CA2870798A1 - Processes for treating reservoir fluid comprising material produced from a hydrocarbon containing reservoir - Google Patents

Abstract

There is provided a process for treating a reservoir fluid-comprising mixture, comprising: producing a reservoir fluid-comprising mixture, including oil and water, from a hydrocarbon containing reservoir; at a pressure that is greater than atmospheric pressure, separating an oil-lean mixture from the reservoir fluid-comprising mixture; at a pressure that is greater than atmospheric pressure, effecting separation, from the oil- lean mixture, of a scale forming-lean liquid and a scale forming-rich material, by evaporation or ceramic membrane filtration; producing pressurized steam from the scale forming-lean liquid using a steam generator; and supplying the pressurized steam to the hydrocarbon containing reservoir for effecting mobilization of hydrocarbons within the hydrocarbon containing reservoir.

Description

, PROCESSES FOR TREATING RESERVOIR FLUID COMPRISING MATERIAL
PRODUCED FROM A HYDROCARBON CONTAINING RESERVOIR
FIELD
[0001] The present disclosure relates to recovery and reuse of water from reservoir fluid comprising material produced from a hydrocarbon containing reservoir.
BACKGROUND

[0002] Some hydrocarbon production processes, such as Steam-Assisted Gravity Drainage ("SAGD"), inject steam into a hydrocarbon-containing reservoir to stimulate production of hydrocarbons. SAGD uses a pair of wells to produce a hydrocarbon from a hydrocarbon containing reservoir. Typically the well pair includes two horizontal wells vertically spaced from one another, with the upper well used to inject steam into the reservoir and the lower well to produce the hydrocarbon. The steam operates to generate a steam chamber in the reservoir, and thermal heat from the steam operates to lower the viscosity of the hydrocarbon, allowing for gravity drainage, and thereby production from the production well. The produced fluids typically include a mixture of hydrocarbons and water, the water resulting from the condensing of the steam (referred to as "produced water").

[0003] For economic and environmental reasons, it is desirable to recycle the produced water. Typically, the produced water is treated to remove, amongst other things, oils and solids, and then converted into steam using a steam generator.

[0004] The internal energy of produced fluids is not insignificant.
However, such energy is not being optimally used to drive existing treatment processes.
SUMMARY

[0005] In some implementations, there is provided a process for treating a reservoir fluid-comprising mixture, including producing the reservoir fluid-comprising mixture, including oil and water, from a hydrocarbon-containing reservoir; at a pressure that is greater than atmospheric pressure, separating an oil-lean mixture from the reservoir fluid-comprising mixture such that the concentration of oil within the oil-lean mixture is greater than 10 ppm; at a pressure that is greater than atmospheric pressure, separating a scale forming-lean liquid and a scale forming-rich material from the oil-lean mixture, by evaporation or membrane filtration; producing pressurized steam from the scale forming-lean liquid using a steam generator; and supplying the pressurized steam to the hydrocarbon containing reservoir for effecting mobilization of hydrocarbons within the hydrocarbon containing reservoir.

[0006] In some implementations, the process further includes prior to producing the pressurized steam, supplying the scale forming-lean liquid to a tank, wherein the tank is disposed at a pressure that is greater than atmospheric pressure.

[0007] In some implementations, the concentration of oil within the oil-lean mixture is between 10 ppm and 250 ppm.

[0008] In some implementations, the concentration of oil within the oil-lean mixture is between 10 ppm and 100 ppm.

[0009] In some implementations, the concentration of oil within the oil-lean mixture is between 10 ppm and 30 ppm.

[0010] In some implementations, the pressure is at least 20 kPa above atmospheric pressure.

[0011] In some implementations, the membrane filtration includes ceramic membrane filtration.

[0012] In some implementations, there is provided a process for treating a reservoir fluid-comprising mixture, including: fluidically coupling the wellhead to a steam generator via a fluid passage of a fluid conductor; producing, through a wellhead, the reservoir fluid-comprising mixture, including oil and water, from a hydrocarbon-containing reservoir; separating an oil-lean mixture from the reservoir fluid-comprising mixture such that the concentration of oil within the oil-lean mixture is greater than 10 ppm; supplying the oil-lean mixture to a scale-forming solids separator, wherein the scale-forming solids separator includes an evaporator or a membrane filtration unit operation; separating, from the oil-lean mixture, a scale forming-lean liquid and a scale forming-rich material, using the evaporator; such that each one of (i) the separating of , s the oil-lean mixture from the reservoir fluid-comprising mixture, (ii) the supplying of the oil-lean mixture to the evaporator, and (iii) the separating, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, using the evaporator is effected within the fluid passage, and the entirety of the fluid passage is disposed at a pressure that is greater than atmospheric pressure; producing pressurized steam from the scale forming-lean liquid using the steam generator; and supplying the pressurized steam to the hydrocarbon containing reservoir to effect mobilization of hydrocarbons within the hydrocarbon containing reservoir.

[0013] In some implementations, the process further includes prior to producing the pressurized steam, supplying the scale forming-lean liquid to a tank, wherein the tank is disposed at a pressure that is greater than atmospheric pressure, and wherein the supply the scale forming-lean liquid to a tank is effected within the fluid passage.

[0014] In some implementations, the concentration of oil within the oil-lean mixture is between 10 ppm and 250 ppm.

[0015] In some implementations, the concentration of oil within the oil-lean mixture is between 10 ppm and 100 ppm.

[0016] In some implementations, the concentration of oil within the oil-lean mixture is between 10 ppm and 30 ppm.

[0017] In some implementations, the pressure is at least 20 kPa above atmospheric pressure.

[0018] In some implementations, the membrane filtration includes ceramic membrane filtration.

[0019] In some implementations, there is provided a process for treating a reservoir fluid-comprising mixture, including: producing the reservoir fluid-comprising mixture, including oil and water, from a hydrocarbon containing reservoir; at a pressure that is greater than atmospheric pressure, separating an oil-lean mixture from the reservoir fluid-comprising mixture; at a pressure that is greater than atmospheric pressure, effecting separation, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material; supplying the scale forming-lean liquid to a tank that is disposed at a pressure that is greater than atmospheric pressure; supplying the scale forming-lean liquid from the tank to a steam generator; producing pressurized steam from the scale forming-lean liquid using the steam generator; and supplying the pressurized steam to the hydrocarbon containing reservoir to effect mobilization of oil within the hydrocarbon containing reservoir.

[0020] In some implementations, the temperature of the scale forming-lean liquid within the tank is greater than 100 degrees Celsius.

[0021] In some implementations, the separation, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, is effected by evaporation.

[0022] In some implementations, the separation, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, is effected by pressurized hot lime softening,

[0023] In some implementations, the separation, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, is effected by membrane filtration.

[0024] In some implementations, the membrane filtration includes ceramic membrane filtration.

[0025] In some implementations, the pressure is at least 20 kPa above atmospheric pressure.

[0026] In some implementations, there is provided a process for treating a reservoir fluid-comprising mixture, including: fluidically coupling the wellhead to a steam generator via a fluid passage of a fluid conductor; producing, through a wellhead, the reservoir fluid-comprising mixture including oil and water, from a hydrocarbon containing reservoir; separating an oil-lean mixture from the reservoir fluid-comprising mixture;
supplying the oil-lean mixture to a scale forming solids separator;
separating, from the oil-lean mixture, a scale forming-lean liquid and a scale forming-rich material, using the scale forming solids separator; supplying the scale forming-lean liquid to a tank that is disposed at a pressure that is greater than atmospheric pressure; supplying the scale forming-lean liquid from the tank to a steam generator; such that each one of (i) the separating of the oil-lean mixture from the reservoir fluid-comprising mixture, (ii) the supplying of the oil-lean mixture to the scale forming solids separator, (iii) the separating, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, using the scale forming solids separator, (iv) the supplying of the scale forming-lean liquid to a tank that is disposed at a pressure that is greater than atmospheric pressure, and (v) the supplying of the scale forming-lean liquid from the tank to the steam generator is effected within the fluid passage, and the entirety of the fluid passage is disposed at a pressure that is greater than atmospheric pressure;
producing pressurized steam from the scale forming-lean liquid using the steam generator; and supplying the pressurized steam to the hydrocarbon containing reservoir to effect mobilization of hydrocarbons within the hydrocarbon containing reservoir.

[0027] In some implementations, the temperature of the scale forming-lean liquid within the tank is greater than 100 degrees Celsius.

[0028] In some implementations, the separation, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, is effected by evaporation.

[0029] In some implementations, the separation, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, is effected by pressurized hot lime softening.

[0030] In some implementations, the separation, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, is effected by ceramic membrane filtration.

[0031] In some implementations, the pressure is at least 20 kPa above atmospheric pressure.

[0032] In some implementations, there is provided a process for treating a reservoir fluid-comprising mixture, including: fluidically coupling the wellhead to a steam generator via a fluid passage of a fluid conductor; producing, through a wellhead, the reservoir fluid-comprising mixture including oil and water, from a hydrocarbon containing reservoir; separating an oil-lean mixture from the reservoir fluid-comprising mixture;
supplying the oil-lean mixture to a scale forming solids separator including an evaporator; separating, from the oil-lean mixture, a scale forming-lean liquid and a scale forming-rich material, using the scale forming solids separator; such that each one of (i) the separating of the oil-lean mixture from the reservoir fluid-comprising mixture, (ii) the supplying of the oil-lean mixture to the scale forming solids separator, and (iii) the separating, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, using the scale forming solids separator is effected within the fluid passage, and the entirety of the fluid passage is disposed at a pressure that is greater than atmospheric pressure; producing pressurized steam from the scale forming-lean liquid using the steam generator; and supplying the pressurized steam to the hydrocarbon containing reservoir to effect mobilization of hydrocarbons within the hydrocarbon containing reservoir.

[0033] In some implementations, the pressure is at least 20 kPa above atmospheric pressure.

[0034] In some implementations, the process further includes progressively reducing pressure along a section of the fluid passage, from downstream of the wellhead to the evaporator.

[0035] In some implementations, there is provided a process for treating a reservoir fluid-comprising mixture, including: fluidically coupling the wellhead to an evaporator via a fluid passage of a fluid conductor extending upstream from the evaporator;
producing, through a wellhead, the reservoir fluid-comprising mixture, including oil and water, from a hydrocarbon containing reservoir; separating an oil-lean mixture from the reservoir fluid-comprising mixture; supplying the oil-lean mixture to the evaporator;
separating, from the oil-lean mixture, an aqueous liquid distillate and a scale forming-rich material, using the evaporator; such that each one of (i) the separating of the oil-lean mixture from the reservoir fluid-comprising mixture, (ii) the supplying of the oil-lean mixture to the evaporator, and (iii) the separating, from the oil-lean mixture, of an aqueous liquid distillate and a scale forming-rich material, using the evaporator is effected within the fluid passage, and the entirety of a section of the fluid passage, that is upstream of the evaporator, is disposed at a temperature that is greater than, or equal to, the boiling point temperature of the oil-lean mixture at the pressure within the evaporator;
producing pressurized steam from the aqueous liquid distillate using the steam , generator; and supplying the pressurized steam to the hydrocarbon containing reservoir to effect mobilization of hydrocarbons within the hydrocarbon containing reservoir.

[0036] In some implementations, the temperature is greater than, or equal to, the boiling point temperature of water at 20 kPa above atmospheric pressure.

[0037] In some implementations, the process further includes after the separating, from the oil-lean mixture, a scale forming-lean liquid and a scale forming-rich material, using the evaporator, and prior to the producing pressurized steam from the scale forming-lean liquid using the steam generator, cooling the reservoir fluid-comprising mixture with the scale forming-lean liquid.

[0038] In some implementations, the effected cooling is such that the temperature of the oil-lean mixture is greater than, or equal to, the boiling point temperature of the oil-lean mixture at the pressure within the evaporator.

[0039] In some implementations, the effected cooling is such that the temperature of the oil-lean mixture is greater than, or equal to, the boiling point temperature of water at 20 kPa above atmospheric pressure.

[0040] In some implementations, the effected cooling is such that the temperature of the cooled reservoir fluid-comprising mixture is such that the specific gravity of water, within the cooled reservoir fluid-comprising mixture, is greater than the specific gravity of oil, within the cooled reservoir fluid-comprising mixture, by a difference of between 20 kg/m3 and 70 kg/m3.

[0041] In some implementations, the temperature of the aqueous liquid distillate is greater than 100 degrees Celsius.

[0042] In some implementations, the process further includes progressively reducing temperature along the section of the fluid passage, from downstream of the wellhead to the evaporator.

[0043] In some implementations, there is provided a process for treating a reservoir fluid-comprising mixture, including: producing the reservoir fluid-comprising mixture, including oil and water, from a hydrocarbon-containing reservoir; at a pressure that is greater than atmospheric pressure, separating the reservoir fluid-comprising mixture , into an oil-lean mixture and an oil-rich mixture; at a pressure that is greater than atmospheric pressure, supplying the oil-lean mixture to a direct-contact steam generator (DCSG), for use as feedwater for the DCSG; operating the DCSG to produce pressurized steam; and supplying the pressurized steam to the hydrocarbon containing reservoir for effecting mobilization of hydrocarbons within the hydrocarbon-containing reservoir.

[0044] In some implementations, the supplying of the oil-lean mixture to the DCSG
includes: supplying the oil-lean mixture to a tank, wherein the tank is disposed at a pressure that is greater than atmospheric pressure; and supplying the oil-lean mixture from the tank to the DCSG.

[0045] In some implementations, the separating of the reservoir fluid-comprising mixture is performed at a temperature higher than 100 C.

[0046] In some implementations, the supplying of the oil-lean mixture to the DCSG
is performed at a temperature higher than 100 C.

[0047] In some implementations, the concentration of oil in the oil-lean mixture is at most 500 ppm.

[0048] In some implementations, the concentration of oil in the oil-lean mixture is between 100 ppm and 500 ppm.

[0049] In some implementations, there is provided a process for treating a reservoir fluid-comprising mixture, including: fluidically coupling the wellhead to a direct-contact steam generator (DCSG) via a fluid passage of a fluid conductor; producing, through a wellhead, the reservoir fluid-comprising mixture including oil and water, from a hydrocarbon-containing reservoir; separating the reservoir fluid-comprising mixture into an oil-lean mixture and an oil-rich mixture; supplying the oil-lean mixture to a direct-contact steam generator (DCSG), for use as feedwater for the DCSG; such that each one of (i) the separating of the oil-lean mixture from the reservoir fluid-comprising mixture, and (ii) the supplying of the oil-lean mixture to the DCSG, is effected within the fluid passage, and the entirety of the fluid passage is disposed at a pressure that is greater than atmospheric pressure; operating the DCSG to produce pressurized steam;

and supplying the pressurized steam to the hydrocarbon containing reservoir for effecting mobilization of hydrocarbons within the hydrocarbon-containing reservoir.

[0050] In some implementations, the supplying of the oil-lean mixture to the DCSG
includes:

[0051] In some implementations, the tank is disposed at a pressure that is greater than atmospheric pressure; and supplying the oil-lean mixture from the tank to the DCSG.

[0052] In some implementations, the separating of the reservoir fluid-comprising mixture is performed at a temperature higher than 100 C.

[0053] In some implementations, the supplying of the oil-lean mixture to the DCSG
is performed at a temperature higher than 100 C.

[0054] In some implementations, the concentration of oil in the oil-lean mixture is at most 500 ppm.

[0055] In some implementations, the concentration of oil in the oil-lean mixture is between 100 ppm and 500 ppm.

[0056] In some implementations, there is provided a process for recovering hydrocarbons from a hydrocarbon-bearing reservoir, including: injecting at least a portion of the steam into the hydrocarbon-bearing reservoir to heat and mobilize hydrocarbons therein; producing a production fluid from the hydrocarbon-bearing reservoir at a wellhead, the production fluid including mobilized hydrocarbons and produced water and having a production fluid pressure that is above atmospheric pressure; supplying feedwater derived from at least a portion of the produced water to a steam generator; and handling at least a portion of the produced water in order to produce feedwater for supplying to a steam generator, while maintaining the produced water from the wellhead until the steam generator at produced water pressures that are above atmospheric pressure.

[0057] In some implementations, the handling of the produced water includes water treatment steps in order to remove impurities from the produced water to provide a , treated water stream for use as part of the feedwater, and the steam generator includes a Once-Through Steam Generator (OTSG).

[0058]
In some implementations, the water treatment steps include an evaporation stage.

[0059] In some implementations, the production fluid is separated into a hydrocarbon-rich stream and a produced water stream prior to subjecting the produced water stream to the water treatment steps.

[0060]
In some implementations, the handling of the produced water includes storing the produced water in a pressurized storage vessel prior to supplying at least a portion of the produced water to the steam generator that includes a Direct-Contact Steam Generator (DCSG).

[0061]
In some implementations, the production fluid is separated into a hydrocarbon-rich stream and a produced water stream prior to supplying the produced water stream to the pressurized storage vessel.

[0062]
In some implementations, the hydrocarbon containing reservoir is an oil sands reservoir.
BRIEF DESCRIPTION OF DRAWINGS

[0063]
Figure 1 is a schematic illustration of a well pair in an oil sands reservoir for implementation of a steam-assisted gravity drainage process;

[0064]
Figure 2 is a process flow diagram illustrating a system for reusing water in a hydrocarbon recovery operation.

[0065]
Figure 3 is a process flow diagram illustrating a system for reusing water in a hydrocarbon recovery operation including a Direct-Contact Steam Generator (DCSG).
DETAILED DESCRIPTION

[0066]
Referring to Figures 1 and 2, there is provided a system 100 for recovering and reusing water contained within a reservoir fluid-comprising mixture 110 that is produced from a hydrocarbon-containing reservoir 30. The recovered water is converted to high pressure steam 200 and conducted into the hydrocarbon-containing reservoir for effecting production of hydrocarbons from the reservoir. Amongst other things, the processes employed within the system can be configured to minimize energy losses from the water being recovered, and thereby reduce energy requirements for converting the recovered water into steam with a steam generator 190. In this respect, in some implementations, the process is carried out at a pressure that is greater than atmospheric pressure. In some implementations, the pressure is at least 20 kPa above atmospheric pressure.

[0067] For illustrative purposes below, an oil sands reservoir from which bitumen is being produced using Steam-Assisted Gravity Drainage ("SAGD") is described.
However, it should be understood, that the techniques described could be used in other types of hydrocarbon containing reservoirs and/or with other types of thermal recovery methods that use steam, for example such as cyclic steam stimulation (CSS).

[0068] It should be understood that the term "oil" as used herein is interchangeable with "hydrocarbons", and can for example include bitumen, heavy oil or other hydrocarbons recoverable from a subterranean reservoir.

[0069] The reservoir fluid-comprising mixture 110 is produced from an oil sands reservoir using a SAGD well pair. Referring to Figure 1, in a typical SAGD
well pair, the wells are spaced vertically from one another, such as wells 10 and 20, and the vertically higher well, i.e., well 10, is used for steam injection the SAGD operation, and the lower well, i.e., well 20, is used for producing bitumen. During the SAGD operation, steam injected through the well 10 (typically referred to as the "injection well") is conducted into the reservoir 30. The injected steam mobilizes the bitumen within the oil sands reservoir 30. The mobilized bitumen and steam condensate drains through the interwell region 15 by gravity to the well 20 (typically referred to as the "production well"), collects in the well 20, and is surfaced through tubing or by artificial lift to the surface, where it is produced through a wellhead 25.

[0070] The reservoir fluid-comprising mixture 110 includes oil and water.
In some implementations, the reservoir fluid-comprising mixture 110 has a temperature between 150 degrees Celsius and 250 degrees Celsius. The pressure of the reservoir fluid-., comprising mixture 110 can range from 1000 kPa to 4000 kPa (gauge), and is dependent on the pressure within the reservoir 30.

[0071] In some implementations, the reservoir fluid-comprising mixture 110 is conditioned, prior to separation into the reservoir fluid-comprising mixture material components, to produce a treated reservoir fluid-comprising mixture. In some implementations, conditioning of the reservoir fluid-comprising mixture 110 can include cooling of the reservoir fluid-comprising mixture 110, for example by passing the fluid-comprising mixture 110 through a heat exchanger.
Recycling and re-use of produced water

[0072] Referring to Figure 2, downstream separation processes effect separation of an oil-lean mixture 120 from the reservoir fluid-comprising mixture 110 (see below). In some implementations, such separation processes are temperature dependent.
Temperature affects both density and viscosity, and both of these parameters affect separation efficiency. To improve such separation, the reservoir fluid-comprising mixture 110 can be cooled prior to effecting the separation. In cases where the fluid temperature of the reservoir fluid-comprising mixture 110 is relatively low (such as, for example, 165 degrees Celsius or less), limited or no cooling can be required.

[0073] In some implementations, the temperature of the cooled reservoir fluid-comprising mixture 110 is such that the specific gravity of water, within the cooled reservoir fluid-comprising mixture 110, is greater than the specific gravity of oil, within the cooled reservoir fluid-comprising mixture 110, by a difference of between 20 kg/m3 and 70 kg/m3.

[0074] In some implementations, the conditioning of the reservoir fluid-comprising mixture 110 includes admixing diluent 220 with the reservoir fluid-comprising mixture 110. The admixing of the diluent 220 enables transport of the recovered oil through a pipeline. The diluent 220 also assists in the separation of the oil-lean mixture 120 from the cooled reservoir fluid-comprising mixture 110. The more diluent 220 that is added, the greater the density difference between the diluted oil and the water.
Diluent is expensive and some losses generally occur to the gas phase. Accordingly, in some implementations, diluent addition is minimized and limited to what is required such that the diluted oil meets the sales pipeline specifications. In some implementations, the treating can include both cooling of the reservoir fluid-comprising mixture and admixing of the reservoir fluid-comprising mixture 110 with diluent 220, in any order.

[0075]
In other implementations, instead of cooling the reservoir fluid-comprising mixture 110, the conditioning of the reservoir fluid-comprising mixture 110 includes heating the reservoir fluid-comprising mixture 110 such that the density of oil becomes sufficiently greater than the density of water so as to enable a desired separation of the oil-lean mixture 120 from the reservoir fluid-comprising mixture 110. In this case, no diluent or a reduced amount of diluent is added. In some implementations, the separation of the oil-lean mixture 120 from the heated reservoir fluid-comprising mixture 110 is effected at about a temperature of 225 degrees Celsius.

[0076]
The oil-lean mixture 120 is separated from the reservoir fluid-comprising mixture 110 (conditioned or unconditioned) within an oil separator 138. In some implementations, the reservoir fluid-comprising mixture 110 is separated into the oil-lean mixture 120 and an oil-rich mixture 130. In some implementations, the oil separator 138 includes three stages 140, 150, and 155. Typically, separation in stages 140 and 150 is effected by gravity separation, while separation in stage 155 functions to provide final polishing after the gravity separation to effect production of the oil-lean mixture 120.
The total number of stages being determined based on a desired separation efficiency, while in keeping with a desire to optimize utilization of capital.

[0077]
In some implementations, the stage 150 is effected within a vessel including electrostatic grids to assist in the separation. In some implementations, the stage 150 is not necessarily effected within a vessel, but rather a separation device that uses accelerated gravity forces, such as a hydrocyclone or a centrifuge.
In some implementations, the stages 140 and 150 can be combined into a single stage.

[0078]
In some implementations, heavier liquid phase products 142, 152, generated from, respectively, stages 140, 150, are combined into an intermediate oil-lean mixture 118. In some implementations, the oil-rich mixture 130 is conducted to a product holding tank or produced fluid separator 162. Gaseous material 144, 154, 262, produced from, respectively, stages 140, 150, 162 is managed by a vapour handling system. In some implementations, gaseous material 140, 150, 162 is combined and can be used as fuel for steam generation. Produced hydrocarbons 264 can be recovered from the product holding tank 162 for further processing or to be directly sent to sales. In some scenarios, diluent 220 can be added to the produced hydrocarbons 264 such that a viscosity suitable for transportation is obtained.

[0079] In some implementations, the intermediate oil-lean mixture 118 is supplied to a de-oiling separator 155 for effecting separation of an oil-rich separation product 124 and the oil-lean mixture 120. The separation can be effected by any one, or any combination, of gravity separation, filters (coalescing, granular media, cartridge, membrane, screen, pre-coat or types otherwise capable of filtering oil droplets), gas flotation units, hydrocyclones, centrifuges, and devices to improve coalescing such as plate packs.

[0080] In some implementations, the oil-lean mixture 120 is supplied to a scale forming solids separator 160 for effecting separation, from the oil-lean mixture 120, of a scale forming-lean liquid 170 and a scale forming-rich material 165. The scale forming-rich material can be, for example, dissolved solids, suspended solids, or free oil. This separation can be effected, for example, by evaporation, pressurized hot lime softening in combination with ion exchange, or membrane filtration (such as ceramic membrane filtration) in combination with ion exchange. In this respect, in some implementations, the scale forming solids separator 160 can include an evaporator, a pressurized hot lime softening unit operation, or a membrane filtration unit operation (for example, a ceramic membrane filtration unit operation). Scale forming solids that are concentrated within the scale forming-rich material, by virtue of the separation, include calcium-comprising compounds, magnesium-comprising compounds, and silica. In some implementations, the scale forming-lean liquid 170 is disposed at a temperature that is greater than 100 degrees Celsius. When the steam generator 190 is susceptible to scaling, such as is typically the case with a once-through steam generator (OTSG), removal of scale-forming materials, prior to supplying of the liquid 170 to the steam generator 190, can be desirable so as to mitigate scaling of the steam generator 190.

,

[0081] In some implementations, prior to the supplying of the oil-lean mixture 120 to the scale forming solids separator 160, the oil-lean mixture 120 is admixed with chemical agents 125 for supporting or enabling processes effected within the separator 160, or for mitigating against undesirable process conditions within the separator 160. In some implementations, where the separator 160 is an evaporator, the chemical agents 125 can be a pH attenuating agent for mitigating against scale formation. In some implementations, the chemical agents 125 are introduced downstream of the separation of the oil-lean mixture 120 from the reservoir fluid-comprising mixture 110 so as not to unnecessarily consume the chemical agents 125 prior to introduction to the separator 160.

[0082] In some implementations, prior to the supplying of the oil-lean mixture 120 to the scale forming solids separator 160, the oil-lean mixture 120 is admixed with make-up water 122. The make-up water 122 can be added to compensate for reservoir losses of steam, and losses within the processing system, such as losses within purge streams. The make-up water 122 is typically introduced downstream of the separation of the oil-lean mixture 120 from the reservoir fluid-comprising mixture 110 so as not to use up capacity within the oil separator 138.

[0083] The scale forming-lean liquid 170 is conducted to a steam generator 190 for conversion to pressurized steam 200 for use in recovering oil from the hydrocarbon containing reservoir 30. In this respect, the pressurized steam is conducted to the hydrocarbon containing reservoir 30 to effect mobilization of bitumen within the oil sands reservoir 30.

[0084] In some scenarios, the separating of the oil-lean mixture 120 from the reservoir fluid-comprising mixture 110 is such that the concentration of oil within the oil-lean mixture is greater than 10 ppm. In some implementations, the concentration of oil within the oil-lean mixture is between 10 ppm and 250 ppm. In some implementations, the concentration of oil within the oil-lean mixture is between 10 ppm and 100 ppm. In some implementations, the concentration of oil within the oil-lean mixture is between 10 ppm and 30 ppm. Separation processes, for effecting the separation, from the oil-lean mixture 120, of the scale forming-lean liquid 170, in the form of evaporation, or membrane filtration (for example, ceramic membrane filtration) in combination with ion exchange, are, typically, better able to process the oil-lean mixture 120 having relatively higher oil contents, than other separation processes. As a result, less costly de-oiling equipment is required to effect the production of the oil-lean mixture 120, having a relatively higher oil content, when such separation processes are employed.

[0085] In some implementations, prior to being conducted to the steam generator 190, the scale forming-lean liquid 170 can be supplied to a tank 230. In some implementations, the tank 230 has a volume equivalent to that of providing for a residence time, for scale forming-lean liquid 170 being received from the separator 160, of at least about 15 minutes. In some implementations, the tank 230 functions as a buffer for receiving surges in production of the scale forming-lean liquid 170, and for allowing steam generation to continue during upsets within upstream equipment (such as for example, when operation of the separator 160 becomes suspended) or allowing production of scale forming-lean liquid 170 to continue during upsets within downstream equipment (such as, for example, when the steam generator 190 shuts down). In some implementations, the tank 230 is a pressurized storage vessel.

[0086] The wellhead 25 is in fluid communication with the steam generator 190 via a fluid passage within a fluid conductor 300 for supplying water contained within the reservoir fluid-comprising mixture to the steam generator 190. In some implementations, the optional conditioning of the reservoir fluid-comprising mixture 110, the separating of the oil-lean mixture 120 from the reservoir fluid-comprising mixture 110 (conditioned or unconditioned), the supplying of the oil-lean mixture 120 to the separator 160, and the separating of the scale forming-lean liquid 170 from the oil-lean mixture 120 is effected within the fluid passage. In other implementations, the fluid passage extends from the heat exchanger 210 to the steam generator 190, such that the separating of the oil-lean mixture 120 from the reservoir fluid-comprising mixture 110, the supplying of the oil-lean mixture 120 to the separator 160, the separating of the scale forming-lean liquid 170 from the oil-lean mixture 120, the cooling of the reservoir fluid-comprising mixture 110 by the scale forming-lean liquid 170, and the supplying of the scale forming-lean liquid 170 to the steam generator 190 is effected within the fluid passage. It should be understood that the term "fluid conductor" refers to the various components such as pipes, pipelines, tubes and/or industrial hoses which convey fluids within the system.

[0087] In some implementations, the entirety of the fluid passage of the fluid conductor 300 is disposed at a pressure that is greater than atmospheric pressure. In some implementations, additional compression machinery, downstream of the wellhead 25, for pressurizing the conducted fluid (in these instances, for example, such pressurization is effected by subsurface pumps), is not provided, (in other implementations, compression machinery can be provided immediately downstream of the wellhead 25 for assisting with production from the well) yet the oil-lean mixture 120 is supplied to the separator 160 at a pressure that is greater than atmospheric pressure.
In this respect, the pressure within the fluid passage of the fluid conductor 300 is progressively reduced up to at least the separator 160, but is still maintained above atmospheric pressure within the separator 160. In some implementations, each one of:
(i) the optional conditioning (such as heating or cooling) of the reservoir fluid-comprising mixture, (ii) the separating of an oil-lean mixture from the cooled reservoir fluid-comprising mixture, (iii) the supplying of the oil-lean mixture to the separator 160, (iv) the separating of the scale forming-lean liquid 170 from the oil-lean mixture 120, (v) the cooling of the reservoir fluid-comprising mixture 110 by the scale forming-lean liquid 170, and (vi) the supplying of the scale forming-lean liquid 170 to the steam generator 190 is effected at a pressure that is greater than atmospheric pressure. In some implementations, this pressure is at least 20 kPa above atmospheric pressure.
In some implementations, pressure along a section of fluid passage, from downstream of the wellhead 25 to the evaporator 160, is progressively reduced.

[0088] In some implementations, by avoiding having to, as an intermediate step between the wellhead and the separator 160, reduce fluid pressure within the fluid passage, such as, to atmospheric pressure, and then elevate the fluid pressure to above atmospheric pressure (e.g., when an intermediate unit operation is provided and operated at atmospheric pressure, such as an atmospheric storage tank), it can be possible to avoid capital cost associated with additional compression machinery that can be required to effect the supply of the scale-forming lean liquid 170 to the steam generator 190 at a sufficiently high pressure. Such compression machinery can include , compression machinery disposed upstream of the separator 160 for supplying the oil-lean mixture to the separator 160 at a pressure that is greater than atmospheric pressure.

[0089]
When the separator 160 includes an evaporator, by supplying the oil-lean mixture 120 to the evaporator at a pressure that is greater than atmospheric pressure, the evaporator can be operated more efficiently or can occupy a smaller footprint.

[0090]
When the separator 160 includes an evaporator, the evaporator effects evaporation of a portion of the oil-lean mixture 120 to produce the scale forming-lean liquid 170 in the form of an aqueous liquid distillate. The residue remaining after the evaporation of a portion of the oil-lean mixture 120 includes dissolved solids.
Periodically, this residue is purged from the evaporator 160 as the scale forming-rich material 165 for disposal.

[0091]
In some implementations, the reservoir fluid-comprising mixture 110 is indirectly cooled by the scale forming-lean liquid 170. In this respect, the scale forming-lean liquid is supplied to the heat exchanger 210. Such supplying effects indirect heat transfer communication between the supplied scale forming-lean liquid 170 and the reservoir fluid-comprising mixture 110 within the heat exchanger 210. As a result, heat is transferred, within the heat exchanger 210, from the hotter reservoir fluid-comprising mixture 110 to the cooler scale forming-lean liquid 170, thereby effecting cooling of the reservoir fluid-comprising mixture 110, without requiring an external heat sink.

[0092]
In some implementations, where the separator 160 includes an evaporator, an upstream fluid passage portion of the fluid conductor 300 is provided, and the upstream fluid passage portion extends upstream from the evaporator 160, and the entirety of the upstream fluid passage portion is disposed at a temperature that is at least (i.e., greater than or equal to) the boiling point temperature of the oil-lean mixture 120 at the pressure within the evaporator 160.
In some implementations, this temperature is at least the boiling point temperature of water at 20 kPa above atmospheric pressure.
In some implementations, each one of: (i) the optional conditioning (such as heating or cooling) of the reservoir fluid-comprising mixture, (ii) the separating of an oil-lean mixture from the cooled reservoir fluid-comprising mixture, and (iii) the supplying of the oil-lean mixture to the separator 160 is effected at a temperature that is at least (i.e. greater than or equal to) the boiling point temperature of the oil-lean mixture 120 at the pressure within the evaporator 160, such as at least the boiling point temperature of water at 20 kPa above atmospheric pressure. In some implementations, the temperature along the section of fluid passage 300, from downstream of the wellhead to the evaporator, is progressively reduced to the boiling point temperature of the oil-lean mixture 120 at the pressure within the evaporator 160.

[0093] In some implementations, by avoiding having to, e.g., as an intermediate step between the wellhead and the separator 160, reduce temperature within the fluid passage below that of the boiling point temperature of the oil-lean mixture 120 at the pressure within the evaporator 160, and then to elevate the temperature to, or above, the boiling point temperature of the oil-lean mixture 120 at the pressure within the evaporator, it can be possible to avoid costs associated with additional heating of the scale-forming lean liquid 170 prior to supply to, or within, the evaporator.

[0094] In some implementations, the scale forming-lean liquid 170 is the aqueous liquid distillate, such that the aqueous liquid distillate 170 is supplied to the heat exchanger 210 to function as the cooling fluid. The reservoir fluid-comprising mixture 110 is cooled by the aqueous liquid distillate 170 to a temperature that is sufficient to enable the desired separation of the oil-lean mixture 120 from the reservoir fluid-comprising mixture 110 within the oil separator 138 but is maintained at a temperature that is greater than, or equal to, the boiling point temperature of the oil-lean mixture 120 at the pressure within the evaporator 160 (for example, greater than, or equal to, the boiling point temperature of water at 20 kPa above atmospheric pressure). In some implementations, the cooling of the reservoir fluid-comprising mixture 110 is to a temperature that is sufficiently high such that, even with heat losses, after the separation of the oil-lean mixture from the cooled reservoir fluid-comprising mixture 110, the temperature of the oil-lean mixture 120 being supplied to the evaporator 160 is greater than, or equal to, the boiling point temperature of the oil-lean mixture at the pressure within the evaporator 160. In some implementations, the temperature of the oil-lean mixture, supplied to the evaporator 160, is greater than, or equal to, the boiling point temperature of water at 20 kPa above atmospheric pressure. Again, this can potentially eliminate the requirement for either a heat exchange step between the hotter distillate 170 and the incoming feed of the oil-lean mixture 120 to the evaporator 160, or the input of additional heat within the evaporator processes.

[0095] In some implementations where cooling of the reservoir fluid-comprising mixture 110 is being effected by the aqueous liquid distillate 170 , the cooling is such that a desired separation of the oil-lean mixture 120 from the reservoir fluid-comprising mixture 110 is facilitated, while still enabling the supply of the oil-lean mixture 120 to the evaporator at a temperature that is greater than, or equal to, the boiling point temperature of the oil-lean mixture at the pressure within the evaporator 160.
In other implementations, there is additional quenching effect provided by added diluent, make-up water, and other cooler process streams, and such additional quenching effect complements the heat exchange between the aqueous liquid distillate 170 and the reservoir fluid-comprising mixture 110 such that an additional external heat sink is not required for facilitating a desired separation of the oil-lean mixture 120 from the reservoir fluid-comprising mixture 110 while still enabling the supply of the oil-lean mixture 120 to the evaporator 160 at a temperature that is greater than, or equal to, the boiling point temperature of the oil-lean mixture at the pressure within the evaporator 160. In some cases, an additional external heat sink can be provided if such operational flexibility is desired and additional cooling, prior to supplying of the oil-lean mixture 120 to the evaporator 160, is required. Alternatively, the operating temperature of the evaporator 160 could be reduced (such as by reducing the pressure of the oil-lean mixture 120 being supplied to the evaporator) so as to avoid incorporation of an additional external heat sink.
Direct-contact steam generator implementations

[0096] Referring to Figure 3, in some implementations, the steam generator 190 is a Direct-Contact Steam Generator (DCSG). The DCSG generates steam 200 by directly contacting feedwater with a hot combustion gas which is produced using fuel 266 (for example, natural gas) and an oxidizing gas 268 (for example, an oxygen-enriched gas mixture, such as purified oxygen). Depending on the oxidizing gas 268 and fuel 266 that are used, the combustion gas can include various amounts of carbon dioxide (CO2) as well as other gases such as carbon monoxide (CO), hydrogen (H2), nitrogen based compounds (N0x) such as nitric oxide (NO) and nitrogen dioxide (NO2) and/or sulfur based compounds (S0x) such as sulfur oxides. The fuel 266 and oxidizing gas 268 can be premixed prior to reaching a burner and a flame is generated in a combustion chamber, thereby forming the hot combustion gas. The feedwater is typically run down the combustion chamber in jacketed pipes and into an evaporation chamber, and the hot combustion gas evaporates the feedwater in the evaporation chamber, thereby generating the outlet stream (also referred to herein as a "combustion mixture" or a "steam-0O2 mixture") which includes steam and combustion gas.

[0097] The DCSG 190 can operate using different types of fuel 266, such as natural gas, syngas, refinery fuel gas, coke, asphaltenes or mixtures thereof. The flexibility in the types of fuel that can be used provides an advantage against escalating natural gas prices or natural gas supply interruptions. The DCSG 190 can operate effectively with low feedwater quality, and in some scenarios with feedwater quality that is considered unacceptable for use in other types of steam generators such as an OTSG or drum boiler. The feedwater can typically include fresh water, recycled produced water from a steam-assisted hydrocarbon recovery process or a mixture thereof. Recycled produced water can include high levels of contaminants and impurities (such as residual hydrocarbons, inorganic compounds and/or suspended solids).

[0098] As a DCSG can operate using low quality feedwater, the oil-lean mixture 120 separated from the reservoir fluid-comprising mixture 110 in the oil separator 138 can be directly supplied back to the DCSG without being treated in the scale forming solids separator 160 described above. There is therefore provided a process for treating the reservoir-comprising mixture using a DCSG as a steam generator.

[0099] Still referring to Figure 3, the reservoir fluid-comprising mixture 110 is separated in the oil separator 138 to obtain the oil-lean mixture 120 and the oil-rich mixture 130. The oil separator 138 can be as described above and include several separation units, or can simply include a single water-oil separator such as a free-water knockout. In some scenarios, the concentration of oil in the oil-lean mixture 120 is up to 1000 ppm or up to 500 ppm. In some scenarios, the concentration of oil in the oil-lean 4.
mixture 120 is between 100 ppm and 500 ppm. In some implementations, the oil-lean mixture 120 is stored in a tank 230 (for example, a pressurized storage vessel) before being used as feedwater for the DCSG 190, as required. In some implementations, the feedwater for the DCSG 190 includes the oil-lean mixture 120, make-up water 122 or a mixture thereof. The tank 230 can be used as described above.

[0100] In some implementations, the oil-rich mixture 130 is conducted to holding tank or fluid separator 162, and can be separated into gaseous material 262 and produced hydrocarbons 264. In some implementations, the gaseous material 262 can be used as all or part of the fuel 266 for the DCSG. The produced hydrocarbons 264 can be stored or sold. In some scenarios, diluent 220 can be added to the produced hydrocarbons 264 until a viscosity suitable for transport of the produced hydrocarbons 264 is reached.

[0101] Optionally, the oil-lean mixture 120 can be subjected to additional purification steps such as de-oiling steps or solids removal steps prior to being used as feedwater for the DCSG 190. Such purification steps can for example include filtration of some of the solids.

[0102] Similarly as above, the wellhead 25 is in fluid communication with the DCSG
190 via a fluid passage within a fluid conductor 300 for supplying water contained within the reservoir fluid-comprising mixture to the DCSG 190. The separating of the oil-lean mixture 120 from the reservoir fluid-comprising mixture 110, the supplying of the oil-lean mixture 120 to the tank 230, and the supplying of the oil-lean mixture from the tank 230 to the DCSG 190 is effected within the fluid passage.

[0103] In some implementations, the entirety of the fluid passage of the fluid conductor 300 is disposed at a pressure that is greater than atmospheric pressure. In some implementations, the fluid within the fluid passage is also kept at a temperature higher than 100 degrees Celcius.

[0104] In some implementations, each one of: (i) the separating of the oil-lean mixture from the cooled reservoir fluid-comprising mixture, (ii) the supplying of the oil-lean mixture to the tank 230, (iii) the supplying of the oil-lean mixture to the steam generator 190 is effected at a pressure that is greater than atmospheric pressure and, in -some implementations, at a temperature which is kept higher than 100 degrees Celcius.
In some implementations, this pressure is at least 20 kPa above atmospheric pressure.

[0105] Reference throughout the specification to "one embodiment/implementation,"
"an embodiment/implementation," "some embodiments/implementations," "one aspect,"
"an aspect," or "some aspects" means that a particular feature, structure, method, or characteristic described in connection with the embodiment/implementation or aspect is included in at least one embodiment/implementation of the present invention.
In this respect, the appearance of the phrases "in one embodiment/implementation" or "in an embodiment/implementation" or "in some embodiments/implementations" in various places throughout the specification are not necessarily all referring to the same embodiment/implementation. Furthermore, the particular features, structures, methods, or characteristics can be combined in any suitable manner in one or more embodiments/implementations.

[0106] Each numerical value should be read once as modified by the term "about"
(unless already expressly so modified), and then read again as not so modified unless otherwise indicated in context. Also, in the summary and this detailed description, it should be understood that a concentration range listed or described as being useful, suitable, or the like, is intended that any and every concentration within the range, including the end points, is to be considered as having been stated. For example, "a range of from 1 to 10" is to be read as indicating each and every possible number along the continuum between about 1 and about 10. Thus, even if specific data points within the range, or even no data points within the range, are explicitly identified or refer to only a few specific data points, it is to be understood that inventors appreciate and understand that any and all data points within the range are to be considered to have been specified, and that inventors have disclosed and enabled the entire range and all points within the range.

[0107] In the above description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the present disclosure.
However, it will be apparent to one skilled in the art that these specific details are not required in order to practice the present disclosure. Although certain dimensions and materials are described for implementing the disclosed example implementations, other suitable dimensions and/or materials can be used within the scope of this disclosure.
All such modifications and variations, including all suitable current and future changes in technology, are believed to be within the sphere and scope of the present disclosure.
All references mentioned are hereby incorporated by reference in their entirety.

Claims (57)

1. A process for treating a reservoir fluid-comprising mixture, comprising producing the reservoir fluid-comprising mixture, including oil and water, from a hydrocarbon-containing reservoir;
at a pressure that is greater than atmospheric pressure, separating an oil-lean mixture from the reservoir fluid-comprising mixture such that the concentration of oil within the oil-lean mixture is greater than 10 ppm;
at a pressure that is greater than atmospheric pressure, separating a scale forming-lean liquid and a scale forming-rich material from the oil-lean mixture, by evaporation or membrane filtration;
producing pressurized steam from the scale forming-lean liquid using a steam generator; and supplying the pressurized steam to the hydrocarbon containing reservoir for effecting mobilization of hydrocarbons within the hydrocarbon containing reservoir.

2. The process as claimed in claim 1, further comprising: prior to producing the pressurized steam, supplying the scale forming-lean liquid to a tank, wherein the tank is disposed at a pressure that is greater than atmospheric pressure.

3. The process as claimed in claim 1 or 2, wherein the concentration of oil within the oil-lean mixture is between 10 ppm and 250 ppm.

4. The process as claimed in claim 1 or 2, wherein the concentration of oil within the oil-lean mixture is between 10 ppm and 100 ppm.

5. The process as claimed in claim 1 or 2, wherein the concentration of oil within the oil-lean mixture is between 10 ppm and 30 ppm.

6. The process as claimed in any one of claims 1 to 5, wherein the pressure is at least 20 kPa above atmospheric pressure.

7. The process as claimed in any one of claims, wherein the membrane filtration comprises ceramic membrane filtration.

8. A process for treating a reservoir fluid-comprising mixture, comprising:
fluidically coupling the wellhead to a steam generator via a fluid passage of a fluid conductor;
producing, through a wellhead, the reservoir fluid-comprising mixture, including oil and water, from a hydrocarbon-containing reservoir;
separating an oil-lean mixture from the reservoir fluid-comprising mixture such that the concentration of oil within the oil-lean mixture is greater than ppm;
supplying the oil-lean mixture to a scale-forming solids separator, wherein the scale-forming solids separator includes an evaporator or a membrane filtration unit operation;
separating, from the oil-lean mixture, a scale forming-lean liquid and a scale forming-rich material, using the evaporator;
such that each one of (i) the separating of the oil-lean mixture from the reservoir fluid-comprising mixture, (ii) the supplying of the oil-lean mixture to the evaporator, and (iii) the separating, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, using the evaporator is effected within the fluid passage, and the entirety of the fluid passage is disposed at a pressure that is greater than atmospheric pressure;
producing pressurized steam from the scale forming-lean liquid using the steam generator; and supplying the pressurized steam to the hydrocarbon containing reservoir to effect mobilization of hydrocarbons within the hydrocarbon containing reservoir.

9. The process as claimed in claim 8, further comprising: prior to producing the pressurized steam, supplying the scale forming-lean liquid to a tank, wherein the tank is disposed at a pressure that is greater than atmospheric pressure, and wherein the supply the scale forming-lean liquid to a tank is effected within the fluid passage.

10. The process as claimed in claim 8 or 9, wherein the concentration of oil within the oil-lean mixture is between 10 ppm and 250 ppm.

11. The process as claimed in claim 8 or 9, wherein the concentration of oil within the oil-lean mixture is between 10 ppm and 100 ppm.

12. The process as claimed in claim 8 or 9, wherein the concentration of oil within the oil-lean mixture is between 10 ppm and 30 ppm.

13. The process as claimed in any one of claims 8 to 12, wherein the pressure is at least 20 kPa above atmospheric pressure.

14. The process as claimed in any one of claims 8 to 13, wherein the membrane filtration comprises ceramic membrane filtration.

15. A process for treating a reservoir fluid-comprising mixture, comprising:
producing the reservoir fluid-comprising mixture, including oil and water, from a hydrocarbon containing reservoir;
at a pressure that is greater than atmospheric pressure, separating an oil-lean mixture from the reservoir fluid-comprising mixture;
at a pressure that is greater than atmospheric pressure, effecting separation, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material;

supplying the scale forming-lean liquid to a tank that is disposed at a pressure that is greater than atmospheric pressure;
supplying the scale forming-lean liquid from the tank to a steam generator;
producing pressurized steam from the scale forming-lean liquid using the steam generator; and supplying the pressurized steam to the hydrocarbon containing reservoir to effect mobilization of oil within the hydrocarbon containing reservoir.

16. The process as claimed in claim 15, wherein the temperature of the scale forming-lean liquid within the tank is greater than 100 degrees Celsius.

17. The process as claimed in claim 15 or 16, wherein the separation, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, is effected by evaporation.

18. The process as claimed in claim 15 or 16, wherein the separation, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, is effected by pressurized hot lime softening,

19. The process as claimed in claim 15 or 16, wherein the separation, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, is effected by membrane filtration.

20. The process as claimed in claim 19, wherein the membrane filtration comprises ceramic membrane filtration.

21. The process as claimed in any one of claims 15 to 20, wherein the pressure is at least 20 kPa above atmospheric pressure.

22. A process for treating a reservoir fluid-comprising mixture, comprising:
fluidically coupling the wellhead to a steam generator via a fluid passage of a fluid conductor;

producing, through a wellhead, the reservoir fluid-comprising mixture including oil and water, from a hydrocarbon containing reservoir;
separating an oil-lean mixture from the reservoir fluid-comprising mixture;
supplying the oil-lean mixture to a scale forming solids separator;
separating, from the oil-lean mixture, a scale forming-lean liquid and a scale forming-rich material, using the scale forming solids separator;
supplying the scale forming-lean liquid to a tank that is disposed at a pressure that is greater than atmospheric pressure;
supplying the scale forming-lean liquid from the tank to a steam generator;
such that each one of (i) the separating of the oil-lean mixture from the reservoir fluid-comprising mixture, (ii) the supplying of the oil-lean mixture to the scale forming solids separator, (iii) the separating, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, using the scale forming solids separator, (iv) the supplying of the scale forming-lean liquid to a tank that is disposed at a pressure that is greater than atmospheric pressure, and (v) the supplying of the scale forming-lean liquid from the tank to the steam generator is effected within the fluid passage, and the entirety of the fluid passage is disposed at a pressure that is greater than atmospheric pressure;
producing pressurized steam from the scale forming-lean liquid using the steam generator; and supplying the pressurized steam to the hydrocarbon containing reservoir to effect mobilization of hydrocarbons within the hydrocarbon containing reservoir.

23.
The process as claimed in claim 22, wherein the temperature of the scale forming-lean liquid within the tank is greater than 100 degrees Celsius.

24. The process as claimed in claim 22 or 23, wherein the separation, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, is effected by evaporation.

25. The process as claimed in claim 22 or 23, wherein the separation, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, is effected by pressurized hot lime softening.

26. The process as claimed in claim 22 or 23, wherein the separation, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, is effected by ceramic membrane filtration.

27. The process as claimed in any one of claims 22 to 26, wherein the pressure is at least 20 kPa above atmospheric pressure.

28. A process for treating a reservoir fluid-comprising mixture, comprising:
fluidically coupling the wellhead to a steam generator via a fluid passage of a fluid conductor;
producing, through a wellhead, the reservoir fluid-comprising mixture including oil and water, from a hydrocarbon containing reservoir;
separating an oil-lean mixture from the reservoir fluid-comprising mixture;
supplying the oil-lean mixture to a scale forming solids separator including an evaporator;
separating, from the oil-lean mixture, a scale forming-lean liquid and a scale forming-rich material, using the scale forming solids separator;
such that each one of (i) the separating of the oil-lean mixture from the reservoir fluid-comprising mixture, (ii) the supplying of the oil-lean mixture to the scale forming solids separator, and (iii) the separating, from the oil-lean mixture, of a scale forming-lean liquid and a scale forming-rich material, using the scale forming solids separator is effected within the fluid passage, and the entirety of the fluid passage is disposed at a pressure that is greater than atmospheric pressure;
producing pressurized steam from the scale forming-lean liquid using the steam generator; and supplying the pressurized steam to the hydrocarbon containing reservoir to effect mobilization of hydrocarbons within the hydrocarbon containing reservoir.

29. The process as claimed in claim 28, wherein the pressure is at least 20 kPa above atmospheric pressure.

30. The process as claimed in claim 28 or 29, further comprising, progressively reducing pressure along a section of the fluid passage, from downstream of the wellhead to the evaporator.

31. A process for treating a reservoir fluid-comprising mixture, comprising:
fluidically coupling the wellhead to an evaporator via a fluid passage of a fluid conductor extending upstream from the evaporator;
producing, through a wellhead, the reservoir fluid-comprising mixture, including oil and water, from a hydrocarbon containing reservoir;
separating an oil-lean mixture from the reservoir fluid-comprising mixture;
supplying the oil-lean mixture to the evaporator;
separating, from the oil-lean mixture, an aqueous liquid distillate and a scale forming-rich material, using the evaporator;
such that each one of (i) the separating of the oil-lean mixture from the reservoir fluid-comprising mixture, (ii) the supplying of the oil-lean mixture to the evaporator, and (iii) the separating, from the oil-lean mixture, of an aqueous liquid distillate and a scale forming-rich material, using the evaporator is effected within the fluid passage, and the entirety of a section of the fluid passage, that is upstream of the evaporator, is disposed at a temperature that is greater than, or equal to, the boiling point temperature of the oil-lean mixture at the pressure within the evaporator;
producing pressurized steam from the aqueous liquid distillate using the steam generator; and supplying the pressurized steam to the hydrocarbon containing reservoir to effect mobilization of hydrocarbons within the hydrocarbon containing reservoir.

32. The process as claimed in claim 31, wherein the temperature is greater than, or equal to, the boiling point temperature of water at 20 kPa above atmospheric pressure.

33. The process as claimed in claim 31 or 32, further comprising, after the separating, from the oil-lean mixture, a scale forming-lean liquid and a scale forming-rich material, using the evaporator, and prior to the producing pressurized steam from the scale forming-lean liquid using the steam generator, cooling the reservoir fluid-comprising mixture with the scale forming-lean liquid.

34. The process as claimed in claim 33, wherein the effected cooling is such that the temperature of the oil-lean mixture is greater than, or equal to, the boiling point temperature of the oil-lean mixture at the pressure within the evaporator.

35. The process as claimed in claim 33 or 34, wherein the effected cooling is such that the temperature of the oil-lean mixture is greater than, or equal to, the boiling point temperature of water at 20 kPa above atmospheric pressure.

36. The process as claimed in any one of claims 33 to 35, wherein the effected cooling is such that the temperature of the cooled reservoir fluid-comprising mixture is such that the specific gravity of water, within the cooled reservoir fluid-comprising mixture, is greater than the specific gravity of oil, within the cooled reservoir fluid-comprising mixture, by a difference of between 20 kg/rn3 and 70 kg/rn3.

37. The process as claimed in any one of claim 31 to 36, wherein the temperature of the aqueous liquid distillate is greater than 100 degrees Celsius.

38. The process as claimed in any one of claims 31 to 37, further comprising:
progressively reducing temperature along the section of the fluid passage, from downstream of the wellhead to the evaporator.

39. A process for treating a reservoir fluid-comprising mixture, comprising:
producing the reservoir fluid-comprising mixture, including oil and water, from a hydrocarbon-containing reservoir;
at a pressure that is greater than atmospheric pressure, separating the reservoir fluid-comprising mixture into an oil-lean mixture and an oil-rich mixture;
at a pressure that is greater than atmospheric pressure, supplying the oil-lean mixture to a direct-contact steam generator (DCSG), for use as feedwater for the DCSG;
operating the DCSG to produce pressurized steam; and supplying the pressurized steam to the hydrocarbon containing reservoir for effecting mobilization of hydrocarbons within the hydrocarbon-containing reservoir.

40. The process as claimed in claim 39, wherein the supplying of the oil-lean mixture to the DCSG comprises:
supplying the oil-lean mixture to a tank, wherein the tank is disposed at a pressure that is greater than atmospheric pressure; and supplying the oil-lean mixture from the tank to the DCSG.

41. The process as claimed in claim 39 or 40, wherein the separating of the reservoir fluid-comprising mixture is performed at a temperature higher than 100°C.

42. The process as claimed in any one of claims 39 to 41, wherein the supplying of the oil-lean mixture to the DCSG is performed at a temperature higher than 100°C.

43. The process as claimed in any one of claims 39 to 42, wherein the concentration of oil in the oil-lean mixture is at most 500 ppm.

44. The process as claimed in any one of claims 39 to 43, wherein the concentration of oil in the oil-lean mixture is between 100 ppm and 500 ppm.

45. A process for treating a reservoir fluid-comprising mixture, comprising:
fluidically coupling the wellhead to a direct-contact steam generator (DCSG) via a fluid passage of a fluid conductor;
producing, through a wellhead, the reservoir fluid-comprising mixture including oil and water, from a hydrocarbon-containing reservoir;
separating the reservoir fluid-comprising mixture into an oil-lean mixture and an oil-rich mixture;
supplying the oil-lean mixture to a direct-contact steam generator (DCSG), for use as feedwater for the DCSG;
such that each one of (i) the separating of the oil-lean mixture from the reservoir fluid-comprising mixture, and (ii) the supplying of the oil-lean mixture to the DCSG, is effected within the fluid passage, and the entirety of the fluid passage is disposed at a pressure that is greater than atmospheric pressure;
operating the DCSG to produce pressurized steam; and supplying the pressurized steam to the hydrocarbon containing reservoir for effecting mobilization of hydrocarbons within the hydrocarbon-containing reservoir.

46. The process as claimed in claim 45, wherein the supplying of the oil-lean mixture to the DCSG comprises:
supplying the oil-lean mixture to a tank, wherein the tank is disposed at a pressure that is greater than atmospheric pressure; and supplying the oil-lean mixture from the tank to the DCSG.

47. The process as claimed in claim 45 or 46, wherein the separating of the reservoir fluid-comprising mixture is performed at a temperature higher than 100°C.

48. The process as claimed in any one of claims 45 to 47, wherein the supplying of the oil-lean mixture to the DCSG is performed at a temperature higher than 100°C.

49. The process as claimed in any one of claims 45 to 48, wherein the concentration of oil in the oil-lean mixture is at most 500 ppm.

50. The process as claimed in any one of claims claim 45 to 49, wherein the concentration of oil in the oil-lean mixture is between 100 ppm and 500 ppm.

51. A process for recovering hydrocarbons from a hydrocarbon-bearing reservoir, comprising:
injecting at least a portion of the steam into the hydrocarbon-bearing reservoir to heat and mobilize hydrocarbons therein;
producing a production fluid from the hydrocarbon-bearing reservoir at a wellhead, the production fluid comprising mobilized hydrocarbons and produced water and having a production fluid pressure that is above atmospheric pressure;
supplying feedwater derived from at least a portion of the produced water to a steam generator; and handling at least a portion of the produced water in order to produce feedwater for supplying to a steam generator, while maintaining the produced water from the wellhead until the steam generator at produced water pressures that are above atmospheric pressure.

52. The process of claim 51, wherein the handling of the produced water comprises water treatment steps in order to remove impurities from the produced water to provide a treated water stream for use as part of the feedwater, and the steam generator comprises a Once-Through Steam Generator (OTSG).

53. The process of claim 52, wherein the water treatment steps include an evaporation stage.

54. The process of claim 53, wherein the production fluid is separated into a hydrocarbon-rich stream and a produced water stream prior to subjecting the produced water stream to the water treatment steps.

55. The process of claim 51, wherein the handling of the produced water comprises storing the produced water in a pressurized storage vessel prior to supplying at least a portion of the produced water to the steam generator that comprises a Direct-Contact Steam Generator (DCSG).

56. The process of claim 55, wherein the production fluid is separated into a hydrocarbon-rich stream and a produced water stream prior to supplying the produced water stream to the pressurized storage vessel.

57.
The process as claimed in any one of claims 1 to 56, wherein the hydrocarbon containing reservoir is an oil sands reservoir.