Related Applications

[0001] This application claims priority from, and the benefit of 35 USC 1 19(e) in relation to, US application No. 62/515527 filed 5 June 2017, which is hereby incorporated herein by reference in its entirety.

Technical Field

[0002] The invention relates to the fields of steam generation, water treatment, and electrical generation. Particular embodiments may use heat from electrical generation processes to generate steam for use in steam-assisted gravity drainage (SAGD) resource (e.g. oil) extraction or similar resource extraction techniques or other industrial processes using purified water.

Background

[0003] Figure 1 A is a schematic depiction of a typical prior art SAGD process (system) 100 for resource (e.g. oil) extraction from underground deposits. In a typical SAGD oil production process 100, water needs to be treated to a high level of purity, so that it can be used to produce high pressure steam 16 that is used for extracting oil from geological formations. Typically, pure water 1 1 is converted to high pressure steam 16 using a Once Through Steam Generator (OTSG), a drum boiler, or similar boiler 12 (referred to herein, without loss of generality, as OTSG 12). OTSG 12 typically burns natural gas 101 and converts input water 1 1 to high pressure steam 16, with C0 ₂ and other combustion waste products (not shown). Not all of the water 1 1 supplied to OTSG 12 is converted to high pressure steam 16. About 20% of water 1 1 supplied to OTSG is so-called "blowdown" waste water. Also, about half of the blowdown (-10% of input water 1 1 ) supplied to OTSG 12 may be returned to walnut filter 7 or elsewhere in process 100, as described in more detail below. The other half of the blowdown (- 10% of input water 1 1 ) is true waste 15F, which must be managed as described below. As a result, about 80% of water 1 1 supplied to OTSG 12 is used to produce high pressure steam 16.

[0004] When used in a SAGD process, high pressure steam 16 allows the oil to flow from the geological formations and into wells, after which the combination of oil and water/steam 1 is typically pumped to the surface. The combined oil and the high temperature water 1 are typically separated at the surface in a free water knockout tank (FWKO) 2, which is an oil/water separator. Oil 14 is extracted from FWKO 2 for further processing. There is a general desire to re-use some of the water 3 separated from oil 14 in FWKO 2. The separated water 3 typically has to be cooled (not shown) from a temperature typically between 130 °-180 °C down to 60 °-80 °C, so the cooled water 4 can be treated. Separated water 3 typically contains colloidal solids, some oil remnants, and scaling parameters such as silica, calcium, magnesium, and other scaling parameters. When high pressure steam 16 is injected into the geological formation, approximately 3%-10% of the water that makes up steam 16 is lost, so process 100 typically requires the introduction of makeup water 24. Makeup water 24 is typically not high quality water and often contains total dissolved solids and possibly some pollutants.

[0005] Cooled water 4 may represent the combination of separated water 3 and makeup water 24. Cooled water 4 is typically of insufficient purity to be re-used by OTSG 12 and consequently, cooled water 4 must be treated. The conventional method of treatment involves:

• Using chemical processing and additives at block 5 to help make remaining oil

separate from the water. The chemicals used in the block 5 process are expensive.

• After the addition of chemicals in block 5, the water is typically treated by a flotation system known as an induced gas flotation (IGF) system 6. IGF 6 typically requires nitrogen to be added to the water and the nitrogen is typically captured in a closed system (to be reused). The addition of nitrogen causes the oil in the water to float to the surface. The top float layer of oil is typically skimmed off the top of the flotation cell and then pumped as sludge 15A to an oil sludge tank (not expressly shown). Sludge 15A, which is a waste product of process 100, typically must be managed in accordance with local environmental and/or waste management regulations, which can be difficult and/or expensive.

• Following IGF 6, the water is filtered with a walnut shell filter (WSF) 7, which adsorbs the organics in the water. WSF 7 typically has to be backwashed after the pressure to push the water through the filter reaches a level of 1 .5-3 bar, for example.

Backwash water 15B generated during this backwash process is a waste product of process 100 and typically must be managed in accordance with local environmental and/or waste management regulations, which can be difficult and/or expensive.

• Following WSF 7, the water is treated by a clarifier 8, where chemicals are added.

The water to be treated is first chemically treated to cause the scaling parameters (like silica, calcium, magnesium, and/or the like) to be converted to discrete solids commonly referred to as suspended solids. To cause silica to be converted from a dissolved solid to a suspended solid, MgO or similar chemical(s) are typically added to the water to be treated. To convert calcium and magnesium from dissolved solids to suspended solids, NaOH, lime (CaOH), or similar chemical(s) are added to the water to be treated. To help the solids settle in clarifier 8, a destabilizing chemical like alum or PACI or similar chemical(s) may be added. The chemical(s) used in the clarification process can be costly. The settled solids 15C from clarifier 8 are a waste product of process 100 and typically have to be removed from clarifier 8 and then dewatered by a centrifuge 8A and/or a process similar to a centrifuge prior to being managed in accordance with local environmental and/or waste management regulations, which can be difficult and/or expensive.

• Following clarifier 8, a sand filter 9 is typically used to filter any solids that did not settle in clarifier 8. Sometimes this filter 9 is called an after filter (AF) 9. Filter 9 typically has to be backwashed, when the pressure across filter 9 rises to a certain level such as 1 .5-3 bar. Backwash water 15D generated during this backwash process is a waste product of process 100 and typically must be managed in accordance with local environmental and/or waste management regulations, which can be difficult and/or expensive. In addition, the volumes of backwash water 15D can be high. • Following sand filter 9, the water is typically treated with an ion exchange resin by a demineralizer 10 to remove calcium and magnesium residuals in the water. The ion exchange resins used in demineralizer 10 need to be rinsed and regenerated. The resultant rinse water 15E is a waste product of process 100 and typically must be managed in accordance with local environmental and/or waste management regulations, which can be difficult and/or expensive.

[0006] After these treatment steps, the output water 1 1 is ready for use by OTSG 12 to make steam 16. However because water 1 1 is not a high quality water, OTSG 12 typically generates wastewater known as blowdown. The blowdown from OTSG 12 is typically on the order of approximately 20% of input water 1 1 . Approximately half of the blowdown (-10% of input water 1 1 ) may be returned (at 13) to walnut filter 7 or elsewhere in the front end of the treatment system. The other half of the blowdown (-10% of input water 1 1 ) is true waste 15F and typically must be managed in accordance with local environmental and/or waste management regulations, which can be difficult and/or expensive. The remaining 80% of input water 1 1 is made into steam 16.

[0007] Figure 1 B schematically illustrates a typical gas-based electrical generation process 200. The gas consumed in electrical generation process 200 is typically natural gas 70, but other gasses (e.g. biological gasses) can also be used. A gas-burning turbine 40 burns gas 70 to produce electricity 45. The combustion process in turbine 40 typically generates CO ₂ and other combustion by-products (not expressly shown). Waste heat 41 from gas turbine 40 may be used as a heat source for a boiler (e.g. an OTSG or a heat recovery steam generator (HRSG)) 42. Water 52 used as the input for boiler 42 typically needs to have sufficient purity. Some of the input water 52 for boiler 42 typically comes from an external natural source or another external source of water that is not part of the water cycle in electricity-generating process 200. This component of input water 52 may be referred to as makeup water 65. Makeup water 65 is typically treated prior to use (as explained in more detail below). Boiler 42 converts input water 52 into high pressure steam 43, which may be in turn used to drive a steam turbine 47 to generate more electricity 46. Boiler 42 typically also consumes natural gas 70 and generates CO ₂ and other combustion by-products. [0008] After steam turbine 47 has used some of the energy of the high pressure steam 43, the output steam is low pressure (LP) steam 48. LP steam 48 is typically cooled back into water (referred to as condensate water) 51 by a cooling tower 50. Cooling tower 50 typically uses cold water or air or both 201 to cool LP steam 48 into condensate water 51. Cooling tower 50 is expensive to operate and is energy intensive.

[0009] Condensate water 51 and the treated makeup water 65 provide the total input water 52 needed for boiler 42 to make high pressure steam 43. There are water losses during electricity-generating process 200. When LP steam 48 is cooled, less than 100% of the input water 52 water is recovered for reuse back to boiler 42. As a result, there is a need for makeup water 65. To ensure that makeup water 65 has sufficient purity, water from an external source 60 (typically a river, a lake, or some other external source) undergoes a treatment process prior to being used as makeup water 65. Typically, external source water 60 is first treated with chemicals 61 to remove scaling parameters and/or solids. In addition to chemical treatment, colloidal solids are typically removed by ultrafiltration (UF) membranes or sand filters or both 62. Further, high pressure reverse osmosis (RO) membranes 63 are typically used to remove the dissolved solids and additional scaling parameters to produce a high quality makeup water 65. Using high pressure RO

membranes 63 is energy intensive. The process for treating external source 60 to produce sufficiently pure makeup water 65 has high capital and operating costs. In addition, a percentage of the water treated by RO membranes 63 is rejected and this reject water 64 has to be disposed of which can be costly and difficult.

[0010] The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.

Summary

[0011] This invention has a number of aspects. These aspects may be applied individually or in any combinations. Some aspects provide means for producing oil and electricity in a combined process. [0012] One aspect of the invention provides a system for generating oil and electricity. The system comprises an evaporator for producing steam and high purity water. The steam is provided to a resource extraction process which generates a mixture of oil and water. The high purity water is provided to an electricity-generating process. The system also comprises an oil-water separator which separates the mixture of oil and water to produce oil and input water for the evaporator. Excess heat from the electricity-generating process is provided to the evaporator.

[0013] Another aspect of the invention provides a method for generating oil and electricity. The method comprises separating a mixture of oil and water which is generated by a resource extraction process. The separated water is then used to generate steam and high purity water. The steam is provided to the resource extraction process which produces the mixture of oil and water, and the high purity water is provided to an electricity-generating process. Excess heat produced by the electricity-generating process is used to generate the steam and the high purity water.

[0014] Another aspect of the invention provides a system for generating oil and electricity. The system comprises a boiler for producing steam from input water. Substantially all of the energy for the boiler is provided by waste heat from an electricity-generating process. The steam from the boiler is provided to a resource extraction process which generates a mixture of oil and water. The system also comprises an oil-water separator which separates the mixture of oil and water to produce oil and the input water for the boiler.

[0015] Another aspect of the invention provides a method for generating oil and electricity. The method comprises separating a mixture of oil and water which is generated by a resource extraction process. The separated water is then used to generate steam. The steam is provided to the resource extraction process which produces the mixture of oil and water. Substantially all of the energy for the boiler is provided by waste heat from an electricity-generating process.

[0016] Another aspect of the invention provides a method for generating oil and electricity.

The method comprises: receiving a mixture of oil and water generated by a resource extraction process; separating the oil from the water in the mixture to thereby generate separated water; generating steam using the separated water; using the steam in the resource extraction process to extract oil from a geological formation, thereby producing the mixture of oil and water; generating electricity in an electricity-generating process; and extracting waste heat from the electricity-generating process and using the waste heat to provide substantially all of the energy used for generating the steam using the separated water.

[0017] Generating electricity in the electricity-generating process may comprise using a gas turbine powered by natural gas. Extracting waste heat from the electricity-generating process may comprise extracting heat from the gas turbine.

[0018] Separating the oil from the water in the mixture to thereby generate separated water may comprise separating the oil from the water in a free water knock out tank.

[0019] Generating the steam using the separated water may comprise using the separated water to generate input water provided to a boiler and boiling the input water provided to the boiler to generate the steam. Using the separated water to generate input water provided to the boiler may comprise using a membrane treatment process to treat the separated water to thereby generate the input water provided to the boiler. Using the membrane treatment process to treat the separated water may be performed with separated water that is at a temperature greater than 100°C. Using the membrane treatment process to treat the separated water may be performed with separated water that is at a temperature greater than 130°C.

[0020] Generating steam using the separated water may further comprise generating blowdown water and the method may further comprise treating the blowdown water using at least a membrane treatment process to generate treated blowdown water and combining the treated blowdown water with the input water provided to the boiler. After being treated by the membrane treatment process, the blowdown water may be further treated by one or more of an evaporation process, and a membrane distillation process to generate the treated blowdown water. Treating the blowdown water by one or more of an evaporation process, and a membrane distillation process may comprise generating brine comprising a concentration of minerals that is high relative to the water at other locations of the method. Some of the minerals may be extracted from the brine. [0021 ] Another aspect of the invention comprises a system for generating oil and electricity. The system comprises: a boiler for producing steam from input water, wherein substantially all of the energy used by the boiler for producing the steam from the input water is provided by waste heat from an electricity-generating process; a resource extraction unit which receives the steam from the boiler and uses the steam to extract oil from a geological formation and, in so extracting the oil from the geological formation, generates a mixture of oil and water; and an oil-water separator which separates the mixture of oil and water to produce oil and the input water for the boiler.

[0022] The electricity-generating process may comprise a gas turbine powered by natural gas. The oil-water separator may comprise a free water knock out tank.

[0023] The input water for the boiler may be treated by a membrane treatment unit at a temperature greater than 100 °C prior to being provided from the oil-water separator to the boiler. The input water for the boiler is treated by a membrane treatment unit at a

temperature greater than 130 °C prior to being provided from the oil-water separator to the boiler.

[0024] Blowdown water from the boiler may be treated by at least a membrane treatment unit and combined with the input water provided to the boiler. After being treated by the membrane treatment unit, the blowdown water may be further treated by one or more of an evaporator, and a membrane distillation unit to generate pure water wherein the pure water is combined with the input water provided to the boiler. The one or more of the evaporator, and the membrane distillation unit may generate brine comprising a concentration of minerals that is high relative to the water at other locations of the system. A mineral extraction unit may be used to extract at least some of the minerals from the brine.

[0025] Another aspect of the invention comprises a method for generating oil and electricity.

The method comprises: receiving a mixture of oil and water generated by a resource extraction process; separating the oil from the water in the mixture to thereby generate separated water; generating steam and high purity water using the separated water; using the steam in the resource extraction process to extract oil from a geological formation, thereby producing the mixture of oil and water; and using the high purity water to generate electricity in an electricity-generating process; wherein generating steam and high purity water using the separated water comprises extracting excess heat from the electricity- generating process.

[0026] Separating the oil from the water in the mixture to thereby generate the separated water may comprise using a free water knock out tank.

[0027] Generating the steam and the high purity water using the separated water may comprise using the separated water to generate input water provided to an evaporator and performing an evaporation process to generate the steam and the separated water. Using the separated water to generate input water provided to the evaporator may comprise using a membrane treatment process to treat the separated water to thereby generate the input water provided to the evaporator. The separated water may be at a temperature greater than 100°C. The separated water may be at a temperature greater than 130°C.

[0028] Using the high purity water to generate electricity in the electricity-generating process may comprise generating steam using the high purity water and using the steam in a steam turbine to generate the electricity. Generating steam using the high purity water may comprise boiling the high purity water in a boiler. Boiling the high purity water in the boiler may comprise generating blowdown water and the method may comprise combining the blowdown water with the separated water.

[0029] Using the steam in the resource extraction process may comprise reheating the steam in a reheater prior to using the steam to extract oil from the geological formation.

[0030] Another aspect of the invention provides a system for generating oil and electricity. The system comprises: an evaporator for producing steam and high purity water from input water; a resource extraction unit which receives the steam from the evaporator and uses the steam to extract oil from a geological formation and, in so extracting the oil from the geological formation, generates a mixture of oil and water; an oil-water separator which separates the mixture of oil and water to produce oil and the input water; an electricity- generating unit which uses the high purity water from the evaporator to generate electricity; and wherein excess heat produced by the electricity-generating unit is used by the evaporator to produce the steam and high purity water.

[0031 ] The oil-water separator may comprise a free water knock out tank. [0032] The system may comprise a membrane treatment unit for treating the input water at a temperature greater than 100 °C prior to providing the input water to the evaporator. The temperature may be greater than 130°C.

[0033] The electricity-generating unit which uses the high purity water from the evaporator to generate electricity may comprise a boiler which uses the high purity water to create steam and a steam turbine which uses the steam to create electricity. The boiler may produce blowdown water and the blowdown water may be combined with the input water.

[0034] The system may comprise a reheater which receives steam from the evaporator and reheats the steam prior to using the steam to extract oil from the geological formation.

[0035] Another aspect of the invention provides a method for generating oil and electricity. The method comprises: providing a combination of a resource extraction process which generates dirty water, a water-purification process for generating high purity water from the water to be treated and an electricity-generating process for generating electricity; using waste heat from the electricity-generating process in the water-purification process; and using high purity water generated by the water purification process in the electricity- generating process.

[0036] The water purification process may create steam and the method may comprise using the steam in the resource extraction process.

[0037] Further aspects of the invention and features of specific embodiments of the invention are described herein.

Brief Description of the Drawings

[0038] Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.

[0039] Figure 1 A is a schematic depiction of a prior art SAGD oil extraction process. [0040] Figure 1 B is a schematic depiction of a prior art electricity-generating process. [0041] Figure 2 is a schematic depiction of a combined SAGD resource extraction and electricity-generating process according to a particular embodiment.

[0042] Figure 2A is a block diagram of a method for producing oil and electricity using the system shown in Figure 2.

[0043] Figure 3 is a schematic depiction of a combined SAGD resource extraction and electricity-generating process, according to one embodiment of the invention.

[0044] Figure 3A is a block diagram of a method for producing oil and electricity using the system shown in Figure 3.

Description

[0045] Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.

[0046] One aspect of the invention provides a combination of a first industrial process (e.g. a SAGD resource extraction process) which generates (e.g. as a by-product) dirty water (i.e. water to be treated), a simplified water purification process for generating high purity water from the water to be treated, and an electricity-generating process. The water purification process and/or the industrial process may use waste energy (e.g. heat) available from the electricity-generating process. The electricity-generating process may use the high purity water generated by the water purification process.

[0047] Figure 2 schematically depicts a combination SAGD resource extraction and electricity-generating process 300 according to a particular embodiment. Process 300 generates a mixture of oil and water 1 that is similar to the oil-water mixture 1 described in SAGD oil extraction process 100 (Figure 1 A). Oil-water mixture 1 is provided to FWKO 2, which operates as discussed above to extract oil 14 and to generate dirty water 3 which is treated in a water purification process 301 , as discussed further below. [0048] The water 3 to be treated may be at a pressure above 1 bar and at temperatures above 100°C. In some embodiments, water 3 to be treated is in a temperature range between 130 °C-180 °C. Water purification process 301 of combined process 300 may benefit from heating the water being treated to temperatures significantly greater than 100°C. This can be accomplished by using waste heat from the electricity-generating process 303 (described further below) or, additionally or alternatively, external heat sources.

[0049] Water purification process 301 involves first chemically treating water 3 using chemical processing and additives at block 302. The block 302 chemical treatment may cause the scaling parameters like silica, calcium, magnesium, and/or the like to be converted to discrete solids, commonly referred to as suspended solids. To cause silica to be converted from a dissolved solid to a suspended solid, MgO and/or similar chemical(s) may be added to the water 3 being treated. To convert calcium and/or magnesium from dissolved solids to suspended solids, NaOH, lime (CaOH), and/or other chemical(s) may be added to the water 3 being treated. Benefit(s) of the block 302 chemical processing over the block 5 chemical processing in conventional SAGD process 100 (Figure 1 A) include that the amount of chemicals is reduced significantly and there is no need for chemicals to aid in the separation of oil and no need for chemicals to aid in the settling of solids. Instead, in process 300, there is no need for solids to be separated by chemical processing (in block 302) because, in process 300, solids are separated by RSL Membranes™ (in block 22).

[0050] Water 21 output from chemical treatment block 302 is then treated by Replaceable Skin Layer (RSL) Membranes™ 22 which are marketed by David Bromley Engineering Ltd. under the tradename "nanoflotation" (see http://www.dbe2000.com/nanoflotation-low- enerqy-low-cost-water-treatment/ and the document entitled "Summary-of-nanoflotation-jan- 26-13.pdf", both of which are hereby incorporated by reference herein) or equivalent. RSL Membranes™ 22 are also described in US patent publication No. US 2013/0270191 , which is hereby incorporated herein by reference. RSL Membranes™ 22 use a highly charged skin layer, causing the solids to separate from water 21 . RSL Membranes™ 22 may remove suspended solids and oil from water 21 , so that water 21 A output from RSL Membranes™ 22 is suitable for treatment in an evaporator 23. A benefit of RSL Membranes™ 22 (relative to prior art techniques) is that RSL Membranes™ 22 can treat water 21 at high temperatures, so that water 21 does not have to be cooled and reheated via heat exchangers, as is required in prior art SAGD process 100. In some embodiments, water 21 entering membrane treatment unit 22 may be at temperatures above 100 °C. In some embodiments, this water may be at temperatures in a range of 120°C-180 °C. In some embodiments, this water may be at temperatures above 130 °C. The lack of heat exchanger in water purification process 301 also eliminates the need for chemicals to prevent scaling in the heat exchanger.

[0051] Next, water 21 A which is output from RSL Membranes™ 22 is provided to evaporator 23. Evaporator 23 has wastewater (known as blowdown) 25, which can be as high as 40% of its feed water (RSL Membrane™ output water 21 A), but evaporator blowdown 25 is dependent on the quality of water 21 A being fed into evaporator 23.

Evaporator blowdown 25 will typically comprise a relatively high amount of solids and scaling parameters. With the addition of chemicals, some of these solids can be removed by a second RSL Membrane™ 28. Once evaporator blowdown 25 is treated by second RSL Membrane™ 28, the treated water 25A from second RSL Membrane™ 28 may be combined with RSL Membrane™ output water 21 A (from first RSL Membrane™ 22) to provide the input feed water to evaporator 23. RSL Membranes™ 22, 28 will generate solids/sludge 27, which may be sent to a sludge drying process unit 30. Sludge drying process unit 30 may obtain heat 29 from the treated high purity water 26 output from evaporator 23.

[0052] Evaporator 23 is used to create steam 81 for SAGD resource extraction process (system) 304. The specific components of SAGD resource extraction process (system) 304 are known to those skilled in the art of resource extraction and are not detailed herein. A challenge with the use of evaporator 23 is that it has a relatively high energy demand (e.g. approximately 14kWh/m ³ ). Energy for evaporator 23 may be provided by LP steam 48 output from steam turbine 47 of electricity-generating process 303. Combined SAGD and electricity-generating process 300 may reduce or eliminate the need for cooling tower 50 used in the prior art electricity-generating process 200 (Figure 1 B). Cooling of LP steam 48 in combined SAGD and electricity-generating process 300 is instead accomplished by directing LP steam 48 to evaporator 23. In addition, heat 29 from the treated water 26 output from evaporator 23 may be used by sludge dryer 30 to dry sludge 27. The combination of these two energy uses (the use of heat 48 from electricity-generating process 200 by evaporator 23 and the use of heat 29 rom evaporator 23 by sludge dryer 30)reduces or eliminates the need for a cooling tower 50. These features of combined SAGD and electricity-generating process 300 represent significant capital and operating cost reductions.

[0053] The operation of evaporator 23 may be dependent on heat energy from LP steam 48 output from electricity-generating process 303. High temperature RSL Membrane™-treated (partially treated) water 21 A may enter the chamber (not shown) of evaporator 23, typically under pressure above atmospheric pressure (e.g. 2 to 13 bar-gauge), but on some occasions partially treated water 21 A can enter evaporator 23 at atmospheric pressure. When treated water 21 A enters the chamber of evaporator 23, evaporator 23 may be operated under different pressure conditions, such as: (a.) less than atmospheric pressure (vacuum); (b.) atmospheric pressure; or (c.) above atmospheric pressure; to provide the highest level of efficiency in reducing the volume of evaporator blowdown 25. LP steam 48 (output from steam turbine 47) may be applied directly or indirectly to evaporator 23. For example, LP steam 48 can be added indirectly to the inside of tubes inside evaporator 23, where the hot outside surface of such tubes may cause a surface area for the injected partially treated water 21 A to evaporate. If partially water 21 A enters evaporator 23 that is being operated at a pressure less than that of the partially treated water 21 A as it enters evaporator 23, the partially treated water 21 A will flash creating water vapour, which will be vented from evaporator 23. Much of the remainder of the partially treated water 21 A that does not vaporize will be exposed to the surfaces of the hot tubes carrying LP steam 48.

[0054] Additionally or alternatively, LP steam 48 can be applied directly into evaporator 23 to cause contact with partially treated water 21 A. Using this technique, the heat energy of LP steam 48 will be transferred to water that does not flash when it enters the chamber of evaporator 23, causing such water to vaporize and be vented from evaporator 23.

[0055] Additionally or alternatively, the heat energy of LP steam 48 can be used to heat a gas or air under pressure and the heated, pressurized air or gas may be added to evaporator 23 to thereby cause heat from the heated, pressurized gas to cause the partially treated water 21 A that did not flash when it entered evaporator 23, to vaporize because of the addition of the heat energy in the added heated, pressurized gas. The vaporized water may be vented from evaporator 23.

[0056] Vaporized water that is vented from evaporator 23 may be condensed to provide high quality output water 26. Any heat 29 extracted from evaporator 23 and/or its vaporized output water 26 may be used to dry sludge 27 at sludge drying process unit 30.

[0057] As LP steam 48 is used for energy provided to evaporator 23, LP steam 48 cools to become wet steam 81 as it exits from evaporator 23. Wet steam 81 may then be reheated by reheater 82. Reheater 82 may use natural gas 70 or biogas in a combustion process. The output of reheater 82 is a high pressure (HP) steam 83 which may be used as the steam 16 added to the geological formation for SAGD oil recovery system (process) 304. Advantageously, in combined SAGD and electricity-generating process 300, a high quality and high thermal energy LP steam 48 is produced from electrical generation process 303 which thereby eliminates the need for OTSG 12 of the prior art SAGD process 100 (Figure 1 A) and the correspondingly high levels of OTSG blowdown 15F.

[0058] As discussed above, evaporator 23 produces purified water 26 which may be used as input water 52 for boiler 42 of electricity-generating process 303. The ability to use evaporator output water 26 as input water 52 for boiler 42 eliminates the need for a makeup water system (including chemical treatment block 61 , UF membranes 62, and RO membranes 63 ) and also eliminates RO reject water 64, thereby reducing capital, operating energy, and C0 ₂ emissions significantly relative to prior art electricity-generating process 200 (see Figure 1 B).

[0059] With the production of high purity water 26 from evaporator 23, high purity water 26 may be used as input water 52 to generate HP steam 43 in boiler 42 of electricity- generating process 303. Because water 26, 52 is relatively high purity, the blowdown 44 from boiler 42 will be correspondingly low (approximately 3%) and the cost and complexity of managing blowdown water 44 will be correspondingly reduced. In some embodiments blowdown water 44 may be fed to RSL Membranes™ 22 to be treated along with the dirty water 3 from FWKO 2. [0060] In the illustrated example embodiment, makeup water 24 may be used in water purification process 301 to balance any water losses resulting from the use of HP steam 16 in the geological formation being treated and through evaporation losses throughout combined process 300. Combined SAGD and electricity-generating process 300 provides a relatively high level of water recycling because of the water purification process 301 , which reduces to almost zero the amount of waste water to be removed from the plant site where combined process 300 is implemented. The only significant removal of water from

combined process 300 is through natural losses or the removal of solids with a small percentage of water.

[0061 ] Water purification process 301 shown in Figure 2 could be used to treat other forms of waste water (e.g. from other industrial processes) and may be combined with electrical generation process 303. In such embodiments, water used for input 52 in electrical generation process 303 may be treated wastewater from sources other than from geological formations being treated in a SAGD process. Instead, such wastewater could be any wastewater that needs treatment. By way of non-limiting example, such wastewaters could comprise leachate from landfills, reverse osmosis reject waters, toxic waters, or any water that would need treatment via evaporation. Since this waste water is added to the water cycle, some of this water may be lost naturally in the cycle. The extra water not lost 26 may be discharged or used for other purposes. A benefit of the Figure 2 embodiment 300 is that the water to be discharged 26 will have a very high purity like water 52 shown in Figure 2.

[0062] Aspects of some embodiments of this invention may include capturing C0 ₂ 71 from the use of natural gas 70 as the fuel source for the gas turbine 40, boiler 42, and/or reheater 82. Collected C0 ₂ 71 may be injected with HP steam 16 into the geological formation for storage and/or solvent to enhance oil recovery or any other potential use.

[0063] Figure 2A depicts a method 350 for producing oil and electricity using combined process 300. Method 350 begins in block 352, where oil-water mixture 1 is separated into oil 14 and dirty water 3. This separation occurs, for example, in FWKO tank 2. In block 354, water 3 is partially treated and then provided to evaporator 23. The block 354 partial treatment of dirty water 3 may comprise treating dirty water 3 with chemicals and/or other additives (as in block 302 in Figure 2), and/or treating water 3 using RSL Membrane(s)™ 22 before the water reaches evaporator 23.

[0064] In block 356, evaporator 23 produces steam 81 and high purity water 26. In block 358, steam 81 is provided to the resource extraction (e.g. SAGD) or other industrial process (system) 304 which uses the steam. In the case of the SAGD process (system) 304 shown in Figure 2, SAGD process produces oil-water mixture 1 . Block 358 may also comprise reheating steam 81 in reheater 82 to produce HP steam 16, 83. In block 360, purified water 26 output from evaporator 23 is provided to steam turbine 47, which generates electricity 46. Water 26 output from evaporator 23 may first be provided to boiler 42, which generates steam 43 that is in turn provided to steam turbine 47. Excess heat 48 generated by steam turbine 47 as it produces electricity 46 may be provided to evaporator 23 and used by evaporator (in block 356) to generate steam 81 and high purity water 26.

[0065] Figure 3 schematically depicts another combination SAGD resource extraction and electricity-generating process 400, according to another embodiment of the invention.

Process 400 comprises a SAGD resource extraction process (system) 404 which generates a mixture of oil and water 1 that is similar to the oil-water mixture 1 described in processes 100 (Figure 1 A) and 300 (Figure 2). The specific components of SAGD resource extraction process (system) 404 are known to those skilled in the art of resource extraction and are not detailed herein. Oil-water mixture 1 is provided to FWKO 2, which extracts oil 14 and generates dirty water 3. Dirty water 3 is treated by a water purification process 301 . Water purification process 301 comprises RSL Membrane(s)™ 22, as described above in relation to process 300. As discussed above, a membrane treatment process comprising RSL Membranes™ may operate on water that is much hotter than water treated with convention treatment processing technology (see Figure 1 A). In some embodiments, dirty water 3 entering membrane treatment unit 22 may be at temperatures above 100 °C. In some embodiments, this water may be at temperatures in a range of 120°C-180 °C. In some embodiments, this water may be at temperatures above 130 °C. Although not expressly shown in Figure 3, water purification process 401 may comprise a chemical treatment process similar to chemical treatment process 302 (Figure 2) discussed above which may be used to treat dirty water 3 upstream of RSL Membrane(s)™ 22. Makeup water 24 may be provided to RSL Membrane(s)™ 22 and/or upstream of RSL Membrane(s)™ 22.

Additionally or alternatively, makeup water 24A can be provided to water 22A which is output from RSL Membrane(s)™ 22. In such embodiments, makeup water 24A may need to be treated by water treatment processes and/or equipment (not shown in Figure 3), such that it is of sufficient purity for input to, and use in, boiler 42. For example, makeup water 24A may be treated in the manner described above for makeup water 65 in relation to Figure 1 B.

[0066] In the process 400 of the Figure 3 embodiment, output water 22A from RSL

Membrane™ 22 is provided directly to boiler 42. Boiler 42 may, for example, comprise an OTSG or HRSG. As with process 300 of Figure 2, heat 41 for boiler 42 is provided by a gas turbine 40, which is fed with natural gas 70. In process 400 of the Figure 3 embodiment, gas turbine 40 forms at least part of electricity-generating process 403 and heat 41 is produced as gas turbine 40 generates electricity 45, which may be output from electricity-generating process 403. Heat 41 may be waste or excess heat generated during the operation of gas turbine 40.

[0067] As described above, boiler 42 produces blowdown water 44. Blowdown water 44 may be provided to second RSL Membrane(s)™ 28, which may in turn provide output water 28A to evaporator 23. Heat used in evaporator 23 may be provided by electric heating elements (not shown) which may be powered by electricity 45 output from electricity- generating process 403 and gas turbine 40. In some embodiments (not shown), some or all of water 28A output from RSL Membranes™ 28 is directly combined with water 22A (i.e. without first being fed through evaporator 23). RSL Membrane™ 28 and evaporator 23 may function in the same manner as described in relation to process 300 (Figure 2). Some or all of water 28A may optionally additionally or alternatively be treated in a membrane distillation process 103. Membrane distillation process 103 may comprise RSL

Membranes™ (although this is not necessary). Water 26 which is output from evaporator 23 and/or membrane distillation process 103 (and which may be referred to as treated blowdown water 26) may be combined with water 22A and provided to boiler 42. As described above, treated blowdown water 26 has a high purity. The combination of trated blowdown water 26 and water 22A may have a sufficient purity and/or temperature that boiler 42 only requires heat 41 from gas turbine 40 to turn this combination into steam 16. In some embodiments, boiler stack gas 106 (containing waste heat) from boiler 42 may be used by a heat exchanger 106 to heat water 26 before water 26 is input into boiler 42. Once this heat is expended from boiler stack gas 106, the cooled gas may be exhausted by vents 1 10.

[0068] Heat 41 , provided by gas turbine 40 may (in optional combination with pre-heating input water 22A using boiler stack gas 106) be sufficient to allow boiler 42 to turn water 22A (or the combination of water 22A and water 26) into steam 16, suitable for use in SAGD process (system) 404. Natural gas 70 may not need to be provided to boiler 42 in process 400; all or substantially all of the energy required by boiler 42 may be provided in the form of heat 41 from electricity-generating process 403 and optionally from waste heat 106 from boiler 42 itself. In particular, RSL Membrane™ 22 may provide output water 22A which is of a sufficient purity and/or temperature that a relatively low amount of heat 41 is needed to turn water 22A into steam 16 (as compared to the energy input requirements of prior art boiler 12) of the Figure 1 A SAGD process. RSL Membrane(s)™ 22 can treat water which is at a higher temperature than, for example, the water 1 1 which is input to boiler 12 in process 100 or cooled water 4 which is input to the water treatment equipment 6, 7, 8, 9, 10 of process 100. Thus, water 22A provided to boiler 42 in process 400 may be of a

(potentially substantially) higher temperature than water 1 1 provided to boiler 12 in processes 100. For these reasons, heat 41 provided by gas turbine 40 may be, on its own, sufficient to allow boiler 42 to produce steam 16 (suitable for SAGD usage) from water 22A. This eliminates the need to provide natural gas 70 to boiler 42, which is typically necessary (i.e. in the prior art) to provide enough energy to allow boiler 42 to produce steam 16.

Eliminating the need for natural gas supplied to boiler 42 reduces the operating and capital costs of process 400 compared to prior art systems, and may also reduce emissions (such as CO ₂ emissions).

[0069] The total oil 14 and electricity 45 produced by process 400 is greater than the amount of energy produced in processes 100 and 200, and process 400 is more efficient in that it requires a lower level of input natural gas 70 and produces a higher level of output energy (in the form of oil 14 and electricity 45) and/or a lower level of emissions (e.g. C0 ₂ emissions).

[0070] In particular, process 400 is more efficient with respect to electrical power production and greenhouse gas generation than two standard prior art systems: a "base" system which comprises processes 100 (SAGD resource extraction) and 200 (electricity-generating) operating separately; and a theoretical "combined" system which is similar to process 400, but which also requires natural gas 70 to provide heat to boiler 42 (using so-called "duct burning"), because the "combined" system uses a different water treatment system that requires dirty water 3 from FWKO 2 to be cooled prior to treatment and consequently requires additional energy in boiler 42. For a normalized amount of oil production (in this example, 5,247 cubic metres per day), process 400 and the "base" system will each produce approximately 310MW of electricity per day, while the "combined" prior art system will generate 175MW per day, due to the "combined" process using (i.e. burning) some of its natural gas to provide additional (duct-burning) heat to boiler 42, instead of gas turbine 40. In addition, process 400 and the "combined" prior art system will each produce

approximately 3,560 tonnes of greenhouse gases (e.g. C0 ₂ ) per day, while the "base" system will produce approximately 4,910 tonnes of greenhouse gases (due to the inefficiency of operating processes 100 and 200 separately, instead of in combination, as is the case in processes 300 and 400 and as is the case in the theoretical "combined" system). Thus, compared to the "base" system, process 400 generates the same amount of electricity and oil, but produces far less emissions (i.e. C0 ₂ emissions). Compared to the "combined" prior art system, process 400 produces the same amount of oil and emissions, but also produces far more electricity. Thus, process 400 can be said to be more efficient than both of these prior art systems.

[0071] Water purification process 401 shown in Figure 3 could be used to treat other forms of waste water (e.g. from other industrial processes) and may be combined with electrical generation process 403. Such wastewater could be any wastewater that needs treatment. By way of non-limiting example, such wastewaters could comprise leachate from landfills, reverse osmosis reject waters, toxic waters, or any water that would need treatment via evaporation. Since this waste water is added to the water cycle, some of this water may be lost naturally in the cycle. The extra water not lost 26 may be discharged or used for other purposes.

[0072] As described above in relation to process 300, C0 ₂ 71 captured from gas turbine 40 and/or boiler 42 may optionally be injected with steam 16 into the geological formation for storage and/or solvent to enhance oil recovery and/or any other potential use.

[0073] Each of RSL Membranes™ 22, 28, gas turbine 40, evaporator 23, membrane distillation process 103 and boiler 42 may produce sludge, brine, or other waste products which must be disposed of. However, process 400 may produce less waste material than is produced in processes 100 and 200 described above, particularly since blowdown water 44 from boiler 42 is treated (i.e. by RSL Membrane™ 28, evaporator 23, and/or optional membrane distillation process 103) and combined with water 22A which is input to boiler 42. The combination of water 22A and water 26 may be of relatively high purity, such that blowdown 44 from boiler 42 is correspondingly low. In particular, the use of evaporator 23, membrane distillation process 103 and/or RSL Membrane™ 28 may reduce water consumption by up to 20% and waste production by up to 80% compared to processes 100 and 200 described above.

[0074] By removing sludge/waste solids 100 from water 3 by RSL Membrane™ 22, and removing sludge/waste solids 101 from blowdown water 44 by RSL Membrane™ 28, the resulting brine 102 extracted from evaporator 23 (and/or membrane distillation process 103) may be relatively rich in valuable products such as rare earth minerals. Such minerals may be extracted from brine 102 by a mineral extraction process (unit) 104.

[0075] Figure 3A depicts a method 450 for producing oil and electricity using process 400. Method 450 begins in block 452, where oil-water mixture 1 is separated into oil 14 and dirty water 3. This separation occurs, for example, in free water knock out tank 2. In block 454, water 3 is provided to boiler 42. This step may comprise, for example, first treating water 3 chemically and in RSL Membrane(s)™ 22 before water (in the form of water 22A) is provided to boiler 42.

[0076] In block 456, steam 16 is generated by boiler 42, using water 22A which is provided to boiler 42. As discussed above, all or substantially all of the energy which is required by boiler 42 to produce steam 16 may be provided by waste heat 41 from gas turbine 40 of electricity-generating process 303, which produces electricity 45. In block 458, steam 16 is provided to the resource extraction process (system) 404 which generates oil-water mixture 1 .

[0077] While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions, and sub-combinations thereof. It is therefore intended that the invention be interpreted to include all such modifications, permutations, additions, and sub-combinations as are consistent with the broadest interpretation of the specification as a whole.