Oxygen content testing device

Abstract

The present invention relates to an oxygen content testing device for testing the oxygen content in a liquid, which comprises a testing container provided with two fluid inlets; a first testing pipeline and a second testing pipeline connecting the testing device, the first testing pipeline and the second testing pipeline are respectively connected to the two fluid inlets and the testing container, and a probe extending into the testing container is arranged on the dissolved oxygen tester. The present invention can continuously measure the oxygen content, realizes the on-line detection of the dissolved oxygen content in the high-pressure pipeline of the oil and gas field, avoids the error caused by contaminating the sample during the sampling and detection process, and thus improves the accuracy of the detection result.

Description

Technical Field

[0001] The present invention relates to an oxygen content testing device for testing the oxygen content in a liquid. Background Art

[0002] In recent years, with the increase in the water cut of crude oil in major domestic oilfields and the popularization and application of gas injection technology, oxygen is often mixed into the production system pipelines and equipment during the oil production process. After the oxygen is mixed in, it is easy to cause problems such as pipeline corrosion and perforation, which is one of the main influencing factors leading to the corrosion and failure of oil and gas facilities. The problem of oxygen mixing has gradually attracted the attention of oil and gas producers. During the oil production process, measuring the oxygen content has become a very important link.

[0003] At present, the oxygen testing in major domestic oilfields generally adopts the method of on-site sampling and indoor testing. The above detection methods mainly have the following problems: First, it is inevitable to contact air during the sampling and testing process, which will cause multiple contaminations of the sample and reduce the accuracy of the test results; Second, the test is usually carried out at normal temperature and pressure, and the test results must be combined with operating condition parameters such as the operating temperature, pressure, and medium composition of the sampling pipeline and converted into the oxygen content in its in-situ state, reducing the accuracy of the test results. Summary of the Invention

[0004] In view of the above problems, the present invention proposes an oxygen content testing device, which can measure the liquid-phase oxygen content, realizes the on-line detection of the dissolved oxygen content in high-pressure pipelines in oil and gas fields, avoids errors caused by contaminating samples during the sampling and detection processes, and thus improves the accuracy of the detection results.

[0005] The invention proposes an oxygen content testing device, comprising:

[0006] A test container, on which two fluid inlets are provided;

[0007] A first test pipeline and a second test pipeline connecting the test container, the first test pipeline and the second test pipeline are respectively connected to the two fluid inlets;

[0008] And

[0009] A dissolved oxygen tester connected to the test container, on which a probe extending into the test container is provided.

[0010] A further improvement of the present invention is that the first test pipeline includes a water test pipeline, on which a sampling valve is provided, and the water test pipeline is connected to the test container through a first liquid inlet valve.

[0011] A further improvement of the present invention lies in that the second test pipeline includes an oil-water test pipeline, a filtering device is arranged on the oil-water test pipeline, and a second liquid inlet valve is arranged between the oil-water test pipeline and the test container.

[0012] A further improvement of the present invention lies in that the filtering device includes a primary filter and a secondary filter connected in series.

[0013] A further improvement of the present invention lies in that a first three-way valve is arranged at the outlet position of the primary filter, and a second three-way valve is arranged at the outlet position of the secondary filter.

[0014] A further improvement of the present invention lies in that a filter element made of porous ceramic material is arranged in the primary filter, and a filter element made of polypropylene material is arranged in the secondary filter.

[0015] A further improvement of the present invention lies in that a probe protection tube is arranged on the test container, and the probe of the dissolved oxygen tester extends into the test container through the probe protection tube.

[0016] A further improvement of the present invention lies in that a waste liquid discharge port is arranged at the bottom of the test container, and a safety valve is arranged at the top of the test container.

[0017] A further improvement of the present invention lies in that a liquid level gauge is arranged on the side wall of the test container, and a gas / water discharge port is arranged at the upper part of the test container.

[0018] A further improvement of the present invention lies in that a second gas / water discharge port is arranged at the upper end of the test container, and the test container can discharge gas and water through the second gas / water discharge port.

[0019] Compared with the prior art, the advantages of the present invention are as follows:

[0020] The oxygen content testing device of the present invention can measure the liquid-phase oxygen content, realizes the on-line detection of the dissolved oxygen content in the high-pressure pipeline of the oil and gas field, avoids the error caused by contaminating the sample during the sampling and detection process, and thus improves the accuracy of the detection result.

[0021] In the oxygen content testing device of the present invention, the test container is respectively connected to the first test pipeline and the second test pipeline. For relatively pure water, it can directly enter the test container through the first test pipeline for testing. For fluids with poor appearance conditions, it needs to pass through the second test pipeline, be filtered first, and then enter the test container for testing. In this way, the accuracy of the measurement is ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of an oxygen content testing device according to an embodiment of the present invention.

[0023] In the drawings, like parts are designated by like reference numerals. The drawings are not drawn to actual scale.

[0024] The meanings of the reference numerals in the drawings are as follows: 1, test container; 2, first test pipeline; 3, second test pipeline; 11, probe protection tube; 12, waste liquid discharge port; 13, safety valve; 14, liquid level gauge; 15, first gas / water discharge port; 16, second gas / water discharge port; 21, water test pipeline; 22, first liquid inlet valve; 31, oil-water test pipeline; 32, primary filter; 33, secondary filter; 34, first three-way valve; 35, second three-way valve; 36, second liquid inlet valve. Detailed implementation manners

[0025] The present invention will be further described below in conjunction with the drawings.

[0026] Figure 1 Schematically shows an oxygen content testing device according to an embodiment of the present invention. The oxygen content testing device according to the present invention can perform liquid-phase oxygen content measurement, realizes on-line detection of dissolved oxygen content in high-pressure pipelines of oil and gas fields, avoids errors caused by contaminating samples during sampling and detection processes, and thus improves the accuracy of detection results.

[0027] As Figure 1 shown, the oxygen content testing device described in this embodiment includes a test container 1. Two fluid inlets are provided on the test container 1, and both of the two fluid inlets are provided on the side wall of the test container 1. In this embodiment, the two fluid inlets are respectively used to introduce relatively pure water and relatively complex oil-water fluid. The oxygen content testing device described in this embodiment further includes a first test pipeline 2 and a second test pipeline 3, and the first test pipeline 2 and the second test pipeline 3 are respectively connected to the two fluid inlets. The first test pipeline 2 is used to circulate a fluid with strong fluidity and relatively pure, and it is connected to the fluid inlet for circulating gas / water fluid. The second test pipeline 3 is used to circulate a fluid with poor fluidity and complex composition, and it is connected to the fluid inlet for circulating oil-water fluid. The oxygen content testing device described in this embodiment further includes a dissolved oxygen tester, and a probe for testing oxygen content is provided on the dissolved oxygen tester, and the probe extends into the interior of the test container 1. The dissolved oxygen tester can measure the oxygen content in the fluid medium in the test container 1. Preferably, the dissolved oxygen tester adopts a fluorescence-type on-line oxygen content tester.

[0028] The oxygen content testing device according to this embodiment can introduce a relatively pure fluid, such as water or a water-vapor mixed fluid, into the test container 1 through the first test pipeline 2, and the second test pipeline 3 can introduce an oil-water mixed fluid into the test container 1. During the test, the test pipeline can be selected according to the type of the medium to be measured.

[0029] In one embodiment, the first test pipeline 2 includes a water test pipeline 21, and the water test pipeline 21 is configured to be able to circulate relatively pure water or a gas / water mixed fluid. A sampling valve is provided on the water test pipeline 21. A first liquid inlet valve 22 is provided at the outlet position of the water test pipeline 21, and the first liquid inlet valve 22 is connected to the fluid inlet on the test container 1 corresponding to the first test pipeline 2.

[0030] In one embodiment, the second test pipeline 3 includes an oil-water test pipeline 31, the oil-water test pipeline 31 can circulate an oil-water mixture, a filtering device provided on the oil-water test pipeline 31, and a second liquid inlet valve 36 provided between the oil-water test pipeline 31 and the test container 1.

[0031] In the oxygen content testing device according to this embodiment, the test container 1 is respectively connected to the first test pipeline 2 and the second test pipeline 3. For relatively pure water or a gas / water mixture, it can directly enter the test container 1 through the first test pipeline 2 for testing. For a fluid with a relatively complex medium composition, it needs to pass through the second test pipeline 3, be filtered first, and then enter the test container 1 for testing. In this way, the measurement accuracy is ensured.

[0032] In one embodiment, the filtering device includes several stages of filters connected in series. In this embodiment, two-stage filtering is adopted. The filters include a primary filter 32 and a secondary filter 33, and the secondary filter 33 is provided downstream of the primary filter 32.

[0033] By filtering the oil-water through the filtering device in this embodiment, substances such as crude oil, suspended solids or sand in the oil-water mixture can be filtered out. Through the method of hierarchical filtering, the filtering effect is better. In this embodiment, the primary filter 32 can filter the crude oil in the oil-water mixed fluid, and the secondary filter 33 can further filter impurities such as sediment. The test accuracy of the dissolved oxygen tester is improved after being filtered by the filter.

[0034] In one embodiment, a first three-way valve 34 is provided at the outlet position of the primary filter 32, and a second three-way valve 35 is provided at the outlet position of the secondary filter 33. When testing using the oxygen content testing device according to this embodiment, the state of the filtered medium is observed through the first three-way valve 34 and the second three-way valve 35, and it is judged whether the test requirements are met. If there is still a large amount of crude oil or impurities in the medium, the filter element of the filter needs to be replaced and the test is carried out again.

[0035] In one embodiment, a filter element is provided inside the primary filter 32. The filter element preferably uses a porous ceramic material. By providing a filter element of the porous ceramic material, the crude oil component in the oil-water mixed fluid can be effectively filtered. The filter element of the secondary filter 33 preferably uses a polypropylene-based material and is used to filter suspended solids, sediment and other impurities.

[0036] In one embodiment, a probe protection tube 11 is provided on the test container 1, and the probe of the dissolved oxygen tester extends into the test container 1 through the probe protection tube 11. In a preferred embodiment of the present invention, the probe is provided at the top of the test container 1, and the probe protection tube 11 is made of a stainless steel tube. Using a stainless steel tube can conveniently avoid being corroded and improve the service life; at the same time, the stainless steel tube has good strength and can avoid the fluid entering the test container 1 from impacting and damaging the probe.

[0037] In one embodiment, a waste liquid discharge port 12 is provided at the bottom of the test container 1, and the waste liquid discharge port 12 is used to discharge the waste liquid after the test. A safety valve 13 is provided at the top of the test container 1, and pressure relief can be carried out through the safety valve 13 when the pressure in the test container 1 is relatively high. By providing the safety valve 13, it can be avoided that when the pressure of the pipeline to be tested is greater than the pressure bearing limit of the test container 1, the test container 1 is damaged or fails, thereby improving the equipment safety and avoiding accidents.

[0038] In one embodiment, a liquid level gauge 14 is provided on the side wall of the test container 1. A first gas / water discharge port 15 is provided at the upper part of the test container 1, and a gas / water discharge valve is provided on the first gas / water discharge port 15. When using this embodiment, the liquid level in the measuring container can be observed through the liquid level gauge 14 to judge whether it meets the test requirements. When the liquid level gauge 14 fails, it can be adjusted by controlling the gas / water discharge valve until the liquid level meets the test requirements.

[0039] In one embodiment, a second gas / water discharge port 16 is provided at the upper end of the test container 1, and the second gas / water discharge port 16 is provided at the top of the test container 1. When the medium flow rate is relatively fast, the first gas / water discharge port 15 can be opened, or the first gas / water discharge port 15 and the second gas / water discharge port 16 can be opened simultaneously. When the medium flow rate is relatively slow, the second gas / water discharge port 16 can be opened and the first gas / water discharge port 15 can be closed to meet the test requirements and improve the test accuracy.

[0040] The working process of using the oxygen content testing device according to this embodiment is as follows.

[0041] When measuring the in-situ dissolved oxygen content in the test water pipeline, open the first liquid inlet valve 22 and the first gas / water discharge port 15 to connect the first test pipeline 2 and the test container 1. At the same time, close the second liquid inlet valve 36, the second gas / water discharge port 16 and the waste liquid discharge port 12. Open the sampling valve in the first test pipeline 2 and introduce the fluid in the first test pipeline 2 into the test container 1. Observe the liquid level through the liquid level gauge 14. After the liquid level is higher than the probe protection tube of the dissolved oxygen tester and a certain amount of liquid is discharged from the first gas / water discharge port 15, adjust the size of the sampling valve to reduce the flow rate. Turn on the dissolved oxygen tester. After the instrument shows a stable reading, record the data. Finally, close the sampling valve and slowly open the waste liquid discharge port 12 to discharge the aqueous solution in the test container 1. If the pressure of the test water pipeline is higher than the pressure bearing limit value of the test container 1, stay away from the safety valve 13 before opening the water sampling valve. However, after the test, the instrument reading needs to be converted into the in-situ dissolved oxygen content at the operating temperature and pressure of the water pipeline.

[0042] When testing the in-situ dissolved oxygen content in an oil pipeline with high water content, open the first three-way valve 34, the second three-way valve 35 and the second liquid inlet valve 36 to connect the oil-water test pipeline 31 with the test container 1. At the same time, open the first gas / water discharge port 15, and close the first liquid inlet valve 22, the second gas / water discharge port 16 and the waste liquid discharge port 12. Open the sampling valve in the second test pipeline 3, and introduce the oil-water mixture filtered by the primary filter 32 and the secondary filter 33 into the test container 1. Observe the liquid level in the liquid level gauge 14. After the liquid level is higher than the probe protection tube 11 and liquid discharges from the first gas / water discharge port 15, adjust the size of the sampling valve to reduce the flow rate. Then turn on the dissolved oxygen tester. After the reading of the instrument is stable, record the data. Finally, close the sampling valve in the second test pipeline 3, slowly open the waste liquid discharge port 12 to discharge the liquid in the test container 1. To ensure that the medium discharged after the oil-water mixture is filtered by the two-stage filter is an aqueous solution with less oil content, turn the second three-way valve 35 to discharge the medium filtered by the oil-water secondary filter 33, and observe the water quality condition after filtration. If the water quality meets the requirements, continue the test; if the water quality does not meet the requirements, the filter element in the filter needs to be replaced.

[0043] Although the present invention has been described with reference to the preferred embodiments, various modifications can be made thereto and components therein can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. An oxygen content testing device, characterized in that, Comprising: A test container (1) having two fluid inlets provided thereon; a probe protection tube (11) provided on the test container (1); A first test pipeline (2) and a second test pipeline (3) connected to the test container (1), the first test pipeline (2) and the second test pipeline (3) being respectively connected to the two fluid inlets; and A dissolved oxygen tester connected to the test container (1), the dissolved oxygen tester having a probe extending into the test container (1), and the probe of the dissolved oxygen tester extending into the test container (1) through the probe protection tube (11); The second test pipeline (3) includes an oil-water test pipeline (31), a filtering device is provided on the oil-water test pipeline (31), and a second liquid inlet valve (36) is provided between the oil-water test pipeline (31) and the test container (1); The filtering device includes a primary filter (32) and a secondary filter (33) connected in series; A first three-way valve (34) is provided at the outlet position of the primary filter (32), and a second three-way valve (35) is provided at the outlet position of the secondary filter (33); The primary filter (32) is internally provided with a filter element made of porous ceramic material, and the secondary filter (33) is internally provided with a filter element made of polypropylene material.

2. The oxygen content testing device according to claim 1, characterized in that, The first test pipeline (2) includes a water test pipeline (21), a sampling valve is provided on the water test pipeline (21), and the water test pipeline (21) is connected to the test container (1) through a first liquid inlet valve (22).

3. The oxygen content testing device according to claim 1 or 2, characterized in that, A waste liquid discharge port (12) is provided at the bottom of the test container (1), and a safety valve (13) is provided at the top of the test container (1).

4. The oxygen content testing device according to claim 1 or 2, characterized in that, A liquid level gauge (14) is provided on the side wall of the test container (1), and a first gas / water discharge port (15) is provided at the upper part of the test container (1).

5. The oxygen content testing device according to claim 1 or 2, characterized in that A second gas / water discharge port (16) is provided at the upper end of the test container (1).

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