Device and method for measuring output liquid of coal bed methane well

Abstract

The invention discloses a device and a method for measuring output liquid of a coal bed methane well. The device comprises a buffer vessel, a fluid flowmeter and a connecting pipe, wherein the buffer vessel is provided with an inlet and an output of output liquid, the top of the buffer vessel is provided with a gas outlet, and the bottom of the buffer vessel is provided with a solid phase outlet; the fluid flowmeter and the connecting pipe constitute a U-shaped pipeline, and the fluid flowmeter is at the bottom of the U-shaped pipeline; and two ends of an exhaust pipe are respectively connected with the gas outlet of the buffer vessel and the liquid outlet of the U-shaped pipeline. The method is as follows: after the output liquid of the coal bed methane well is separated by the buffer vessel, the output liquid passes through the flowmeter to be measured. The method enables the liquid to be separated from solid phase coal dust and gas prior to passing through the flowmeter, and only the liquid passes through the fluid flowmeter. Therefore, the measuring accuracy is improved. When the output liquid is small in amount, the physical principle of the U-shaped pipeline is used for improving the measuring accuracy. The measuring method is high in accuracy, can be used for metering the output liquid of the coal bed methane well, the output oil or water in an oil gas well or other similar working conditions.

Description

Technical field [0001] The invention belongs to the field of liquid measurement, and specifically relates to a device and method for measuring the produced liquid of a coalbed methane well. Background technique [0002] Although it is known that the main component of the liquid produced by CBM wells is water, it also contains a small amount of pulverized coal and gas. Both pulverized coal and gas have a greater impact on the accuracy of liquid measurement. However, general liquids are still widely used in CBM wells. Flowmeter, the main problems of this measurement method are: [0003] 1. The pulverized coal will adhere to the impeller of the flowmeter, and the measurement will be inaccurate due to affecting the normal rotation of the impeller. [0004] 2. When the gas is compressed in the formation and discharged to the ground together with the liquid in the form of small bubbles, the pressure of the bubbles in the process of flowing from the bottom of the well to the ground will co...

AI Technical Summary

Problems solved by technology

No matter which flow form will greatly affect the speed of the impeller of the flowmeter due to the existence of gas, resulting in problems with the accuracy of liquid metering

[0005] 3. When the amount of produced liquid is small, it may occur that the produced liquid cannot fill the ground measuring pipe section equipped with the flow meter. At this time, although there is liquid flowing through, the impeller rotates slowly, resulting in accurate liquid measurement. degree of problems

If the liquid level is lower than the impeller of the flowmeter, the impeller will not rotate, and liquid metering cannot be performed at this time

[0006] The appearance of the above situations will not only affect the measurement accuracy of the liquid, but more importantly, the above three situations will easily lead people to misjudge the production status of the coalbed methane well, especially when the gas volume in the liquid is large or the liquid production rate is low. Larger errors in measurement accuracy lead to serious misjudgments of the production status of coalbed methane wells, which are prone to irreparable major economic losses

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