An oil and gas multiphase flow system suitable for use with a sulphur-containing fluid

Abstract

The application discloses a kind of oil-gas mixed transport system suitable for sulfur-containing fluid, comprising: two circulating tanks, the circulating tank is connected to medium inlet manifold by inlet pipeline, is connected to medium outlet manifold by outlet pipeline, and any circulating tank has liquid phase in conveying medium remaining, the liquid phase is circulated as working fluid inside the device;Power pump, the inlet of the power pump is alternatively communicated with the bottom of two circulating tanks by reversing valve group, and the outlet is alternatively communicated with the top of two circulating tanks by reversing valve group;Intelligent control system is configured to monitor the liquid level in the circulating tank and control the switching action of the reversing valve group.

Description

Technical Field

[0001] This application relates to the field of oil and gas mixed transportation technology, and in particular to an oil and gas mixed transportation system suitable for sulfur-containing fluids. Background Technology

[0002] In related technologies, sulfur-containing fluids are highly corrosive and toxic. Traditional transportation methods using mechanical gas compressors to directly compress sulfur-containing gases are highly susceptible to corrosion from hydrogen sulfide on high-speed rotating components and precision seals, leading to rapid equipment failure, frequent maintenance, and even the potential safety hazard of toxic media leaks. This is the primary critical equipment safety issue that needs to be addressed.

[0003] Secondly, gas-liquid two-phase mixtures (such as condensate gas) are prone to forming unstable slug flows in pipelines. This can cause severe vibrations and pressure fluctuations in pipelines and equipment, seriously affecting the continuity and stability of transportation. Furthermore, the intermittent operation mode of a single container (such as single-tank intake, pressurization, and emptying circulation) can lead to periodic interruptions in the transportation process. When the tank switches its operating state (such as emptying and refilling), the downstream outlet will experience a media interruption, making continuous transportation impossible and affecting production efficiency and downstream process stability. Utility Model Content

[0004] This application aims to at least solve one of the technical problems existing in the prior art. To this end, one object of this application is to propose an oil and gas mixed transportation system suitable for sulfur-containing fluids, which can conveniently realize oil and gas mixed transportation and is resistant to H2S.

[0005] In a first aspect, embodiments of this application propose an oil-gas mixed transportation system suitable for sulfur-containing fluids, comprising: two circulation tanks, each circulation tank being connected to a medium inlet manifold via an inlet pipe and to a medium outlet manifold via an outlet pipe, wherein either circulation tank contains a residual liquid phase of the transported medium, the liquid phase circulating within the device as a working fluid; a power pump, the inlet of which is alternately connected to the bottom of the two circulation tanks via a reversing valve assembly, and the outlet of which is alternately connected to the top of the two circulation tanks via a reversing valve assembly; and an intelligent control system configured to monitor the liquid level within the circulation tanks and control the switching action of the reversing valve assembly.

[0006] Its effectiveness lies in enabling the safe and efficient transport of highly corrosive and potentially toxic sulfur-containing gas-liquid mixtures (such as condensate oil and gas containing 10% H2S). Specifically, the system utilizes a circulating working fluid driven by a pump to form a flexible piston, directly squeezing and compressing the separated gas within a sealed tank. This avoids corrosive gases flowing directly through precision power equipment and safely, continuously, and stably pressurizes and transports high-pressure gas-liquid mixtures for convenient transport of oil-gas mixtures.

[0007] Furthermore, the medium inlet manifold is located at the top of the circulation tank. After being pressurized by the power pump, the working fluid is pumped to the top of the circulation tank to compress the gas and drive the liquid outward.

[0008] Furthermore, the medium inlet manifold is adapted to working conditions where the gas content of the gas-liquid mixture is 0% to 100%; in pure liquid working conditions, the circulation tank only serves as a buffer chamber, and the power pump directly pressurizes the liquid; in pure gas working conditions, the working liquid retained in the circulation tank is pressurized and injected into the top of the tank, and then discharged after compressing the gas.

[0009] Furthermore, a one-way valve assembly is provided between the inlet and outlet pipelines.

[0010] Furthermore, the intelligent control system drives the reversing valve assembly through the instrument air system.

[0011] Furthermore, a replaceable adsorption layer is added inside the circulation tank to divide the tank into an upper cavity and a lower cavity; the upper cavity is suitable for contacting sulfur-containing gas-liquid media; the lower cavity is suitable for containing working fluid.

[0012] Furthermore, the adsorption layer is constructed as a double layer, with the upper layer being a high-porosity metal-based carrier and the lower layer being a solid desulfurizing agent packed bed.

[0013] Furthermore, a fixing rod extends from the center of the adsorption layer, and the fixing rod is fixed to the tank body of the circulation tank by a flange. The fixing rod passes through the center of the adsorption layer and is threadedly connected to the fixing rod.

[0014] Furthermore, the inner wall of the upper cavity is provided with a corrosion-resistant layer.

[0015] Furthermore, a manual opening and closing valve is also provided at the top of the upper cavity. The manual opening and closing valve is connected to an inert gas source. When opened, nitrogen gas is injected into the upper cavity to maintain positive pressure in the upper and lower cavities.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0018] Figure 1 This is a partial structural schematic diagram of an oil and gas mixed transportation system suitable for sulfur-containing fluids according to some embodiments of this application;

[0019] Figure 2 This is a schematic diagram of a circulating tank structure according to some embodiments of this application;

[0020] Figure 3 This is a schematic cross-sectional view of a circulating tank according to some embodiments of this application;

[0021] Figure 4 yes Figure 3 A magnified view of a portion of region A in the middle.

[0022] Figure label:

[0023] 1-Mixing tank

[0024] 10-Left tank, 20-Right tank, 30-Power pump, 31-Cavity, 40-Reversing valve assembly, 50-Adsorption layer, 51-Upper layer, 52-Lower layer, 60-Fixing rod, 61-Top flange, 70-Manual on / off valve;

[0025] 100 - Medium inlet manifold, 200 - Medium outlet manifold. Detailed Implementation

[0026] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0027] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0028] In the description of this application, "first feature" and "second feature" may include one or more of the features.

[0029] In the description of this application, "multiple" means two or more.

[0030] In the description of this application, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or it may include the first and second features not being in direct contact but being in contact through another feature between them.

[0031] In the description of this application, the terms "above," "over," and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicate that the first feature is at a higher horizontal level than the second feature.

[0032] The following is for reference. Figures 1-4 This application describes an oil and gas mixed transportation system suitable for sulfur-containing fluids according to embodiments of the present application, comprising two circulation tanks, namely... Figure 1 The system includes the left tank 10 and right tank 20, power pump 30, reversing valve group 40, and intelligent control system.

[0033] Both the left tank 10 and the right tank 20 are connected to the media inlet manifold 100 via inlet pipes and to the media outlet manifold 200 via outlet pipes. Both the media inlet manifold 100 and the media outlet manifold 200 are located above the circulation tanks. During operation, at least one circulation tank always retains a liquid phase (such as condensate oil) from the transported medium, which is circulated within the system as the working fluid. The inlet of the power pump 30 is alternately connected to the bottom of the two tanks via a reversing valve assembly 40, and its outlet is alternately connected to the top of the two tanks via the same valve assembly.

[0034] In this way, chambers 31 can be set at the inlet and outlet of the power pump 30, serving as external suction and discharge chambers for the power pump 30; thus, under the action of the power pump 30, the suction, separation, and discharge of the gas-liquid mixture are realized. The intelligent control system monitors the liquid level in the tank in real time through a liquid level sensor; for example, when the liquid level in the left tank 10 reaches 85% of the high threshold or the liquid level in the right tank 20 drops to 15% of the low threshold, the reversing valve group 40 is triggered to switch the passage. Thus, under gas-liquid mixing conditions, the gas and liquid are separated through the circulation tank, the power pump 30 pressurizes the liquid, and the flexible water piston formed by the liquid pressurizes the gas, thereby completing the gas-liquid mixing and transportation.

[0035] In detail, the system operation is divided into two phases:

[0036] During the single-sided mixing pipe pressurization stage, taking the right tank 20 as an example, a sulfur-containing gas-liquid mixture (e.g., H2S concentration of 10%) enters the left tank 10 from the inlet manifold. The gas rises and the liquid sinks, forming gas-liquid separation. Simultaneously, the power pump 30 draws working fluid from the bottom of the right tank 20 and pressurizes it to 3.0 MPa, injecting it into the top of the right tank 20 through the top injection pipe. At this time, the high-pressure working fluid forms a flexible piston, squeezing the gas inside the tank downwards to compress it to 2.5 MPa, while simultaneously pushing the liquid out through the outlet manifold.

[0037] During the switching phase, when the liquid level in the left tank 10 rises to 85%, the intelligent control system switches the reversing valve group 40, turning the left tank 10 into a booster tank and the right tank 20 into a suction tank. This switching between the two modes (i.e., the working fluid is drawn from the left tank 10 after the liquid level is sufficiently high) achieves continuous mixed transportation of sulfur-containing media.

[0038] Therefore, the system utilizes the circulating working fluid to form a flexible piston under the drive of the pump, which directly squeezes and compresses the separated gas in the sealed tank, thereby avoiding the direct flow of corrosive gas through the precision power equipment, and safely, continuously and stably pressurizing and transporting the high-pressure gas-liquid mixture, so as to facilitate the transportation of oil-gas mixtures.

[0039] In the aforementioned embodiments, the medium inlet manifold 100 is adapted to working conditions where the gas-liquid mixture has a gas content of 0% to 100%.

[0040] In some special cases, during pure liquid operation, the circulating tank serves only as a buffer chamber, and the power pump 30 directly pressurizes the liquid; for example, when transporting sulfur-containing crude oil (0% gas-liquid ratio), the circulating tank acts only as a buffer chamber. The power pump 30 directly extracts the liquid from the tank, pressurizes it to 2.8 MPa, and discharges it without any gas-phase compression. During pure gas operation, the working fluid retained in the circulating tank is pressurized and injected into the top of the tank, and then discharged after compressing the gas; for example, when transporting H2S-containing natural gas (100% gas-liquid ratio), the residual condensate oil in the tank serves as the working fluid. The power pump 30 extracts the condensate oil, pressurizes it to 4.0 MPa, injects it into the top of the tank, and compresses the gas with an inlet pressure of 0.3 MPa to 1.5 MPa for discharge.

[0041] In some examples, a one-way valve assembly is provided between the inlet and outlet pipelines to automatically open the pipeline when the system stops to prevent pressure buildup; and the intelligent control system drives the reversing valve assembly 40 through the instrument ventilation system.

[0042] Specifically, a check valve assembly is installed between the inlet and outlet manifolds. When the system shuts down due to power failure, the inlet pressure opens the check valve assembly, allowing the medium to flow directly to the outlet via a bypass pipeline, effectively preventing flange leakage caused by system pressure buildup. The intelligent control system drives the pneumatic actuator of the reversing valve assembly 40 through the instrument air system, maintaining the instrument air pressure at 0.6-0.8 MPa. The control system also integrates a 4G module to remotely transmit operating data to the monitoring center, enabling automatic alarms for pressure and level exceeding limits.

[0043] As mentioned above, oil and gas mixtures are usually mixed with H2S. Therefore, based on the H2S content and operating conditions at the site, sulfur-resistant carbon steel, stainless steel, and duplex stainless steel that meet the requirements of NACE / ISO standards can be selected to effectively isolate corrosive media, significantly extend equipment life, and reduce costs.

[0044] To further mitigate the impact of H2S on the system, in some embodiments, a replaceable adsorption layer 50 (e.g., ...) is added inside the circulation tank. Figure 3 (As shown). The adsorption layer 50 divides the tank into two independent chambers:

[0045] The upper chamber, located above the adsorption layer 50, directly contacts the sulfur-containing gas-liquid medium (such as an oil-gas mixture with an H2S concentration of 15%); the lower chamber, located below the adsorption layer 50, contains condensate oil from the conveying medium as the working fluid (or supplements with inert liquid).

[0046] like Figure 3 As shown, the adsorption layer 50 is disposed inside the circulation tank and adheres to the inner wall of the tank. A fixing rod 60 is vertically positioned at the center of the adsorption layer 50, with its top end penetrating the top flange 61 of the circulation tank. The fixing rod 60 is quickly fixed to the top of the circulation tank via the flange, and can be used with double O-rings to achieve a sealed isolation of the lower cavity, allowing the adsorption layer 50 to be disassembled and replaced within 30 minutes, significantly reducing maintenance costs. Furthermore, the fixing rod 60 can be partially configured as a threaded rod, threadedly connected to the center of the adsorption layer 50, thereby allowing adjustment of the position of the adsorption layer 50 within the circulation tank.

[0047] In some preferred embodiments, such as Figure 4 As shown, the adsorption layer 50 is constructed as a double-layer composite structure: the upper layer 51 is a high-porosity metal-based carrier, such as an anti-sulfur alloy wire mesh, and the lower layer 52 is a solid desulfurizing agent packed bed, such as zinc oxide or iron oxide-based particles. Sulfur-containing oil and gas enter from the inlet and are forced to flow through the adsorption layer 50, thereby minimizing the sulfur content in the upper cavity and resulting in an even lower sulfur content in the oil and gas mixture entering the lower cavity. Furthermore, it can be disassembled and replaced via a flange after a period of time. Correspondingly, the upper cavity is lined with an H2S-resistant material to create a corrosion-resistant layer, such as an H2S-resistant coating, rubber, or FRP. In some examples, the top of the circulation tank is removable, allowing the top of the circulation tank to be opened and the attached adsorption layer 50 removed after a period of time. This corrosion-resistant layer can then be replaced to ensure the corrosion resistance of the upper cavity. The lower cavity can be constructed with conventional materials such as anti-sulfur carbon steel, stainless steel, or duplex stainless steel.

[0048] In some embodiments, a manual opening and closing valve 70 is also provided at the top of the upper cavity. The manual opening and closing valve 70 is connected to an inert gas source. When opened, it injects nitrogen into the lower cavity to maintain positive pressure between the upper and lower cavities.

[0049] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0050] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A system for transporting mixed oil and gas containing sulfur fluids, characterized in that, include: Two circulation tanks are connected to the medium inlet manifold via inlet pipes and to the medium outlet manifold via outlet pipes. Each circulation tank contains a residual liquid phase from the conveying medium, which circulates within the device as the working fluid. A power pump, the inlet of which is alternately connected to the bottom of two circulation tanks through a reversing valve assembly, and the outlet of which is alternately connected to the top of two circulation tanks through a reversing valve assembly; The intelligent control system is configured to monitor the liquid level in the circulating tank and control the switching action of the reversing valve group.

2. The oil and gas mixed transportation system suitable for sulfur-containing fluids according to claim 1, characterized in that, The medium inlet manifold is located at the top of the circulation tank. After being pressurized by the power pump, the working fluid is pumped to the top of the circulation tank to compress the gas and drive the liquid outward.

3. The oil and gas mixed transportation system suitable for sulfur-containing fluids according to claim 1, characterized in that, The medium inlet manifold is adapted to working conditions where the gas-liquid mixture has a gas content of 0% to 100%. In pure liquid operation, the circulation tank only serves as a buffer chamber, and the power pump directly pressurizes the liquid; In pure gas operation, the working fluid retained in the circulation tank is pressurized and injected into the top of the tank, and then discharged after being compressed into gas.

4. The oil and gas mixed transportation system suitable for sulfur-containing fluids according to claim 1, characterized in that, A one-way valve assembly is provided between the inlet and outlet pipelines.

5. The oil and gas mixed transportation system suitable for sulfur-containing fluids according to claim 1, characterized in that, The intelligent control system drives the reversing valve group through the instrument air system.

6. The oil and gas mixed transportation system suitable for sulfur-containing fluids according to claim 1, characterized in that, A replaceable adsorption layer is added inside the circulation tank to divide the tank into an upper cavity and a lower cavity; The upper cavity is suitable for contacting sulfur-containing gaseous-liquid media; The lower cavity is adapted to contain the working fluid.

7. The oil and gas mixed transportation system suitable for sulfur-containing fluids according to claim 6, characterized in that, The adsorption layer is constructed as a double layer, with the upper layer being a high-porosity metal-based support and the lower layer being a solid desulfurizing agent packed bed.

8. The oil and gas mixed transportation system suitable for sulfur-containing fluids according to claim 6 or 7, characterized in that, A fixing rod extends from the center of the adsorption layer. The fixing rod is fixed to the tank body of the circulation tank by a flange. The fixing rod passes through the center of the adsorption layer and is threadedly connected to the fixing rod.

9. The oil and gas mixed transportation system suitable for sulfur-containing fluids according to claim 6, characterized in that, The inner wall of the upper cavity is provided with a corrosion-resistant layer.

10. The oil and gas mixed transportation system suitable for sulfur-containing fluids according to claim 6, characterized in that, The upper cavity is also equipped with a manual opening and closing valve. The manual opening and closing valve is connected to an inert gas source. When opened, nitrogen gas is injected into the upper cavity to maintain positive pressure in the upper and lower cavities.

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