Patent Grant
12078043
The invention relates to a steam generator tool and in particular a steam generator tool and a method for generating steam from inputs of water, fuel and oxygen.
There are numerous oil reservoirs throughout the world that contain viscous hydrocarbons, often called “bitumen”, “tar”, “heavy oil”, or “ultra heavy oil” (collectively referred to herein as “heavy oil”), where the heavy oil can have viscosities in the range of 3,000 to over 1,000,000 centipoise. The high viscosity hinders recovery of the oil since it cannot readily flow from the formation.
For economic recovery, heating the heavy oil, such as with steam injection, to lower the viscosity is the most common recovery method. Normally, heavy oil reservoirs would be produced by cyclic steam stimulation (CSS), steam drive (Drive), and steam assisted gravity drainage (SAGD), where steam is injected from the surface into the reservoir to heat the oil thereby reducing the oil viscosity enough for efficient production.
Surface injection of steam has a number of limitations due to inefficient surface boilers, energy loss in surface lines and energy loss in the well. Standard oil field boilers convert 85 to 90% of the fuel energy to steam, surface pipelines will lose 5 to 25% of the fuel energy depending on length of pipelines and insulation quality and lastly, the wellbore heat losses can be up to 5-15% of the fuel energy depending on well depth and insulating methods in the well. Thus, energy losses can total more than 50% of the fuel energy prior to the steam reaching the reservoir. In deep heavy oil reservoirs, surface steam injection often results in hot water, rather than steam, reaching the reservoir due to heat losses.
In addition, numerous heavy oil reservoirs will not respond to conventional steam injection since many have little or no natural drive pressure of their own. Even when reservoir pressure is initially sufficient for production, the pressure obviously declines as production progresses. Consequently, conventional steaming techniques are of little value in these cases, since the steam produced is at a low pressure, for example, several atmospheres. As a result, continuous injection of steam or a “steam drive” is generally out of the question. As a result, a cyclic technique, commonly known as “huff and puff” has been adopted in many steam injection operations. In this technique, steam is injected for a predetermined period of time, steam injection is discontinued and the well shut in for a predetermined period of time, referred to as a “soak”. Thereafter, the well is pumped to a predetermined depletion point and the cycle repeated. However, the steam penetrates only a very small portion of the formation surrounding the well bore, particularly because the steam is injected at a relatively low pressure.
Another problem with conventional steam generation techniques is the production of air pollutants, namely, CO2, SO2, NOx and particulate emissions. Several jurisdictions have set maximum emissions for such steaming operations, which are generally applied over wide areas where large heavy oil fields exist and steaming operations are conducted on a commercial scale. Consequently, the number of steaming operations in a given field can be severely limited and in some cases it has been necessary to stage development to limit air pollution.
It has also been proposed to utilize high pressure combustion systems at the surface. In such systems, water is vaporized by the flue gases from the combustor and both the flue gas and the steam are injected down the well bore. This essentially eliminates, or at least reduces, the requirement to address the air pollution from the combustion process as all combustion products are injected into the reservoir and a large portion of the injected pollutants remain sequestered in the oil reservoir. The injected mixture conventionally has a composition of about 60% to 70% steam, 25% to 35% nitrogen, about 4% to 5% carbon dioxide, less than 1% oxygen, depending if excess of oxygen is employed for complete combustion, and traces of SO2 and NOx. The SO2 and NOx, of course, create acidic materials. However, potential corrosion effects of these materials can be substantially reduced or even eliminated by proper treatment of the water used to produce the steam and dilution of the acidic compounds by the injected water.
There is a recognized bonus to such an operation, where a combination of steam, nitrogen and carbon dioxide are utilized, as opposed to steam alone. In addition to heating the reservoir and oil in place by condensation of the steam, the carbon dioxide dissolves in the oil, particularly in areas of the reservoir ahead of the steam where the oil is cold and the nitrogen pressurizes or re-pressurizes the reservoir.
A very serious problem, however, with the currently proposed above ground high pressure system is that it involves complex compression equipment and a large combustion vessel operating at high pressures and high temperatures. This combination requires skilled mechanical and electrical personnel to safely operate the equipment.
One solution to the problems of the surface generation is to position a steam generator downhole at a point adjacent the formation to be steamed, which injects a mixture of steam and flue gas into the formation. This also has the above-mentioned advantages of lowering the depth at which steaming can be economically and practically feasible and improving the rate and quantity of production by the injection of the steam-flue gas mixture.
While many downhole steam generators have been proposed, current designs are generally very complex causing issues during manufacture and operation. Additionally, current designs require frequent maintenance due to hard water build up or ignitor failures, as the downhole conditions are extreme. Durability is very important since any time maintenance is required, the tool must be removed from the well which is time consuming and expensive.
Therefore, a durable steam generator tool is required. Such a tool can be used on surface or downhole.
In accordance with one aspect, the invention relates to a tool for generating steam and combustion gases for producing oil from an oil well, the tool comprising: a first end configured to receive inputs, the inputs including air, fuel and water; an ignition component arranged within the tool configured to ignite fuel and air to generate a flame; a combustion chamber accommodating the flame and extending at a second end opposite the first end, defined by a wall and an outlet configured to allow the exit of combusted products; and a water passageway that extends from the first end of the main body and terminates at a nozzle on an outer surface of the tool, the nozzle directing flow of water at least in part axially along an exterior length of the wall, wherein water is at least partially vaporized along the exterior length of the wall to generate steam.
In another embodiment, the invention relates to a method for generating steam from the steam generator tool for producing oil from the oil reservoir, the method comprising: supplying air, water, fuel and power or control to the steam generator; ejecting water from a nozzle on an exterior surface of the steam generator; igniting a flame using an ignition component; vaporizing water ejected from the nozzle by allowing water to flow along a length of an exterior surface of a wall of the combustion chamber towards an outlet of the combustion chamber while combusted products from the flame are flowing inside the combustion chamber towards the outlet of the combustion chamber; and directing the steam and the combusted products into the oil reservoir.
Another aspect of the invention relates to a tool for generating steam and combustion gases for producing oil from an oil well, the tool comprising: a first end configured to receive inputs, the inputs including air, water and fuel, wherein the air enters the tool at a port on an upper portion of the first end, the port devoid of any connections and configured to open the tool to an outer surface; a site on the first end of the tool configured to couple input lines of water and fuel to the tool; an ignition component arranged within the main body configured to ignite air and fuel to generate a flame; a combustion chamber accommodating the flame and extending at a second end opposite the first end, the combustion chamber defined by a wall and an outlet configured to allow exit of combusted products into the well; and a passageway within the tool from the port to the combustion chamber to allow flow of air from the port to the combustion chamber.
For a better appreciation of the invention, the following Figures are appended:
The detailed description and examples set forth below are intended as a description of various embodiments of the present invention and are not intended to represent the only embodiments contemplated by the inventor. The detailed description includes specific details for providing a comprehensive understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details.
The invention generally relates to a steam generator tool and method of steam generation, either downhole or on the surface, for steam and flue gas injection into an oil reservoir.
While steam injection is often used in the recovery of heavy oil, aspects of the invention are not limited to use in the recovery of heavy oil but are applicable to general steam generation. Applications include but are not limited to steam generation for heavy oil recovery or other industrial applications, water purification etc. In addition, the steam generator tool when employed for heavy oil recovery may be used in any of multiple configurations, for example, on surface, downhole in vertical, horizontal or other wellbore orientations.
With reference to the drawings,
The coupling component, flow diversion component 4, ignition component 5, etc. may be separate, but coupled parts of the tool or they may be permanently coupled, such as integral, but simply functional areas of the tool.
In use, one or more supply lines 1 may be provided for coupling to the tool for delivery of inputs. Lines 1 are received at the tool coupling component 2. The tool's coupling component 2 is configured to receive and couple with any lines 1. Inputs may be received by the component 2 with connections that may be appropriately sealed and allow for ease of replacement, repair and modification. For example, the tool coupling component 2 may include one or more connectors providing a link between the multiple inputs and passages leading to the flow diversion component 4. The lines 1 may provide pressurized delivery of inputs such as oxidant (for example air), fuel and water, or ignition control to the tool coupling component 2.
The flow diversion component 4 delivers fuel and air from component 2 to the ignition component 5 and delivers water from component 2 to the nozzles 6. The flow diversion component 4 has a first end 41, which receives supplies from the tool coupling component 2. The flow diversion component 4 directs the supplies within the tool for their use and consumption. Fuel and air may be supplied into the tool by the lines 1, diverted through the tool by the flow diversion component 4 and released into combustion chamber 74, where they are combusted. Water may be introduced into the tool from line 1, diverted to water nozzles 6 by the flow diversion component 4, where the water is released and, in use, partially vaporized to steam as the water flows along the combustion chamber outer wall or into the hot combustion gases exiting the combustion chamber.
Specifically, flow diversion component 4 includes a plurality of passageways 4a, 4b, 4c through which the inputs of fuel, water and oxidant flow. The passageways include: an oxidant passageway 4a extending from the first end of the tool, such as from an inlet thereon, to the combustion chamber, a water passageway 4b extending from the tool's coupling component 2 to the nozzles 6a and a fuel passageway 4c extending from the tool's coupling component 2 to the combustion chamber 74. Flow diversion component 4 can also accommodate power/control lines or passageways, extending between upper end 41 and various locations in the tool such as ignition component 5.
The ignition component 5 is configured to ignite the fuel and oxidant flowing into the combustion chamber, for example in typical embodiments, ignition component 5 has a portion open to the combustion chamber 74. Once ignited, the fuel and oxidant flows continue to flow into, and burn within, the combustion chamber 74. The ignition component may be a spark generator, heated surface, etc. In another embodiment, the ignition component may include a delivery system for pyrophoric or hypergolic liquids.
The ignition component 5 may be controlled by a control system that determines when the ignition component is operated. The control system may have other operations such as to regulate the stability of the flame, the degree of fuel combustion, or to measure the stoichiometric data, pressure of air and fuel supplied to the tool. Therefore the control system may include sensors such as located within the flow diversion component 4, ignition component 5 or combustion chamber 74. The tool may, for example, have an ignition control line that couples with a control line 19 in line 1. Ignition control line 19 may require electrical connections at component 2.
The combustion chamber 74 extends at the second end of the tool opposite the upper end. The combustion chamber is defined as the space within a tubular wall 7 extending at the second end. The tubular wall has a length L extending axially from a closed end, base wall 50 to an open end that forms an outlet 40 from the chamber. Length L may be between 300 and 1000 mm between the closed end and the open end, depending on the tool operation parameters and output requirements.
The combustion chamber wall 7 has an interior surface 71 facing into the combustion chamber and an exterior surface 72, which in the embodiment of
The combustion chamber 74 is defined within the confines of the base wall 50 and the interior surface 71 and its length L is between base wall 50 and outlet 40, which also defines the long axis of the tool and chamber 74. During operation, the flame resides in the combustion chamber 74, with the combustion products exiting the combustion chamber at the outlet 40.
The diameter of the outlet 40 of the combustion chamber may vary. In one embodiment, the diameter across the outlet 40 is smaller than the largest diameter across the combustion chamber 74. In other words, the diameter across the opening at outlet 40 may be smaller than the largest dimension across the inner diameter of wall 7. Wall 7 may, therefore, include a tapering end that defines the narrowed outlet 40. This tapered end may be referred to as a combustion nozzle 75. The combustion nozzle 75 influences the exiting combustion gases, as they are converged when passing through the narrower diameter. Thus, combustion nozzle 75 generates a backpressure in chamber 74, thereby influencing the evacuation of fluids from the chamber and mitigating backflow of fluids up into the combustion chamber.
As will be appreciated, with the fuel and oxidant entering the combustion chamber at or adjacent the base wall 50, the flame becomes anchored near the base wall and is protected within wall 7. Intense heat is generated by the flame from where it is anchored and downstream thereof along the flame and the path of the combustion products from the flame. The wall 7 of the combustion chamber, therefore, becomes extremely hot at a position radially outwardly from where the flame is anchored and downstream thereof to the outlet 40. The heat is transferred from the interior surface 71 to the exterior surface 72.
Nozzles 6 are connected at the ends of water passageways 4b. The nozzles are positioned on the exterior surface of component 4 adjacent wall 7 and are oriented and configured to spray water therefrom along the combustion wall's exterior surface 72 toward outlet 40. As water flows along the combustion chamber wall 7 towards the outlet 40 of the combustion chamber, the heated exterior surface 72 of the combustion chamber at least partially vaporises the water into steam. In particular, the heat from the flame F, at the exterior surface 72, causes the water ejected from nozzles to be at least partially vaporized to steam. In particular, rather than being positioned to eject water into the combustion chamber where the water could adversely affect the flame, the nozzles are positioned outside the chamber on exterior surface 72. As such, the nozzle orifices open adjacent to the radially outer facing surface 72 of the combustion chamber wall and in one embodiment are configured to eject water at least in part axially along the outer surface 72 of the wall 7.
Nozzles 6 in addition to their location on the exterior surface of the tool, may be positioned at approximately the location where the fuel and oxidant enter the combustion chamber. For example, the flame becomes anchored at or slightly downstream of where air and fuel are combined and ignited, in the combustion chamber. Thus, while the nozzles 6 are on the exterior surface of the tool outside the combustion chamber, the nozzles may be positioned at approximately the same axial position as the passageway openings of air 4a and fuel 4c to chamber 74. This positions the nozzles at the approximately the same axial position as where fuel and air are entering the combustion chamber and just upstream of where the fuel and air are combusting. Therefore, the location of nozzles 6 at approximately the same axial position as the passageway openings of air 4a and fuel 4c to chamber 74, allows water to be released from passageways 4b through the nozzles at a cooler area on the exterior surface of the tool, while water is directed to pass along or impinge on the much hotter tool surface radially outwardly from where the flame sets up.
In the illustrated embodiment, the openings for passageways of air 4a and fuel 4c to chamber 74 are at base wall 50 and therefore nozzles 6 are located at approximately the location of the base wall 50, which is the upper, closed end of the combustion chamber. The nozzles are positioned near or on the outer surface of the combustion chamber wall radially outwardly from the base wall 50 of the combustion chamber 74. In one embodiment, the nozzles may be on the exterior surface of the flow diversion component 4 positioned substantially level, for example substantially coplanar with the ignition component 5 and the openings for passageways of air 4a and fuel 4c within combustion chamber 74, which are all at base wall 50.
The position of the nozzles at the same axial position as base wall 50 ensures that water is released from passageways 4b through the nozzles before the water reaches the hottest area of the tool, which is on wall 7 between where the flame becomes anchored and the outlet end 40. Thus, water passageways 4b extend only through coupling component 2 and flow diversion component 4 to reach nozzles 6 and they do not extend through the tool adjacent past the hottest area of the tool. In one embodiment, passages 4b terminate at nozzles 6 without passing within wall 7.
The application of water from nozzles 6 to the exterior surface 72 generates a cooling effect at wall 7 where water partially vaporizes to form steam. Thus, this nozzle position protects the combustion chamber wall 7 from thermal degradation and provides a uniform temperature distribution around the combustion chamber wall 7. Also, while prior art tools experienced problems with scale build up and plugging of the water passageways and nozzles, the present tool positions the nozzles upstream from the hottest area of the tool to avoid scaling in the water passages and nozzles. While scaling may occur on the exterior surface of the tool, for example, on exterior surface 72 of wall 7, the large, open surface area ensures such scale does not occlude the water spray and tends fall away or be knocked off. While prior tools sometimes required softened water, the current tool with its unique nozzle positioning can work with impure water sources such as process water, surface water, brackish water, etc.
In one embodiment, exterior surface 72 of wall 7 is treated to resist buildup of scale from water evaporation. For example, the exterior surface at least between nozzles 6 and outlet end 40 may be polished or coated with a non-stick coating such as Teflon™, titanium ceramic compounds or similar materials. This surface treatment facilitates scale removal during use and routine maintenance.
Nozzles 6 may be spaced apart about a circumference of the tool such that water is applied around the entire circumference of exterior surface 72. The number of nozzles 6 depends on the flow rate, expected pressure losses and combustion chamber length.
In one embodiment, as shown in
Nozzles 6 may be selected for various spray delivery types including fan, jet/stream, mist, or spray. Additionally, the water pressure and water flow rate may be varied depending on the size of the tool, design criteria and power requirements of the tool.
If there is a desire for higher steam quality or the combustion products exiting the outlet are found to be too hot, it may be beneficial to provide further water extension conduits 12 with distal ends having nozzles 12a thereon, as shown in
Nozzles 12a are positioned close to the outlet 40, where hot combustion gases exit the tool into space 21. Thus, nozzles 12a of extension conduits 12 can be positioned to eject the water close to or directly into the combustion gases. Water supplied to the tool is directed into water extension conduits 12 and ejected by nozzles 12a into the space 21 where hot combustion gases exit from outlet 40 of the combustion chamber, thereby vaporizing the water to steam. There may be a plurality of water extension conduits 12 and nozzles 12a as shown in
Water extension conduits 12 may deliver water directly to the outlet 40 where combustion gases exit into space 21. The introduction of water directly into the exiting combustion gases, may serve to more directly cool the combustion gases. In particular, water extension conduits 12 permit direct cooling of the hot combustion gases 21 that pass from the outlet 40 of the combustion chamber. The water extension conduits 12 may eject water axially relative to the wall or may be angled inward towards the outlet 40 of the combustion chamber. Thus, water ejected from the nozzles 12a may be directed axially or at an angle radially inwardly toward or below the outlet. For example, a distal end of the water extension conduits 12 may be angled a at least 45° towards the outlet 40 providing ejection of water into the space 21 below the outlet where hot combustion gases exit the combustion chamber. The number of water extension conduits 12 may vary depending on the desired steam quality to be obtained, size of the well, application and design of the tool. For example, for a tool intended for use in a well having an inner diameter of less than 229 mm or less than 178 mm, between 4 and 8 water extension conduits 12 may be provided.
Water extension conduits 12 with nozzles 12a have the greatest effect at a low power setting, for example 5 million BTU/hr. In this case, the water ejected from nozzles 12a helps to cool the hot combustion gases exiting the outlet 40 of the combustion chamber.
Water extension conduits 12 are connected to the tool by mechanical coupling or welding. As shown in
As noted, the tool can be used downhole or on surface. When used downhole, the tool is installed with combustion chamber 74 and nozzles 6 open to the area of the well, such as a formation 11 to be steam treated.
Isolating packer 3 is installed concentrically around the outer surface of the tool, above the tool on a connected but separate tool or on the lines 1. The packer 3 is initially in a retracted position, when not in use or when being tripped into the well, but when in position in the well, it is set by expanding the packer elements.
In one embodiment, the isolating packer is installed about a circumference of the tool between the coupling component 2 and the nozzles 6. Thus, when set in the well, the coupling component is uphole of the packer and nozzles 6 and outlet 40 are downhole of packer 3. Packer 3 isolates coupling component 2 from communication with the nozzles except through passageways 4a, 4b, 4c.
When installed in a well, an annular cooling system 23 may be employed uphole of the tool above packer 3.
The reducer cone includes conical, funnel shaped, tapering side walls that converge from an inlet, open upper end 14a to an outlet, open lower end 14b. The cone's lower end has a smaller diameter opening than its upper end. The wider upper end is positioned on the tool closer to the outlet 40 than the lower end 14b.
In one embodiment, the open upper end 14a of reducer cone 14 has a diameter greater than the diameter across outlet 40 and forces any unvaporized water, steam passing along the outer surface 72 to converge with the combustion gases exiting outlet 40. In particular, the upper end 14a forces the fluids in space 21 to converge to pass through the smaller diameter lower outlet 14b. In one embodiment, the upper end of reducer cone 14 is about the same diameter as the wellbore casing in which the tool is to be used, which is about the same diameter of packer 3 when set. Therefore, any fluids in area 21 below outlet 40 have to pass through the reducer cone as they move away from the tool. The smaller diameter lower outlet 14b may be lengthened by a cylindrically shaped solid wall extension of consistent diameter, to control flow dynamics of exiting steam and combustion flue gases. For example, the extension may mitigate the formation of eddy currents as fluids exit cone 14.
Reducer cone 14 may be coupled onto the tool in any of various ways, such that it is positioned substantially concentric with, and spaced below, the outlet 40. If there is concern about tool control or casing damage, the converging structure may include a substantially solid cylindrical housing 8 to couple cone 14 in position on the tool. Such a tool is illustrated in
Optionally, a non-stick treatment, such as a coating as noted above, may be applied to the interior surface of the outer housing.
In another embodiment, as illustrated in
In one embodiment, support arms 13 are connected by a collar 13a, secured concentrically on the tool above nozzles 6, for example, to the outer surface of component 4 below packer 3. Supports 13 then extend down along the main body and the combustion chamber wall and axially beyond outlet 40. Support arms 13 are, therefore, longer than the length L of wall 7 to extend from above nozzles 6 to terminate below outlet 40.
Support arms 13 and/or collar 13a may be further configured to act as centralizers for the tool relative to the casing in which the tool is installed. For example, the supports and/or collar 13a may protrude diametrically beyond the diameter of the tool's main body, components 2 and 4, to define an effective outer diameter that is about the same diameter as the wellbore casing in which the tool is to be used. Where the support arms are used as centralizers, there may be at least three spaced apart support rods that extend axially from at or above shoulder 65 and are circumferentially spaced to define an effective outer diameter that is about the same diameter as the wellbore casing in which the tool is to be used, which is about the same diameter as the upper end of cone 14 and of packer 3, when set, which is greater than the outer diameters of each of the tool components 2, 4 and wall 7.
The reducer cone upper end 14a rests close to or against the well casing 9, since as noted, the upper end diameter is about the same as the casing in which the tool is installed. In one embodiment, there is a seal 15 on the upper end of reducer cone 14. The seal may be a ring that extends around the entire circumference of upper end 14a and the ring diameter is selected to be biased against the well casing 9. Seal 15 may be made of a variety of high temperature resilient materials, for example, high temperature rubber compounds, Teflon or similar materials.
In this embodiment, the well casing 9 is used to contain the water, steam and combustion products within the well below nozzles. For example, water from nozzles 6 and resulting steam flows along the space between well casing 9, arms 13 and wall 7, until it reaches seal 15 and cone 14 where it is converged inwardly into the flue gases exiting from outlet 40.
In another embodiment, a plurality of the lines may be bundled, for example configured as a multi-conduit umbilical 1a, as shown in
The outer diameter of the lines 1, 1a may depend on the pressure requirements of the application of the tool. For example, for heavy oil production, the outer diameter of the tubing may range between 60 and 114 mm and between 15 and 60 mm for Armorpak tubing. Inputs lines such as air line 17 or fuel line 18 may deliver the largest volume of inputs to the tool when compared to water 20 and therefore may be configured to rigidly secure the tool 100 to the surface during downhole applications.
In an alternative embodiment shown in
Air from within well casing 9 can flow into port 90 and be diverted via the flow diversion component 4 to chamber 74. During downhole operations, annular bypass via port 90 permits lower operating pressures at the surface of the well compared to line delivery of oxidant, as the flow area in the annulus is several times larger than the flow area through input lines 1. As a result, the port 90 may be useful when well casing 9 is narrow to provide optimal operating pressures at the surface of the tool. In addition, compressors used to deliver inputs downhole may be more economical when air is delivered through port 90. By using the annulus to deliver air through port 90, supplementary fuel 17 and water 20 may be delivered through input lines 1.
In another aspect of the invention as shown in
The outer diameter of the steam generator tool 100 may vary depending on the inner diameter of the well casing 9. The steam generator tool must have an outer diameter smaller than the inner diameter of the well casing 9. Typically, the inner diameter of the well may be less than 200 mm or less than 125 mm, in such cases the tool may have a maximum outer diameter of about 190 to 120 mm to fit within well casing 9.
During downhole applications of the steam generator tool, the outer diameter of the tool may be limited by the size of the well casing 9, whereas during surface applications of the tool there is no size limitation.
In another embodiment there is provided, a method for generating steam such as for injection to a reservoir 11 for producing oil from the oil reservoir. The method comprises: supplying air, water and fuel to the steam generator tool; igniting the fuel to create a flame within the combustion chamber 74; ejecting water out of the nozzles 6 along the exterior of the combustion chamber wall 7 such that the water partially vaporizes to form steam and flows along an exterior surface 72 of the combustion chamber wall 7 while combustion gases from the flame flow within the combustion chamber through the inner diameter defined within the interior surface 71 of the wall; and mixing the steam and the combustion gases at an outlet 40 of the combustion chamber. The mixture of steam and combustion gases may be communicated to the reservoir.
Supply of air, water and fuel to the tool may be achieved using various methods. For example, the multi-conduit umbilical may supply inputs to the tool. Alternatively, the space between the tool and the well casing 9, specifically the annulus may provide a path for inputs such as air, where the tool includes port 90. The ignition component 5 may be used to initiate combustion of the supplied fuel and air to produce the flame within the interior of the combustion chamber. Water flowing into the tool via the multi-conduit umbilical may be ejected through water nozzles 6 outside of the combustion chamber where the flame is anchored. Nozzles 6 may be oriented so that the water may be ejected at least in part axially towards the outlet 40 of the combustion chamber. Water flowing along the length L of the heated combustion chamber wall 7, cools the wall and is vaporized to steam. Only when the steam and any unvaporized water reach the lower end of the wall do they contact flue gases exiting at outlet 40.
The steam and combustion gases, and any unvaporized water, may be directed to converge, for example, by passing through reducer cone 14 before entering the oil reservoir 11. The reducer cone funnels and forces mixing of the steam and/or water after travelling along the combustion chamber wall 7 and combustion gases exiting the outlet 40 of the combustion chamber. This increases steam quality and reduces flue gas exit temperatures.
Because the tool vaporizes water on its outer surface, water supplied to the tool 100 may be impure, for example, fresh water, brackish water or seawater. The steam generated by the tool 100 may include super-heated steam.
A variety of different fuels may be employed, for example, natural gas, synthetic gas, propane, hydrogen or liquid fuels.
For use in typical oil reservoirs, the pressure of air or gases may be controlled to about 20 atmospheres (2,000 kPa) to about 70 atmospheres (7,000 kPa) and the output of the tool may be controlled to above 10 MM Btu/hr.
The tool is composed of materials selected to the rigors of down hole such as high temperatures, steam and corrosive fluids.
The components of the steam generator tool 100 are simple and flexible permitting ease of use, inspection, repair and modification. The tool and method of using the tool to produce steam reduces or delays environmental pollution. Due to the design and configuration of the components, the tool is able withstand high temperatures and pressures over repeated use. In addition, the tool is capable of pressurizing and/or re-pressurizing the oil reservoir as combustion gases and steam may be injected into the well at various pressures. The high power output of the tool provides extended operation in many applications.
Clauses
The description and drawings are to enable the person of skill to better understand the invention. The invention is not be limited by the description and drawings but instead given a broad interpretation.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CA2020/051071 | 8/6/2020 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2021/026638 | 2/18/2021 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4452309 | Widmyer | Jun 1984 | A |
| 4540052 | Hitzman | Sep 1985 | A |
| 4558743 | Ryan et al. | Dec 1985 | A |
| 4574886 | Hopkins et al. | Mar 1986 | A |
| 20130341026 | Alifano et al. | Dec 2013 | A1 |
| 20150198025 | Baird | Jul 2015 | A1 |
| Number | Date | Country |
|---|---|---|
| 86103584 | Oct 1987 | CN |
| 1033095 | May 1989 | CN |
| 2358341 | Jan 2000 | CN |
| 101067372 | Nov 2007 | CN |
| 102046918 | May 2011 | CN |
| 102353033 | Feb 2012 | CN |
| 102906368 | Jan 2013 | CN |
| 104508236 | Apr 2015 | CN |
| 104520528 | Apr 2015 | CN |
| 2316648 | Feb 2008 | RU |
| 2007136457 | Apr 2009 | RU |
| 2013053048 | Apr 2013 | WO |
| Entry |
|---|
| PCT/CA2020/051071, “Notification of Transmittal of the International Search Report and the Written Opinion of the International Searching Authority, or the Declaration”, ISA, Nov. 20, 2020, pp. 1-9. |
| Number | Date | Country | |
|---|---|---|---|
| 20220275715 A1 | Sep 2022 | US |
| Number | Date | Country | |
|---|---|---|---|
| 62885078 | Aug 2019 | US |
