CA3051874C

CA3051874C - System and method for upgrading bitumen in situ using slow reacting nano-catalyst

Info

Publication number: CA3051874C
Application number: CA3051874A
Authority: CA
Inventors: Bruce James; Jian Li; Iftikhar Huq
Original assignee: Suncor Energy Inc
Current assignee: Suncor Energy Inc
Priority date: 2019-08-13
Filing date: 2019-08-13
Publication date: 2022-07-05
Anticipated expiration: 2039-08-13
Also published as: CA3051874A1

Abstract

Provided herein are systems and methods to upgrade hydrocarbons in situ using slow-reacting nanocatalysts. These systems and methods are particularly applicable to thermal bitumen recovery processes such as SAGD and CSS. The slow-reacting nanocatalysts can be injected into the sump around a producer well located beneath an injector well in a reservoir undergoing SAGD and production can be slowed to increase the contact time between the slow-reacting catalysts and the bitumen in the sump to increase the extent of upgrading. The slow-reacting catalysts can also be injected in a reservoir undergoing CSS, particularly prior to the shut-in phase during which the slow-reacting catalysts are left in the reservoir for a period of time sufficient for desired upgrading to occur.

Description

SYSTEM AND METHOD FOR UPGRADING BITUMEN IN SITU USING SLOW REACTING
NANO-CATALYST
TECHNICAL FIELD
[0001] The following relates to systems and methods for upgrading bitumen in situ by injecting a slow-reacting nano-catalyst into a hydrocarbon reservoir, for example, using a producer or infill well.
BACKGROUND

[0002] Bitumen is known to be considerably viscous, does not flow like conventional crude oil, and can be present in an oil sand reservoir. As such, bitumen is recovered using what are considered non-conventional methods. For example, bitumen reserves are typically extracted from a geographical area using either surface mining techniques, wherein overburden is removed to access the underlying pay (e.g., oil sand ore-containing bitumen) and transported to an extraction facility; or using in situ techniques, wherein subsurface formations (containing the pay) are heated such that the bitumen is caused to flow into one or more wells drilled into the pay while leaving formation rock in the reservoir in place. Both surface mining and in situ processes produce a bitumen product that is subsequently sent to an upgrading and refining facility, to be refined into one or more petroleum products.

[0003] Bitumen reserves that are too deep to feasibly permit bitumen recovery by mining techniques are typically accessed by drilling wellbores into the hydrocarbon bearing formation (i.e., the pay) and implementing an in situ technology. There are various in situ technologies available, such as steam driven-based techniques (e.g., Steam Assisted Gravity Drainage (SAGD) and Cyclic Steam Stimulation (CSS)), steam-solvent co injection techniques (e.g., expanding solvent-SAGD (ES-SAGD)) and waterless solvent-based techniques (e.g., Electromagnetic Assisted Solvent Extraction (EASE)).

[0004] In a common implementation of the SAGD method, a pair of horizontally oriented wells are drilled into the bitumen reserve, such that the pair of horizontal wells are vertically aligned with respect to each other and separated by a relatively small distance, typically in the order of several meters. The well installed closer to the surface and above the other well is generally referred to as an injector well, and the well positioned below the injector well is referred to as a producer well. The injector well and the producer well are then connected to various equipment installed at a surface site. The injector well facilitates steam injection into the reservoir. The injected steam propagates vertically and laterally into the reservoir to develop what is referred to as a steam chamber. Latent heat released by the injected steam mobilizes 23699376.1 the bitumen, which drains due to gravity and is produced along with condensed water in the producer well.

[0005] Produced bitumen is a heavy crude oil which typically contains a large fraction of complex long-chain hydrocarbon molecules. Depending on the extraction process used, bitumen product may not meet pipeline specifications for transport over long distances. Pipeline specifications are usually met by either upgrading the bitumen, or by diluting the bitumen with light oil. However, the diluent used to meet pipeline specifications can be considered expensive, and can account for a meaningful portion of pipeline volumes, driving up transportation costs and limiting pipeline capacity. There is thus an ongoing need to reduce or eliminate the use of diluent for bitumen transportation.

[0006] A known solution to this transportation problem is to partially upgrade bitumen after oil recovery. This involves upgrading the quality of the bitumen just enough to reduce or eliminate the need for diluent for transportation. Another potential solution is in situ upgrading of bitumen.

[0007] In situ upgrading of bitumen and heavy oil, especially catalytic upgrading, is currently considered to be a desirable next-generation technology. One existing method of in situ upgrading involves thermal cracking at the mobile oil zone ahead of a combustion front, and subsequent entry of partially upgraded oil into a horizontal well that is pre-packed with pelleted fast reacting catalysts. A known drawback associated with this method is that production lines can become blocked because of coke and metals deposited on the pelleted catalyst. It is known that the use of less expensive, dispersed unsupported transition metal nano-catalysts, such as Fe-based unsupported catalysts, can minimize coke formation since nano-sized catalysts expose more active sites and possess shorter diffusion routes.
Still, these catalysts can lack cracking functionality offered by supports such as zeolite, alumina or silica, and can require longer reaction times to achieve similar levels of upgrading.

[0008] It would be advantageous to have a process for implementing in situ catalytic upgrading in a bitumen recovery technique that addresses at least one of the above-noted issues or disadvantages.

23699376.1 SUMMARY

[0009] Provided herein are systems and methods to upgrade hydrocarbons in situ using slow-reacting nanocatalysts. These systems and methods are particularly applicable to thermal bitumen recovery processes such as SAGD and CSS. The slow-reacting nanocatalysts can include iron, or vanadium based unsupported transitional metal catalysts due to their low cost and high availability. The slow-reacting nanocatalysts can be injected into the sump around a producer well located beneath an injector well in a reservoir undergoing SAGD
and production can be slowed to increase the contact time between the slow-reacting catalysts and the bitumen in the sump to increase the extent of upgrading. The slow-reacting catalysts can also be injected in a reservoir undergoing CSS, particularly prior to the shut-in phase during which the slow-reacting catalysts are left in the reservoir for a period of time sufficient for desired upgrading to occur. The systems and methods provided herein can improve the economics of thermal bitumen recovery processes by partially or completely eliminating the need to add diluent to the produced bitumen prior to shipping, which can be considered expensive.

[0010] In an aspect, there is provided a method for upgrading hydrocarbons in a reservoir in situ, the method comprising: delivering a slow reacting catalyst into the reservoir to contact the hydrocarbons; and allowing a sufficient contact time between the slow reacting catalyst and the bitumen to at least partially upgrade the bitumen.

[0011] In an implementation of the method, the reservoir is an oil sands reservoir.

[0012] In another implementation of the method, the hydrocarbons comprise bitumen.

[0013] In yet another implementation of the method, the hydrocarbons comprise heavy oil.

[0014] In yet another implementation of the method, the slow reacting catalyst is an unsupported transition metal catalyst.

[0015] In yet another implementation of the method, the unsupported transition metal catalyst comprises pyrite-based compounds.

[0016] In yet another implementation of the method, the unsupported transition metal catalyst comprises iron-based compounds.

[0017] In yet another implementation of the method, the unsupported transition metal catalyst comprises vanadium-based compounds.

[0018] In yet another implementation of the method, a cyclic steam stimulation (CSS) process is implemented in the reservoir, comprising a well used for injection and production.

23699376.1

[0019] In yet another implementation of the method, a steam-assisted gravity drainage (SAGD) process is implemented in the reservoir, comprising a substantially horizontal producer well having an adjustable production rate and a substantially horizontal injector well having an adjustable steam injection rate.

[0020] In yet another implementation of the method, the slow reacting catalyst is delivered into the hydrocarbon reservoir by injection through the producer well into a sump around the producer well, the sump comprising heated bitumen and condensate water, and the catalyst being dispersed therethrough, to continuously produce upgraded bitumen.

[0021] In yet another implementation of the method, the production rate is decreased to achieve the sufficient contact time between the slow reacting catalyst and the bitumen in the sump to produce the upgraded bitumen.

[0022] In yet another implementation of the method, the slow reacting catalyst is delivered by injection through an infill well into a virgin bitumen formation above a steam chamber in the reservoir to induce bitumen upgrading.

[0023] In yet another implementation of the method, the slow reacting catalyst is delivered by injection through an infill well into a bitumen formation at the top of a steam chamber to accelerate bitumen upgrading.

[0024] In yet another implementation of the method, the slow reacting catalyst is delivered by injection through an infill well into a lean zone in the reservoir to accelerate bitumen upgrading.

[0025] In yet another implementation of the method, the lean zone is below a shale layer.

[0026] In yet another implementation of the method, an upgrading reaction between the bitumen and the catalyst yields gases to produce a steam-assisted gravity push (SAGP) effect pushing bitumen in a desired direction.

[0027] In yet another implementation of the method, a steam-assisted gravity drainage (SAGD) process is occurring in the reservoir, the reservoir comprises at least two pairs of producer and injector wells, and the slow reacting catalyst is delivered by injection through an infill well into a bitumen formation between adjacent pairs of producer and injector wells.

[0028] In yet another implementation of the method, in situ bitumen upgrading is induced in the bitumen formation between the adjacent pairs.

23699376.1

[0029] In yet another implementation of the method, in situ bitumen upgrading is accelerated in the bitumen formation between the adjacent pairs.

[0030] In yet another implementation of the method, a steam-assisted gravity push (SAGP) effect pushes upgraded bitumen from the bitumen formation between the adjacent pairs towards the producer wells of the adjacent pairs.

[0031] In yet another implementation of the method, at least some upgraded bitumen that is not collected by the pair of producer wells is collected by the infill well.

[0032] In yet another implementation of the method, the method further comprises the steps of: injecting the catalyst into the reservoir; injecting steam into the reservoir to heat the bitumen;
shutting in the reservoir; and producing upgraded bitumen.

[0033] In another aspect, provided is a method for winding down bitumen or heavy oil production in a mature reservoir having undergone a thermal bitumen or heavy oil recovery process, the method comprising: injecting slow reacting catalyst through at least one of an injector well, a producer well, and an infill well; shutting in the at least one injector well, producer well, or infill well; leaving the slow reacting catalyst in the reservoir to upgrade the bitumen to a desired extent; and producing the bitumen or heavy oil.

[0034] In an implementation of the method, the bitumen or heavy oil is left in the reservoir for a pre-determined length of time.

[0035] In yet another implementation of the method, the extent of upgrading is tested at one or more regular intervals until the desired extent is reached.

[0036] In yet another implementation of the method, the hydrocarbons comprise bitumen.

[0037] In yet another implementation of the method, the hydrocarbons comprise heavy oil.

[0038] In yet another aspect, provided is a method for increasing in situ upgrading of hydrocarbons in a reservoir having moving condensed steam, the method comprising: injecting a catalyst into at least one zone in the reservoir having high levels of moving condensed steam.

[0039] In an implementation of the method, at least one zone is a lean zone and/or a lean zone below a shale layer.

[0040] In yet another implementation of the method, the hydrocarbons comprise bitumen or heavy oil.

23699376.1

[0041] In yet another aspect, provided is a method for in situ upgrading of hydrocarbons in a sump around a producer well in a reservoir, the reservoir undergoing a steam assisted gravity drainage (SAGD) process, the method comprising: a) injecting slow reacting catalyst into the sump around a producer well to contact the hydrocarbons; b) producing the hydrocarbons continuously and testing the hydrocarbons at one or more regular intervals to determine an extent of upgrading; c) if the hydrocarbons are not upgraded to a desired extent, slowing production and repeating step b); and d) if the hydrocarbons are upgraded to the desired extent, repeating step b).

[0042] In yet another aspect, provided is a method for in situ upgrading of hydrocarbons in a reservoir, the reservoir undergoing a cyclic steam stimulation (CSS) process, the method comprising: a) injecting a slow reacting catalyst into the reservoir to contact the hydrocarbons;
b) injecting steam into the reservoir; c) shutting in the reservoir for a pre-determined period of time and testing the hydrocarbons at one or more regular intervals to determine an extent of upgrading; d) if the hydrocarbons are not upgraded to a desired extent, extending, shortening or leaving unchanged the pre-determined period of time and repeating step c); and e) if the hydrocarbons are upgraded to the desired extent, producing the hydrocarbons.

[0043] In an implementation of the method, the method further comprises: f) if economically feasible, repeating the method from step a); and g) if not economically feasible, terminating the CSS process.

[0044] In another implementation of the method, the pre-determined period of time corresponds to a sufficient contact time between the slow reacting catalyst and the hydrocarbons to upgrade the hydrocarbons to the desired extent.

[0045] In yet another implementation of the method, the pre-determined period of time is at least 5 days.

[0046] In yet another implementation of the method, the pre-determined period of time is at least 2 weeks.

[0047] In yet another implementation of the method, the pre-determined period of time is at least one month.

[0048] In an implementation of the methods, the slow reacting catalyst is injected into the reservoir while suspended in a solution.
CPST Doc: 297317.1 Date Recue/Date Received 2020-10-14

[0049] In another implementation of the methods, the solution comprises one or more polymers.

[0050] In yet another implementation of the methods, the one or more polymers comprise xantham gum.

[0051] In yet another implementation of the methods, the solution comprises one or more surfactants.

[0052] In yet another implementation of the methods, the one or more surfactants comprise at least one of cetrimonium bromide (CTAB) and sodium dodecylbenzenesulfonate (SDBS).

[0053] In yet another implementation of the methods, the one or more surfactants are injected into the reservoir prior to the injection of the slow reacting catalyst.

[0054] In yet another implementation of the methods, testing the extent of upgrading comprises obtaining samples of the bitumen or heavy oil and measuring an API
gravity value.

[0055] In yet another implementation of the methods, testing the extent of upgrading comprises obtaining samples of the bitumen or heavy oil and measuring a concentration of saturates, aromatics, resins and asphaltenes (SARA) of the samples.

[0056] In yet another implementation of the methods, testing the extent of upgrading comprises measuring at least one of asphaltenes, 2-methylanthracene, and alkanes.

[0057] In yet another implementation of the methods, the hydrocarbons comprise bitumen or heavy oil.

[0058] In yet another aspect, provided is a system for in situ upgrading of hydrocarbons in a reservoir undergoing a steam assisted gravity drainage (SAGD) process, the system comprising: a producer well positioned in the reservoir; an injector well positioned in the reservoir above the producer well; a sump around the producer well; a source of steam; a source of slow reacting catalyst; injection equipment for the steam; injection equipment for the slow reacting catalyst; equipment for determining an extent of upgrading of the hydrocarbons as they are produced.

[0059] In yet another aspect, provided herein is a system for in situ upgrading of hydrocarbons in a reservoir undergoing a cyclic steam stimulation (CSS) process, the system comprising: a well positioned in the reservoir; a source of steam; a source of slow reacting catalyst; injection equipment for the steam and slow reacting catalyst;
equipment for determining an extent of upgrading of the hydrocarbons in the reservoir.

23699376.1

[0060] In an implementation of the systems, the equipment can determine an API gravity value of the hydrocarbons.

[0061] In another implementation of the systems, the equipment can determine a level of at least one of saturates, aromatics, resins and asphaltenes.

[0062] In another implementation of the systems, the equipment can determine a level of at least one of asphaltenes, 2-methylanthracene, and alkanes

[0063] In yet another implementation of the systems, the source of slow reacting catalyst is a solution comprising a suspension of the slow reacting catalyst.

[0064] In yet another implementation of the systems, the solution comprises one or more polymers.

[0065] In yet another implementation of the systems, the solution comprises one or more surfactants.

[0066] In yet another implementation of the systems, the hydrocarbons comprise bitumen or heavy oil.
BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Embodiments will now be described with reference to the appended drawings wherein:

[0068] FIG. 1 is a cross-sectional view of a system for in situ upgrading of bitumen in the sump of a producer.

[0069] FIG. 2 is a flow chart illustrating a method for optimizing in situ upgrading of bitumen in the sump of a producer well in a SAGD process.

[0070] FIG. 3 is a cross-sectional view of a system for upgrading bitumen in situ in a virgin bitumen reservoir above a steam chamber in a SAGD process.

[0071] FIG. 4 is a cross-sectional view of a system for accelerating upgrading of bitumen in situ by injecting catalyst into a lean zone at the top of a steam chamber in a SAGD process.

[0072] FIG. 5 is a cross-sectional view of a system for upgrading bitumen in situ around an infill well in a virgin bitumen reservoir between two steam chambers in a SAGD
process.

[0073] FIG. 6 is a cross-sectional view of a system for upgrading bitumen in situ by injecting catalyst at a well near the top of a steam chamber in a SAGD
process.

23699376.1

[0074] FIG. 7 is a cross-sectional view of a system for upgrading bitumen in situ by injecting catalyst into a reservoir in a CSS process.

[0075] FIG. 8 is a flow chart illustrating a method for upgrading bitumen in situ in a cyclic steam stimulation system.
DETAILED DESCRIPTION

[0076] The use of catalysts for in situ bitumen upgrading has been considered in existing research. Such existing research shows that nano-particles can cause upgrading of bitumen by breaking the sulfur bonds holding the asphaltenes together, thereby reducing the asphaltene content and viscosity of the bitumen. However, a significant focus of previous work has been on examining catalysts that react very quickly, such as those used in upgraders and refineries.
Catalysts typically used for upgrading or cracking bitumen in refineries or upgraders on surface, such as molybdenum and nickel, work at high temperatures and have to be very fast reacting because of the large volumes of bitumen being upgraded each day. Such catalysts are typically supported by zeolite, alumina, or silica, which can provide enhanced cracking functionality.
These fast reacting catalysts can be considered expensive and are therefore not economical to inject into a subsurface formation to upgrade bitumen in situ. Other catalysts, such as unsupported transition metal nanocatalysts, cannot react with bitumen quickly enough to be used in a refinery. However, these catalysts can be of lower cost and can thus be more economical to inject into a reservoir, particularly where all or some of the catalysts are unrecoverable from the reservoir. These slower reacting catalysts can sufficiently upgrade bitumen in situ in a thermal recovery process such as SAGD, as a longer contact time between the bitumen and the catalyst can be achieved in the subsurface relative to in a refinery. The contact time in the subsurface can be on the order of days to weeks, and potentially years.

[0077] Known unsupported transition metal catalysts can include, but are not limited to, molybdenum-, nickel-, iron-, tungsten-, and vanadium-based catalysts. Examples of unsupported molybdenum-based catalysts can include, but are not limited to, molybdenum (IV) sulfide (MoS2) and molybdenum (VI) oxide (Mo03). An example of unsupported nickel-based catalysts includes nickel (II) oxide (NiO). Examples of unsupported iron-based catalysts can include, but are not limited to, pyrite (FeS2), troilite (FeS) and pyrrhotite (Fei,S). It can be appreciated that Fe-based unsupported catalysts, and in particular, pyrite, are considered to be attractive with respect to cost and availability.

23699376.1

[0078] The terms "catalyst", "catalysts", " nano-catalyst", and "nano-particle catalyst" are used interchangeably from hereon in and all refer to slow-reacting catalysts having a particle size on the nanoscale. The term "slow-reacting catalyst" will be understood to mean a catalyst that upgrades bitumen too slowly to be economically or commercially feasible for use in bitumen refineries or that upgrades bitumen slower than those conventionally used in bitumen refineries.
Suitable slow-reacting catalysts include pyrite. In some implementations, some other iron- and vanadium-based compounds may be suitable slow-reacting catalysts.

[0079] The phrases "residence time of the catalyst" or "residence time of the slow-reacting catalyst" or "contact time" as used herein refer to the amount of time that the bitumen is in contact with the injected catalyst.

[0080] The terms "level of upgrading", "degree of upgrading" and "extent of upgrading" used herein all refer to the extent to which bitumen or heavy oil has been upgraded. One method of estimating the extent of upgrading of bitumen of a bitumen sample taken from a reservoir is to measure the concentration of 2-methylanthracene, alkanes and asphaltenes. High concentrations of 2-methylanthracene and alkanes, and a low concentration of asphaltenes can be indicative of upgrading.

[0081] The term "sufficient contact time" used herein refers to a contact time between the bitumen and the catalyst that is sufficient to at least partially upgrade the bitumen. At least partially upgraded bitumen may be suitable for pipeline transportation without adding any diluent, or it may require a lesser amount of dilution prior to transportation as compared to bitumen that has not been at least partially upgraded.

[0082] As noted above, an advantage of using a slow reacting nano-catalyst, is that the catalyst is generally much cheaper than a fast reacting catalyst, which is too expensive to inject into the ground. The slow reacting and cheaper catalyst can be injected into the sump of a producer well, particularly one that is mature and/or approaching the end of its production life and/or in infill wells to take advantage of the longer contact time.
Particularly, the catalyst can be injected into the sump of a well that has slowed or ceased production. The catalyst can be left in the reservoir for an extended period of time during which the bitumen would slowly be upgraded by the catalyst in the presence of the residual heat. After this extended period of time, which can be as long as multiple years, the residual upgraded bitumen can be collected using the producer well.

23699376.1

[0083] The catalyst can be injected into the reservoir as a suspension of catalyst nanoparticles in water. It is known that when nanoparticles are injected into a porous medium, they have a tendency to agglomerate due to the attractive forces between particles. Such agglomeration can result in the formation of larger particles from the nanoparticles, which can result in deposition and destabilization of the suspension of nanoparticles in the aqueous medium. This, in turn, can clog pores in the formation into which the suspension is injected, thereby inhibiting the dispersion of the catalyst particles. It has been shown that suspensions of nickel nanoparticles in water can be at least partially stabilized by xantham gum. Thus, in order to mitigate the clogging of pores in the reservoir, the injected catalyst nanoparticle suspension can comprise polymers, such as xantham gum, that are known to stabilize nanoparticle suspensions.

[0084] It is known that the concentration of surfactant in a nanoparticle suspension can play an important role in the transfer of particles to the oil-water interface. A
surfactant such as cetrimonium bromide (CTAB) and/or sodium dodecylbenzenesulfonate (SDBS) can be injected into the reservoir prior to the introduction of the particles. The injected surfactant solution can create an oil-water emulsion, thereby increasing the oil-water interface area and also positively charging these interfaces. Then, catalyst nanoparticles, suspended in a solution of xantham gum in water, can be injected. The electrostatic interactions between polymer and surfactant molecules can move the nanoparticles to oil-water interfaces. Movement of the catalyst nanoparticles to the oil-water interface can be necessary to allow interaction between the catalyst and the oil (i.e., to allow the reaction between the catalyst and the bitumen). It can be appreciated that other known surfactants can be used, preferably at a concentration conducive to the migration of catalyst nanoparticles to the oil-water interface, to create an oil-water emulsion in the reservoir prior to the introduction of the catalyst nanoparticles. It can also be appreciated that other known polymers can be used in preparing nanoparticle suspensions for injection into the reservoir.

[0085] Slow reacting catalysts can also be implemented as part of a wind-down strategy in a SAGD process. During wind-down, steam injection is gradually reduced and the amount of recoverable oil in the drainage volume gradually decreases. Catalyst can be injected during the wind-down phase to upgrade the remaining bitumen in situ. Although the pressure and temperature of the steam chamber decrease during the wind-down phase, the residual heat can be sufficient to help facilitate the reaction between the catalyst and the bitumen. When the 23699376.1 wind-down phase is completed, the remaining bitumen in contact with the catalyst can be left to upgrade over an extended period of time, as discussed above.

[0086] Slow reacting nano-catalysts can also be injected into the sump of a producer well during normal SAGD operation. Since the catalyst reacts slowly, it can be important to ensure that the bitumen is in contact with the catalyst long enough for a desired degree of upgrading to occur. To increase the contact time to achieve a sufficient contact time between the catalyst and the bitumen, production can be slowed. If production is slowed, the size of the sump can increase, and thus injection of steam can be adjusted as necessary to maintain the interface between the producer and injector wells. The bitumen in the sump can be in contact with the nano-catalyst for up to several weeks, depending on sump size and production rates.

[0087] Recent geochemical data from a post steam core well (observed well) suggests that in situ upgrading can be occurring in the absence of injected catalyst during a SAGD process. It is found that in situ upgrading can be occurring in the absence of injected catalyst due to the presence of moving steam in at least some SAGD fields having mobile water. The observed well is located in an area where the steam chamber is less developed compared to surrounding areas. Alkanes and elevated levels of 2-methylanthracene were found in the bitumen in that well. The presence of alkanes and elevated levels of 2-methylanthracene is indicative of in situ bitumen upgrading. Alkanes and elevated levels of 2-methylanthracene are not normally present in virgin bitumen reservoirs in that geographical area. It was also found that the concentrations of such compounds increase with increasing reservoir temperature. All samples taken from the observed well showed a reduced asphaltene content relative to virgin reservoirs, which is also indicative of upgrading. The most upgraded of these samples is believed to be from a reservoir zone that has been in contact with hot moving steam condensate longer than the other zones from which samples were obtained. In view of these observations, it may be that the more readily available a sample is to the movement of condensed steam, the more upgraded the sample can be. As such, mass transfer allowed by water mobility could be a key controlling parameter for in situ upgrading. Moreover, the presence of natural materials that can catalyze bitumen upgrading, such as nodules of pyrite, could contribute to such in situ upgrading.

[0088] Lean zones often exist in reservoirs undergoing SAGD. The presence of lean zones can result in high steam-to oil ratios (SORs) since they behave as "thief zones" which absorb heat and steam due to high levels of mobile water. In view of their high levels of mobile water, the lean zones could act as conduits for the injected catalyst. In other words, catalyst can be 23699376.1 injected into lean zones to help disperse catalyst deep into the reservoir to contact a maximal amount of bitumen. Additionally, lean zones can be conduits for steam. Bitumen that is exposed to both moving steam and catalyst can have an accelerated rate of upgrading relative to bitumen that is exposed to moving steam or catalyst alone.

[0089] The above principles can also apply to a CSS process. During the soak, or shut in phase of a CSS process, heat from the steam injected through a producer/injector well during the injection phase can be distributed through the reservoir. As discussed in greater detail below, the well can be shut in for a period of time sufficient for uniform heat distribution to occur.
It is known that the bitumen in the steam chamber is at least partially heated by convective heat transfer. Accordingly, the catalyst can be injected into areas of the reservoir where the bitumen is exposed to the highest levels of convective heat transfer (i.e., moving condensed steam). As discussed above, bitumen that is exposed to both moving condensed steam and catalyst can have an accelerated rate of upgrading relative to bitumen exposed to moving condensed steam or catalyst alone. If the reservoir undergoing CSS contains geological features such as lean zones, which are often located below shale layers, the catalyst can be injected into such zones to help disperse catalyst deep into the reservoir to contact a maximal amount of bitumen. In view of their high levels of mobile water, the lean zones could act as conduits for the injected catalyst and for steam. Bitumen exposed to steam and catalyst moving through the lean zones can have a higher rate of upgrading.

[0090] When lean zones are present in a reservoir undergoing SAGD, the operating steam pressure is typically reduced to reduce the water loss to the lean zone, which can accentuate the impact of any barriers in the formation, thereby giving rise to high SORs and low production rates. Additionally, if the cap rock above the pay in a SAGD process is compromised, the operating steam pressure can also be reduced, giving rise to the same issues.
The lower production rates are a result of the slower drainage of the more viscous bitumen at the lower temperature of the steam chamber. Slow reacting catalyst can be utilized to further decrease the viscosity of the bitumen via in situ upgrading to increase the rate of bitumen drainage in a steam chamber having a lower temperature as a result of the necessary reduction of steam operating pressure due to the presence of lean zones, and compromised cap rock.

[0091] It is also known that the upgrading reactions between bitumen and catalysts can produce CO2 and other gases. Instead of solely relying on co-injecting gases through injector wells during a SAGD process, the gases produced as a result of the upgrading reactions can contribute a steam-assisted gravity push (SAGP) effect. Leveraging this effect, a nano-catalyst 23699376.1 can be injected through an infill or other additional well that is positioned above the injector-producer well pair to both upgrade the bitumen in situ and, through the production of CO2 and other gases (such as methane and possibly H2S), push the bitumen being upgraded down towards the producer well(s). Additionally, CO2 production can reduce bitumen viscosity, facilitating gravity drainage.

[0092] While the example systems and methods provided herein are directed to SAGD and CSS processes, it can be appreciated that these principles can be applied to any other in situ oil recovery techniques, and in particular, thermal recovery techniques, where the slow reacting catalyst can be kept in contact with bitumen for periods of time that allow sufficient upgrading of the bitumen. It has been shown that SAGD processes are generally carried out at pressures and temperatures that are compatible with in situ upgrading reactions, particularly in situ upgrading reactions using unsupported dispersed nanocatalysts such as trimetallic nanocatalysts.

[0093] Turning now to the figures, FIG. 1 illustrates a bitumen reserve such as that found in the Canadian oil sands, hereinafter referred to as the "pay 180"; which is accessed for in situ bitumen recovery. The pay 180 typically includes a number of geological materials such as a rock matrix, sand, and fluid such as the bitumen that is being targeted. A
formation at least partially underlies the pay 180 and is hereinafter referred to as the "underlying formation 190".
In the example shown in FIG. 1, the pay 180 itself underlies a layer of overburden 170 between the pay 180 and the surface 160. In the implementation shown in FIG. 1, a producer well 120 and an injector well 110 are situated within the pay 180. A sump 100 exists around the producer well 120, and the sump 100 is a liquid pool comprising heated bitumen and condensate water. Slow reacting nano-catalyst particles 130 are injected through the producer 120 into the sump 100 where they disperse throughout the sump 100. The slow reacting nano-catalyst particles 130 come into contact with bitumen and break the sulfur bonds holding the asphaltenes together, reducing the ashpaltene content and viscosity of the bitumen. It can be appreciated that the slow reacting nano-catalyst can be injected concurrently with, or after, surfactants and/or polymers into the sump 100 to prevent aggregation of nano-catalyst particles.
It is known that certain surfactants and/or polymers can also allow the nano-catalyst particles to become attached to sand grains. The bitumen can be in contact with the nano-catalyst for up to several weeks, depending on sump size and production rates.

[0094] The flow chart shown in FIG. 2, illustrates a process whereby bitumen is upgraded in situ by injecting nano-catalyst into the sump 100 around a producer well 120 during normal 23699376.1 operation in a SAGD process. Nano catalyst particles can be injected into the sump 100 at step 200. Bitumen in the sump can then be catalytically upgraded in situ at step 210 as it is produced at a low rate in step 220. The extent of upgrading of the bitumen being continuously produced can be determined at regular intervals at step 230. If the bitumen is upgraded to the extent that it, for example, meets pipeline specifications for shipping, the parameters of the SAGD process can be maintained and the extent of upgrading can be measured again a short time thereafter. If the bitumen is not upgraded to a sufficient extent, and it is feasible to slow production (240), production can be slowed at step 250. It may be noted that it would not be feasible to slow production if, for example, the production rate was so slow that the process was not economical (240). In this case, the process can revert back to step 200 and inject more catalyst. This can help to increase the extent of upgrading if, for example, the catalyst has not spread throughout the entirety of the sump 100, and thus not a meaningful portion or none of the bitumen has been in contact with the catalyst. At step 200, the nano-catalyst can be coated with surfactant so that it can attach to quartz grains, and to prevent the catalyst from aggregating and/or blocking pores in the reservoir. Furthermore, steam injection can either be stopped or continue while the catalyst is injected at step 200.

[0095] It can be appreciated that in the process of FIG. 2, at step 200, the catalyst can be injected into the sump through a producer well 120 and/or an injector well 110.

[0096] The extent of bitumen upgrading can be estimated by obtaining samples of the bitumen or heavy oil and measuring an API gravity value and/or a concentration of saturates, aromatics, resins and asphaltenes (SARA) of the samples. It will be appreciated that any appropriate known or future known methods of determining the extent of bitumen upgrading can be implemented alternatively to, or concurrently with, the above-noted methods.

[0097] In the implementation shown in FIG. 3, slow reacting nano-catalyst particles 340 are injected through an infill well 300 into a virgin zone 350 above steam chamber 330. Steam chamber 330 can be created by injecting steam through the injector well 110, and heated bitumen and condensate water flows down the edges of the chamber and is collected at producer well 120.
In this implementation, bitumen upgrading is introduced into virgin zone 350.
The bitumen that is upgraded in virgin zone 350 can be collected by the infill well 300 and can also flow down and enter steam chamber 330 where it is eventually collected by producer well 120.

[0098] As noted above, some experimental data has shown that the largest amount of upgrading occurs at the top of the steam chamber, corresponding to the part of the reservoir CPST Doc: 297318.1 Date Recue/Date Received 2020-10-14 that has been in contact with hot moving steam condensate the longest. It is therefore assumed from the distribution of upgrading that the more readily available a part of the reservoir is to the movement of condensed steam, the more upgraded it will be. The delivery of the slow reacting nano-catalyst into the reservoir can be targeted accordingly; to either accelerate upgrading occurring in areas of the reservoir having been in contact with hot moving steam condensate, or to introduce upgrading to other areas of the reservoir. Catalyst can thus be injected into "lean zones", which have high levels of mobile water and can act as conduits for steam and catalyst.
Thus, lean zones can be utilized to facilitate the dispersion of catalyst through the reservoir to contact bitumen being exposed to mobile water. Moreover, injection of catalyst into lean zones can accelerate upgrading of bitumen that can already be occurring due to exposure to moving condensed steam.

[0099] In the implementation shown in FIG. 4, catalyst 440 is injected through infill well 400 into lean zone 460. Lean zone 460 is located below shale layer 450. Lean zone 460 is located at the top of steam chamber 430 in this example illustration. Bitumen in and near lean zone 460 is exposed to high levels of moving condensed steam and can be upgraded from the steam exposure alone. As such, by introducing catalyst 440 in and near lean zone 460, and at the top of steam chamber 430, upgrading can be accelerated. The upgraded bitumen in zone 460 can be collected by the infill well 400 and/or the producer well 120.

[00100] In the implementation shown in FIG. 5, an infill well 540 is located in virgin bitumen zone 550 between two producer wells 500 and two injector wells 510. Slow reacting nano-catalyst particles 520 can be injected into the virgin bitumen zone 550 located somewhere between the two steam chambers 530. In this implementation, bitumen upgrading is introduced into virgin zone 550. The arrows in FIG. 5 are provided only to illustrate a possible flow path of bitumen in the steam chambers 530 and virgin bitumen zone 550. A portion of the upgraded bitumen that cannot be collected by producer wells 500 can be collected by infill well 540. The upgrading reactions between the catalyst 520 and the bitumen in virgin zone 550 produce gases which can push upgraded bitumen from virgin zone 550 towards steam chambers 530 through a SAGP effect, where the upgraded bitumen is heated and collected by producer wells 500.
Additionally, the decrease in viscosity resulting from upgrading of the bitumen in virgin zone 550 can facilitate its collection by infill well 540.

[00101] It can be appreciated that bitumen upgrading already occurring in a heated bitumen zone between producer and injector pairs can be accelerated by injecting nano-catalyst through an infill well.

23699376.1

[00102] In the implementation shown in FIG. 6, the nano-catalyst particles 630 are injected into the reserve through the infill well 640 in the steam chamber 650. The upgrading reaction between the slow reacting nano-catalyst particles and the bitumen causes the production of gases including carbon dioxide and methane. The generation of these gases can cause a SAGP
effect. The SAGP
effect can push the heated bitumen downwards in the general direction of the arrows illustrating a postulated flow path of heated bitumen, down past injector well 610 towards producer well 620.

[00103] Known techniques of using SAGP rely on co-injecting gas with steam through injector wells. It can be appreciated that the methods described herein provide a method of producing the SAGP effect without needing to co-inject gas through the injector wells, which can result in cost savings. The methods described herein can also be used to decrease the amount of gas co-injected into the reservoir, if combined with existing methods of leveraging SAGP.

[00104] FIG. 7 illustrates a bitumen reservoir such as that found in the Canadian oil sands, hereinafter referred to as the "pay 742"; which is accessed for in situ bitumen recovery. The pay 742 typically includes a number of geological materials such as a rock matrix, sand, and fluid such as the bitumen that is being targeted. A formation at least partially underlies the pay 742, and is hereinafter referred to as the "underlying formation 744". In the example shown in FIG. 7, the pay 742 itself underlies a layer of overburden 746 between the pay 742 and the surface 748. In the implementation shown in FIG. 7, a CSS process is provided wherein in situ upgrading of bitumen using a slow reacting catalyst is implemented. The CSS process is split into four phases. In phase 700, catalyst 702 is injected through vertical producer/injector well 750 into pay 742.
Catalyst 702 can be coated with surfactant so that it can attach to quartz grains, and to prevent the catalyst from aggregating and/or blocking pores in the reservoir. The arrows in phase 700 illustrate the flow of the catalyst 702 into pay 742. In phase 710, or the "huff' phase, steam 712 is injected through well 750 to produce heated zone 740. The arrows in heated zone phase 710 illustrate the flow of steam 712 down well 750 into heated zone 740. In phase 720, which is commonly referred to as the "soak" or "shut in phase", the bitumen is heated by the convection of water in heated zone 740. The bitumen upgrading can be accelerated during the shut-in phase due to heating resulting from the convection of water. The duration of phase 720 can be extended as long as is necessary to allow sufficient in situ upgrading of the bitumen.
In phase 730, which is commonly referred to as the "puff" or "production phase", the bitumen in heated zone 740 can be produced over a period of weeks or months. The arrows in phase 730 illustrate the flow of heated, at least partially upgraded bitumen 732 as it is produced through well 750.
CPST Doc: 297319.1 Date Recue/Date Received 2020-10-14

[00105] The flow chart shown in FIG. 8 illustrates a process for controlling in situ upgrading according to the modified general CSS process described in FIG.7. At step 800, slow reacting catalyst is injected into the reservoir. As discussed above, the catalyst can be injected as a suspension in a solution comprising dissolved polymer and/or surfactant which can stabilize the catalyst nanoparticle suspension and/or allow the catalyst nanoparticles to attach to rock or sand grains. A surfactant solution can also be injected prior to the injection of nanocatalyst for the reasons discussed above. Steam is then injected into the reservoir at step 810, which is immediately followed by step 820 which is the shut-in phase. At step 830, the extent of bitumen upgrading can be estimated at regular time intervals by analyzing core samples at various locations in the heated zone to determine the amount of alkanes, 2-methylanthracene, and asphaltenes present relative to the composition of the virgin reservoir. If the bitumen is not sufficiently upgraded, the shut-in phase can continue until a desired level of upgrading is reached. If at step 830, the bitumen has upgraded to a desirable extent, the production phase begins at step 840. When production is done, at step 850, it is decided whether to start another cycle of the process. If it is not desirable to start another cycle, the process moves to step 870 and the cycle is terminated. Otherwise, if it is believed that more catalyst is needed (step 860), the process starts again at step 800. If no more catalyst is needed (step 860), the process starts again at step 810.

[00106] The methods described herein can result in, or at least contribute to, a higher valued product that is easier to produce and ship with less total energy input.
Accordingly, this can increase revenue and lower the environmental footprint resulting from in situ bitumen recovery operations.

[00107] For simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.
In addition, numerous specific details are set forth in order to provide a thorough understanding of the examples described herein. However, it will be understood by those of ordinary skill in the art that the examples described herein may be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the examples described herein. Also, the description is not to be considered as limiting the scope of the examples described herein.

[00108] The examples and corresponding diagrams used herein are for illustrative purposes only. Different configurations and terminology can be used without departing from the principles 23699376.1 expressed herein. For instance, components and modules can be added, deleted, modified, or arranged with differing connections without departing from these principles.

[00109] The steps or operations in the flow charts and diagrams described herein are just for example. There may be many variations to these steps or operations without departing from the principles discussed above. For instance, the steps may be performed in a differing order, or steps may be added, deleted, or modified.

[00110] Although the above principles have been described with reference to certain specific examples, various modifications thereof will be apparent to those skilled in the art as outlined in the appended claims.

23699376.1

Claims

Claims:

1. A method for upgrading hydrocarbons in a reservoir in situ, the method comprising:
delivering a slow reacting catalyst into the reservoir to contact the hydrocarbons; and allowing a sufficient contact time between the slow reacting catalyst and the hydrocarbons to at least partially upgrade the hydrocarbons.

2. The method of claim 1 wherein the reservoir is an oil sands reservoir.

3. The method of claim 1 or 2 wherein the hydrocarbons comprise bitumen.

4. The method of claim 1 or 2 wherein the hydrocarbons comprise heavy oil.

5. The method of any one of claims 1 to 4 wherein the slow reacting catalyst is an unsupported transition metal catalyst.

6. The method of claim 5 wherein the unsupported transition metal catalyst comprises pyrite-based compounds.

7. The method of claim 5 wherein the unsupported transition metal catalyst comprises iron-based compounds.

8. The method of claim 5 wherein the unsupported transition metal catalyst comprises vanadium-based compounds.

9. The method of any one of claims 1 to 8 wherein a cyclic steam stimulation (CSS) process is implemented in the reservoir, comprising a well used for injection and production.

10. The method of any one of claims 1 to 8 wherein a steam-assisted gravity drainage (SAGD) process is implemented in the reservoir, comprising a substantially horizontal producer well having an adjustable production rate and a substantially horizontal injector well having an adjustable steam injection rate.

CPST Doc: 375116.1 Date Recue/Date Received 2021-08-31

11. The method of claim 10 wherein the slow reacting catalyst is delivered into the hydrocarbon reservoir by injection through the producer well into a sump around the producer well, the sump comprising heated bitumen and condensate water, and the catalyst being dispersed therethrough, to continuously produce upgraded bitumen.

12. The method of claim 11 wherein the production rate is decreased to achieve the sufficient contact time between the slow reacting catalyst and the bitumen in the sump to produce the upgraded bitumen.

13. The method of any one of claims 1 to 10 wherein the slow reacting catalyst is delivered by injection through an infill well into a virgin bitumen formation above a steam chamber in the reservoir to induce bitumen upgrading.

14. The method of any one of claims 1 to 10 wherein the slow reacting catalyst is delivered by injection through an infill well into a bitumen formation at the top of a steam chamber to accelerate bitumen upgrading.

15. The method of any one of claims 1 to 10 wherein the slow reacting catalyst is delivered by injection through an infill well into a lean zone in the reservoir to accelerate bitumen upgrading.

16. The method of claim 15 wherein the lean zone is below a shale layer.

17. The method of claim 1 or claim 2 wherein an upgrading reaction between the hydrocarbons and the catalyst yields gases to produce a steam-assisted gravity push (SAGP) effect pushing hydrocarbons in a desired direction.

18. The method of any one of claims 3 to 16 wherein an upgrading reaction between the bitumen and the catalyst yields gases to produce a steam-assisted gravity push (SAGP) effect pushing bitumen in a desired direction.

19. The method of any one of claims 1 to 8 wherein a steam-assisted gravity drainage (SAGD) process is occurring in the reservoir, the reservoir comprises at least two pairs of CPST Doc: 375116.1 Date Recue/Date Received 2021-08-31 producer and injector wells, and the slow reacting catalyst is delivered by injection through an infill well into a bitumen formation between adjacent pairs of producer and injector wells.

20. The method of claim 19 wherein in situ bitumen upgrading is induced in the bitumen formation between the adjacent pairs.

21. The method of claim 19 wherein in situ bitumen upgrading is accelerated in the bitumen formation between the adjacent pairs.

22. The method of any one of claims 19 to 21 wherein a steam-assisted gravity push (SAGP) effect pushes upgraded bitumen from the bitumen formation between the adjacent pairs towards the producer wells of the adjacent pairs.

23. The method of any one of claims 19 to 22 wherein at least some upgraded bitumen that is not collected by the pair of producer wells is collected by the infill well.

24. The method of claim 10 when dependent on claim 1 or claim 2, further comprising the steps of:
injecting the catalyst into the reservoir;
injecting steam into the reservoir to heat the hydrocarbons;
shutting in the reservoir; and producing upgraded hydrocarbons.

25. The method of claim 10 when dependent on any one of claims 3 to 8, further comprising the steps of:
injecting the catalyst into the reservoir;
injecting steam into the reservoir to heat the bitumen;
shutting in the reservoir; and producing upgraded bitumen.

26. A method for winding down hydrocarbon production in a mature reservoir having undergone a thermal hydrocarbon recovery process, the method comprising:
injecting slow reacting catalyst through at least one of an injector well, a producer well, and an infill well;

CPST Doc: 375116.1 Date Recue/Date Received 2021-08-31 shutting in the at least one injector well, producer well, or infill well;
leaving the slow reacting catalyst in the reservoir to upgrade the hydrocarbons to a desired extent; and producing the hydrocarbons.

27. The method of claim 26 wherein the hydrocarbons are left in the reservoir for a pre-determined length of time.

28. The method of claim 26 wherein the extent of upgrading is tested at one or more regular intervals until the desired extent is reached.

29. A method for increasing in situ upgrading of hydrocarbons in a reservoir having moving condensed steam, the method comprising:
injecting a slow reacting catalyst into at least one zone in the reservoir having high levels of moving condensed steam.

30. The method of claim 29 wherein the at least one zone is a lean zone and/or a lean zone below a shale layer.

31. A method for in situ upgrading of hydrocarbons in a sump around a producer well in a reservoir, the reservoir undergoing a steam assisted gravity drainage (SAGD) process, the method comprising:
a) injecting slow reacting catalyst into the sump around the producer well to contact the hydrocarbons;
b) producing the hydrocarbons continuously and testing the hydrocarbons at one or more regular intervals to determine an extent of upgrading;
c) if the hydrocarbons are not upgraded to a desired extent, slowing production and repeating step b); and d) if the hydrocarbons are upgraded to the desired extent, repeating step b).

32. A method for in situ upgrading of hydrocarbons in a reservoir, the reservoir undergoing a cyclic steam stimulation (CSS) process, the method comprising:
a) injecting a slow reacting catalyst into the reservoir to contact the hydrocarbons;
b) injecting steam into the reservoir;

CPST Doc: 375116.1 Date Recue/Date Received 2021-08-31 c) shutting in the reservoir for a pre-determined period of time and testing the hydrocarbons at one or more regular intervals to determine an extent of upgrading;
d) if the hydrocarbons are not upgraded to a desired extent, extending, shortening or leaving unchanged the pre-determined period of time and repeating step c); and e) if the hydrocarbons are upgraded to the desired extent, producing the hydrocarbons.

33. The method of claim 32, further comprising:
f) if meeting at least one economic criterion, repeating the method of claim 30 from step a); and g) if not meeting the at least one economic criterion, terminating the CSS
process.

34. The method of claim 32 or 33 wherein the pre-determined period of time corresponds to a sufficient contact time between the slow reacting catalyst and the hydrocarbons to upgrade the hydrocarbons to the desired extent.

35. The method of any one of claims 32 to 34 wherein the pre-determined period of time is at least 5 days.

36. The method of any one of claims 32 to 34 wherein the pre-determined period of time is at least two weeks.

37. The method of any one of claims 32 to 34 wherein the pre-determined period of time is at least one month.

38. The method of any one of claims 11 to 37 wherein the slow reacting catalyst is injected into the reservoir while suspended in a solution.

39. The method of claim 38 wherein the solution comprises one or more polymers.

40. The method of claim 39 wherein the one or more polymers comprise xantham gum.

41. The method of claim 39 or 40 wherein the solution comprises one or more surfactants.

CPST Doc: 375116.1 Date Recue/Date Received 2021-08-31

42. The method of claim 41 wherein the one or more surfactants comprise at least one of cetrimonium bromide (CTAB) and sodium dodecylbenzenesulfonate (SDBS).

43. The method of claim 41 or 42 wherein the one or more surfactants are injected into the reservoir prior to the injection of the slow reacting catalyst.

44. The method of any one of claims 28 or 31 to 43 wherein testing to determine the extent of upgrading comprises obtaining samples of the hydrocarbons and measuring an API gravity value.

45. The method of any one of claims 28 or 31 to 43 wherein testing to determine the extent of upgrading comprises obtaining samples of the hydrocarbons and measuring a concentration of saturates, aromatics, resins and asphaltenes (SARA) of the samples.

46. The method of any one of claims 28 or 31 to 43 wherein testing to determine the extent of upgrading comprises measuring at least one of asphaltenes, 2-methylanthracene, and alkanes.

47. The method of any one of claims 32 to 46, wherein the hydrocarbons comprise bitumen, heavy oil, or bitumen and heavy oil.

48. A system for in situ upgrading of hydrocarbons in a reservoir undergoing a steam assisted gravity drainage (SAGD) process, the system comprising:
a producer well positioned in the reservoir;
an injector well positioned in the reservoir above the producer well;
a sump around the producer well;
a source of steam;
a source of slow reacting catalyst;
injection equipment for the steam;
injection equipment for the slow reacting catalyst;
equipment for determining an extent of upgrading of the hydrocarbons as they are produced.

CPST Doc: 375116.1 Date Recue/Date Received 2021-08-31

49. A system for in situ upgrading of hydrocarbons in a reservoir undergoing a cyclic steam stimulation (CSS) process, the system comprising:
a well positioned in the reservoir;
a source of steam;
a source of slow reacting catalyst;
injection equipment for the steam and slow reacting catalyst;
equipment for determining an extent of upgrading of the hydrocarbons in the reservoir.

50. The system of claim 48 or 49 wherein the equipment can determine an API
gravity value of the hydrocarbons.

51. The system of any one of claims 48 to 50 wherein the equipment can determine a level of at least one of saturates, aromatics, resins and asphaltenes.

52. The system of any one of claims 48 to 51 wherein the equipment can determine a level of at least one of asphaltenes, 2-methylanthracene, and alkanes.

53. The system of any one of claims 48 to 52 wherein the source of slow reacting catalyst is a solution comprising a suspension of the slow reacting catalyst.

54. The system of claim 53 wherein the solution comprises one or more polymers.

55. The system of claim 53 or 54 wherein the solution comprises one or more surfactants.

56. The system of any one of claims 48-55 wherein the hydrocarbons comprise bitumen.

57. The system of any one of claims 48-55 wherein the hydrocarbons comprise heavy oil, or bitumen and heavy oil.

CPST Doc: 375116.1 Date Recue/Date Received 2021-08-31