Evaluation device and evaluation experiment method for inhibition effect of asphaltene inhibitor

Abstract

The invention relates to an evaluation device and an evaluation experiment method for the inhibition effect of an asphaltene inhibitor, the device comprises a constant-temperature water bath, a deposition sheet and a differential pressure transducer, an asphaltene deposition pipeline is arranged in the constant-temperature water bath, and one end of the asphaltene deposition pipeline is connected with a liquid adding pump through a pipeline; the other end of the asphaltene deposition pipeline is connected with the liquid recoverer through a pipeline; a three-way valve is arranged on the pipeline between the liquid recoverer and the asphaltene deposition pipeline and is connected with a second nitrogen tank; the deposition sheet is arranged in the asphaltene deposition pipeline; the pressure difference sensors are arranged at the two ends of the asphaltene deposition pipeline respectively and used for measuring the pressure difference of the two ends of the asphaltene deposition pipeline. The device tests the effectiveness of the inhibitor in the actual operation environment by simulating different temperature, pressure and fluid conditions, can simulate the actual operation conditions, assesses the effect of the inhibitor in the aspect of reducing sediment generation, accurately assesses the performance of the inhibitor, and provides a scientific basis for the application of the inhibitor.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum and natural gas, and in particular relates to an evaluation device and an evaluation experimental method for the inhibition effect of an asphaltene inhibitor. Background Art

[0002] Asphaltene is a high molecular compound that may cause a series of problems during the refining, transportation and use of oil, affecting production efficiency and equipment safety. Asphaltene is mainly composed of high molecular organic matter. As temperature changes and fluid flows, asphaltene may be deposited in oil and gas pipelines, storage tanks and equipment. This deposition not only causes pipeline blockage, but also may affect fluidity and heat conduction efficiency. In addition, asphaltene has high viscosity and density, and its formation is closely related to factors such as the composition, temperature and pressure of crude oil. The deposition of asphaltene will cause corrosion and wear of equipment and increase maintenance costs.

[0003] Asphaltene inhibitors can reduce or prevent the deposition of asphaltene on pipelines and equipment by changing the phase behavior of asphaltene, reducing its viscosity or enhancing fluid fluidity. These inhibitors are usually some surfactants or polymer materials. With the continuous development of oil extraction technology, more and more low-grade oil fields and heavy oil fields are put into development, and the demand for asphaltene inhibitors is particularly important. Effective asphaltene inhibitors can significantly improve the fluidity of oil, reduce transportation costs and equipment maintenance frequency, thereby improving overall production efficiency. Reducing the deposition of asphaltene is not only crucial to the safe operation of equipment, but also helps to reduce the environmental impact of the oil and gas industry and reduce resource waste.

[0004] However, there are relatively few evaluation standards and methods for the effect of asphaltene inhibitors, most of which are static tests. The formation of asphaltene is related to many factors, including temperature, pressure, and flow state, and these complex reaction mechanisms need to be considered during the research and development process. This makes it impossible for technicians to accurately understand the performance of asphaltene inhibitors in actual applications. Technicians in related fields cannot obtain the inhibitory effect data of asphaltene inhibitors in actual operations, which makes them face greater uncertainty when selecting and applying inhibitors. This makes it difficult to predict and evaluate the effect of asphaltene inhibitors, which affects the promotion and application of the technology.

[0005] In view of this situation, the present invention provides an evaluation device and an evaluation experimental method for the inhibition effect of an asphaltene inhibitor, which can accurately evaluate the performance of the inhibitor and provide a scientific basis for its application. Summary of the invention

[0006] In view of at least one of the problems in the above-mentioned prior art, the purpose of the present invention is to provide an evaluation device and an evaluation experimental method for the inhibitory effect of asphaltene inhibitors, which can test the effectiveness of the inhibitors in the actual operating environment by simulating different temperatures, pressures and fluid conditions. This dynamic test can better reflect the actual application effect than static tests. The device can simulate actual operating conditions, evaluate the effect of the inhibitors in reducing deposit formation, accurately evaluate the performance of the inhibitors, and provide a scientific basis for their application.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] An evaluation device for the inhibition effect of an asphaltene inhibitor, comprising:

[0009] A constant temperature water bath, in which an asphaltene deposition pipeline is arranged, one end of the asphaltene deposition pipeline is connected to a liquid adding pump through a pipeline; the other end of the asphaltene deposition pipeline is connected to a liquid recovery device through a pipeline; a three-way valve is arranged on the pipeline between the liquid recovery device and the asphaltene deposition pipeline, and the three-way valve is connected to a second nitrogen tank;

[0010] A deposition sheet, disposed in the asphaltene deposition pipeline;

[0011] The differential pressure sensors are respectively arranged at two ends of the asphaltene deposition pipeline to measure the differential pressure at the two ends of the asphaltene deposition pipeline.

[0012] Preferably, the liquid adding pump comprises a fuel adding pump and a drug adding pump connected in parallel.

[0013] Preferably, a mixer is provided on the pipelines at the output ends of the refueling pump and the dosing pump.

[0014] Preferably, a first nitrogen tank is provided on the pipeline at the liquid inlet end of the mixer.

[0015] Preferably, the differential pressure sensor is connected to a data collector and a data processor in sequence.

[0016] Preferably, the deposition sheets are provided in two pieces, and the two deposition sheets are parallel to each other.

[0017] Preferably, meshes are provided on both of the two deposition sheets.

[0018] Preferably, one of the two deposition plates is a fixed plate, and the other is a rotating plate capable of rotating relative to the fixed plate.

[0019] An experimental method for evaluating the inhibition effect of an asphaltene inhibitor is completed based on any of the above-mentioned evaluation devices for the inhibition effect of an asphaltene inhibitor, and comprises the following steps:

[0020] Injecting crude oil configured with asphaltene inhibitor into the liquid injection pump;

[0021] Turn on the constant temperature water bath and set the experimental temperature;

[0022] opening the second nitrogen tank, and adjusting the pressure of the asphaltene deposition pipeline through the second nitrogen tank;

[0023] Injecting the crude oil into the asphaltene deposition pipeline at a set flow rate through a liquid addition pump;

[0024] Within a set experimental time and at set intervals, the pipeline pressure at the inlet and outlet of the asphaltene deposition pipeline is recorded each time by a differential pressure sensor;

[0025] Take out the sedimentation sheet and observe the asphaltene deposition condition on the sedimentation sheet.

[0026] Preferably, the opening and closing degrees of the two deposition sheets are adjusted to adjust the mesh size thereon, and the above steps are repeated to evaluate the asphaltene deposition conditions of the two deposition sheets at different opening and closing degrees.

[0027] The present invention adopts the above technical solution, which has the following advantages:

[0028] 1. The evaluation device and evaluation experimental method for the inhibition effect of asphaltene inhibitors provided by the present invention test the effectiveness of the inhibitors in an actual operating environment by simulating different temperature, pressure and fluid conditions. This dynamic test can better reflect the actual application effect than a static test. The device can simulate actual operating conditions, evaluate the effect of the inhibitors in reducing sediment formation, accurately evaluate the performance of the inhibitors, and provide a scientific basis for their application, thereby reducing the cleaning and maintenance costs of equipment and pipelines and extending the service life of the equipment.

[0029] 2. The evaluation device and evaluation experimental method for the inhibition effect of asphaltene inhibitor provided by the present invention adjust the opening and closing degrees of the two deposition sheets to adjust the mesh size thereon, and evaluate the inhibition effect of the asphaltene inhibitor at different opening and closing degrees of the two deposition sheets. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a connection diagram of the device for evaluating the inhibition effect of asphaltene inhibitor provided in the first embodiment of the present invention.

[0031] Figure 2 It is a schematic diagram of the fixed plate and the rotating plate provided in the asphaltene deposition pipeline according to the first embodiment of the present invention.

[0032] Figure 3 It is a cross-sectional schematic diagram showing that the fixed sheet and the rotating sheet provided in the first embodiment of the present invention are completely overlapped.

[0033] Figure 4It is a cross-sectional schematic diagram of the situation where the rotating plate provided in the first embodiment of the present invention overlaps with the fixed plate after rotating 30°.

[0034] Figure 5 It is a flowchart of the steps of the experimental method for evaluating the inhibition effect of asphaltene inhibitors provided in Example 2 of the present invention.

[0035] Markings in the accompanying drawings:

[0036] 1 is a liquid adding pump, 2 is a first nitrogen tank, 3 is a constant temperature water bath, 4 is a differential pressure sensor, 5 is an asphaltene deposition pipeline, 6 is a deposition plate, 601 is a fixed plate, 602 is a rotating plate, 603 is a bevel gear, 604 is a knob, 7 is a data collector, 8 is a liquid recovery device, 9 is a second nitrogen tank, 10 is a data processor, 11 is a mixer, and 12 is a three-way valve. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are 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 work are within the scope of protection of the present invention.

[0038] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "front", "backward", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the system or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention. The arrows in the accompanying drawings represent the flow direction of the substance.

[0039] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "assembly", "setting", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] The present invention provides an evaluation device and an evaluation experimental method for the inhibition effect of an asphaltene inhibitor. By simulating different temperatures, pressures and fluid conditions, the effectiveness of the inhibitor in an actual operating environment is tested. This dynamic test can better reflect the actual application effect than a static test. The device can simulate actual operating conditions, evaluate the effect of the inhibitor in reducing sediment formation, accurately evaluate the performance of the inhibitor, and provide a scientific basis for its application.

[0041] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0042] Example 1

[0043] Please refer to Figure 1 The present embodiment provides an evaluation device for the inhibition effect of an asphaltene inhibitor, which tests the effectiveness of the inhibitor in an actual operating environment by simulating different temperatures, pressures and fluid conditions. This dynamic test can better reflect the actual application effect than a static test. The device can simulate actual operating conditions and evaluate the effect of the inhibitor in reducing deposit formation, thereby reducing the cleaning and maintenance costs of equipment and pipelines and extending the service life of the equipment.

[0044] The evaluation device includes a constant temperature water bath 3, a deposition sheet 6 and a differential pressure sensor 4. An asphaltene deposition pipeline 5 is arranged in the constant temperature water bath 3. One end of the asphaltene deposition pipeline 5 is connected to the liquid adding pump 1 through a pipeline; the other end of the asphaltene deposition pipeline 5 is connected to the liquid recovery device 8 through a pipeline; a three-way valve 12 is arranged on the pipeline between the liquid recovery device 8 and the asphaltene deposition pipeline, and the three-way valve 12 is connected to the second nitrogen tank 9; the deposition sheet 6 is arranged in the asphaltene deposition pipeline 5; the differential pressure sensor 4 is respectively arranged at both ends of the asphaltene deposition pipeline 5 to measure the pressure difference at both ends of the asphaltene deposition pipeline 5.

[0045] Specifically, the constant temperature water bath 3 is filled with liquid, and the asphaltene deposition pipeline 5 is immersed in the liquid. By setting the heating temperature of the constant temperature water bath 3, the passage of the fluid in the asphaltene deposition pipeline 5 at different temperatures can be simulated.

[0046] The length of the asphaltene deposition pipeline 5 in the device can range from 8m to 30m, and the inner diameter can range from 1mm to 5mm. The liquid adding pump 1 can be a screw pump to deliver liquid at a constant flow rate.

[0047] In this embodiment, the liquid adding pump 1 includes a refueling pump and a dosing pump connected in parallel. Crude oil is added to the refueling pump and inhibitor is added to the dosing pump. When working, they are mixed in the mixer 11 on the pipeline at the output end of the refueling pump and the dosing pump.

[0048] A first nitrogen tank 2 is provided on the pipeline at the liquid inlet end of the mixer 11, and the first nitrogen tank 2 is connected to the pipeline inlet as a constant pressure nitrogen source. At the end of the experiment, the first nitrogen tank 2 is opened, and the remaining liquid in the pipeline is gradually discharged from the outlet. Under the condition of constant flow, nitrogen blows out the liquid in the capillary at a constant flow rate, while the deposited asphaltene cannot be blown out. The blown liquid passes through the weighing mass of the liquid recovery device 8, and the change of the liquid mass in the liquid recovery device 8 over time is recorded. Since the flow rate is constant, the liquid mass is linearly positively correlated with time. When the liquid in the deposition section is discharged, the deposited asphaltene occupies a part of the volume, the liquid volume decreases, and the liquid discharged at a constant flow rate decreases, so the slope of the liquid mass in the liquid recovery device 8 over time decreases. Therefore, combined with the capillary diameter and the nitrogen flow rate, the thickness of the asphaltene deposition can be inverted.

[0049] In this embodiment, the differential pressure sensor 4 is sequentially connected to the data collector 7 and the data processor 10. The differential pressure data measured by the differential pressure sensor 4 is transmitted to the data processor 10 for processing by the data collector 7. The data processor 10 may be a computer.

[0050] Specifically, during the experiment, the differential pressure sensor 4 uses a high-precision differential pressure sensor to continuously measure the pressure drop in the asphaltene deposition pipeline 5. The measurement data is recorded and analyzed in real time by a computer. This real-time monitoring can provide important fluid dynamics data, thereby providing a basis for subsequent inhibitor performance evaluation. The change in pressure drop not only reflects the flow characteristics of the fluid in the asphaltene deposition pipeline 5, but also indicates the deposition of asphaltene. The pipeline is immersed in a water bath to maintain isothermal conditions so that the total flow rate of the pipeline is maintained in a laminar state.

[0051] Please refer to Figure 2 In this embodiment, two deposition sheets 6 are provided, and the two deposition sheets 6 are parallel to each other.

[0052] Specifically, both deposition sheets are sapphire deposition sheets. Sapphire has extremely high hardness and can withstand high pressure and high temperature environments. Its corrosion resistance also enables it to perform well in various fluid media. The diameter of the deposition sheet is 1 mm to 2 mm, which is smaller than the inner diameter of the asphaltene deposition pipeline 5.

[0053] In this embodiment, meshes are formed on both deposition sheets; one of the two deposition sheets is a fixed sheet 601 , and the other is a rotating sheet 602 that can rotate relative to the fixed sheet 601 .

[0054] Specifically, the fixed sheet 601 can be fixedly connected to the asphaltene deposition pipeline 5 through a connecting rod; the central axis of the rotating sheet 602 is provided with an axial hole, and a rotating shaft is arranged in the axial hole, and the rotating shaft is connected to the asphaltene deposition pipeline 5 through a connecting rod; a 45-degree bevel tooth is processed on one side of the edge of the rotating sheet 602, so that the rotating sheet 602 becomes a bevel gear, and a bevel gear 603 meshing with the rotating sheet 602 is horizontally arranged on the top of the rotating sheet 602, and a knob 604 is arranged on the outside of the asphaltene deposition pipeline 5, and the knob 604 is connected to the center of the bevel gear 603 through a connecting rod. When it is necessary to adjust the opening and closing degree of the mesh on the two deposition sheets, the knob 604 is rotated, and the knob 604 drives the bevel gear 603 to rotate, and the bevel gear 603 drives the rotating sheet 602 to rotate, thereby realizing the adjustment of the opening and closing degree of the mesh on the rotating sheet 602 and the fixed sheet 601.

[0055] Specifically, two sapphire deposition sheets are used to simulate the surface of the wellhead, and meshes of specific size and shape are designed on them. The arrangement and size of the meshes can be designed as needed to ensure the efficiency and controllability of the fluid flow in the asphaltene deposition pipeline 5. The fixed sheet 601 is fixed in the pipeline so that it can remain stationary during the flow of crude oil. The mesh structure of the fixed sheet 601 allows the liquid to successfully flow through the pipeline while successfully depositing asphaltene on the fixed sheet 601; the other sapphire rotating sheet 602 is rotated by a knob outside the pipeline, allowing the angle of the rotating sheet 602 to be adjusted according to demand. By adjusting the angle of the rotating sheet 602, the overlap degree of the fixed sheet 601 and the rotating sheet 602 can be changed. When the meshes of the two deposition sheets are staggered, the effective area for the fluid to flow through will be reduced, thereby reducing the rate of fluid flow; conversely, when the meshes of the two deposition sheets overlap, the area of ​​fluid circulation increases and the flow rate increases. This control mechanism can simulate a variety of asphaltene deposition environmental conditions. After the experiment, the sapphire deposition sheet 6 is disassembled to further observe the asphaltene particles deposited on the deposition sheet. The asphaltene deposition rate and deposition amount under the influence of different inhibitors can be further studied and the basic physical properties of the sediment can be analyzed. The effectiveness of the inhibitor can be evaluated by measuring the weight change of asphaltene deposition under controlled experimental conditions.

[0056] Example 2

[0057] Please refer to Figure 3 The experimental method for evaluating the inhibition effect of asphaltene inhibitors provided in this embodiment is completed using the evaluation device for the inhibition effect of asphaltene inhibitors in Example 1, and includes the following steps:

[0058] S01, injecting crude oil containing asphaltene inhibitor into the liquid adding pump 1;

[0059] S02, open the constant temperature water bath 3, and set the experimental temperature;

[0060] S03, opening the second nitrogen tank 9, and adjusting the pressure of the asphaltene deposition pipeline 5 through the second nitrogen tank 9;

[0061] S04, injecting crude oil into the asphaltene deposition pipeline 5 at a set flow rate through the liquid adding pump 1;

[0062] S05, within the set experimental time and at the set intervals, the pipeline pressure at the inlet and outlet of the asphaltene deposition pipeline 5 is recorded by the differential pressure sensor 4 each time;

[0063] S06. Take out the deposition sheet 6 and observe the asphaltene deposition condition on the deposition sheet 6.

[0064] In specific applications, the temperature control range of the constant temperature water bath 3 is from room temperature to 170°C, and the temperature control accuracy reaches ±0.1°C; the pressure adjustment range of the asphaltene deposition pipeline 5 is from 0 to 80MPa. The device can simulate different temperature, pressure and fluid conditions to test the effectiveness of the inhibitor in the actual operating environment.

[0065] In the experiment, 500 ml of crude oil and asphaltene inhibitor can be injected into different liquid adding pumps 1 respectively. By controlling the two liquid adding pumps 1, the configuration of mixed liquids with different concentrations can be realized, and the mixed output can be realized in the mixer 11. The experimental temperature is set by the constant temperature water bath 3, and the temperature error is controlled to be less than 0.5°C; when the device reaches the set pressure and temperature, the crude oil is injected into the asphaltene deposition pipeline 5 at a flow rate of 3 mL / h in a laminar state, and the flow rate is maintained for 20 hours, and the pipeline pressure at the inlet and outlet of the asphaltene deposition pipeline 5 is measured at every 10s time interval, and the pressure drop in the asphaltene deposition pipeline 5 is continuously measured by the differential pressure sensor 4. The measured data is recorded and analyzed in real time by a computer to obtain fluid dynamics data, which provides a basis for the subsequent inhibitor performance evaluation; after the experimental time is reached, the deposition sheet 6 is taken out, and the deposition sheet 6 is placed under a microscope for observation to observe the asphaltene deposition condition on the deposition sheet 6.

[0066] In this embodiment, the mesh size is adjusted by adjusting the opening and closing degree of the two deposition sheets. The opening and closing degree of the two deposition sheets can be set for each experiment, for example, the opening and closing degree is 0 degrees or 30 degrees, and steps S01 to S06 are repeated to evaluate the asphaltene deposition conditions of the two deposition sheets at different opening and closing degrees.

[0067] After the test, the constant pressure nitrogen in the first nitrogen tank 2 at the pipeline inlet is opened, and the second nitrogen bottle 9 is closed. Under the action of the constant pressure nitrogen, the remaining liquid in the pipeline is gradually discharged from the outlet to the liquid recovery device 8 and weighed.

[0068] The experimental method for evaluating the inhibitory effect of the asphaltene inhibitor of this embodiment can effectively evaluate the effectiveness of the inhibitor by quantitatively measuring the weight change of asphaltene deposition under controlled experimental conditions.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An evaluation device for the inhibition effect of asphaltene inhibitors, characterized in that: include: A constant temperature water bath, in which an asphaltene deposition pipeline is arranged, one end of the asphaltene deposition pipeline is connected to a liquid adding pump through a pipeline; the other end of the asphaltene deposition pipeline is connected to a liquid recovery device through a pipeline; a three-way valve is arranged on the pipeline between the liquid recovery device and the asphaltene deposition pipeline, and the three-way valve is connected to a second nitrogen tank; A deposition sheet, disposed in the asphaltene deposition pipeline; The differential pressure sensors are respectively arranged at two ends of the asphaltene deposition pipeline to measure the differential pressure at the two ends of the asphaltene deposition pipeline.

2. The device for evaluating the inhibitory effect of asphaltene inhibitor according to claim 1, characterized in that: The liquid adding pump comprises a fuel adding pump and a medicine adding pump connected in parallel.

3. The device for evaluating the inhibitory effect of asphaltene inhibitor according to claim 2, characterized in that: A mixer is arranged on the pipelines at the output ends of the refueling pump and the dosing pump.

4. The device for evaluating the inhibitory effect of asphaltene inhibitor according to claim 3, characterized in that: A first nitrogen tank is arranged on the pipeline at the liquid inlet end of the mixer.

5. The device for evaluating the inhibitory effect of asphaltene inhibitor according to claim 1, characterized in that: The differential pressure sensor is connected to the data collector and the data processor in sequence.

6. The device for evaluating the inhibitory effect of asphaltene inhibitor according to claim 1, characterized in that: The deposition sheets are provided in two pieces, and the two deposition sheets are parallel to each other.

7. The device for evaluating the inhibitory effect of asphaltene inhibitor according to claim 6, characterized in that: The two deposition sheets are both provided with meshes.

8. The device for evaluating the inhibitory effect of asphaltene inhibitor according to claim 7, characterized in that: The two deposition plates, one of which is a fixed plate, and the other is a rotating plate capable of rotating relative to the fixed plate.

9. An experimental method for evaluating the inhibitory effect of asphaltene inhibitors, characterized in that: The evaluation device for the inhibition effect of the asphaltene inhibitor according to any one of claims 1 to 8 is completed, comprising the following steps: Injecting crude oil configured with asphaltene inhibitor into the liquid injection pump; Turn on the constant temperature water bath and set the experimental temperature; opening the second nitrogen tank, and adjusting the pressure of the asphaltene deposition pipeline through the second nitrogen tank; Injecting the crude oil into the asphaltene deposition pipeline at a set flow rate through a liquid addition pump; Within a set experimental time and at set intervals, the pipeline pressure at the inlet and outlet of the asphaltene deposition pipeline is recorded each time by a differential pressure sensor; Take out the sedimentation sheet and observe the asphaltene deposition condition on the sedimentation sheet.

10. The experimental method for evaluating the inhibition effect of asphaltene inhibitor according to claim 9, characterized in that: The opening and closing degrees of the two deposition sheets are adjusted to adjust the mesh size thereon, and the above steps are repeated to evaluate the asphaltene deposition conditions of the two deposition sheets at different opening and closing degrees.

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