Device and method for testing normal-temperature and normal-pressure performance of hydrate in-situ separation desander

Abstract

The invention discloses a normal-temperature and normal-pressure performance testing device for a hydrate in-situ separation desander, and mainly solves the problems of high experiment difficulty and high cost of a heat and pressure preservation performance test in the prior art. The device comprises a substitute sample preparation device, a mixing tank communicated with the substitute sample preparation device, a pump communicated with the mixing tank, a frequency converter connected with the pump, a hydrate in-situ separator communicated with the outlet end of the pump through a conveying pipe, and a plurality of sensor assemblies mounted on the conveying pipe, the sample processing device is used for analyzing samples at each sampling port of the hydrate in-situ separator; and the data acquisition processor is used for displaying information of the sensor assembly and performing data analysis on the sample processing device. Through the scheme, the device and the method for testing the performance of the hydrate in-situ separation desander at normal temperature and normal pressure are realized, the purposes of simplifying the performance testing steps and equipment, reducing the testing difficulty and improving the testing efficiency are achieved, and the device and the method have very high practical value and popularization value.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrate exploitation, and in particular relates to a device and method for testing the performance of a hydrate in-situ separation and desander at normal temperature and pressure. Background Art

[0002] Natural gas hydrates have been proven to be one of the most promising clean energy sources, and their effective exploitation is expected to solve my country's energy security problem. So far, the hydrate trial production has shown that the sand production is serious during the exploitation process, resulting in a high sand content in the hydrate slurry, which ultimately makes the hydrate exploitation production difficult and costly. Therefore, new separation and sand removal technologies and equipment are urgently needed. The "solid fluidization" and "pressure reduction method" have proposed the use of in-situ separation desanders to separate sand, water, and gas to remove sand, indicating that the in-situ separation desander has been selected as the most promising separation equipment in the hydrate desander technology. The performance of the desander determines the efficiency of separation and sand removal, and ultimately determines the efficiency of hydrate exploitation, which can have a key impact on the commercial exploitation of marine hydrates.

[0003] However, the experimental test method for hydrates is mainly proposed based on the conditions of heat preservation and pressure maintenance. The main reason is that hydrates undergo phase changes, and experimental research needs to be carried out under heat preservation and pressure maintenance to ensure the reliability of the results. For example, the "high-pressure reactor test device for hydrate testing" mentioned in patent number "20232183641124" is mainly used to provide a heat preservation and pressure maintenance environment for related tests of hydrates. However, the conditions of heat preservation and pressure maintenance also cause problems such as difficulty in experimental operation, high cost, and difficulty in obtaining experimental data. For the experimental device and method for the performance test of the in-situ separation and desander of hydrates, the same difficulties exist under heat preservation and pressure maintenance. Therefore, how to ensure the reliability of test results at normal temperature and pressure and conduct performance tests on the in-situ separation and desander of hydrates is a key technical problem that needs to be solved in the field of marine hydrate mining. Summary of the invention

[0004] The purpose of the present invention is to provide a normal temperature and pressure performance testing device and method for a hydrate in-situ separation and desander, mainly to solve the problems of great difficulty and high cost in the thermal insulation and pressure performance testing experiment in the prior art.

[0005] A performance test device for a hydrate in-situ separation and desander at normal temperature and pressure comprises a substitute sample preparation device, a fourth delivery pipe connected to the substitute sample preparation device at one end, a mixing tank connected to the other end of the fourth delivery pipe and used for mixing materials, a pump connected to the outlet end of the mixing tank at an inlet end, a frequency converter connected to the pump and used for controlling the speed of a motor driving the pump, a first delivery pipe connected to the outlet end of the pump at one end, a hydrate in-situ separator having a plurality of sampling ports connected to the inlet of the other end of the first delivery pipe, a second delivery pipe connected to the overflow port of the hydrate in-situ separator at one end and to the feed end of the mixing tank at the other end, a third delivery pipe connected to the underflow port of the hydrate in-situ separator at one end and to the feed end of the mixing tank at the other end, a plurality of sensor assemblies installed on the first delivery pipe, the second delivery pipe and the third delivery pipe and used for real-time monitoring of pressure and flow, a sample processing device used for analyzing samples at each sampling port of the hydrate in-situ separator, and a data acquisition processor used for displaying information of the sensor assemblies and performing data analysis on the sample processing device.

[0006] Furthermore, the first delivery pipe is installed with a first one-way valve, a first flow meter and a first pressure sensor along the fluid running direction, and an inlet sampling point opened at the end of the first delivery pipe and used for sampling.

[0007] Furthermore, the second delivery pipe is installed with a second pressure sensor, a second one-way valve and a second flow meter along the fluid running direction, and an overflow port sampling point is opened at the overflow port end of the second delivery pipe and is used for sampling.

[0008] Furthermore, the third delivery pipe is installed with a third pressure sensor and a third one-way valve along the direction of fluid flow, as well as a bottom flow sampling point opened at the bottom flow end of the third delivery pipe for sampling, wherein the first flow meter and the second flow meter are the same flow meter, the first pressure sensor, the second pressure sensor and the third pressure sensor are the same pressure sensor, and the flow meter and the pressure sensor constitute a sensor assembly.

[0009] Specifically, the fourth delivery pipe is further provided with a fourth one-way valve, wherein the first one-way valve, the second one-way valve, the third one-way valve and the fourth one-way valve are the same one-way valves.

[0010] The testing method of the performance testing device of the hydrate in-situ separation and desander at normal temperature and pressure comprises the following steps:

[0011] (S1) preparing a substitute that meets the test requirements using a substitute sample preparation device at normal temperature and pressure;

[0012] (S2) After the substitute is evenly mixed in a mixing tank, the sample is sent to a hydrate in-situ separator by controlling the output pressure and flow rate of the pump by a frequency converter, and sampling is performed at the inlet sampling point;

[0013] (S3) separating the substitute by an in-situ hydrate separator, and sampling at the overflow port and the underflow port respectively;

[0014] (S4) processing the removed sample by a sample processing device;

[0015] (S5) analyzing the pressure, flow and sample through a data acquisition processor;

[0016] (S6) Adjust the frequency converter to adjust the pump displacement, and repeat steps (S2) to (S6).

[0017] Specifically, in the step (S1), the samples are required to meet the requirements of similar density and similar particle size.

[0018] Specifically, in the step (S4), the sample taken out is dried, sorted and weighed by a sample processing device.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) Based on the similarity of physical properties, a performance test device and method for an in-situ hydrate separation and desander at room temperature and pressure were proposed, which simplified the performance test steps and equipment, reduced the test difficulty, and improved the test efficiency. This effectively overcame the problems of the existing thermal insulation and pressure performance test experiments being difficult and costly, and improved the hydrate mining efficiency.

[0021] (2) The experimental device of the present invention is equipped with a closed loop circuit for batching, sampling, monitoring, etc., which allows the recycling of materials and facilitates sampling, effectively improving the utilization efficiency of materials and devices, while reducing the energy consumption of the entire experimental system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the present invention.

[0023] Figure 2 This is a comparison chart between the particle size distribution of the surrogate sample prepared in the present invention and the actual hydrate particle size distribution.

[0024] Figure 3 This is a comparison chart of separation efficiency of multiphase test of the present invention.

[0025] In the above drawings, the component names corresponding to the reference numerals are as follows:

[0026] 1-alternative sample preparation device, 2-mixing tank, 3-pump, 4-frequency converter, 5-first delivery pipe, 6-hydrate in-situ separator, 7-second delivery pipe, 8-third delivery pipe, 9-sample processing device, 10-data acquisition processor, 11-first one-way valve, 12-first flow meter, 13-first pressure sensor, 14-inlet sampling point, 15-second pressure sensor, 16-second one-way valve, 17-second flow meter, 18-overflow sampling point, 19-third pressure sensor, 20-third one-way valve, 21-bottom flow sampling point, 22-fourth delivery pipe, 23-fourth one-way valve. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with the accompanying drawings and examples. The embodiments of the present invention include but are not limited to the following examples.

[0028] Example

[0029] like Figures 1 to 3 As shown, a performance test device for a hydrate in-situ separation and desander at normal temperature and pressure is characterized in that it comprises a substitute sample preparation device 1, a fourth delivery pipe 22 connected to the substitute sample preparation device 1 at one end, a mixing tank 2 connected to the other end of the fourth delivery pipe 22 and used for mixing materials, a pump 3 connected to the outlet end of the mixing tank 2 at an inlet end, a frequency converter 4 connected to the pump 3 and used for controlling the rotation speed of an electrode inside the pump, a first delivery pipe 5 connected to the outlet end of the pump 3 at one end, a hydrate in-situ separator 6 having a plurality of sampling ports and an inlet connected to the other end of the first delivery pipe 5, and a hydrate in-situ separator 6 having a plurality of sampling ports ... A second delivery pipe 7 connected to the overflow port of the hydrate in-situ separator 6 and the other end connected to the feed end of the mixing tank 2, a third delivery pipe 8 connected to the underflow port of the hydrate in-situ separator 6 at one end and the feed end of the mixing tank 2 at the other end, a plurality of sensor components installed on the first delivery pipe 5, the second delivery pipe 7 and the third delivery pipe 8 for real-time monitoring of pressure and flow, a sample processing device 9 for analyzing samples from each sampling port of the hydrate in-situ separator 6, and a data acquisition processor 10 for displaying sensor component information and performing data analysis on the sample processing device 9. The experimental device is equipped with a closed loop of batching, sampling, monitoring, etc., so that materials can be recycled, sampling is convenient, and material slurry is effectively saved and energy consumption is reduced.

[0030] Preliminary preparation for the experiment:

[0031] Mud and sand preparation: In this embodiment, the density of the sand is 2600 kg / m 3 The quartz sand is selected according to the particle size distribution ratio of the hydrate sediment in the South my country Sea. The sand particles are screened by a particle size screener such as a standard sieve. Then, the particle size distribution of the sand is measured by a dry and wet dual-purpose laser particle size analyzer until the particle size meets the test requirements. The specific particle size volume distribution curve Figure 2 shown.

[0032] Preparation of hydrate substitute: From the research results, it can be seen that the main physical parameters affecting particle separation are material density and particle size, so paraffin is selected as a hydrate substitute in this example. The hydrate particle size ratio is carried out in the same way as the sand particle size ratio, assuming that the particle size distribution is the same as that of sand.

[0033] From the particle size distribution curve Figure 2 It can be seen that the particle size distribution of the formulated test particles is basically consistent with the particle distribution of the sediment obtained from the test mining, which ensures the reliability of the separation test at normal temperature and pressure.

[0034] According to Figure 1 As shown in the figure, the various devices and components are connected, and the prepared paraffin is placed in the substitute sample preparation device 1 at normal temperature and pressure, and an appropriate amount of substitute, that is, paraffin and sand, is sent to the mixing tank 2 for material mixing through the fourth one-way valve 23 through the fourth conveying pipe 22. The mixing tank 2 rotates to mix the materials. After the mixing tank mixes the materials, they are sucked in through the suction port of the pump 3, and then discharged from the discharge port to the inlet of the hydrate in-situ separator 6. After passing through the in-situ separator, the mixed materials are discharged from the bottom flow port and the overflow port respectively, and then returned to the mixing tank; the motor is controlled by the inverter 4 The rotation speed is controlled to realize the control of the pump flow and obtain the required flow parameters; flow meters and pressure sensors are installed at the inlet and outlet of the in-situ separator, and the flow and pressure at each position of the separator can be monitored in real time, and the monitored data can be displayed on the data acquisition processor 10; there is an inlet sampling point 14 at the inlet of the in-situ separator, an overflow sampling point 18 at the overflow port position, and an underflow port sampling point 21 at the underflow port position. All the samples taken out are processed by the sample processing device 9, and the test data is uploaded to the data acquisition processor 10 for processing. The above system can be used to conveniently and quickly perform real-time sampling monitoring and observe the separation performance of the in-situ separator. The test system adopts a cyclic operation, which can greatly save water and materials, and can perform large flow tests. When no sampling is taken, all sampling ports are in a closed state, and the direction of all one-way valves is consistent with the direction of fluid flow, ensuring that the fluid does not flow back when the entire device is running and stopped, thereby ensuring the reliability of the test.

[0035] Combined with relevant working conditions, the steps of the test method are as follows:

[0036] (1) Carry out clean water test with a flow rate of 15m 3 / h steady flow for 2 minutes to test the tightness of the pipeline, and then adjust the frequency converter to obtain a flow rate of 5-20m 3 Split ratio and pressure drop within the range of / h;

[0037] (2) Conduct single-phase sand separation tests;

[0038] 1) Add sand into the mixing tank according to the sand volume concentration of 15 vol%, start the mixing mechanism in the mixer to mix until the materials are observed to be evenly mixed;

[0039] 2) Start the pump to deliver the mixed slurry to the in-situ separator and adjust the frequency of the inverter to make the flow rate reach 5-20m 3 / h range, observe the flowmeter and pressure sensor at the inlet and overflow of the in-situ separator, and start sampling after the flow and pressure tend to be stable, and repeat the above steps to obtain samples at different flow rates;

[0040] 3) Measure the volume of the sample, filter with filter cloth to obtain the sand particles at the inlet and outlet, then dry and weigh them to obtain the mass of the sand phase at the inlet and outlet, and calculate the separation efficiency.

[0041] (3) Conduct a test on the separation of sand, hydrate and water mixtures. Take samples of sand and hydrate at the underflow and overflow ports at different sand volume concentrations, different hydrate substitute volume concentrations and different flow rates, and calculate the sand removal efficiency and hydrate recovery efficiency.

[0042] 1) Add materials into the mixing tank according to the volume concentration of hydrate 10vol% and the volume concentration of sand 15vol%, start the mixing mechanism to mix until the materials are observed to be mixed evenly, start the pump to start conveying the mixed slurry to the in-situ separator, and adjust the frequency of the inverter to a flow rate of 5-18m 3 / h, observe the flowmeter and pressure sensor at the inlet and overflow of the in-situ separator until the flow and pressure become stable and then start sampling. Repeat the above steps to obtain inlet and outlet samples at different flow rates;

[0043] 2) Maintain flow rate at about 15m 3 / h, hydrate volume concentration 1vol%, respectively proportion the required sand volume concentration of 1-10vol% materials and add them into the mixing tank, repeat the above mixing and observation steps to obtain inlet and outlet samples under different sand volume concentrations;

[0044] 3) Maintain flow rate at about 15m 3 / h, sand volume concentration of 15 vol%, respectively proportion the required sand volume concentration of 1-10 vol% materials and add them into the mixing tank, repeat the above mixing and observation steps to obtain inlet and outlet samples at different hydrate volume concentrations;

[0045] 4) Measure the volume of the sample, filter with filter cloth to obtain the sand and hydrate substitute particles at the inlet and outlet, then dry and weigh them to obtain the mass of the sand phase and hydrate substitute phase at the inlet and outlet, and calculate the separation efficiency.

[0046] The flow rate obtained from the test is 5 to 18 m 3The sand removal efficiency and hydrate recovery efficiency in the range of / h are compared with the numerical simulation results. Figure 3 As shown in the figure, it can be seen that the variation trends of the experimental values ​​and the simulation values ​​of the sand removal efficiency and the hydrate recovery efficiency are consistent, which proves the feasibility of the invention.

[0047] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any changes made by adopting the design principles of the present invention and performing non-creative work on this basis should fall within the protection scope of the present invention.

Claims

1. Hydrate in-situ separation and desander performance test device at normal temperature and pressure, characterized in that: The invention comprises a substitute sample preparation device (1), a fourth delivery pipe (22) having one end connected to the substitute sample preparation device (1), a mixing tank (2) connected to the other end of the fourth delivery pipe (22) and used for mixing materials, a pump (3) having an inlet end connected to the outlet end of the mixing tank (2), a frequency converter (4) connected to the pump (3) and used for driving the motor speed of the pump, a first delivery pipe (5) having one end connected to the outlet end of the pump (3), a hydrate in-situ separator (6) having a plurality of sampling ports and an inlet connected to the other end of the first delivery pipe (5), and one end connected to the overflow port of the hydrate in-situ separator (6). , a second delivery pipe (7) having one end connected to the feed end of the mixing tank (2), the other end of which is connected to the bottom flow outlet of the hydrate in-situ separator (6), and the other end of which is connected to the feed end of the mixing tank (2), a third delivery pipe (8) having one end connected to the bottom flow outlet of the hydrate in-situ separator (6) and the other end connected to the feed end of the mixing tank (2), a plurality of sensor components installed on the first delivery pipe (5), the second delivery pipe (7) and the third delivery pipe (8) and used for real-time monitoring of pressure and flow, a sample processing device (9) for analyzing samples from each sampling port of the hydrate in-situ separator (6), and a data acquisition processor (10) for displaying information of the sensor components and performing data analysis on the sample processing device (9).

2. The hydrate in-situ separation and desander performance testing device at normal temperature and pressure according to claim 1, characterized in that: The first delivery pipe (5) is provided with a first one-way valve (11), a first flow meter (12) and a first pressure sensor (13) along the fluid running direction, and an inlet sampling point (14) opened at the end of the first delivery pipe (4) and used for sampling.

3. The hydrate in-situ separation and desander performance testing device at normal temperature and pressure according to claim 2, characterized in that: The second delivery pipe (7) is provided with a second pressure sensor (15), a second one-way valve (16) and a second flow meter (17) along the direction of fluid flow, and an overflow sampling point (18) is provided at the overflow end of the second delivery pipe (6) for sampling.

4. The hydrate in-situ separation and desander performance testing device at normal temperature and pressure according to claim 3, characterized in that: The third delivery pipe (8) is provided with a third pressure sensor (19) and a third one-way valve (20) along the direction of fluid flow, and a bottom flow sampling point (21) is provided at the bottom flow end of the third delivery pipe (7) for sampling, wherein the first flow meter (12) and the second flow meter (17) are the same flow meters, the first pressure sensor (13), the second pressure sensor (15) and the third pressure sensor (19) are the same pressure sensors, and the flow meters and the pressure sensors constitute a sensor assembly.

5. The hydrate in-situ separation and desander performance testing device at normal temperature and pressure according to claim 4, characterized in that: The fourth delivery pipe (22) is also provided with a fourth one-way valve (23), wherein the first one-way valve (11), the second one-way valve (16), the third one-way valve (20) and the fourth one-way valve (23) are identical one-way valves.

6. The method for testing the performance of the hydrate in-situ separation and desander at normal temperature and pressure according to any one of claims 1 to 5, characterized in that: The following steps are involved: (S1) preparing a substitute that meets the test requirements using a substitute sample preparation device at normal temperature and pressure; (S2) After the substitute is evenly mixed in a mixing tank, the sample is sent to a hydrate in-situ separator by controlling the output pressure and flow rate of the pump by a frequency converter, and sampling is performed at the inlet sampling point; (S3) separating the substitute by an in-situ hydrate separator, and sampling at the overflow port and the underflow port respectively; (S4) processing the removed sample by a sample processing device; (S5) analyzing the pressure, flow and sample through a data acquisition processor; (S6) Adjust the frequency converter to adjust the pump displacement, and repeat steps (S2) to (S6).

7. The method for testing the performance of the hydrate in-situ separation and desander at normal temperature and pressure according to claim 6, characterized in that: In the step (S1), the samples are required to have similar density and similar particle size.

8. The method for testing the performance of the hydrate in-situ separation and desander at normal temperature and pressure according to claim 7, characterized in that: In the step (S4), the sample taken out is dried, sorted and weighed by a sample processing device.

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