STEAM GENERATION PROCESS FOR ENHANCED OIL RECOVERY

• US 20100170453A1
• Filed: 12/10/2009
• Published: 07/08/2010
• Est. Priority Date: 12/12/2008
• Status: Active Grant

• Current Assignee: Ex-Tar Technologies Inc.
• Original Assignee: Ex-Tar Technologies Inc.
• Inventors: BETZER-ZILEVITCH, Maoz
• Granted Patent: US 8,789,608 B2
• Time in Patent Office: Days
• US Class Current: 122/6.R
• CPC Class Codes: B03D 1/02 Froth-flotation processes
• CPC Class Codes: B03D 1/1475 Flotation tanks having means for discharging the pulp, e.g. as a bleed stream
• CPC Class Codes: B03D 1/247 Mixing gas and slurry in a device separate from the flotation tank, i.e. reactor-separator type
• CPC Class Codes: E21B 43/24 using heat, e.g. steam injection
• CPC Class Codes: E21B 43/241 combined with solution mining of non-hydrocarbon minerals, e.g. solvent pyrolysis of oil shale
• CPC Class Codes: E21B 43/35 specially adapted for separating solids down-hole drilling fluid separation systems E21B21/002; separating solids from drilling fluids E21B21/065
• CPC Class Codes: E21B 43/40 Separation associated with re-injection of separated materials E21B43/385 takes precedence
• CPC Class Codes: Y02P 70/10 Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier
• CPC Class Codes: Y02P 80/15 On-site combined power, heat or cool generation or distribution, e.g. combined heat and power [CHP] supply

Abstract

The present invention is a system and method for steam production for extraction of heavy bitumen. The method includes mixing fuel and oxidizing gases, combusting the mixture, mixing combustion gas with water containing solids and organics, separating solids, using heat from the separated gas to produce distilled water, recycling the distillation facility brine with the combustion gas and removing solids thereof, generating steam from the distilled water and injecting the steam through an injection well or using it above ground for oil recovery. The system includes a combustion boiler, a direct contact steam generator, a gas-solids separator, and a heat exchanger with a water treatment facility like a distillation facility. The water feed of the present invention can be water separated from produced oil and/or low quality water salvaged from industrial plants, such as refineries and tailings as make-up water.

Claims

1. A method for steam production for extraction of heavy bitumen, with zero liquid discharge, said method comprising the steps of:

(a) mixing carbon-based fuel and oxidizing gases, wherein said carbon-based fuel is comprised of carbon fuel or hydrocarbon fuel and wherein said oxidizing gases are comprised of oxygen, air, or enhanced air;

(b) combusting the mixture under pressure and temperature so as to produce a combustion gas;

(c) mixing said combustion gas with liquid water having solids and organics so as to transfer said liquid water from a liquid phase to a gas phase;

(d) separating solids from the gas phase;

(e) using heat from the gas phase to evaporate water to produce de-mineralized distilled water and concentrated brine;

(f) recycling the concentrated brine back to step (c) and mixing with said combustion gas;

(g) using the produced distilled water for steam generation through non-direct heat exchange; and

(h) using produced steam to recover oil.

2. The method described in claim 1, wherein said liquid water having solids and organics mixes with the fuel prior to the combustion or injects directly to the combustion reaction so as to control the combustion temperature and transfer said liquid water from a liquid phase to a gas phase.

3. The method for steam generation of claim 1, further comprising:

recovering a portion from the combustion heat for the generated of steam from said de-mineralized water.

4. The method of steam generation of claim 1, further comprising:

mixing said combustion gas with liquid water to wet-scrub solids and acid gases in order to produce a clean, wet saturated steam and combustion gas mixture and liquid water with the scrubbed solids and gases; and

recycling at least some of said liquid water containing the scrubbed material back to the step of transferring said liquid water from a liquid phase to a gas phase.

5. The method of steam generation of claim 1, wherein the carbon-based fuel contains sulfur, the method further comprising:

mixing the fuel or the water with alkaline compounds like lime stone, so as to remove SO2 at the combustion stage and to produce a lean SO2 gas mixture wherein the scrubbed solids are comprised of calcium sulfite or calcium sulfate or both.

6. The method of steam generation of claim 1, wherein the carbon-based fuel contains sulfur, the method further comprising:

mixing the combustion gas with liquid water and alkaline compounds, said alkaline compound being comprised of calcium, so as to remove SOX and NOX in order to produce a clean, wet saturated steam and gas mixture and liquid water with the scrubbed solids and gases; and

recycling at least some water containing the scrubbed solids and gases back to the step of transferring said liquid water from a liquid phase to a gas phase.

7. The method of steam generation of claim 5, wherein said alkaline compounds contains lime softening sludge which is a lime softening water treatment facility waste to remove the acid gases and in particularly the SO2.

8. The method of steam generation of claim 1, wherein the step of combustion and mixing said combustion gas with liquid water having solids and organics so as to transfer said liquid water from a liquid phase to a gas phase is located in an integrated combustion and direct contact steam generator reactor, wherein most water evaporates to steam.

9. The method of steam generation of claim 1, wherein the step of mixing said combustion gas is located in a direct contact steam generator reactor, wherein most water evaporates during conversion to steam. Said direct contact steam generator reactor comprises a horizontal rotating reactor, a fluidized bed reactor, or an up-flow reactor to generate a stream of gas and solids.

10. The method of steam generation of claim 1, wherein the step of mixing said combustion gas is located in a pressurized spray dryer, consuming contaminated water for conversion to steam.

11. The method of steam generation of claim 1, wherein the gas after the step of using the heat of said gas and condensing the water is non-condensable combustion gas, said method further comprising:

using the pressure of the non-condensable combustion gas to generate a vacuum to operate the distillation facility before it is released to the atmosphere.

12. The method of steam generation of claim 11, wherein if an air separation unit was not used and air was used as an oxidizer, the method further comprises using a membrane to separate CO2 from the non-condensable combustion gas, wherein discharged pressure will be used for the step of separating the gases on the membrane;

and

using the CO2 for Enhanced Oil Recovery or for sequestration.

13. The method of claim 1, where the distillation facility is Multi Effect Distillation facility, Multi Stage Flashing facility, Mechanical Vapor Compression or a combination of them.

14. The method of claim 1, where the high pressure steam is generated through a fluidized bed boiler, OTSG (Once Through Steam Generator), Co-Gen or industrial steam boiler.

15. The method of claim 1 where the heat transfer from the combustion gas and steam mixture and the distillation facility is done in a direct contact heat exchange between liquid water and the gas phase.

16. The method of claim 1, where the separated solids are mixed with sludge waste, like Mature Fine Tailings or concentrated brine, to consume waste, reduce dust and to generate a stable solid material that can be disposed in a land-fill and support traffic.

17. The method of claim 1, where the produced steam is injected through an injection well into an underground formation to recover heavy oil.

18. The method of claim 1, where the produced steam is used in an open oilsands mine to flash solvents and for process water heat-up.

19. A method for producing steam for injection into an underground formation through an injection well to extract heavy bitumen, the method comprising the steps of:

generating pumpable fuel slurry from carbon base fuel and water having levels of solids and organics, wherein said carbon-based fuel is comprised of carbon or hydrocarbon fuel like coal, petcoke or asphaltin and said water can be tailing water, brine, lime softener sludge or any other available water source;

mixing said fuel and oxidizing gases, and wherein said oxidizing gases are comprised of oxygen, air, or enhanced air;

combusting the mixture under a controlled pressure and temperature so as to produce heat, steam and combustion gases;

mixing the combustion gases with liquid water having levels of solids, organics and alkaline material to react with combustion acid gas, said liquid water transferring from a liquid phase to a gas phase;

separating solids from the gas phase;

recovering heat and water from the gas phase;

using the recovered heat and water for generating steam;

injecting the generated steam into a heavy oil formation through an injection well;

recovering water and heavy bitumen from a well; and

separating the bitumen from the mixture to produce bitumen and produced water.

20. A system for producing steam for injection into an underground formation to extract heavy bitumen with zero liquid discharge, the system comprising:

a combustion boiler, mixing fuel with oxidation gases therein, forming a mixture, combusting the mixture under high pressures and temperatures therein to generate combustion gases, recovering a portion of the combustion heat to generate steam;

a direct contact steam generator, mixing said combustion gases generated by the combustion boiler with water containing high levels of solids therein to form a steam and combustion gas mixture, evaporating the water in the combustion gas mixture to leave the solids in a dry form, wherein the direct contact steam generator is in fluid connection to the combustion boiler and to a water treatment facility;

a gas-solid separator unit, the combustion gases and steam mixture being transferred thereto and removing dry form solids from the gas-solid separator unit, where the gas-solid separation unit is in fluid connection with the direct contact steam generator;

a distillation water treatment plant, generating a stream of de-mineralized water and concentrated brine using heat from the combustion gas and steam from the separator unit, wherein the distillation water treatment plant can be MED, MSF, MVC or combination of them which is in fluid connection with the combustion boiler and the direct contact steam generator; and

an enhanced oil recovery facility, having a steam injection well, a bitumen and water production well and a separation facility to separate the bitumen from the water in fluid connection to the steam boiler and to the water treatment plant.

21. The system of claim 20, further comprising:

a steam generation and wash vessel, the combustion gases being transferred thereto and washing the combustion gas mixture in the steam generation and wash vessel with water at a saturated temperature and pressure, and scrubbing any remaining solids and acid gases from the combustion gas mixture to form the saturated clean steam and gas mixture, wherein the clean steam and gas mixture is injected into the underground formation to extract the heavy bitumen.

22. The system of claim 20, wherein said combustion boiler is comprised of an atmospheric boiler, combusting fuel and generating steam from de-mineralized water and being in fluid connection to said water treatment plant, wherein said direct contact steam generation is comprised of internal combustion means to generate the heat and combustion gases for operation, mixing said combustion gases generated by the internal combustion with water containing high levels of solids therein to form a combustion gas mixture, and evaporating the water in the combustion gas mixture to leave the solids in a dry form, wherein the direct contact steam generator is in fluid connection with the atmospheric boiler and the water treatment facility.

23. The system of claim 20, wherein said combustion boiler is integrated with the a direct contact steam generator and comprised of mixing fuel with oxidation gases therein, forming a mixture, combusting the mixture under high pressures and temperatures, possibly with lime stone therein to generate combustion gases, recovering a portion of the combustion heat to generate steam, mixing water containing high levels of solids therein to form a steam and combustion gas mixture, evaporating the water in the combustion gas mixture to leave the solids in a dry form, wherein the boiler is a fluidized bed, and wherein the integrated boiler and direct contact steam generation is in fluid connection to the gas-solid separator unit and to the enhanced oil recovery facility.