Device and method for ultrahigh-precision quantitative characterization of reservoir fluid occurrence state

Abstract

The invention relates to the technical field of oil and gas exploration, and discloses a device and method for quantitatively representing the occurrence state of oil reservoir fluid with ultrahigh precision, the device comprises a test module, the test module comprises a plurality of flow modules and a plurality of simulation pieces, the simulation pieces are respectively arranged in the flow modules, and the simulation pieces are used for simulating different types of oil reservoirs; one end of the flowing module is communicated with the injection part, the injection part is used for injecting light crude oil, heavy crude oil and methylbenzene into the flowing module, and the other end of the flowing module is communicated with the fluid receiving device; the pressure and temperature adjusting system is used for adjusting the pressure and the temperature in the flow module; and the removing part is positioned on one side of the flowing module and is used for removing the residual fluid on the simulation part. The device has the functions of automatic cleaning, high temperature and high pressure and multi-condition combination, accurately represents the occurrence state rule of light oil and heavy oil in different types of oil reservoirs, and provides a theoretical basis for fluid mobility evaluation and development scheme optimization in the oil reservoir development process.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas exploration, and in particular to a device and method for ultra-high precision quantitative characterization of the occurrence state of oil reservoir fluid. Background Art

[0002] Oil reservoirs are controlled by multiple phases of tectonic movement and diagenesis, with low-permeability, ultra-low-permeability, and tight reservoirs widely distributed. However, due to low reservoir permeability and the development of micro- and nano-pore throats, the fluid distribution is complex. On the one hand, complex interface phenomena lead to abnormal fluid orientation and spatial distribution, and the residence time and migration characteristics of fluids in non-equilibrium states are significantly different from those in conventional reservoirs. On the other hand, the scale effect of confined space means that the distribution state within the pore throat is significantly controlled by the interaction between the fluid and the pore wall. The development of low-, ultra-low-permeability, and tight oil reservoirs is heavily dependent on the fluid distribution state in their micro- and nano-scale reservoirs. During development, they face problems such as "low crude oil utilization rate, difficulty in replenishing reservoir energy, and slow recovery rate increase."

[0003] Specifically, the spatial distribution of crude oil in low-permeability, ultra-low-permeability, and tight reservoirs is influenced by multiple factors, including pore-throat structure, wettability, and capillary forces. The fluid's occurrence exhibits a pronounced scale effect. Micro- and nano-scale pore-throat systems exert significant constraints on crude oil, leading to highly heterogeneous distribution within the reservoir. Crude oil can exist as a bulk phase within larger pores, or as a thin film adhering to pore walls or stagnating at pore-throat interfaces.

[0004] In recent years, research on the fluid distribution in low-permeability, ultra-low-permeability, and tight oil reservoirs has focused on the distribution of crude oil in porous media and the mechanisms of fluid-solid interaction, including the proportion of fluids in different distribution states and the pore size of the distribution. Existing studies have shown that the spatial distribution of fluids within micro- and nano-pore throats is controlled by multiple factors, including pore throat structure, surface wettability, fluid composition, and the capillary / viscous force ratio. Specifically, crude oil may exist as a bulk phase within a relatively large pore network, adhere to the pore wall as an adsorbed thin film, or form a meniscus at the pore throat junction. This complex distribution leads to significant deviations from the Darcy flow theory, which is based on conventional reservoirs, in low-permeability reservoirs, manifesting as sudden changes in the starting pressure gradient, nonlinear flow characteristics, and increased stress sensitivity.

[0005] However, existing research often simplistically categorizes fluid occurrence into movable and immovable fluids, focusing on qualitative description and inference of the specific occurrence state. Accurately characterizing the fluid occurrence state is crucial. The spatial distribution of fluids directly impacts reservoir development outcomes. Existing techniques for analyzing microscopic occurrences utilize conventional optical microscopes. However, grinding rock samples can disrupt microscopic fluid occurrences. Furthermore, conventional optical microscopes have extremely low longitudinal resolution, making it difficult to accurately characterize fluid occurrence patterns in bulk and within micro- and nano-pore throats. Furthermore, they fail to consider the impact of reservoir type, mineralogy, and crude oil properties on fluid occurrence.

[0006] The existing technology still has the following defects: the fluid occurrence state is simply divided into movable fluid and immovable fluid, and the actual occurrence state is mostly concentrated in the qualitative description and inference stage; traditional characterization methods are difficult to accurately describe the fluid occurrence state in the bulk phase and micro-nano pore throats; the influence of reservoir type and minerals in the reservoir is not considered; and the influence of crude oil properties in the reservoir, such as light oil and heavy oil, is not considered.

[0007] Therefore, there is an urgent need for an ultra-high-precision device and method for quantitatively characterizing the occurrence state of reservoir fluids to solve the above problems. Summary of the Invention

[0008] The purpose of the present invention is to provide an apparatus and method for ultra-high precision quantitative characterization of the occurrence state of reservoir fluids, so as to solve the problems existing in the above-mentioned prior art.

[0009] To achieve the above-mentioned object, the present invention provides the following solution: The present invention provides an apparatus for ultra-high-precision quantitative characterization of the occurrence state of reservoir fluids, comprising:

[0010] The test module includes a plurality of flow modules and a plurality of simulation components, wherein the simulation components are respectively arranged in the plurality of flow modules, and the plurality of simulation components are used to simulate different types of oil reservoirs;

[0011] An injection piece, one end of the flow module is connected to the injection piece, the injection piece is used to inject light crude oil, heavy crude oil and toluene into the flow module, and the other end of the flow module is connected to the fluid receiving device;

[0012] a pressure and temperature regulating system, provided on the flow module, for regulating the pressure and temperature within the flow module;

[0013] The cleaning member is located on one side of the flow module and is used to clean the residual fluid on the simulation member.

[0014] Preferably, the simulation component includes a quartz chip, and the quartz chip is arranged on the flow module.

[0015] Preferably, the number of the quartz chips is four, two of which are coated with SiO2 coatings, and the other two are coated with mineral coatings.

[0016] Preferably, the injection component includes a light crude oil container, a heavy crude oil container and a toluene container, and the light crude oil container, the heavy crude oil container and the toluene container are all connected to an injection pump.

[0017] Preferably, the cleaning element includes a plasma laser emitting device.

[0018] Preferably, the mineral coating is an Al2O3 coating, a MgO coating and a Fe2O3 coating.

[0019] Preferably, it further comprises a data acquisition device connected to the injection piece for collecting experimental data.

[0020] Preferably, light oil and heavy oil are respectively injected into the two flow modules where the two quartz chips coated with SiO2 coating are located and the two flow modules where the two quartz chips coated with mineral coating are located.

[0021] Preferably, the temperature regulated in the flow module is at most 200° C., and the pressure regulated is at most 100 MPa.

[0022] A method for ultra-high precision quantitative characterization of reservoir fluid occurrence state, comprising the following steps:

[0023] installing the plurality of simulation members in the plurality of flow modules respectively, and clearing the fluid on the simulation members by the clearing member;

[0024] injecting toluene into the flow module to obtain baseline data;

[0025] Adjusting the temperature and pressure of the flow module and injecting light oil or heavy oil into the flow module to simulate experiments with different types of oil reservoirs and different types of crude oil;

[0026] After the simulation is completed, toluene is injected into the flow module for flushing.

[0027] Compared with the prior art, the present invention has the following advantages and technical effects:

[0028] The present invention provides an apparatus and method for ultra-high-precision quantitative characterization of the occurrence state of oil reservoir fluids. When in use, several simulation parts are placed in several flow modules to simulate different types of oil reservoirs. The residual fluid on the simulation parts is first cleaned by the provided cleaning parts to ensure the cleanliness of the surface of the simulation parts. Light crude oil and heavy crude oil are injected into the flow modules through the provided injection parts to simulate experiments of different types of oil reservoirs and oil qualities. The temperature and pressure in the experiment are adjusted by the provided pressure and temperature regulation system, and the experimental device is cleaned by the injection parts. The present application provides a micro-scale fluid occurrence experimental device with automatic cleaning, high temperature and high pressure, and multi-condition combined testing, which accurately characterizes the occurrence state laws of light oil and heavy oil in different types of oil reservoirs at the micro-nano scale, and provides a theoretical basis for fluid mobility evaluation and development plan optimization during oil reservoir development. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive work.

[0030] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0031] Figure 2 Schematic diagram of the adsorption characteristics of light oil and SiO2 coated chip of the present invention;

[0032] Figure 3 Schematic diagram of the adsorption characteristics of light oil and mineral coating chip of the present invention;

[0033] Figure 4 Schematic diagram of the adsorption characteristics of heavy oil and SiO2 coated chip of the present invention;

[0034] Figure 5 Schematic diagram of the adsorption characteristics of heavy oil and mineral coating chip of the present invention;

[0035] Figure 6 Schematic diagram of atomic force microscope imaging of crude oil adsorption layer under four conditions of the present invention;

[0036] Among them, 1. Quartz chip; 2. Flow module; 3. Plasma laser emission device; 4. Data acquisition device; 5. Light crude oil container; 6. Heavy crude oil container; 7. Toluene container; 8. Switch; 9. Injection pump; 10. Test module; 11. Pressure and temperature regulation system; 12. Flow path valve; 13. Fluid receiving device. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] Reference Figures 1-6 The present invention provides an ultra-high-precision quantitative characterization device for the occurrence state of reservoir fluids, comprising:

[0040] The test module 10 includes a plurality of flow modules 2 and a plurality of simulation components, wherein the plurality of simulation components are respectively arranged in the plurality of flow modules 2 and the plurality of simulation components are used to simulate different types of reservoirs;

[0041] Injection piece: one end of the flow module 2 is connected to the injection piece, and the injection piece is used to inject light crude oil, heavy crude oil and toluene into the flow module 2. The other end of the flow module 2 is connected to the fluid receiving device 13;

[0042] A pressure and temperature regulating system 11 is provided on the flow module 2 and is used to regulate the pressure and temperature within the flow module 2;

[0043] The cleaning piece is located on one side of the flow module 2 and is used to clean the residual fluid on the simulation piece.

[0044] In one embodiment of the present invention, when in use, several simulation parts are placed in several flow modules 2 to simulate different types of oil reservoirs. The residual fluid on the simulation parts is first cleaned by the provided cleaning parts to ensure the cleanliness of the surface of the simulation parts. Light crude oil and heavy crude oil are injected into the flow modules 2 through the provided injection parts to simulate experiments of different types of oil reservoirs and oil qualities. The temperature and pressure in the experiment are adjusted by the provided pressure and temperature adjustment system 11, and the experimental device is cleaned through the injection parts.

[0045] As an optional embodiment, the simulation component includes a quartz chip 1 , which is disposed on the flow module 2 .

[0046] In one embodiment of the present invention, the quartz chip 1 is configured to simulate different types of oil reservoirs.

[0047] As an optional embodiment, the number of the quartz chips 1 is four, wherein two quartz chips 1 are coated with SiO 2 coatings, and the other two quartz chips 1 are coated with mineral coatings.

[0048] In one embodiment of the present invention, a SiO2 coating is added to the quartz chip 1 to represent a conventional sandstone reservoir, and a mineral coating is applied to the quartz chip 1 to represent a clay mineral reservoir.

[0049] As an optional embodiment, the injection component includes a light crude oil container 5 , a heavy crude oil container 6 and a toluene container 7 , and the light crude oil container 5 , the heavy crude oil container 6 and the toluene container 7 are all connected to an injection pump 9 .

[0050] In one embodiment of the present invention, the light crude oil container 5 is used to store light crude oil, the heavy crude oil container 6 is used to store heavy crude oil, and the toluene container 7 is used to store toluene. The light crude oil, heavy crude oil or toluene is injected into the flow module 2 through the provided injection pump 9. At the same time, a switch 8 is installed on each pipeline for control, and a flow path valve 12 is provided at the feed end of the flow module 2.

[0051] As an optional embodiment, the cleaning element includes a plasma laser emitting device 3 .

[0052] In one embodiment of the present invention, the residual fluid on the chip is removed by the provided plasma laser emitting device 3 .

[0053] As an optional embodiment, the mineral coating is an Al2O3 coating, a MgO coating, and a Fe2O3 coating.

[0054] In one embodiment of the present invention, the injected Al2O3 coating, MgO coating and Fe2O3 coating are used to reflect the oil reservoir containing clay minerals mainly composed of illite and kaolinite.

[0055] As an optional embodiment, a data acquisition device 4 is further included, which is connected to the injection piece and is used to collect experimental data.

[0056] In one embodiment of the present invention, the data acquisition device 4 is preferably a computer, which is used to collect experimental data.

[0057] As an optional embodiment, light oil and heavy oil are respectively injected into the two flow modules 2 where the two quartz chips 1 coated with SiO2 are located and the two flow modules 2 where the two quartz chips 1 coated with mineral are located.

[0058] In one embodiment of the present invention, light oil and heavy oil are injected into four flow modules 2, and the corresponding combinations of chips in the flow modules 2 are SiO2 coating + light oil, mineral coating + light oil, SiO2 coating + heavy oil, and mineral coating + heavy oil.

[0059] As an optional embodiment, the temperature regulated in the flow module 2 is at most 200° C., and the pressure regulated is at most 100 MPa.

[0060] In one embodiment of the present invention, the upper limit of the regulated temperature and the upper limit of the pressure in the flow module 2 are 200° C. and 100 MPa, respectively.

[0061] A method for ultra-high precision quantitative characterization of reservoir fluid occurrence state, comprising the following steps:

[0062] Installing a plurality of simulation components in a plurality of flow modules 2 respectively, and clearing the fluid on the simulation components by using a cleaning component;

[0063] Toluene was injected into flow module 2 to obtain baseline data;

[0064] Adjust the temperature and pressure of the flow module 2 and inject light oil or heavy oil into the flow module 2 to simulate experiments with different types of oil reservoirs and different types of crude oil;

[0065] After the simulation is completed, toluene is injected into the flow module 2 for flushing.

[0066] In one embodiment of the present invention, during the experiment, four flow modules 2 were respectively equipped with two SiO2-coated chips and two mineral-coated chips. The four chips were passed through a plasma laser emission device 3 to break up any fluid originally attached thereto for at least 30 minutes to ensure the cleanliness of the quartz chip surface.

[0067] Toluene was injected into the four flow modules 2 of the microscale fluid storage experimental device at a flow rate of 0.1 mL / min to obtain stable baseline data;

[0068] The temperature and pressure of the four flow modules 2 were raised to 130°C and 30 MPa, and light oil and heavy oil were injected into the four flow modules 2 of the microscale fluid storage experimental device at a flow rate of 0.1 mL / min, respectively, until the four conditions of SiO2 coating + light oil, mineral coating + light oil, SiO2 coating + heavy oil, and mineral coating + heavy oil were met. The baseline data did not change within 20 minutes. Toluene was then injected at a flow rate of 0.1 mL / min to flush the chip to remove loose crude oil components.

[0069] To ensure data reliability, at least three independent replicates were performed to obtain highly reproducible frequency and dissipation versus time curves. The fluid distribution characteristics of the two coated chips and the two crude oil types were characterized using frequency and dissipation parameters.

[0070] Based on atomic force microscopy, the chips of SiO2 coating + light oil, mineral coating + light oil, SiO2 coating + heavy oil, and mineral coating + heavy oil were scanned after the above experiments, and parameters such as surface roughness and adsorption layer thickness were obtained.

[0071] Under the conditions that the crude oil adsorption layer is rigid, uniformly distributed, and its thickness is below the critical value, the mass change and frequency shift follow the Sauerbrey equation, as shown in the calculation formula:

[0072]

[0073] Where α is the instrument constant, with a value of 17.7 ng / (Hz·cm2), Δf is the change in resonant frequency, in Hz, and β is the number of overtones. This study uses a value of 5 based on experience from QCM-D experiments.

[0074] Reference Figure 2-5 Light crude oil exhibited progressive adsorption on the SiO2-coated chip surface, with the frequency shift (Δf) ultimately stabilizing at -19.61 Hz, corresponding to an energy dissipation (ΔD) of 2.85 × 10⁻⁶. After 6500 seconds of adsorption, a 1000-second rinse with toluene induced only a 1.91-Hz frequency recovery. In contrast, the clay mineral-coated chip exhibited significantly enhanced crude oil adsorption. During the light crude oil injection phase, Δf rapidly decreased to -40.85 Hz. After toluene rinsing, the residual adsorbed amount increased by 96.8% compared to the SiO2-coated chip, indicating that clay minerals inhibited the desorption of light crude oil by strengthening the oil-solid interfacial interaction. A comparative study of heavy crude oil confirmed the universality of the adsorption effect. After crude oil adsorption on the SiO2-coated chip, Δf and ΔD were -51.63 Hz and 4.15 × 10⁻⁶, respectively. After toluene rinsing, the residual adsorbed crude oil Δf decreased to -47.41 Hz, and ΔD decreased to 2.71 × 10⁻⁶. Clay mineral coating, on the other hand, reduced Δf by 15.9%, stabilizing it at -53.93 Hz after toluene rinsing. The presence of clay minerals increased the adsorption of light and heavy crude oils by 97.3% and 14.4%, respectively. Interfacial modification by clay minerals significantly enhanced the porous medium's ability to retain crude oil components, providing a microscopic explanation for the increased resistance to crude oil migration.

[0075] Reference Figure 6 Light crude oil exhibits a low-volume, continuous spread on the SiO2 coating surface, with a surface roughness Rq of 1.45 nm, indicating that weak van der Waals interactions at the interface allow for the adsorption of small amounts of crude oil. The adsorption layer on the mineral coating surface exhibits a heterogeneous aggregate structure, consisting of densely packed spherical nanoaggregates, with an Rq of 1.68 nm.

[0076] For heavy crude oil, the roughness of the adsorption layer on the SiO2 coating surface increased significantly to 2.3 nm, and the morphology changed from a continuous spreading pattern to a coexistence of discrete micro- and nanoscale aggregates and flat areas, indicating that the high content of macromolecules such as asphaltenes and colloids in heavy crude oil forms a stable micelle structure. When the coating is switched to clay minerals, the average particle size of the heavy component aggregates in the adsorption layer expands to over 200 nm.

[0077] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0078] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A device for ultra-high precision quantitative characterization of reservoir fluid occurrence state, characterized in that: include: A test module (10) includes a plurality of flow modules (2) and a plurality of simulation components, wherein the plurality of simulation components are respectively arranged in the plurality of flow modules (2), and the plurality of simulation components are used to simulate different types of oil reservoirs; An injection piece, one end of the flow module (2) is connected to the injection piece, the injection piece is used to inject light crude oil, heavy crude oil and toluene into the flow module (2), and the other end of the flow module (2) is connected to a fluid receiving device (13); a pressure and temperature regulating system (11), arranged on the flow module (2), for regulating the pressure and temperature within the flow module (2); A cleaning piece is located on one side of the flow module (2) and is used to clean residual fluid on the simulation piece.

2. The device for ultra-high precision quantitative characterization of reservoir fluid occurrence state according to claim 1, characterized in that: The simulation component comprises a quartz chip (1), and the quartz chip (1) is arranged on the flow module (2).

3. The device for ultra-high precision quantitative characterization of reservoir fluid occurrence state according to claim 2, characterized in that: The number of the quartz chips (1) is four, two of which are coated with SiO2 coatings, and the other two of which are coated with mineral coatings.

4. The device for ultra-high precision quantitative characterization of reservoir fluid occurrence state according to claim 1, characterized in that: The injection component comprises a light crude oil container (5), a heavy crude oil container (6) and a toluene container (7), and the light crude oil container (5), the heavy crude oil container (6) and the toluene container (7) are all connected to an injection pump (9).

5. The device for ultra-high precision quantitative characterization of reservoir fluid occurrence state according to claim 1, characterized in that: The cleaning member comprises a plasma laser emitting device (3).

6. The device for ultra-high precision quantitative characterization of reservoir fluid occurrence state according to claim 3, characterized in that: The mineral coatings are Al2O3 coatings, MgO coatings and Fe2O3 coatings.

7. The device for ultra-high precision quantitative characterization of reservoir fluid occurrence state according to claim 1, characterized in that: It also includes a data acquisition device (4) connected to the injection piece for collecting experimental data.

8. The device for ultra-high precision quantitative characterization of reservoir fluid occurrence state according to claim 3, characterized in that: Light oil and heavy oil are respectively injected into the two flow modules (2) where the two quartz chips (1) coated with SiO2 are located and the two flow modules (2) where the two quartz chips (1) coated with mineral are located.

9. The device for ultra-high precision quantitative characterization of reservoir fluid occurrence state according to claim 1, characterized in that: The maximum temperature regulated in the flow module (2) is 200° C., and the maximum pressure regulated is 100 MPa.

10. A method for ultra-high precision quantitative characterization of reservoir fluid occurrence state, applicable to the device for ultra-high precision quantitative characterization of reservoir fluid occurrence state according to claim 1, characterized in that: The following steps are involved: Installing a plurality of the simulation components in a plurality of the flow modules (2) respectively, and clearing the fluid on the simulation components by the cleaning component; Injecting toluene into the flow module (2) to obtain baseline data; Adjusting the temperature and pressure of the flow module (2) and injecting light oil or heavy oil into the flow module (2) to simulate experiments with different types of oil reservoirs and different types of crude oil; After the simulation is completed, toluene is injected into the flow module (2) for flushing.

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