that smaller particles occur at one area and larger particles occur at another area. Other patents such as U.S. Pat. No. 4,047,760 to Ridley and CA 1,123,728 to Rom et al. also describe retorting techniques.

U.S. Pat. No. 4,333,684 to Ricketts, et al., U.S. Pat. No. 4,545,622 to Yang, U.S. Pat. No. 4,489,983 to Ricketts describe methods of blasting subterranean deposits, including oil shale deposits for providing in situ retorting zones.

U.S. Pat. No. 4,101,172 to Rabbitts describes an in situ method of extracting bitumen from oil sand using a bitumen flotation method. Rabbitts describes a method where the overburden is not disturbed and a sealed or closed reservoir is provided.

U.S. Pat. No. 4,302,051 to Bass et al. describes an in situ method for the separation of crude oil from a reservoir whereby the deposit is drilled and flushed with hot water and steam.

International patent application WO 03/060285 to Drake, et al. describes a mechanical device designed to excavate a hydrocarbon containing deposit with a cutter head and separating the hydrocarbon component in an enclosed vessel that is in communication with the cutter head. U.S. Pat. No. 6,152,356 to Minden also describes a mechanical excavation of a tar sand deposit, termed hydraulic removal, and describes hot water/steam injection for the recovery of bitumen.

CA patent application 2,434,329 to Walsh describes a method of barge mining tar sand. The method describes flooding an oil sand deposit and dredge mining the flooded deposit with barges. A floating plant is provided for the dredged product to be processed and the bitumen extracted.

U.S. Pat. No. 3,762,771 to Livingston provides a mine layout for the natural resources development of a broad region. The layout is particularly applicable to the recovery of ore from oil shale and tar sand.

U.S. Pat. No. 4,270,609 to Choules describes a tar sand extraction process. An in situ or ex situ method for separating and recovering bitumen from tar sand by heating the tar sand in an aqueous mixture of floating agent containing ammonia, a transfer agent containing a phosphate or silicon ion and a strong monovalent base.

U.S. Pat. No. 4,034,812 to Widmyer discloses a method whereby viscous petroleum may be recovered from a subterranean deposit, such as tar sand. Widmyer describes injecting hot fluid, such as hot water or steam, into the deposit and maintaining a pressure on the deposit so as to heat the deposit.

U.S. Pat. No. 4,406,499 to Yildirim describes that bitumen is recovered from an underground tar sand formation by an in situ percolation process. The process includes drilling a bore hole and enlarging the hole by radially hydraulic jetting to form a slurry. The resulting slurry is then treated in situ with hot alkaline water to separate the bitumen from the sand matrix.

U.S. Pat. No. 4,475,592 to Pachovsky describes an in situ recovery process whereby bitumen is recovered from a subterranean formation of heavy oil sand traversed by at least one injection well and at least one associated production well in fluid communication with the injection well. Injection of hot fluids, such as low quality steam, are injected into the injection wells to release the bitumen from the heavy oil sand.

Canadian patent 2,559,833 to Keele describes an in situ oil sand recovery process whereby a subterranean oil sand deposit is blasted to fragment the deposit prior to fluid extraction.

SUMMARY

In accordance with one aspect, there is provided an in situ method for extracting heavy oil from a subterranean deposit, wherein the subterranean deposit includes 2 or more portions, the method including: a) drilling the subterranean deposit to prepare the subterranean deposit for fragmentation, wherein at least one hole is drilled in a first portion to provide a void space within the first portion and to form a drilled first portion; b) fragmenting the drilled first portion to maximize the fragmentation of the first portion thereby forming a fragmented first portion; c) drilling of the fragmented first portion to prepare the fragmented first portion for flooding, wherein one or more wells are drilled to provide for access and retrieval, thereby forming a drilled fragmented first portion; d) flooding the drilled fragmented first portion with a first flood volume of fluid to permit the first flood volume of fluid to admix with the fragmented first portion, to release heavy oil from any inert material so that the heavy oil floats within the first flood volume of fluid in the drilled fragmented first portion thereby forming a flooded first portion; e) recovering the heavy oil; and f)repeating steps a)-e) for each of a second or more portions.

In another aspect, there is provided an in situ method for extracting heavy oil from a subterranean deposit, wherein the subterranean deposit includes 2 or more portions, the method including: a) drilling the subterranean deposit to prepare the subterranean deposit for fragmentation, wherein at least one hole is drilled in each portion to provide a void space within the first portion and to form a drilled deposit; b) fragmenting a drilled first portion to maximize the fragmentation of the first portion thereby forming a fragmented first portion; c) drilling of the fragmented first portion to prepare the fragmented first portion for flooding, wherein one or more wells are drilled to provide for access and retrieval, thereby forming a drilled fragmented first portion; d) flooding the drilled fragmented first portion with a first flood volume of fluid to permit the first flood volume of fluid to admix with the fragmented first portion, to release heavy oil from any inert material so that the heavy oil floats within the first flood volume of fluid in the drilled fragmented first portion thereby forming a flooded first portion; e) recovering the heavy oil; and f) repeating steps b)-f) for each of a second or more portions.

In another aspect, there is provided an in situ method for extracting heavy oil from a subterranean deposit, the method including: a) drilling the subterranean deposit to provide a void space within the subterranean deposit, thereby providing access to the subterranean deposit for flooding and fragmentation, to form a drilled deposit; b) fragmenting the drilled deposit by injection of high pressure fluids to maximize the fragmentation of the deposit and to flood the drilled deposit with a first flood volume of fluid to permit the first flood volume of fluid to admix with the fragmented deposit, to release heavy oil from any inert material so that the heavy oil floats within the first flood volume of fluid thereby forming a flooded fragmented deposit; c) drilling of the flooded fragmented deposit, wherein one or more wells are drilled to provide for retrieval, thereby forming a drilled flooded fragmented deposit; and d) retrieving the heavy oil.

In another aspect, there is provided an in situ method for extracting heavy oil from a subterranean deposit, the method including: a) drilling the subterranean deposit to provide a void space within the subterranean deposit, thereby providing access to the subterranean deposit for fragmentation, flooding, and retrieval to form a drilled deposit; b) fragmenting the drilled deposit by injection of high pressure fluids to maximize the fragmentation of the deposit and to flood the drilled deposit with a first flood volume of fluid to permit the first flood volume of fluid to admix with the fragmented deposit, to release heavy oil from any inert material so that the heavy oil floats within the first flood volume of fluid thereby forming a flooded fragmented deposit; and c) retrieving the heavy oil.

In another aspect, there is provided an in situ method for extracting heavy oil from a subterranean deposit, wherein the subterranean deposit includes 2 or more portions, the method including: a) drilling the subterranean deposit to prepare the subterranean deposit for fragmentation, wherein at least one hole is drilled in a first portion to provide a void space within the first portion to form a drilled first portion; b) fragmenting the drilled first portion by injection of high pressure fluids to maximize the fragmentation of the first portion and to flood the drilled first portion with a first flood volume of fluid to permit the first flood volume of fluid to admix with the fragmented first portion, to release heavy oil from any inert material so that the heavy oil floats within the first flood volume of fluid in the drilled fragmented first portion thereby forming a fragmented flooded first portion; c) drilling of the fragmented flooded first portion to prepare the fragmented flooded first portion for recovery, wherein one or more wells are drilled to provide for access and retrieval, thereby forming a drilled fragmented flooded first portion; d) retrieving the heavy oil; and e) repeating steps a)-d) for each of the second or more portions.

The fragmenting may be by one or more of the following: blasting; injection of high pressure fluids; and electrical fragmentation. The fragmenting may be by blasting. The fragmenting may be by injection of high pressure fluids. The blasting may include: loading the at least one hole with at least one explosive charge; and detonating the explosive charge. A limit to the deposit may be defined by creating a boundary at the periphery of the deposit prior to fragmentation. The boundary may be defined using a closely spaced line of bore holes charged with explosives for detonation, whereby the detonation produces the boundary. The drilling of the fragmented deposit may include: drilling at least one well into the fragmented deposit; and inserting into the at least one well at least one perforated casing per well, wherein the at least one perforated casing is operable to receive fluid into the at least one perforated casing. The at least one well may be an access well to facilitate flooding of the drilled fragmented portion. The at least one well may be an access and retrieval well to facilitate flooding of the drilled fragmented portion and to facilitate recovering the heavy oil floating within the flood volume of fluid in the flooded portion. The at least one well may include at least two wells, wherein one well may be an access well to facilitate flooding of the drilled fragmented portion and another well may be a retrieval well to facilitate recovering the heavy oil floating within the flood volume of fluid in the flooded portion. The fluid may be selected from at least one of the group consisting of: water, steam, air, compressed air, carbon dioxide, light oil, solvent, and oxygen. The fluid may be compressed air. The fluid may be water. The water may be between 20° C. and 100° C. The water may be between 25° C. and 100° C. The water may be between 30° C. and 100° C. The water may be between 35° C. and 100° C. The water may be between 40° C. and 100° C. The water may be between 45° C. and 100° C. The water may be between 50° C. and 100° C. The water may be between 55° C. and 100° C. The water may be between 60° C. and 100° C. The water may be between 65° C. and 100° C. The water may be between 70° C. and 100° C. The water may be between 75° C. and 100° C. The water may be between 70° C. and 95° C. The water may be between 70° C. and 90° C. The water may be between 60° C. and 90° C. The water may be between 65° C. and 90° C. The water may be between 65° C. and 85° C. The water may be between 65° C. and 80° C. The water may be between 80° C. and 100° C. The water may be between 85° C. and 100° C. The water may be between 90° C. and 100° C. The water may be between 95° C. and 100° C. The water may be between 75° C. and 95° C. The water may be between 75° C. and 90° C. The water may be between 75° C. and 85° C. The water may be between 65° C. and 95° C. The fluid may be steam. The fluid may be recovered from the flooded first portion. The fluid recovered may be reused in a subsequent flooding. The fluid recovered may be further purified before reuse. The fluid may further include an additive that facilitates release of the heavy oil from the blasted deposit. The additive may be selected from at least one or more of the following: surfactants, catalysts, ant-acids, acids, caustics, light oils, and solvents. The method may further include the addition of permeability reducing materials to a treated portion. The heavy oil may be bitumen. The subterranean deposit may be a subterranean oil sand deposit. The flooding and the recovering may be repeated at least once. The 2 or more portions may be generally in a horizontal plane relative to the surface the deposit and the 2 or more portions may be positioned distally and proximally relative to the surface. The first portion may be the most distal to the surface. The second portion may be the next most distal portion. The more portions may be the next most distal portion. The drilling of the subterranean deposit, the flooded fragmented deposit or the fragmented flooded first portion may include: i) drilling at least one well into the flooded fragmented deposit or fragmented flooded first portion; and ii) inserting into the at least one well at least one perforated casing per well, wherein the at least one perforated casing is operable to receive fluid into the at least one perforated casing. The at least one hole of the drilled first portion or the drilled deposit may be sleaved to facilitate the loading and ignition of explosives. The at least one hole of the drilled first portion or the drilled deposit may be sleaved to facilitate the insertion of a flooding/fragmentation apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a subterranean deposit showing sections 1-8.

FIG. 2A is a cross-section of an overburden (20) and a subterranean deposit (60), that shows upper (30), middle (40), and lower (50) portions of the subterranean deposit.

FIG. 2B is a cross-section focused on the lower portion (50) of a subterranean deposit (60) that illustrates a series of drill holes (187) in the lower portion of the subterranean deposit, wherein the drill holes are made in the subterranean deposit to facilitate the fragmentation of the lower portion of deposit. As shown in the drill holes (187) are initially diagonal and then are generally horizontal.

FIG. 2C is an expanded cross-section of the horizontal portion of the drilled lower deposit (50) and the middle portion (40) prior to fragmentation (upper portion not shown).

FIG. 3A is an end view (section 5) of the cross-section of the horizontal portion of the drilled lower deposit shown in FIG. 2C, featuring a peripheral drill hole (80) and a central void space drill hole (70).

FIG. 3B is a cross-section of a drilled and fragmented first (lower) portion (middle and upper portions are not shown) of a subterranean deposit (90), which also shows vertical drill holes 100, 101, 102, 103, 104, and 105 and horizontal drill hole (210).

FIG. 3C is an end view (section 6) of a cross-section of a fragmented deposit (90).

FIG. 4A is a cross-section of a drilled fragmented deposit (90) showing recovery and flooding wells (100, 101, 102,103, 104, and 105 vertical wells and 210 horizontal well), but not middle and upper portions.

FIG. 4B is a cross-section of a fragmented deposit during recovery showing the movement of fluids within the deposit. In the present figure fluid flow from the horizontal well (210) is shown to be flooding (200) the drilled fragmented deposit (90) and showing both flooding and recovery at the vertical wells (100, 101, 102,103, 104, and 105), but the middle and the upper portions are not shown.

FIG. 5 is a cross-section of a depleted lower portion of a subterranean deposit (55) with water and froth void (54), but not upper portion.

FIG. 6 is a plot of 80% recovery as a function of time and injection rate.

Please note that the Figures presented herein are for illustration purposes only and not intended to limit the methods described herein in any way.

DETAILED DESCRIPTION

Definitions

The term “drilling” as used herein refers to both vertical and non-vertical drilling and boring techniques, and includes vertical drilling; directional drilling or slant drilling; and directional boring or horizontal directional drilling. The “drilling” may be of a subterranean deposit or portion thereof to prepare the subterranean deposit or portion thereof for fragmentation. For example, by the creation of a void space and to allow for the positioning of fragmentation apparatus (for example explosive charges or fluid injection pipes) within the subterranean deposit or portion thereof. In some circumstances, for example where a portion of a deposit has already been extracted and a water and froth void has been created, less or minimal further drilling may be needed to provide a void space for a subsequent layer to be extracted as the water and froth void may serve as a void space into which expansion may occur following blasting to fragment the subsequent layer. Furthermore, “drilling” may be of a fragmented subterranean deposit or portion thereof to prepare the subterranean deposit or portion thereof for flooding and/or recovery of the subterranean deposit or portion thereof. Alternatively, the drilling may also fragment the subterranean deposit or portion thereof (for example, where “drilling” is by high pressure fluid injection). An example of the type of drilling capabilities that may be suitable for the present extraction may be available from the Crossing Company™.

The term “void space” as used herein refers to any region within a subterranean deposit or portion thereof lacking geologic objects (such as oil sands, rocks etc.) and which may facilitate the expansion of the oils sands during fragmentation and/or the positioning of fragmentation apparatus in the deposit or portion thereof. Depending on the method of fragmentation, the proportion of void space relative to oil sands in the subterranean deposit or portion thereof may vary. For example, where a deposit or portion thereof is fragmented by blasting, the void space provided should allow for expansion of the deposit or portion thereof into the void space when the explosives are detonated. Alternatively, where a deposit or portion thereof is fragmented by fluid injection, the initial void space may be small relative to the deposit or portion thereof provided that the fragmented deposit is at least periodically removed from the injection area (for example, with the flow of injection fluid out of a well or where the injection fluid facilitates release of heavy oil from the deposit, whereby the heavy oil and flood fluid may be recovered). Alternatively, the void space may be provided by an extracted adjacent portion of the deposit (for example, a lower portion where a water and froth void has been created) or a naturally occurring void space. The void space may be fluid filled or partially fluid filled. Furthermore, the void space may be provided by drilling one or more holes into the deposit to facilitate expansion of the deposit upon fragmentation.

When a subterranean oil sand deposit is fragmented, the volume of the deposit increases and the volume increase may vary depending on the fragmentation method and the amount of void space provided prior to fragmentation. In general, the volume increase may be 30% of the volume prior to fragmentation. The drilling of the holes prior to fragmentation may be planned so that the volume of the drilled material removed approximates the expanded volume of the drilled and fragmented deposit or portion thereof. Furthermore, the drilled deposit prior to fragmentation may benefit from the addition of a liner to prevent or reduce or delay deformation and/or filling of the drill holes as the deposit may encroach on the drill holes. The liner may not be needed where the insertion of the fragmentation apparatus (for example explosive charges or fluid injection pipes) is not delayed, but may be needed where the fragmentation is not begun soon after drilling of the deposit or portion thereof. In alternative embodiments, the initial drilling of a deposit or portion thereof may be in such a way that fragmentation apparatus (for example explosive charges or fluid injection pipes) may be attached to the end of the drill string so that the fragmentation apparatus may be drawn into the drill holes as the drill string is removed or as it is drilled. Alternatively, the drill string may itself facilitate injection of fluids and indeed the drilling may be by injection of fluids.

The term “subterranean deposit” as used herein is defined as a volume of material that may be at least partly underground and contains a mixture of unwanted materials and desired heavy oil. Examples of subterranean deposits include oil sand, and tar sand. In some cases the oil sand has no overburden or very thin overburden, and should be considered a subterranean deposit as described herein. However, the present method is not limited to the extraction of subterranean deposits or portions thereof of any particular depth or size. For example, subterranean deposits or portions thereof may begin anywhere between 0-500 meters from the surface (or deeper) and includes small volumes (for example, 25 cubic meters). Often in situ methods are only used in deposits less than 100 meters and on relatively large deposit areas, due to the infrastructure required to perform the extraction.

The term “fragmentation” or “fragmenting as used herein may refer to blasting, fluid injection and/or electrical fragmentation or any other fragmentation methods known in the art. Fragmentation may be by one or more of the following: blasting; fluid injection; and electrical fragmentation. The fluid injection may be injection of high pressure fluids.

The term “maximal fragmentation” or “maximum fragmentation” or the like phrases as used herein are meant to encompass the provision of the greatest degree of fragmentation of an individual starting piece as allowed for by the individual site conditions and economic considerations (for example density, depth, charge placement and timing, Relative effectiveness factor (R.E. factor) of the explosives used if fragmentation is by blasting, existing fragmentation, size of the void space and distribution of void space, among others). This typically provides or produces the largest amount of surface area and the highest quantity of new pieces or fragments from the deposit starting material. The fragmentation sizes (average diameter) may vary from millimeter(s) (for example about 0.1 mm) to meters (for example about 20 m) and will depend on the characteristics of a particular deposit and potentially economic and other considerations associated therewith. Specifically, fragmentation sizes (average diameter) may be from about 0.1 mm to about 10 m. Alternatively, fragmentation sizes (average diameter) may be from about 0.1 mm to about 5 m. Alternatively, fragmentation sizes (average diameter) may be from about 0.1 mm to about 100 cm. Alternatively, fragmentation sizes (average diameter) may be from about 0.1 mm to about 50 cm. Alternatively, fragmentation sizes (average diameter) may be from about 0.1 mm to about 10 cm. Alternatively, fragmentation sizes (average diameter) may be from about 0.1 mm to about 5 cm. Alternatively, fragmentation sizes (average diameter) may be from about 0.1 mm to about 4 cm. Alternatively, fragmentation sizes (average diameter) may be from about 0.1 mm to about 3 cm. Alternatively, fragmentation sizes (average diameter) may be from about 0.1 mm to about 2 cm. Alternatively, fragmentation sizes (average diameter) may be from about 0.1 mm to about 1 cm.

Furthermore, it will be appreciated by a person of skill in the art that fragmentation sizes may not be uniform throughout the deposit where there are differing densities etc. of the materials within the deposit. Additionally, it will also be appreciated by a person of skill in the art that fragmentation sizes as set out above would not necessarily apply to non-oil sand or non-tar sand materials which may be within a subterranean deposit, but would not be “extracted” by the methods described herein. For example, limestone or sandstone, boulders or slabs, may be present within a subterranean deposit, which may not fragment the way that the adjacent oil sand or tar sand materials within the deposit or portions thereof are likely to. Some deposits will require less fragmentation and some more fragmentation depending on, but not limited to, considerations like hardness of the deposit, bitumen content of the deposit and moisture content of the deposit etc.

The term “heavy oil” as used herein is defined as a material containing carbon that has a gravity of not more than 25.7° on the American Petroleum Institute (API) Scale. As used herein “heavy oil” comprises both heavy and extra heavy oil. Examples of heavy oil include, but are not limited to, bitumen and crude oil. Crude oil is commonly classified as light, medium, heavy or extra heavy, referring to its gravity as measured on the API scale. The API gravity is measured in degrees and is calculated using the formula API


Gravity=(141.5/S.G.)−131.5

Light oil has an API gravity higher than 31.1° (lower than 870 kilograms/cubic meter), medium oil has an API gravity between 31.1° and 22.3° (870 kilograms/cubic meter to 920 kilograms/cubic meter), heavy oil has an API gravity between 22.3° and 10° (920 kilograms/cubic meter to 1,000 kilograms/cubic meter), and extra heavy oil (e.g. bitumen) has an API gravity of less than 10° (higher than 1,000 kilograms/cubic meter). The Canadian government has only two classifications, light oil with a specific gravity of less than 900 kilograms/cubic meter (greater than 25.7° API) and heavy oil with a specific gravity of greater than 900 kilograms/cubic meter (less than 25.7° API).

Fluid injection and retrieval wells may be installed into a deposit or portion thereof prior to, during and/or after fragmentation. The angles of the wells may vary to optimize the injection and retrieval of fluids and to further optimize the recovery of the bitumen. The pipe installed in the wells may be slotted or perforated or even a combination. The injection of fluids may process and release bitumen from the fragmented deposit or portion thereof. Alternatively, the injection of fluids may fragment, process, and release bitumen from a deposit or portion thereof. When bitumen recovery by repetitive injection of fluids and recovery of the bitumen is completed or the yield becomes uneconomical the process may be stopped. Furthermore, the process may be re initiated depending on the economics of the extraction. Following extraction the deposit or portion thereof that has been extracted may compact to approximately 70 to 90 of the un-extracted pre-fragmentation volume.

The term “overburden” as used herein is any material above the subterranean deposit that may be remain in place during extraction of the subterranean deposit or portions thereof. The overburden may even have some bitumen content, but in general the “overburden” need not be removed and need not be fragmented during fragmentation of the subterranean deposit. Accordingly, the presently described in situ extraction processes need not significantly disrupt the overburden at an extraction site and may thus require less effort in site reclamation.

A “portion” of a subterranean deposit may be defined by one or more boundaries at the periphery of a subterranean deposit and/or at some predefined position within a subterranean deposit (for example, a lower, middle, or upper portion) effectively defining a sub-region of a subterranean deposit to be processed. Alternatively, a subterranean deposit may be divided into portions in any manner. For example, a subterranean deposit may be divided into horizontal sections, vertical sections and/or diagonal sections or combinations thereof. Generally, the division of a subterranean deposit will depend on the shape, depth, volume of the deposit etc. to determine the portioning of the deposit and the order of extraction. Portions of a subterranean deposit may be extracted to optimize the resources available and to maximize the yield from the deposit.

A) Mapping of Deposit

A subterranean deposit or portion thereof may be mapped using techniques available to a person of skill in the art. Methods for mapping the location of a subterranean deposit or portion thereof may consist of various geological and geophysical techniques (for example, gravity surveys, magnetic surveys, seismic surveys etc.) test drilling, and computer modeling.

Modeling methods available to map subterranean deposits are numerous. For example, based on drill hole core analysis and geophysical logging methods a detailed 3 dimensional model can be built with existing computer modeling techniques. Companies such as the Computer Modeling Group Ltd™, Ventex Software Corporation™, and Mincom™ have applications suitable for creating very detailed computer models of a reservoir or ore body or for water flood performance. This in turn is used to determine where best to drill or bore to optimize recovery of the resource.

B) Drilling to Create a Void Space within a Subterranean Deposit or Portion thereof

A subterranean deposit or portion thereof may be drilled to facilitate the expansion of the oils sands during fragmentation and/or the positioning of fragmentation apparatus in the deposit or portion thereof prior to fragmentation. Depending on the method of fragmentation, the proportion of void space relative to oil sands in the subterranean deposit or portion thereof may vary. For example, where a deposit or portion thereof is fragmented by blasting, the void space provided preferably allows for expansion of the deposit or portion thereof into the void space when the explosives are detonated. Alternatively, where a deposit or portion thereof is fragmented by fluid injection, the initial void space may be small relative to the deposit or portion thereof provided that the fragmented deposit is at least periodically removed from the injection area. However, the drilling to provide a void space may be reduced where the void space may be provided by an extracted adjacent portion of the deposit (for example, a lower portion having a water and froth void left behind after the adjacent portion of the deposit was extracted and the bitumen containing fluids were removed leaving a void space or water and froth void), whereby the drilling may only be needed to provide access to fragmentation apparatus (for example to insert explosive charges or fluid injection systems). Furthermore, the void space may be provided by drilling one or more holes into the deposit to facilitate expansion of the deposit upon fragmentation. For example see FIGS. 2B, 2C and 3A.

When a subterranean oil sand deposit is fragmented, the volume of the deposit increases and the volume increase may vary depending on the fragmentation method and the amount of void space provided prior to fragmentation. In general, the volume increase may be about 30% of the volume prior to fragmentation. The drilling of the holes prior to fragmentation may be planned so that the volume of the drilled material removed approximates the expanded volume of the drilled and fragmented deposit or portion thereof. Furthermore, the drilled deposit prior to fragmentation may benefit from the addition of a liner to prevent or reduce or delay collapsing, deformation and/or filling of the drill holes as the deposit may encroach on this space. The liner may not be needed where the insertion of the fragmentation apparatus (for example explosive charges or fluid injection pipes) is not delayed, but may be needed where the fragmentation is not begun immediately or soon after drilling of the deposit or portion thereof. In alternative embodiments, the initial drilling of a deposit or portion thereof may be in such a way that fragmentation apparatus (for example explosive charges or fluid injection pipes) may be attached to the end of the drill string so that the fragmentation apparatus may be drawn into the drill holes as the drill string is removed, or even pulled along behind the drilling operation. Alternatively, the drill string may itself facilitate injection of fluids and indeed the drilling may be by injection of fluids.

C) Fragmentation

Fragmentation of a deposit may be carried out by one or more fragmentation methods. For example, Blasting, fluid injection, electrical fragmentation, etc. However, where fragmentation is via fluid injection (for example, high pressure fluid injection) the flooding may occur simultaneously with the fragmentation. The fragmentation and/or flooding fluids may be between 20 and 100° C. depending on the particular extraction variables associated therewith. As shown in FIGS. 2B and 2C, the subterranean deposit or portion thereof (60 lower portion) may be drilled to produce at least one hole or a series of holes (187). An alternative view (see FIG. 3A) shows an arrangement of drill holes from an end view, where a larger diameter drill hole is shown at 70 and a smaller diameter drill hole on the periphery is shown at 80. The number and the depth of the bore holes (187) will be determined by the depth of the subterranean deposit or portion thereof (i.e. 10, 30, 40, 50) to be blasted and the diameter of the bore hole (187). The bore hole may extend as far down as the bottom of the subterranean deposit (i.e. lower portion 50), lower than the bottom of the subterranean deposit (10) or to a desired distance above the bottom of the subterranean deposit. The arrangement of drill holes may also depend on the method of fragmentation. When fragmentation is by blasting, at least one explosive charge may be placed into a bore hole 80. The at least one explosive charge may be detonated and the subterranean deposit or portion thereof (50) is fragmented to become a fragmented deposit (90). When the fragmentation is by injection of fluids, at least one drill hole is needed to accommodate the fluid injection apparatus and to provide room for the expansion on the deposit or portion thereof during fragmentation or to allow for removal of fragmented deposit and/or released bitumen and/or flood fluids. The fluid injection apparatus may be a slotted or perforated pipe that allows fluids to be injected into the deposit to facilitate fragmentation and/or flooding of the deposit or portion thereof.

Additional drill holes of optimum diameter may be drilled but not loaded with explosive charges. These holes may be strategically located to provide additional space (i.e. void space) for blasting expansion to occur.

Blast design may be based on one or a combination of standard blasting techniques, known to one skilled in the art.

In the embodiment shown in FIGS. 2B, 2C and 3A, the drilled holes (187) represent the free face into which the fragmented or blasted material may expand. In an embodiment where blasting is being used to fragment a deposit, charges may be placed in one or more of the drilled holes (187). Accordingly, the void space provided by the drilling may allow for blasted material and gases created by the explosion to expand. Water resistant explosive charges, or explosive charges encapsulated in water proof containers may be used in methods described herein. The explosive charge may also facilitate detonation under high hydrostatic pressures. Explosive charges that have a relatively low shock energy and a high gas generation property may be better suited to the fragmentation and displacement required by blasting methods described herein. Propellants may also be used in place of common commercial explosives. Alternatively, the blasting may take place in a partially flooded deposit, where fractures, wells and drill holes are flooded before blasting.

The blasting techniques described herein are merely examples to explain possible blasting methods. Any blasting technique known to the skilled practitioner in the blasting art may be used. In particular, the blasting techniques known to provide maximum fragmentation of a subterranean oil sand deposit are preferred.

The subterranean deposit may be blasted to maximize fragmentation of the fragmented deposit (90). To achieve maximum fragmentation the subterranean deposit needs to have a space into which it may expand. Such a space may be provided by the removed drilled material, although any space, including naturally occurring spaces and spaces dug or drilled or bored or otherwise provided into the periphery or interior or both of the subterranean deposit may also assist with maximum fragmentation of the subterranean deposit.

Maximum fragmentation of deposit may provide greater permeability of the deposit for flooding to permit the first flood volume of fluid to admix with the fragmented first portion, which may in turn facilitate the release of heavy oil from any inert material so that the heavy oil floats within the first flood volume of fluid in the drilled fragmented first portion thereby forming a flooded first portion. Maximum permeability allows a greater yield of a heavy oil to be released and recovered.

Maximum fragmentation may also provide for maximum compacting of the depleted deposit (55) after a fluid from a flooded deposit is removed. Maximum compacting of the deposit may also provide a zone which is less permeable to the fluid, thereby reducing leakage of the fluid from an adjacent flooded deposit or portion thereof. Furthermore, maximum compacting provides a more stable surface so that the process can be repeated in close proximity of the depleted deposit.

A geometric distribution of the drilled holes (187) and the elevations and masses of the explosive charges in single or multiple blast holes may be adjusted to create an optimum overlap of the radii of influence to maximize the fragmentation of the fragmented deposit and tailor the expansion of the subterranean deposit to produce a fragmented deposit (90). Furthermore, a line of closely spaced blast holes lightly charged with explosive charges may be used to control the size of the area of fragmentation of the fragmented deposit.

Blasting techniques known to those in the art may also be practiced in order to provide a desired shape and fragmentation of the fragmented deposit (90). For example, the distance from the bottom of the subterranean deposit of the lower most explosive charge in each bore hole may be staggered to maximize the fragmentation of the fragmented deposit (90).

Alternatively, special drilling techniques in which clusters of smaller diameter bore holes may be used to concentrate explosives charges in a deep location to simulate single large explosion may be used. This technique may be applied to a primary drilling and blasting step, after which a smaller diameter blast holes may be distributed and charged in the choke (or buffer) blasting configuration as previously described.

Alternatively, vibratory drilling, or fluid piercing techniques may be used to meet the drilling requirements described herein.

Additional blasting may be done before during or after the fragmented deposit is flooded to assist in the agitation of the fragmented deposit and assist in the release of the heavy oil.

When the fragmentation by fluid injection is sufficient, further drilling may not be needed.

D) Drilling of a Fragmented Deposit

Referring to FIGS. 3B and 4A, the fragmented deposit 90 may then be drilled to provide recovery and flooding wells or fluid wells (100, 101, 102, 103, 104, and 105 vertical wells and 210 horizontal well). One or a plurality of fluid wells (100, 101, 102, 103, 104, 105, and 210) may be drilled into the fragmented deposit 90. The angle of the fluid well may vary depending on the desired result. For example, the fluid well may be substantially horizontal (210), substantially vertical (100, 101, 102, 103, 104, and 105), or at an angle in between horizontal and vertical. A plurality of fluid wells may be provided so that some or all of the fluid wells may be substantially horizontal, substantially vertical, or at an angle in between horizontal and vertical. The location of these fluid recovery wells may be optimized to maximize the recovery of the resource and may even be located below the portion of the subterranean deposit (for example, similar to steam assisted gravity drainage methods).

Once the fluid well is drilled, a perforated or slotted casing may be inserted into the fluid well. The drilling and inserting may be done concurrently. In a particular embodiment, a first substantially horizontal fluid well is drilled and the perforated casing is inserted concurrently. In this embodiment, substantially horizontal means parallel to the bottom of the fragmented deposit. The first fluid well and perforated casing may be placed near the bottom of the fragmented deposit or portion thereof.

Fluid wells (for example, vertical or horizontal or diagonal or combinations thereof) may be drilled and perforated casings may be inserted into a stable layer that lies below or outside of the fragmented deposit. In one embodiment, the stable layer is a limestone layer. In another embodiment the stable layer may be an unblasted portion of the subterranean deposit.

After the fluid wells and perforated casings have been provided in the fragmented deposit, fluid injection equipment, pumping equipment and heating equipment may be installed. A froth sump may also be installed to collect the recovered heavy oil in the form of froth.

E) In Situ Flooding and Recovery of the Heavy Oil

Referring to FIG. 4B, at least one fluid is pumped into the fluid wells (100, 101, 102, 103, 104, 105, and 210) and the perforated casings and the fluid is released into the fragmented deposit (for example, arrows 200) via perforations in the perforated casings (direction of flow of the fluid is illustrated by arrows) thereby forming a flooded deposit. However, different flow arrangements are possible for different embodiments. The perforations may be any combination of holes or slots to facilitate flooding of the fragmented deposit. The fluid will cause the release of the heavy oil from the fragmented deposit. The fragmented deposit may be fully or partially saturated with the fluid. The fluid may be under pressure and may be selected from hot water, hot steam, hot compressed gas, or (e.g., air or CO2). The fragmentation and/or flooding fluids may be between about 20° C. and about 100° C. Alternatively, the fluid may be >30 degrees C. or ambient temperature and heated in situ. Alternatively, the fluid may be <100° C. The flooding of the fragmented deposit may accomplish: conditioning of, agitation of, and heavy oil extraction and flotation from the fragmented deposit.

The fragmented deposit may be flooded or soaked using a fluid that may have a temperature greater than 20 degrees Celsius. Flooding or soaking time may be partially dependent on the fluid temperature used and whether any additives are used to promote extraction. Generally, the longer the fragmented deposit is flooded or soaked the lower the fluid temperature that may be used. For example, modeling suggests that greater than 80% recovery may be achieved in less than 20 days with the injection of 75° C. water at a rate of 10,000 USGPM (see FIG. 6).

The heavy oil is released from the flooded deposit by the heat and agitation effect of the injected fluid as well as the chemical and mechanical properties of the injected fluid. When the fluid contacts the heavy oil in the fragmented deposit the hot fluid raises the temperature of the heavy oil and reduces the viscosity such that the heavy oil may detach from the inert material. This combined with the mechanical and chemical properties of the fluid will facilitate the release of the heavy oil and/or bitumen.

The fragmented deposit may be agitated using the high pressure agitation effect of the injected fluid which may also be injected using a pulsating process. A range of pressures may be used and may include pressures from ambient pressure to over 500 psi in order to condition, agitate and release the heavy oil and/or bitumen from the fragmented deposit. Alternatively, the fluid injected may be at 300-400 psi.

The fluid injected into the fragmented deposit may also provide a plethora of fluid and/or gas bubbles that facilitate and assist in the floatation of the heavy oil and/or bitumen droplets to the surface. Local fluidization may also be used to create passage for the bitumen droplets to rise. The froth that floats to the surface may be continuously taken away from the top surface.

Additives like surfactants, catalysts, ant-acids, acids, solvents and caustics may be used to assist in the releasing of the heavy oil from the inert materials or to improve floatation of the heavy oil on the surface of the fluid. Such additives are known to the skilled practitioner in the art.

As the heavy oil is released from a flooded deposit it moves towards the top of the flooded deposit or portion thereof in the form of froth and may exit the deposit via the wells (for example, 100, 101, 102, 103, 104, 105, and 210). The froth may also be moved by the fluid in a direction of flow of the fluid. The heavy oil may be recovered and collected as froth. The froth may be collected by pumping or draining the froth into holding structures. Vertical lift techniques, known to the skilled practitioner may be used to assist in the optimization of bitumen recovery. Collected froth may be sent to a storage facility or for further treatment at a treatment facility. A flood volume of fluid is typically the amount of fluid required to maximize and optimize the flooding and/or soaking and agitation of the fragmented deposit so that the heavy oil and/or bitumen is released and combined with the fluid to become a froth which floats to the surface of the flooded deposit or portion thereof and once removed via the retrieval wells, a water and froth void (54) and compacted depleted deposit (55) remain.

The specific volume of fluid in a flood volume for the fragmented deposit will vary depending on a number of factors including size dimensions of the fragmented deposit, degree of fragmentation of the fragmented deposit and volume of heavy oil contained in the fragmented deposit, as well as time required for proper soaking, ablation and subsequent release of the heavy oil and/or bitumen from the subterranean deposit.

In place pressure flooding and heavy oil recovery steps may be repeated any number of times to maximize the recovery of the heavy oil. Additional fragmentation, like blasting, may be carried out before, during or after an initial the flooding step or subsequent to a flooding step.

Heat in excess of 100 degrees C. may be used to optimize the lowering of the bitumen density which in turn may assist in the optimization of the recovery of the heavy oil. Light bitumen may be recovered that could be used as a fuel. Alternatively, oxygen or a similar substance may be injected into the lower portion of the deposit and then ignited to release heat and thus facilitate recovery. For example, the Toe to Heal Air Injection (THAI) extraction method.

Instead of bringing the oil sand from a subterranean deposit to a separation vessel, where fluids are added (traditional oil sands mining), fluids may be brought to the subterranean deposit and the processing may be done in the ground (as described herein). The ground in effect may become the separation vessel. The sand sinks to the bottom and the water and heavy oil and/or bitumen float to the surface. The released bitumen may be removed and sent to storage and/or for further processing. Furthermore, any additional waste material (for example, thickened fines and other material) may be pumped back into the depleted deposit to improve the stability of the deposit. The bitumen may contain non bitumen containing fluid or low bitumen content fluid. Such further fluid may be further processed and reused.

The main difference between using the ground as a separation vessel and traditional separation vessels is that materials to be treated in traditional separation vessels are often first mined, crushed and then hydro transported using a series of pipelines to the conventional separation vessel. Furthermore, traditional separation vessels often require the processing of the materials provided in a short amount of time, in order to accommodate new oil sand raw materials arriving from the pipeline. Using methods described herein, the duration of time for which the deposit is flooded with fluid (that is the materials being treated) may range from minutes to hours to days to weeks to months. In general, when the duration of time for which the flooded deposit is flooded with fluid increases, the amount of heavy oil recovered from the deposit is also likely to increase.

Additional blasting may be done after the fragmented deposit is flooded to assist in the agitation of the fragmented deposit and assist in the release of the heavy oil.

To assist with extraction of a subterranean deposit or portion thereof the extraction area may be pressurized enough to keep it open to create a pressurized subterranean chamber, which may facilitate fluid is removal and bitumen removal. The removal of the fluids may also facilitate water reuse for further extractions.

Methods are known in the art for in situ extraction of subterranean deposits, which may be applied to a fragmented deposit. For example: Cyclic Steam Stimulation (CSS) whereby high pressure and high temperature steam is injected into a deposit to facilitate extraction; similarly Steam Assisted Gravity Drainage (SAGD) also uses high pressure and high temperature steam to facilitate extraction; Vapor Extraction Process (VAPEX) is similar to SAGD except that instead of steam solvent is injected into the deposit reduce viscosity and to facilitate extraction; Toe to Heal Air Injection (THAI) in which either air or oxygen (or a similar fluid) is injected into a deposit and ignited to disrupt and heat a deposit. However, many of the above methods require much greater energy expenditures and are economically feasible only on larger deposits. In addition vibratory or consolidation methods may be incorporated to assist in the consolidation of a depleted deposit. The above methods may be implemented alone or in combination to facilitate the extraction of a fragmented deposit.

F) Lean Froth and Froth Treatment and Tailings Treatment

During recovery of the heavy oil, the heavy oil is released from the inert material and with the fluid forms the froth. Depending on how many times the fragmented deposit has been flooded the percentage by weight of heavy oil in the froth will vary. For example, the froth released by a first flooding may have a higher percentage of heavy oil than the froth that is released by a subsequent flooding from the same fragmented deposit. This may be because more of the heavy oil is available to be released in the first flooding of a fragmented deposit than in the second flooding of the same fragmented deposit. The froth that is released in the subsequent flooding may be called lean froth because it does not have as much heavy oil as the froth released by the first flooding.

The first flooding may be composed of two separate fluid injections that are executed at separate times. For example, the fragmented deposit may be flooded by injecting a fluid that is primarily hot water to a level that is near the top of the fragmented deposit, followed by an injection with a fluid that is mostly comprised of compressed air or steam. The compressed air or steam may release a plethora of tiny bubbles and heat that assist in the release of the heavy oil from the inert material.

The froth collected may need to be de-watered and de-aerated. Froth de-watering techniques known to the skilled practitioner, such as cyclones, de-aerators, inclined plate separators and multi stage settling vessels may be used to reduce the fluid content (i.e. the fluid used to flood the fragmented deposit, for example water and air/gas) of the froth. This provides a more pure heavy oil. Secondary floatation techniques may also be used to extract additional heavy oil. Once the fluid content of the froth has been reduced to acceptable levels further upgrading may be achieved using techniques known to the skilled practitioner. The fluid removed from the froth may be recycled and used again. Froth may have a composition of from 10% to 70% heavy oil, 10% to 70% water and 0% to 30% solids. Typical froth has a composition of approximately: 60% heavy oil, 30% water and 10% solids. Lean froth may have a composition of approximately: 10% bitumen, 89% water and 1% solids.

The de-watering of the froth produces a waste or tailings that are often composed of sands, silts and clays. The quantity of tailings produced by in place methods are small when compared to conventional ex situ or conventional surface mining methods. Typically, the sand and/or fines, which are sometimes referred to as the mineral portion of an oil sand deposit can account for over 80% by weight of the oil sand deposit. Some present surface mining techniques mine or dig up the entire oil sand deposit. The oil sand is then processed to release the heavy oil and then the rest of the material, composed mostly of the sand, is pumped as a fluid or slurry to massive tailings ponds.

In methods described herein, the oil sand does not need to be mined or dug up and consequently the large tailings structures or ponds do not have to be constructed. The tailings storage required for methods described herein may consist only of the finer sand and fines material that are released with the heavy oil and/or bitumen during flooding or floatation.

Some mineral, sand, or clay particles may migrate with fluid recovery volume. Such tailings may be treated using techniques that are known by a practitioner in the art and may include the use of a thickener, in-ground thickener or tailings flocculants. Tailings may be returned to a treated deposit.

When material is removed in the drilling or boring steps, this material can be processed above the subterranean deposits using techniques known in the art, or alternatively can be re-injected into the subterranean deposit for processing as discussed above.

G) Reclamation

After in place flooding and heavy oil recovery is complete, the fluid wells may be used to assist in the removal of fluid from the flooded deposit by pumping the fluid in the reverse direction. Additional pumps and wells for providing artificial lift of the fluid to the surface may be used to maximize fluid recovery. Alternatively, artificial lift techniques, known to one skilled in the art, may be utilized during flooding of the deposit. Water and other fluids may be reused to extract from another subterranean deposit or portion thereof. Furthermore, backfilling or pumping back into the depleted deposit with thickened fines and other material may leave the deposit more stable.

As shown in FIG. 5, when flooding has stopped and fluid is removed the remaining materials from the deposit sink and compact providing a depleted deposit (55). The compacted materials in the treated deposit (55) provide a less permeable surface which may be used to reduce or prevent the fluid flowing into the treated deposit (55) from an adjacent fragmented deposit (for example, the middle portion) that is being flooded. Alternatively, the water and froth void (54) that remains following extraction may provide a void space into which an adjacent portion of the deposit may expand during fragmentation (for example, blasting).

To assist in making the treated deposit less permeable if so desired, materials such as fluids with cement like additives (i.e. concrete), high density particulate matter recovered from a treated deposit, bentonite or materials with similar properties may be pumped into the depleted fragmented deposit to reduce the permeability of the treated deposit in preparation for the development of the adjacent untreated deposit.

Methods for decreasing the permeability of a deposit are known to persons skilled in the art and may, for example, include the injection of bentonite into the treated deposit. Bentonite is a clay with a high shrink-swell ratio. Upon wetting, the bentonite will swell to many times its dry volume. Other techniques that impregnate the treated deposit with admixtures or materials that reduce the permeability may be used. For example, fine tailings which may be a waste product of the process may be injected into the treated deposit to assist in making it less permeable. Other methods known to a person of skill in the art to decrease the permeability of a treated deposit, like the use of vibratory equipment may be employed as required to increase compaction of the treated deposit.

Pipe and equipment may be salvaged from the treated deposit (55) for future use and for the extraction of adjacent deposits.

EXAMPLES

Example 1

Large Scale Testing

A field tank test was conducted on 25 cubic meters and repeated. These tests showed that when the hot fluids are injected into a fragmented deposit using slotted or perforated pipe, the mineral portion sank to the bottom of the test, a bitumen bearing froth was released and floated to the surface, and the water released could be recycled for further use. In addition, the depleted deposit was reduced in size by approximately 10 to 15% of the original volume prior to injection of fluids. Suggesting that the void space needed to extract a given deposit or portion thereof may be achieved as the process releases bitumen from the deposit.

Example 2

Computer Modeling

A computer modeling analysis was conducted by the Computer Modeling Group Ltd. (Ian Gates and Jacky Wang) in conjunction with the inventor Howard Keele. For example as seen in FIG. 6, the modeling suggested that greater than 80% recovery may be achieved from a 25 m×25 m×40 m portion of a blasted oil sand deposit may be extracted in less than 20 days with 10,000 US gallons per minute (USGPM) at 75° C. Furthermore, the modeling suggested (results not shown) that following the blasting of an oil sands deposit the injection of hot water raises the oil mobility in several ways. (1) With heat, the viscosity of the oil is reduced. (2) Hot water injection may yield further dilation of the oil sand beyond that achieved by the blasting stage. (3) Thermal expansion of the oil moves the oil from tight pores that may still remain after the blasting stage. (4) The heated oil rises under buoyancy forces since its density is lower than that of the water and cool oil. (5) Heat lowers the interfacial tension between the oil and water phases. (6) The moving hot water entraps oil drops moving the drops to the top of the oil formation.

Furthermore, the injection of air also aids in oil mobilization. (1) Air rising under buoyancy will cause an upward motion of the fluid system, which enhances oil movement in that direction. (2) Air bubbles bind to oil drops and cause the oil to rise at an accelerated rate than that achieved from oil-water density differences alone, whereby the combined air-oil drops have reduced effective density. (3) Air, with its high mobility will help to distribute heat within the formation.

All indications from these studies show that the process can be scaled up. However, some efficiencies are predicted where the size of the portion extracted is reduced. For example, in situations where a deposit is divided into portions prior to extraction, such efficiencies may be realized. Detailed geological analysis, which is standard in the mining and petroleum engineering field, may also dictate the optimum location to start the extraction process and may also dictate the portioning of the deposit. Accordingly, practicality and optimization will dictate the portion size and location of the portion that is treated and when.

Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be readily apparent to those of skill in the art in light of the teachings of this invention that changes and modification may be made thereto without departing from the spirit or scope of the appended claims.

Claims

1. An in situ method for extracting heavy oil from a subterranean deposit, wherein the subterranean deposit comprises 2 or more portions, the method comprising:

a) drilling the subterranean deposit to prepare the subterranean deposit for fragmentation, wherein at least one hole is drilled in a first portion to provide a void space within the first portion and to form a drilled first portion;
b) fragmenting the drilled first portion to maximize the fragmentation of the first portion thereby forming a fragmented first portion;
c) drilling of the fragmented first portion to prepare the fragmented first portion for flooding, wherein one or more wells are drilled to provide for access and retrieval, thereby forming a drilled fragmented first portion;
d) flooding the drilled fragmented first portion with a first flood volume of fluid to permit the first flood volume of fluid to admix with the fragmented first portion, to release heavy oil from any inert material so that the heavy oil floats within the first flood volume of fluid in the drilled fragmented first portion thereby forming a flooded first portion;
e) recovering the heavy oil; and
f) repeating steps a)-e) for each of a second or more portions.

2. The method of claim 1 wherein the drilling the subterranean deposit comprises drilling at least one hole in the first portion and at least one more portion.

3. The method of claim 1, wherein the fragmenting is by one or more of the following: blasting; injection of high pressure fluids; and electrical fragmentation.

4-5. (canceled)

6. The method of claim 1, wherein the blasting comprises:

i) loading the at least one hole with at least one explosive charge; and
ii) detonating the explosive charge.

7. The method of claim 1, wherein a limit to the deposit is defined by creating a boundary at the periphery of the deposit prior to fragmentation, and wherein the boundary is defined using a closely spaced line of bore holes charged with explosives for detonation, whereby the detonation produces the boundary.

8. The method of claim 7, wherein the drilling of the fragmented deposit comprises:

i) drilling at least one well into the fragmented deposit; and
ii) inserting into the at least one well at least one perforated casing per well, wherein the at least one perforated casing is operable to receive fluid into the at least one perforated casing.

9. The method of claim 1 wherein the at least one well is an access well to facilitate flooding of the drilled fragmented portion.

10. The method of claim 1 wherein the at least one well is an access and retrieval well to facilitate flooding of the drilled fragmented portion and to facilitate recovering the heavy oil floating within the flood volume of fluid in the flooded portion.

11. The method of claim 1 wherein the at least one well comprises at least two wells, wherein one well is an access well to facilitate flooding of the drilled fragmented portion and another well a retrieval well to facilitate recovering the heavy oil floating within the flood volume of fluid in the flooded portion.

12. The method of claim 1 wherein the fluid is selected from at least one of the group consisting of: water, steam, air, compressed air, carbon dioxide, light oil, solvent, and oxygen.

13-14. (canceled)

15. The method of claim 12, wherein the fluid is water between 20° C. and 100° C.

17. The method of claim 1 wherein the fluid is recovered from the flooded first portion.

18. The method of claim 17, wherein the fluid recovered is reused in a subsequent flooding.

19. The method of claim 17, wherein the fluid recovered is purified.

20. The method of claim 1 wherein the fluid further comprises an additive that facilitates release of the heavy oil from the blasted deposit.

21. The method of claim 20 wherein the additive is selected from at least one or more of the following: surfactants, catalysts, ant-acids, acids, caustics, light oils, and solvents.

22. The method of claim 1, further comprising the addition of permeability reducing materials to a treated portion.

23. The method of claim 1 wherein the heavy oil is bitumen.

24. The method of claim 1 wherein the subterranean deposit is a subterranean oil sand deposit.

25. The method of claim 1 wherein the flooding and the recovering are repeated at least once.

26. The method of claim 1, wherein the 2 or more portions are generally in a horizontal plane relative to the surface the deposit and the 2 or more portions are positioned distally and proximally relative to the surface.

27. The method of claim 26, wherein the first portion is the most distal to the surface.

28. The method of claim 26, wherein the second portion is the next most distal portion, and wherein each of the more portions is the next most distal portion.

29. An in situ method for extracting heavy oil from a subterranean deposit, the method comprising:

a) drilling the subterranean deposit to provide a void space within the subterranean deposit, thereby providing access to the subterranean deposit for flooding and fragmentation, to form a drilled deposit;
b) fragmenting the drilled deposit by injection of high pressure fluids to maximize the fragmentation of the deposit and to flood the drilled deposit with a first flood volume of fluid to permit the first flood volume of fluid to admix with the fragmented deposit, to release heavy oil from any inert material so that the heavy oil floats within the first flood volume of fluid thereby forming a flooded fragmented deposit;
c) drilling of the flooded fragmented deposit, wherein one or more wells are drilled to provide for retrieval, thereby forming a drilled flooded fragmented deposit; and
d) retrieving the heavy oil.

30. An in situ method for extracting heavy oil from a subterranean deposit, the method comprising:

a) drilling the subterranean deposit to provide a void space within the subterranean deposit, thereby providing access to the subterranean deposit for fragmentation, flooding, and retrieval to form a drilled deposit;
b) fragmenting the drilled deposit by injection of high pressure fluids to maximize the fragmentation of the deposit and to flood the drilled deposit with a first flood volume of fluid to permit the first flood volume of fluid to admix with the fragmented deposit, to release heavy oil from any inert material so that the heavy oil floats within the first flood volume of fluid thereby forming a flooded fragmented deposit; and
c) retrieving the heavy oil.

31. An in situ method for extracting heavy oil from a subterranean deposit, wherein the subterranean deposit comprises 2 or more portions, the method comprising:

a) drilling the subterranean deposit to prepare the subterranean deposit for fragmentation, wherein at least one hole is drilled in a first portion to provide a void space within the first portion to form a drilled first portion;
b) fragmenting the drilled first portion by injection of high pressure fluids to maximize the fragmentation of the first portion and to flood the drilled first portion with a first flood volume of fluid to permit the first flood volume of fluid to admix with the fragmented first portion, to release heavy oil from any inert material so that the heavy oil floats within the first flood volume of fluid in the drilled fragmented first portion thereby forming a fragmented flooded first portion;
c) drilling of the fragmented flooded first portion to prepare the fragmented flooded first portion for recovery, wherein one or more wells are drilled to provide for access and retrieval, thereby forming a drilled fragmented flooded first portion;
d) retrieving the heavy oil; and
e) repeating steps a)-d) for each of the second or more portions.

32. The in situ method of claim 31, wherein the 2 or more portions are generally in a horizontal plane relative to the surface and the 2 or more portions are positioned distally and proximally relative to the surface.

33. The in situ method of claim 32, wherein the first portion is distal to the surface.

34. The method of claim 32, wherein the second portion is the next most distal portion and wherein each of the more portions are the next most distal portion.

35. The method of claim 29, wherein the drilling of the subterranean deposit, the flooded fragmented deposit or the fragmented flooded first portion comprises:

i) drilling at least one well into the flooded fragmented deposit or fragmented flooded first portion; and
ii) inserting into the at least one well at least one perforated casing per well, wherein the at least one perforated casing is operable to receive fluid into the at least one perforated casing.

36. The method of claim 29, wherein the at least one well is an access well to facilitate flooding of the drilled fragmented portion.

37. The method of claim 29, wherein the at least one well is an access and retrieval well to facilitate flooding of the drilled fragmented portion and to facilitate recovering the heavy oil floating within the flood volume of fluid in the flooded portion.

38. The method of claim 29, wherein the at least one well comprises at least two wells, wherein one well is an access well to facilitate flooding of the drilled fragmented portion and another well a retrieval well to facilitate recovering the heavy oil floating within the flood volume of fluid in the flooded portion.

39. The method of claim 29, wherein the fluid is selected from at least one of the group consisting of: water, steam, air, compressed air, carbon dioxide, light oil, light solvent, and oxygen.

40. The method of claim 29, wherein the fluid is at least one of: compressed air, water, steam and oxygen.

41. (canceled)

42. The method of claim 40, wherein the fluid is water between 20° C. and 100° C.

43-44. (canceled)

45. The method of claim 29, wherein the fluid further comprises an additive that facilitates release of the heavy oil from the blasted deposit.

46. The method of claim 45, wherein the additive is selected from at least one or more of the following: surfactants, catalysts, ant-acids, acids, caustics, light oils, and light solvents.

47. The method of claim 29, further comprising the addition of permeability reducing materials to a treated portion.

48. The method of claim 29, wherein the heavy oil is bitumen.

49. The method of claim 29 wherein the subterranean deposit is a subterranean oil sand deposit.

50. The method of claim 29 wherein the flooding and the recovering are repeated at least once.

51. The method of claim 1, wherein the at least one hole of the drilled first portion or the drilled deposit is sleaved to facilitate the loading and ignition of explosives.

52. The method of claim 1, wherein the at least one hole of the drilled first portion or the drilled deposit is sleaved to facilitate the insertion of a flooding/fragmentation apparatus.

Patent History

Publication number: 20140202692
Type: Application
Filed: Jun 28, 2012
Publication Date: Jul 24, 2014
Inventor: Howard Keele (Courtney)
Application Number: 14/130,170