DYNAMIC SUPERCRITICAL CO2 ENVIRONMENT AND A TEST SYSTEM THEREOF

Field of the Invention

5 The present invention relates to a method for subjecting at least one sample to a dynamic liquid CO2 or a supercritical CO2 environment and a test system adapted for performing steps of the method.

Background of the Invention

10 The interest in carbon capture, utilization and storage, in short CCUS, is ever increasing as the effect of CO2 becomes more apparent due to climate change. An old idea is to pump the CO2 from the atmosphere and/or pump CO2 produced at an energy plant into an underground reservoir.

15 It would be preferable if existing or abandoned oil and gas wells could be used in reverse, i.e. pumping CO2, such as liquid CO2, into the oil and gas wells. However, at the moment there is a lot of unknowns, some of which could result in terrible environmental disasters.

20 One of the first raised questions is whether injected CO2 could erode the barriers in abandoned wells. The answer to the question is unknown, and it may be yes in some cases and no in other dependent on the material of the barrier and the local reservoir environment. If the barrier is eroded at an offshore well, then the released CO2 will mix with the ocean and thereby lowering the pH value of the ocean, thereby causing

25 death to the local marine life.

However well integrity is not the only problem for CO2 storage. The components of the well are designed for oil or gas production, however the wear on the components in a high liquid CO2 flow at a pressure equal to or greater than 27 bar are unknown.

30

Furthermore, each reservoir has a specific reservoir environment determined by the reservoir temperature and reservoir pressure and the substances of the reservoir, including the layers above the reservoir, such as limestone, mudstone, or chalk, or the like. The injected liquid CO2 dependent on the reservoir temperature and reservoir

35 pressure may become supercritical CO2, which is known for the low viscosity which may cause erosion damages to barriers in abandoned wells or cause other, at the moment, unknown causes or effects.

Object of the Invention

It is an object of the invention to provide a method and test system for subjecting at least one sample to a dynamic liquid CO2 or a supercritical CO2 environment, such that the at least one sample can be tested in an environment emulating the real environment for CO2 Carbon storage and/or utilization.

Description of the Invention

An object of the invention is achieved by a method for subjecting at least one sample to a dynamic liquid CO2 or a supercritical CO2 environment. The method comprises steps of

- providing a CCUS reactor comprising a reactor chamber with at least one sample,

- adjusting chamber temperature and chamber pressure of the reactor chamber such that the CO2 is liquid CO2 or supercritical CO2;

- producing liquid CO2 or supercritical CO2;

- generating a liquid CO2 flow or a supercritical CO2 flow in the reactor chamber by a step of injecting the produced liquid CO2 or supercritical CO2 into the reactor chamber, thereby subjecting the at least one sample to a dynamic liquid CO2 environment or a dynamic supercritical CO2 environment.

The skilled person would know that the critical point of CO2 is at 31°C and 73.8 bar, thus the environment is controlled by adjusting the chamber temperature and chamber pressure.

The step of producing liquid CO2 or supercritical CO2 may be performed in a CO2 manipulator connected to a CO2 batch where the CO2 manipulator is adapted to adjust the CO2 temperature and the CO2 pressure thereby producing liquid CO2 or supercritical CO2. However, the liquid CO2 or supercritical CO2 could be produced in other ways such as produced offsite and stored in a container.

It is expected that liquid CO2 is to be injected into reservoirs, thus in many cases liquid CO2 is injected into the reactor chamber, thereby generating a liquid CO2 flow in the reactor chamber. It is expected that liquid C02 at low temperatures, such as at or below room temperature, will be less expensive compared to storing supercritical CO2. However, the method can be performed where supercritical CO2 is produced and injected.

The step of injecting the produced liquid CO2 or supercritical CO2 into the reactor chamber generates a liquid CO2 flow or a supercritical CO2 flow in the reactor chamber, which flows past the at least one sample which is thus subjected to a dynamic liquid CO2 or supercritical CO2 environment, thereby better emulating wear of the at least one sample.

The at least one sample may divide the reactor chamber in two parts and the step of injecting the produced liquid CO2 or supercritical CO2 into the reactor chamber also causes an increase in pressure on one side of the sample. Thereby, differential pressure tests can be performed.

The sample may be a barrier material. Thereby, the barrier material can be pressure tested and the test will reveal whether the barrier material is leak proof against liquid CO2 or supercritical CO2 at the temperature and pressure in an underground reservoir or if the barrier material will leak CO2.

The sample may be a seal, which can be tested against liquid CO2 or supercritical CO2 at the same pressures and temperatures present during use.

The sample may be cement, rock, seals, metals, chemicals, or other parts related to reservoirs or wells. The sample may be alternative materials to the materials used in existing wells.

In an aspect, the reactor chamber may be at least partially filled with a reservoir liquid, or reservoir fluid, or brine, or brine with additives, or reservoir solids, or rock materials, or cement.

Each reservoir for storage CO2 will have a local environment not only limited to the reservoir temperature and reservoir pressure. Each reservoir will have different chem- ical components and thus reservoir liquid or fluid may be collected to make more realistic emulations. Typically, the main component of the reservoir liquid is brine.

The reservoir temperature and reservoir pressure may be 100 °C and 300 bar, where CO2 is supercritical. There may be unknown chemical processes under these conditions which may cause barrier material to not be leak proof or cause other material wears.

In an aspect, the liquid CO2 flow or the supercritical CO2 flow may comprise a Reynold’s number from 3,000 to 500,000, or 3,000 to 350,000, or 3,000 to 200,000, or 3,000 to 250,000, or 3,000 to 150,000.

The injected liquid CO2 or the supercritical CO2 will generate a high flow in the reservoir or through the tubing, which flow may be upwards to a Reynold’s number of 500,000.

Thus, the high liquid CO2 flow or high supercritical CO2 flow having a Reynold’s number from 3,000 to 500,000 may cause additional wear on tubing or cement or other parts related to the reservoir.

The wear may be in the form of corrosion.

In an aspect, the method may comprise a step of mixing impurities with the CO2 prior to the step of generating.

CO2 having a purity grade above 99 % or 99.7 % is an off-the-shelf product and it is expected that the CO2 to be pumped into the reservoirs will have a high level of purity. However, it may be preferable to save costs on the purification and as a result the CO2 to be injected into the underground may only have a purity of at least 90 mol %, or 95 mol %, or 98 mol % CO2. However, it is unknown whether this can increase or decrease the wear.

Thus, the step of mixing impurities with the CO2 enables a better emulation in the reactor chamber of the actual environment. The impurities may be H2O, H2S, SOx, NOx, 02, H2, or CO, or other by-products of energy production using fossil fuels.

Other impurities such as trace elements of Hg, As, or Se, may be mixed into the CO2.

In initial experiments, the impurities are expected to be the impurities which would be part of the liquid CO2 or supercritical CO2 when being injected into reservoirs. However, tests are expected to be performed with other impurities for the purpose of testing whether the impurities prevent or lower a wear rate. In this case, the impurities are additives to the CO2 for reducing wear and/or stabilising the reservoir.

The step of mixing may be before, during, or after the step of producing liquid CO2 or supercritical CO2.

In an aspect, the method may include a step of removing CO2 from the reactor chamber.

If CO2 is not removed from the reactor chamber, then the chamber temperature and/or chamber pressure will increase, which may be unwanted. Thus, the CO2 may be removed from the reactor chamber after, before, or during the step of injecting liquid CO2 or supercritical CO2.

Depending on the chamber pressure and the other components in the reactor chamber such as reservoir liquid, or reservoir fluid, or brine, or brine with additives, or reservoir solids, or rock materials, or cement, the liquid CO2 or supercritical CO2 may stabilise at the top or the bottom of the reactor chamber relative to the gravitational vector. Thus, the CCUS reactor may have a first valve and a second valve placed at the top and the bottom of the reactor chamber.

The first valve and the second valve may both be used for removing liquid CO2 or supercritical CO2 or injecting liquid CO2 or supercritical CO2.

The CCUS reactor may have additional valves positioned between the top and bottom for injection or removing liquid CO2 or supercritical CO2. The CO2 may be recirculated and reused in the step of producing liquid CO2 or supercritical CO2. Thereby, the method becomes CO2 neutral as CO2 is reused which also lowers the overall cost of the method.

Furthermore, removed CO2 may be guided into a test loop comprising a filter for filtering the removed CO2 and/or a pH sensor for measuring the pH of the removed CO2. The test loop may be equipped with different test equipment.

There may be a step of generating a secondary flow of reservoir liquid, or reservoir fluid, or brine, or brine with additives by performing a step of injecting reservoir liquid, or reservoir fluid, or brine, or brine with additives, and by performing an act of removing reservoir liquid, or reservoir fluid, or brine, or brine with additives.

The step of generating a secondary flow of reservoir liquid, or reservoir fluid, or brine, or brine with additives, may be performed by performing the step of injecting and the step of removing at the same time.

Thereby, the method is able to perform dual flow experiments increasing the emulation of a reservoir environment.

In an aspect, the removed CO2 may be phase-shifted to gas, and solids may optionally be extracted for analysis.

This greatly increases the methods used for determining wear, such as erosion or corrosion of the at least one sample since the extracted solids can be analysed and an erosion rate can be determined or at least estimated.

Furthermore, the gas may be analysed using spectroscopy or gas chromatographymass spectrometry. Thereby, the method may be used for determining whether the removed CO2 contains the same impurities as prior to be injected into the reactor chamber. The tests may be performed in a test loop.

The CO2 may be recirculated and reused in the step of producing liquid CO2 or supercritical CO2. Thereby, the method becomes CO2 neutral as CO2 is reused. This also lowers the overall cost of the method while providing extra insights into the process in the reactor chamber as solids are extracted and optionally the CO2 gas is analysed using spectroscopy or gas chromatography-mass spectrometry.

In an aspect, the chamber temperature may be between -10 to 300 °C, 31.5 to 200 °C, 80 to 150, °C, or 100 to 130 °C, and/or the chamber pressure may be between 27 bar to 500 bar, or 73.9 to 500 bar, 100 to 400 bar, or 250 to 350 bar, or 300 bar.

The reservoir for storage of the CO2 will in most cases have a reservoir temperature above 50 °C and the reservoir pressure may in some cases be up to 500 bar.

It is expected that the CO2 to be injected will be stored in liquid form at a storage temperature between (-10) to 30 °C at a storage pressure between 27 to 50 bar. CO2 is a liquid at approximately (-10) °C and 27 bar, but a gas if at a lower pressure.

Thus, the range of chamber temperature and chamber pressure enables emulation of components at various stages during the carbon capture storage of CO2.

In an aspect, the method may comprise a step of recirculating the removed CO2 and performing the step of injecting using at least part of the removed CO2.

Thereby, the liquid CO2 and/or the supercritical CO2 flow through the reactor chamber can be repeated in a controlled manner by the step of recirculating such that the tests becomes quantitative and can be repeated. Since the same liquid CO2 and/or the same supercritical CO2 is recirculating.

The injected liquid CO2 or the injected supercritical CO2 is basically a contamination to the emulated reservoir environment in the reactor chamber, thus by performing the step of recirculation then it is possible to flow model the emulated reservoir environment.

The step of recirculating may be included as part of the step of producing since the temperature and/or pressure of the CO2 may need to be adjusted. There may additional be a test loop for measuring the impurities of the removed CO2 such that the step of mixing and step of producing can adjust for any changes to the CO2 such that the impurities of the liquid CO2 and/or the supercritical CO2 does not vary over time.

In an aspect, the step of generating may be repeated with breaks between each repeat, the breaks being between 0.1 to 48 hours, or 1 to 24 hours, or 2 to 12 hours, or 4 to 8 hours, or 6 hours.

The cycling operation of the method between dynamic operation with a flow and static operation with no flow increases the emulation of a reservoir since there will be periods with no injection of liquid CO2 or supercritical CO2.

An object of the invention is achieved by a test system for subjecting at least one sample to liquid CO2 or a supercritical CO2 environment. The test system comprises

- a CCUS reactor, which comprises a reactor chamber and a sample holder in the reactor chamber for holding at least one sample,

- a CO2 manipulator for producing liquid CO2 or supercritical CO2, the CO2 manipulator being in fluid connection with the CCUS reactor, and

- means adapted to execute the method for subjecting at least one sample to a dynamic liquid CO2 or a supercritical CO2 environment as previously described.

Thereby, a test system is provided which is able to subject at least one sample to liquid CO2 or a supercritical CO2 environment, thereby emulating CO2 injection into reservoirs. The test system may emulate the reservoir environment and/or the environment which the components used for CCUS will experience when injecting liquid CO2 or a supercritical CO2 into a reservoir.

The CO2 manipulator may be fed CO2 from a batch of CO2. The CO2 manipulator may comprise a first manipulator chamber for cooling the CO2 such that the CO2 is in the liquid phase. The cooled and liquid CO2 may then be led through one or more pumps for increasing the pressure of the liquid CO2. Afterwards, the C02 manipulator may comprise a second manipulator chamber and/or a heat pump for adjusting the temperature of the liquid CO2. The temperature may be either cooled or heated depending on the wanted characteristics of the CO2 to be injected into the CCUS reactor.

In an aspect, the test system may comprise a manifold unit between the CCUS reactor and the CO2 manipulator, and

- the CCUS reactor comprises a first valve and a second valve, wherein the sample holder is positioned between the first and second valve, wherein the manifold unit is connected to the first and second valve for enabling a liquid CO2 flow or supercritical CO2 flow between the valves.

Depending on the chamber pressure and the chamber temperature, the liquid CO2 flow or supercritical CO2 flow may have a density above or below the other components in the reactor chamber. Thus, the manifold unit enables that CO2 can be removed and injected from either side of the sample holder.

The CCUS reactor may comprise a third valve and a fourth valve adapted for generating a secondary flow of reservoir liquid, or reservoir fluid, or brine, or brine with additives, by performing a step of injecting reservoir liquid, or reservoir fluid, or brine, or brine with additives in the reactor chamber. The secondary flow may be controlled by the manifold unit or by another unit.

Thereby, the test system can perform dual flow experiments increasing the emulation of a reservoir environment.

There may be test loop upstream and/or downstream to the CCUS reactor with test equipment for testing and characterising the second flow.

In an aspect, the test system may be configured for recirculation of CO2 from the CCUS reactor between the first valve and the second valve as a function of the liquid CO2 flow or supercritical CO2 flow in the reactor chamber.

Depending on the specific test system the flow inside the reactor chamber may be from the first valve to the second valve. In this case the test system may be configured to recirculate the removed CO2 from the second valve to first valve. The recirculation path may be through the CO2-manipulator to adjust a temperature and/or pressure of the CO2 to be recirculated.

In another test system the flow inside the reactor chamber may be from the second valve to the first valve. In this case the test system may be configured to recirculate the removed CO2 from the first valve to second valve. The recirculation path may be through the CO2-manipulator to adjust a temperature and/or pressure of the CO2 to be recirculated.

The injected liquid CO2 or the injected supercritical CO2 is basically a contamination to the emulated reservoir environment in the reactor chamber, thus by performing the step of recirculation then it is possible to flow model the emulated reservoir environment.

In an aspect, the test system may comprise a temperature control unit adapted for controlling the chamber temperature and/or adapted for controlling temperature of CO2 downstream and upstream relative to the CCUS reactor.

The temperature control unit may comprise a heat pump.

The temperature control unit can thus be used to control the phase of the CO2 downstream and upstream relative to the CCUS reactor.

The temperature control unit may be adapted to control the temperature in the first manipulator chamber and/or the second manipulator chamber.

In an aspect, the test system may comprise a mixer unit upstream to the CCUS reactor. The mixer unit is configured to mix impurities into the CO2 to emulate that the CO2 to be injected into reservoirs will have a lower purity compared to industrial grade CO2.

In an aspect, the test system may comprise a phase shift unit downstream to the CCUS reactor. The phase shift unit is configured to phase shift CO2 to the gas phase, thereby extracting solids from the CO2. The phase shift unit is in communication with the CO2 manipulator for recirculation of the CO2.

The extracted solids may then be analysed for determining wear of the samples, the wear may be erosion or corrosion.

The temperature control unit may control the temperature at the phase shift unit.

The phase shift unit may comprise a phase shift chamber, wherein the temperature and pressure of the phase shift chamber is controlled such that the liquid CO2 or supercritical CO2 is phase shifted in a controlled manner.

As an example, the phase shift chamber may have a pressure of 60 bar. CO2 will be in the liquid phase at 21 °C and in the gas phase at 22°C. Thus, by choosing the temperature of the phase shift chamber between 40°C to 60°C then the liquid CO2 will vaporize in a controlled manner.

The test system may further comprise a spectroscopy unit or gas chromatographymass spectrometry unit upstream to the phase shift unit. Thereby, the test system can determine whether the removed CO2 contains the same impurities as prior to be injected into the reactor chamber.

In an embodiment, the test system may comprise a test loop between the CO2 batch supplying the CO2 manipulator and the CO2 manipulator, wherein the test loop comprises test equipment for testing and characterising the CO2.

In an embodiment, the test system may comprise a test loop between the CO2 manipulator and CCUS reactor, wherein the test loop comprises test equipment for testing and characterising the CO2.

In an embodiment, the test system may comprise a test loop between the CCUS reactor and the phase shift unit, wherein the test loop comprises test equipment for testing and characterising the CO2. In an embodiment, the test system may comprise a test loop between the CCUS reactor and the phase shift unit, wherein the test loop comprises test equipment for testing and characterising the CO2.

In an embodiment, the test system may comprise a test loop between the phase shift unit and the CO2 manipulator, wherein the test loop comprises test equipment for testing and characterising the CO2.

In an embodiment, the test system may comprise one or more or all of the above- mentioned test loops such that the CO2 may be tested and characterised at each step of the process.

In an aspect, the CCUS reactor may comprise a window extending along a longitudinal direction of the reactor chamber.

This will allow for optical experiments of samples in the reactor chamber.

In an aspect, the CCUS reactor may comprise a wire feedthrough into the reactor chamber and at least one electrode extending from the wire feedthrough, the at least one electrode adapted to connect a sample.

Thereby, the electrical properties of a sample can be studied in-situ which greatly increases precision, when estimating a wear rate.

The invention may include a computer program product comprising instructions to cause the test system to execute the steps of the method for subjecting at least one sample to a dynamic liquid CO2 or a supercritical CO2 environment.

The invention may include a computer-readable medium having stored thereon the computer program.

Description of the Drawing

Embodiments of the invention will be described in the figures, whereon: Fig. 1 illustrates a test system for subjecting at least one sample to liquid CO2 or a supercritical CO2 environment;

Fig. 2 illustrates a CCUS reactor projected onto a reservoir environment; and

Fig. 3 illustrates a method for subjecting at least one sample to a dynamic liquid CO2 or a supercritical CO2 environment.

Detailed Description of the Invention Fig. 1 illustrates a test system 1 for subjecting at least one sample 90 to liquid CO2 or a supercritical CO2 environment.

The test system 1 comprises a CCUS reactor 10. The CCUS reactor 10 comprises a reactor chamber 12 and a sample holder 14 in the reactor chamber 12 for holding at least one sample 90.

The reactor chamber 12 is in the figure shown with a dotted line dividing the reactor chamber 12 to indicate that the reactor chamber 12 may have any length.

In the present example, the sample holder 14 is placed at a bottom of the reactor chamber 12 and the sample holder 14 is holding a series of disc shaped samples 90. In other embodiments the sample holder 14 may be configured to hold a single sample 90, where the sample is arranged to divide the reactor chamber 12 into two sub chambers, thereby the test system 1 can perform differential pressure tests.

The test system 1 further comprises a temperature control unit 40. The temperature control unit 40 is in a fluid or liquid connection with the CCUS reactor 10 such that a chamber temperature can be controlled by controlling the temperature of the fluid or liquid. Since there is a relation between the pressure and temperature, the temperature control unit 40 can at least partly be used for controlling a chamber pressure by increasing or decreasing the temperature.

The temperature control unit 40 may be a heat pump.

The CCUS reactor 10 further comprises a first valve 161 and a second valve 1611. The sample holder 14 is positioned between the first and second valves 161, 1611 such that a flow can be established between the first and second valves 161, 1611. The first and second valves 161, 1611 are bi-directional and the flow can be from the first valve 161 to the second valve 1611 or from the second valve 1611 to the first valve 161.

A manifold unit 30 is connected to the first and second valve 161, 1611 and the manifold unit 30 controls the flow to and from the first and second valve 161, 1611 includ- ing the flow direction. Thus, the manifold unit 30 enables a liquid CO2 flow or supercritical CO2 flow between the valves 161, 1611.

The manifold unit 30 and the valves 161, 1611 can be used to control the chamber pressure by injecting CO2 or removing CO2 from the reactor chamber 12. The CCUS reactor 10 may have additional valves for controlling the chamber pressure.

The test system 1 further comprises a CO2 manipulator 20 for producing liquid CO2 or supercritical CO2. The CO2 manipulator 20 is in fluid connection with the CCUS reactor 10 through the manifold unit 30, which controls the CO2 flow.

The CO2 manipulator 20 is connected to a temperature control unit 40. The temperature control unit 40 may be the same temperature control unit 40, as previously described, if the temperature control unit 40 can produce different temperatures at the same time as the liquid CO2 or the supercritical CO2 injected into the reactor chamber 12 it will rarely have the same temperature as the chamber temperature.

The temperature control unit 40 is in a fluid or liquid connection with the CO2 manipulator 20 such that the CO2 can be manipulated to generate liquid CO2 or supercritical CO2. The temperature control unit 40 may be a heat pump.

The CO2 manipulator 20 has means for increasing or decreasing a pressure of the CO2, such that the CO2 can be manipulated to generate liquid CO2 or supercritical CO2.

The CO2 source for the CO2 manipulator 20 may be a CO2 batch 60 and/or the source may be CO2 from the reactor chamber 12 being recirculated as will be described later.

The test system 1 further comprises a mixer unit 50 upstream to the CCUS reactor 10, where the mixer unit 50 is configured to mix impurities into the CO2. The impurities may be H2O, H2S, SOx, NOx, 02, H2, or CO, or other components.

In the present embodiment, the mixer unit 50 is part of the CO2 manipulator 20, however the mixer unit 50 could be a separate unit. The test system 1 further comprises a phase shift unit 60 downstream to the CCUS reactor 20. The phase shift unit 60 is in the present embodiment connected to the manifold unit 30 and the CO2 manipulator 20 thereby enables a recirculation of CO2.

The phase shift unit 60 is configured to phase shift CO2 to the gas phase. Any solids in the liquid CO2 or supercritical CO2 will be extracted from the gas phase due to gravity. The extracted solids may then be investigated.

The CCUS reactor 1 in figure 1 is a cross-section of the CCUS reactor 1. However, the CCUS reactor 1 may comprise a window extending along a longitudinal direction of the reactor chamber 20, thereby enabling visual inspection and/or optical probing similar to what is shown in the present figure 1.

The test system 1 may comprise one or more or all of the shown test loops 701, 7011, 70III, 70IV, such that the CO2 may be tested and characterised at each step of the process.

Fig. 2 illustrates a CCUS reactor 10 projected onto a reservoir environment. The reservoir environment is an offshore reservoir environment as the ocean 200 is above a reservoir 210 encapsulated in rock 220. The term rock 220 should be interpreted broadly as the reservoir 210 may be encapsulated in chalk, or limestone, or other materials. The skilled person would know which material encapsulates reservoirs 210.

The reservoir 210 is divided by a horizontal black line which dividing the reservoir 210 into two zones as liquid CO2 or supercritical CO2 will be a separate phase in real life reservoirs 210. The exact placement of CO2 depends on the density of the liquid CO2 or supercritical CO2 compared with the components of the reservoir 210.

In the present case, liquid CO2 or supercritical CO2 will compile at the top of the reservoir 210 due to buoyancy.

The CCUS reactor 10 may have all the features described in figure 1. The reactor chamber 12 is partly filled with reservoir liquid or reservoir fluid and liquid CO2 or supercritical CO2 above the reservoir liquid or reservoir fluid, illustrated by the horizontal black line. Above the horizontal black line, the reservoir 210 is filled with CO2 in a liquid phase or a supercritical phase.

In the figure, the sample holder 14 is placed at a bottom of the reactor chamber 12, and the sample holder 14 is holding a series of disc-shaped samples 90. The disc shaped samples 90 are fully emerged in the reservoir liquid or reservoir fluid and will experience a liquid CO2 flow or supercritical CO2 flow while being submerged. In other embodiments, the level of reservoir liquid or reservoir fluid is lower, or the sample holder 14 is longer, or the sample holder 14 is positioned differently, such that some of the disc-shaped samples 90 are above the reservoir liquid or reservoir fluid and some are submerged.

The samples 90 can be other shapes than disc-shaped.

The upper part of the reactor chamber 12 is projected onto the rock formation 220 as the upper part of the reactor chamber 12 may comprise a (not shown) sample holder 14 for holding rock material, or limestone, or chalk, or other forms of material, which encompass reservoirs 210. Thereby, the test system 1 can perform differential pressure tests to check whether the rock material, or limestone, or chalk, or other forms of material, which encompass reservoirs 210 is leak proof against liquid CO2 or supercritical CO2 at different temperatures and different pressures.

Fig. 3 illustrates a method 100 for subjecting at least one sample 90 to a dynamic liquid CO2 or a supercritical CO2 environment.

The method 100 comprises a step of providing 110 a CCUS reactor 10 comprising a reactor chamber 12 with at least one sample 90.

Followed by a step of adjusting 120 chamber temperature and chamber pressure of the reactor chamber 12 such that the CO2 is liquid CO2 or supercritical CO2. The CO2 will likely be stored and transported in a liquid phase to reduce transport costs. The method can thus test the components used during transportation and the components used for injection into the reservoir 210. Furthermore, depending on the reservoir, the CO2 will be liquid CO2 or supercritical CO2, and thus the method can therefore also test the components and the reservoir components for wear due to the liquid CO2 or supercritical CO2.

The step above is followed by a step of producing 130 liquid CO2 or supercritical CO2. The step of producing 130 may be performed at a CO2 manipulator 20.

Followed by a step of generating 140 a liquid CO2 flow or a supercritical CO2 flow in the reactor chamber 12 by a step of injecting 145 the produced liquid CO2 or supercritical CO2 into the reactor chamber 12. Thereby, the method 100 subject the at least one sample 90 to a dynamic liquid CO2 or a dynamic supercritical CO2 environment.

The method may be performed while the reactor chamber 12 is at least partially filled with a reservoir liquid, or reservoir fluid, or brine, or brine with additives, or reservoir solids, or rock materials, or cement.

The step of generating 140 will in most cases generate the liquid CO2 flow or supercritical CO2 flow with a Reynold’s number from 3,000 to 500,000, or 3,000 to 350,000, or 3,000 to 200,000, or 3,000 to 250,000, or 3,000 to 150,000.

The method 100 may comprise a step of mixing 135 impurities with the CO2 prior to the step of generating 140. The step of mixing 135 may be performed before, at the same time, or after, as the act of producing liquid CO2 or a supercritical CO2.

The method 100 includes a step of removing 150 CO2 from the reactor chamber 12, thereby longer flow experiments can be performed. The step of removing 150 and the step of generating 140 may be performed at the same time to keep the chamber pressure relatively stable. The injected CO2 will typically have a temperature between (- 10) to 30°C, thus there may be a small temporary drop in chamber temperature and thus chamber pressure. The removed CO2 may be phase-shifted to gas, and solids are optionally extracted for analysis.

The method is performed while the chamber temperature is between (-10) to 300°C, 31.5 to 200°C, 80 to 150°C, or 100 to 130°C, and/or the chamber pressure is between 27 bar to 500 bar, or 73.9 to 500 bar, 100 to 400 bar, or 250 to 350 bar, or 300 bar.

The injected CO2 will typically be injected with a temperature between (-10) to 30°C, however other temperatures are possible.

The step of generating 140 may be repeated with breaks between each repeat, the breaks being between 0.1 to 48 hours, or 1 to 24 hours, or 2 to 12 hours, or 4 to 8 hours, or 6 hours. Thereby, the method can better emulate an actual reservoir environment, since a reservoir would be subjected to cycling operation with injections of CO2, where the reservoir environment is dynamic, while the reservoir environment is static between injections.

The method may comprise a step of recirculating 132 the removed CO2 and performing the step of injecting () 145 using at least part of the removed CO2.

The step of recirculating 132 may be part of the step of producing 120 as in may be necessary to adjust the temperature and pressure of the CO2 to be recirculated.