Portable sampling device and sampling method for oilfield wellhead produced liquid

Abstract

The invention relates to the technical field of oil well produced liquid measurement, in particular to a portable sampling device and method for oil field wellhead produced liquid. The portable sampling device for the oil field wellhead produced liquid comprises a liquid storage barrel and a sampling cup, the sampling cup is fixedly arranged at an outlet of a liquid drainage pipeline, and a stirrer is fixedly arranged in the liquid storage barrel; the stirrer is fixedly connected with the liquid storage barrel through a motor, and the motor adopts a rechargeable power supply; and the sampling cup is used for adding the emulsifier with the required concentration into the liquid storage barrel, sampling under the stirring state of the stirrer, stirring for 1-10 minutes, and discharging the required oil field wellhead produced liquid with the volume of 500-600mL into the sampling cup through the liquid discharging pipeline, so that the sampling operation is completed. By adopting the stirrer and adding the emulsifier, gas-liquid separation and oil-water two-phase emulsification in the oil field wellhead produced liquid in the sampling device are realized, stable emulsion is formed, a sample in the liquid storage barrel is isotropic, and accurate measurement of the water content of the oil well produced liquid is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of oil well produced fluid measurement, and relates to a portable sampling device and a sampling method for oil field wellhead produced fluid. Background Art

[0002] The accurate measurement of the water content of oil well produced fluid is of great significance to the water production of oil wells, oil-producing strata, estimation of crude oil production, prediction of oil well development life, oil well production quality control, oil well status detection, water injection operations, etc. The sampling work and whether the isotropy of the sample is stable directly affect the accuracy of the analysis. Only by taking accurate oil samples and ensuring the stability of the samples can the water content of the wellhead produced fluid be accurately measured.

[0003] In the daily sampling and analysis process, oil well crude oil samplers or ordinary sampling cups are generally used to take samples and then sent to the laboratory for testing and analysis. The interval from sampling to testing and analysis is generally 10h to 24h. The oilfield wellhead produced fluid is a three-phase mixture of oil, water and gas, which is generally unstable. After standing, the oil, water and gas three-phase separation phenomenon will occur. In the prior art, the oil phase in the taken out oilfield wellhead produced fluid adheres to the wall of the sampling container. During the analysis process, the oil phase adhered to the wall of the sampling container cannot be completely poured into the analysis vessel, so that the oil phase content in the analysis sample is lower than the oil phase content in the actual sample of the oilfield wellhead produced fluid. The analysis sample is not representative, which affects the accurate measurement of the water content of the oilfield wellhead produced fluid.

[0004] Therefore, a portable sampling device and a sampling method for oilfield wellhead produced fluid are provided. It is very necessary to ensure that the sampling of oilfield wellhead produced fluid is stable and representative. Summary of the invention

[0005] The present invention provides a portable sampling device and sampling method for oilfield wellhead produced fluid, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the problem that the existing produced fluid samples in oilfield wellhead produced fluid sampling are not representative, thus affecting the accurate measurement of the water content of the oilfield wellhead produced fluid.

[0006] One of the technical solutions of the present invention is achieved through the following measures: a portable sampling device for produced liquid at the wellhead of an oil field, comprising a liquid storage barrel and a sampling cup, wherein the top inlet of the liquid storage barrel is fixedly connected to a dosing pipeline, the lower inlet of the liquid storage barrel is fixedly connected to a produced liquid inlet pipeline, the bottom outlet of the liquid storage barrel is fixedly connected to a drainage pipeline, the top outlet of the liquid storage barrel is fixedly connected to an exhaust pipeline, a sampling cup is fixedly arranged at the outlet of the drainage pipeline, and an agitator is fixedly arranged inside the liquid storage barrel.

[0007] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions: A motor is fixedly installed on the top of the liquid storage barrel, and the agitator and the liquid storage barrel are fixedly connected through the motor, wherein the motor adopts a rechargeable power supply.

[0008] The above-mentioned feature is that a liquid level meter is fixedly arranged on the liquid storage barrel.

[0009] The above-mentioned dosing pipeline is fixedly provided with a dosing valve, the produced liquid inlet pipeline is fixedly provided with a sampling valve, the drain pipeline is fixedly provided with a drain valve, and the exhaust pipeline is fixedly provided with an exhaust valve.

[0010] The second technical solution of the present invention is achieved by the following measures: A sampling method for implementing a portable sampling device for oilfield wellhead produced fluid is carried out according to the following method: The first step is to prepare an emulsifier with a required ratio; The second step is to connect the oilfield wellhead produced fluid portable sampling device to the oilfield wellhead sampling pipeline; The third step is to start the motor; The fourth step is to perform sampling operations.

[0011] The following is a further optimization and / or improvement of the second technical solution of the above invention: In the first step, the raw materials of the emulsifier are calculated by mass percentage as follows: 10% to 90% of sodium hydroxide and 10% to 90% of sodium dodecylbenzene sulfonate.

[0012] In the fourth step above, the sampling operation process includes: S1, open the dosing valve and add the required amount of emulsifier into the liquid storage tank; S2, open the sampling valve, and when the sampled volume of the produced fluid at the wellhead of the oil field reaches 50% to 70% of the liquid level gauge, close the sampling valve; S3, after the agitator has stirred for the required time, the exhaust valve is opened to exhaust the air; S4, open the drain valve to discharge the required amount of oilfield wellhead produced liquid from the drain pipeline into the sampling cup; S5, close the exhaust valve and drain valve in sequence.

[0013] In the above step S1, the amount of emulsifier added is 10 mg to 500 mg of emulsifier per 1 L of sample in the liquid storage tank.

[0014] In the above step S3, the stirring time is 1 min to 10 min.

[0015] In the above step S4, the sample volume of the oilfield wellhead produced fluid discharged into the sampling cup is 500 mL to 600 mL.

[0016] The present invention realizes the separation of gas and liquid and the emulsification of oil and water phases in the oil field wellhead produced liquid in the sampling device by adopting a stirrer and adding an emulsifier, so as to form a stable emulsion, make the sample in the liquid storage barrel is isotropic, and ensure the accurate measurement of the water content of the oil well produced liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Attached Figure 1 This is a schematic diagram of the process flow of Example 1 of the present invention.

[0018] The codes in the attached drawings are: 1 is a liquid storage barrel, 2 is a sampling cup, 3 is a dosing pipeline, 4 is a produced liquid inlet pipeline, 5 is a discharge pipeline, 6 is an exhaust pipeline, 7 is a stirrer, 8 is a motor, 9 is a liquid level meter, 10 is a dosing valve, 11 is a sampling valve, 12 is a discharge valve, and 13 is an exhaust valve. DETAILED DESCRIPTION

[0019] The present invention is not limited by the following embodiments, and specific implementation methods can be determined according to the technical scheme of the present invention and actual conditions. Unless otherwise specified, the various chemical reagents and chemicals mentioned in the present invention are all known and commonly used chemical reagents and chemicals in the prior art; the percentages in the present invention are all mass percentages unless otherwise specified.

[0020] The present invention will be further described below in conjunction with embodiments: Embodiment 1: As attached Figure 1 As shown, the portable sampling device for produced liquid at the wellhead of an oilfield comprises a liquid storage barrel 1 and a sampling cup 2. The top inlet of the liquid storage barrel 1 is fixedly connected to a dosing pipeline 3, the lower inlet of the liquid storage barrel 1 is fixedly connected to a produced liquid inlet pipeline 4, the bottom outlet of the liquid storage barrel 1 is fixedly connected to a drainage pipeline 5, the top outlet of the liquid storage barrel 1 is fixedly connected to an exhaust pipeline 6, the outlet of the drainage pipeline 5 is fixedly provided with a sampling cup 2, and an agitator 7 is fixedly provided inside the liquid storage barrel 1.

[0021] The present invention adopts a stirrer 7 to fully stir the oilfield wellhead produced liquid in the sampling device, so as to promote the gas phase to fully overflow from the produced liquid, so that the produced liquid is converted from a three-phase mixture of oil, water and gas into a two-phase mixture of oil and water, thereby realizing the gas-liquid separation of the oilfield wellhead produced liquid in the sampling device.

[0022] Embodiment 2: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, a motor 8 is fixedly installed on the top of the liquid storage barrel 1, and the agitator 7 is fixedly connected to the liquid storage barrel 1 through the motor 8, wherein the motor 8 adopts a rechargeable power supply.

[0023] According to needs, the motor 8 can be a pure copper brushless motor with an operating voltage of 21V and a no-load speed of 1500r / min; the rechargeable power supply is powered by 20 to 30 40,000 mAh to 60,000 mAh lithium batteries, which are charged by a matching charger.

[0024] Embodiment 3: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, a liquid level meter 9 is fixedly arranged on the liquid storage barrel 1 .

[0025] According to the needs, the sampling amount is determined by observing the liquid level value of the liquid level meter 9.

[0026] Embodiment 4: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, a dosing valve 10 is fixedly provided on the dosing pipeline 3, a sampling valve 11 is fixedly provided on the produced liquid inlet pipeline 4, a drain valve 12 is fixedly provided on the drain pipeline 5, and an exhaust valve 13 is fixedly provided on the exhaust pipeline 6.

[0027] In the present invention, unless otherwise specified, the equipment and devices used are all the equipment and devices known and used in the art.

[0028] As required, the pipelines and equipment of the portable sampling device for oilfield wellhead produced fluid may be provided with conventional valves, thermometers, pressure gauges, etc. known and used in the art according to production needs.

[0029] Embodiment 5: As attached Figure 1 As shown, the sampling method of the portable sampling device for oilfield wellhead produced fluid is carried out according to the following method: The first step is to prepare an emulsifier with a required ratio; The second step is to connect the oilfield wellhead produced fluid portable sampling device to the oilfield wellhead sampling pipeline; The third step is to start the motor 8; The fourth step is to perform sampling operations.

[0030] Example 6: As an optimization of the above example, in the first step, the raw materials of the emulsifier are calculated by mass percentage as follows: 10% to 90% of sodium hydroxide and 10% to 90% of sodium dodecylbenzene sulfonate.

[0031] Embodiment 7: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, in the fourth step, the sampling operation process includes: S1, open the dosing valve 10 and add the required amount of emulsifier into the liquid storage tank 1; S2, open the sampling valve 11, and when the sampled volume of the produced fluid at the wellhead of the oil field reaches 50% to 70% of the liquid level meter 9, close the sampling valve 11; S3, after the stirrer 7 stirs for the required time, the exhaust valve 13 is opened to exhaust; S4, open the drain valve 12, and discharge the required amount of oilfield wellhead produced liquid from the drain pipeline 5 into the sampling cup 2; S5, close the exhaust valve 13 and the drain valve 12 in sequence.

[0032] As required, the gas is discharged from the exhaust pipeline 6. When the human body feels that there is no gas discharged from the exhaust pipeline 6, the drain valve 12 is opened to drain the liquid.

[0033] Example 8: As an optimization of the above example, in step S1, the amount of emulsifier added is 10 mg to 500 mg of emulsifier per 1 L of sample in the liquid storage tank 1.

[0034] In the present invention, an emulsifier is added to reduce the interfacial tension between the oil and water phases in the produced fluid at the oil field inlet in the sampling device, and then the oil and water are fully mixed by the stirrer 7 to form a stable emulsion.

[0035] Example 9: As an optimization of the above example, in step S3, the stirring time is 1 min to 10 min.

[0036] Embodiment 10: As an optimization of the above embodiment, in step S4, the sample volume of the oilfield wellhead produced fluid discharged into the sampling cup 2 is 500 mL to 600 mL.

[0037] Example 11: The sampling method of the portable sampling device for oilfield wellhead produced fluid is carried out according to the following method: The first step is to weigh 1g of sodium hydroxide and 9g of sodium dodecylbenzene sulfonate respectively, mix them evenly, and obtain an emulsifier; The second step is to connect the produced liquid inlet pipeline 4 to the oil field wellhead sampling pipeline; The third step is to start the motor 8 to put the stirrer 7 in a stirring state; The fourth step is to perform sampling operations: S1, open the dosing valve 10 and add 125 mg of emulsifier into the liquid storage tank 1 with a volume of 1 L; S2, open the sampling valve 11, and when the sampling volume reaches 50% of the liquid level meter 9, close the sampling valve 11; S3, after the stirrer 7 stirs for 10 minutes, the exhaust valve 13 is opened to exhaust; S4, when the human body touches the exhaust pipeline 6 and no gas is discharged, open the drain valve 12, and discharge 500mL of oilfield wellhead produced liquid into the 800mL sampling cup 2, which is recorded as sample 1; S5, close the exhaust valve 13 and the drain valve 12 in sequence, and the sampling is completed.

[0038] After sampling is completed, the waste sample in the liquid storage barrel 1 is discharged into the waste liquid collection barrel through the liquid discharge line 5 and is recycled to the system.

[0039] Example 12: Weigh 5 g of sodium hydroxide and 5 g of sodium dodecylbenzene sulfonate respectively to prepare an emulsifier, add 375 mg of emulsifier to the liquid storage barrel 1, the sampling amount of the oilfield wellhead produced liquid is 75% of the liquid level gauge 9, the stirring time is 1 min, and sampling is carried out according to the method of Example 11 to obtain the oilfield wellhead produced liquid, which is recorded as sample 2.

[0040] Example 13: Weigh 9 g of sodium hydroxide and 1 g of sodium dodecylbenzene sulfonate respectively to prepare an emulsifier, add 7 mg of emulsifier to the liquid storage barrel 1, the sampling amount of the oilfield wellhead produced liquid is 70% of the liquid level gauge 9, the stirring time is 1 min, and sampling is carried out according to the method of Example 11 to obtain the oilfield wellhead produced liquid, which is recorded as sample 3.

[0041] Comparative Example 1: The difference from Example 11 is that no emulsifier was added and no agitator was used during the sampling process, and the oil field wellhead produced fluid was obtained, which was recorded as Sample 4.

[0042] Comparative Example 2: The difference from Example 12 is that no emulsifier was added and no agitator was used during the sampling process, and the oil field wellhead produced fluid was obtained, which was recorded as Sample 5.

[0043] Comparative Example 3: The difference from Example 13 is that no emulsifier was added and no agitator was used during the sampling process, and the oil field wellhead produced fluid was obtained, which was recorded as Sample 6.

[0044] Comparative Example 4: The difference from Example 13 is that the agitator 7 is not used in the sampling process, and the oil field wellhead produced fluid is obtained, which is recorded as Sample 7.

[0045] Comparative Example 5: The difference from Example 13 is that no emulsifier was added during the sampling process, and the oil field wellhead produced fluid was obtained, which was recorded as Sample 8.

[0046] After the oilfield wellhead produced liquid samples 1 to 3 obtained in Examples 11 to 13 and the oilfield wellhead produced liquid samples 4 to 8 obtained in Comparative Examples 1 to 5 were left to stand in the sampling cup for 24 hours, the water content of the samples adhered to the wall of the sampling cup and the samples poured out from the sampling cup were measured according to the distillation method in GB / T8929 "Determination of Water Content in Crude Oil". The measurement results are shown in Table 1. It can be seen from Table 1 that: For the same sample in Examples 11 to 13, the difference in moisture content between the sample adhering to the sampling cup and the sample poured out from the sampling cup is 0.6%, 0.2%, and 0.4%, respectively, and the average difference is 0.4%, which is not much different; for the same sample in Comparative Examples 1 to 5, the difference in moisture content between the sample adhering to the sampling cup and the sample poured out from the sampling cup is 62.2%, 55.1%, 57.9%, 55.8%, and 47.4%, respectively, and the average difference is 55.7%, which is quite different; this shows that in the sampling process, using an emulsifier alone or using a stirrer alone to stir, the samples obtained are not uniform and stable, and the accuracy of the analysis results is poor. Using the method of the present invention, the samples are more uniform and stable, and the analysis results are more accurate.

[0047] In summary, the present invention utilizes a rechargeable power supply to power the agitator motor of the portable sampling device, thereby achieving continuity in multi-point oilfield wellhead produced fluid sampling and saving sampling time; by adding an emulsifier to the sampling device, the taken oilfield wellhead produced fluid forms a stable emulsion, thereby ensuring the accuracy of sample detection.

[0048] The above technical features respectively constitute various embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A portable sampling device for oilfield wellhead produced fluid, characterized in that It includes a liquid storage barrel and a sampling cup. The inlet at the top of the liquid storage barrel is fixedly connected to a dosing pipeline, the inlet at the bottom of the liquid storage barrel is fixedly connected to a produced liquid inlet pipeline, the outlet at the bottom of the liquid storage barrel is fixedly connected to a drainage pipeline, the outlet at the top of the liquid storage barrel is fixedly connected to an exhaust pipeline, a sampling cup is fixedly set at the outlet of the drainage pipeline, and an agitator is fixedly set inside the liquid storage barrel.

2. The portable sampling device for oilfield wellhead produced fluid according to claim 1, characterized in that A motor is fixedly installed on the top of the liquid storage barrel, and the agitator and the liquid storage barrel are fixedly connected through the motor, wherein the motor adopts a rechargeable power supply.

3. The portable sampling device for oilfield wellhead produced fluid according to claim 1 or 2, characterized in that A liquid level gauge is fixedly arranged on the liquid storage barrel.

4. The portable sampling device for oilfield wellhead produced fluid according to claim 1, 2 or 3, characterized in that A dosing valve is fixedly arranged on the dosing pipeline, a sampling valve is fixedly arranged on the produced liquid inlet pipeline, a drain valve is fixedly arranged on the drain pipeline, and an exhaust valve is fixedly arranged on the exhaust pipeline.

5. A sampling method for implementing the portable sampling device for oilfield wellhead produced fluid according to any one of claims 1 to 4, characterized in that Proceed as follows: The first step is to prepare an emulsifier with a required ratio; The second step is to connect the oilfield wellhead produced fluid portable sampling device to the oilfield wellhead sampling pipeline; The third step is to start the motor; The fourth step is to perform sampling operations.

6. The sampling method according to claim 5, characterized in that In the first step, the raw materials of the emulsifier are calculated by mass percentage as follows: 10% to 90% of sodium hydroxide and 10% to 90% of sodium dodecylbenzene sulfonate.

7. The sampling method according to claim 5 or 6, characterized in that In the fourth step, the sampling operation process includes: S1, open the dosing valve and add the required amount of emulsifier into the liquid storage tank; S2, open the sampling valve, and when the sampled volume of the produced fluid at the wellhead of the oil field reaches 50% to 70% of the liquid level, close the sampling valve; S3, after the agitator has stirred for the required time, the exhaust valve is opened to exhaust the air; S4, open the drain valve to discharge the required amount of oilfield wellhead produced liquid from the drain pipeline into the sampling cup; S5, close the exhaust valve and drain valve in sequence.

8. The sampling method according to claim 7, characterized in that In step S1, the amount of emulsifier added is 10 mg to 500 mg of emulsifier per 1 L of sample in the liquid storage tank.

9. The sampling method according to claim 7 or 8, characterized in that In step S3, the stirring time is 1 min to 10 min.

10. The sampling method according to claim 7, 8 or 9, characterized in that In step S4, the sample volume of the oilfield wellhead produced fluid discharged into the sampling cup is 500 mL to 600 mL.

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