Automatic measurement method and system capable of being used for low water yield of coalbed gas well

Abstract

The invention belongs to the technical field of coalbed gas production, and discloses an automatic measurement method and system capable of being used for low water yield of a coalbed gas well. The automatic measurement system includes a sensor control system, a data processing system and a main water way system. In the main water way system, a water outlet of the coalbed gas well is connected with an inlet of a water tank through a water inlet pipeline, an outlet of the water tank is connected with an evaporation tank through a water outlet pipeline, the water outlet pipeline is provided witha drainage pump, a valve and a water meter in sequence; three water level probes are arranged in the water tank, and one of the water level probes is higher than the other two water level probes; thesignal output ends of the three water level probes are connected with the sensor control system; the output end of the sensor control system is connected with the drainage pump for controlling the operation of the drainage pump and further sending a time signal of starting the drainage pump to the data processing system; and the data processing system is used for recording the drainage signal andcalculating the water yield. According to the automatic measurement method and system, the water yield of the coalbed gas well with small water yield can be effectively measured, and the automatic measurement method and system can be widely used in the field of coalbed gas production.

Description

technical field [0001] The invention belongs to the technical field of coal bed gas extraction, and in particular relates to an automatic metering method and system applicable to low water production of coal bed gas wells. Background technique [0002] Water production is a drainage parameter in the process of coalbed methane development and utilization. Accurate measurement of water production is of great significance to the study of the relationship between the height of coalbed methane liquid column, casing pressure, bottomhole flowing pressure, and coal seam water production. On-site coalbed methane wells have different water discharge conditions, such as dripping water and intermittent water discharge. The previous measurement method is to manually go to the site and calculate the daily water output by the time it takes to fill a 5-liter measuring cup. This measurement method will cause the following problems: 1. The water output of the coalbed methane well with the pum...

AI Technical Summary

Problems solved by technology

The past measurement method is to go to the site manually to calculate the daily water output by the time it takes to fill a 5-liter measuring cup. This measurement method will cause the following problems: 1. The water output of the coalbed methane well with the pumping unit is not uniform. Therefore, the water production rate measured during that period is quite different from the average water production rate of the day, and the error will be even greater after back calculation

2. It may take more than an hour to fill a 5-liter measuring cup, which is unacceptable to the inspectors. They can only take part of the water to calculate the daily water content, and the error will become larger

3. The method was used to measure twice in a row on site, and the results were very different

The above phenomena prove that it is impossible to measure accurately with this method

Later, some water meters were connected to the water pipes for measurement, but after investigation, it was reported that the water meters were easily blocked and could not be measured, especially when the water volume was small, and it was easy to settle

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