An online large-range dynamic water level-temperature measurement system for geothermal wells

Abstract

The invention discloses an online wide-range dynamic water level-temperature measuring system of a geothermal well. The online wide-range dynamic water level-temperature measuring system comprises a crank connecting rod piston gas pump, first to fourth two-position three-way solenoid valves, first to second one-position two-way solenoid valves, a gas storage tank, first to second pressure difference sensing transducers, a controller with a display screen, a high-temperature-resistant gas guide signal control cable, a temperature sensor, a temperature transducer and a one-way valve, wherein the high-temperature-resistant gas guide signal control cable and the temperature sensor are placed in a measuring tube of the geothermal well; the temperature sensor, a signal line of the high-temperature-resistant gas guide signal control cable, the temperature transducer and the controller are sequentially connected; electrically controlled ends of first to fourth two-position three-way solenoid valves and the first to second one-position two-way solenoid valves, the signal ends of the first to second pressure difference sensing transducers and a start control end of the crank connecting rod piston gas pump are respectively connected with a connector end of the controller. Since measuring is carried out by combining a pressurizing mode with a gas exhausting mode, the system is very high in precision, is resistant to a high temperature and corrosion, is durable in use, is resistant to vibration and interference, and is capable of operating stably and reliably for a long time.

Description

technical field [0001] The invention relates to the field of geothermal well measurement, in particular to an online large-range dynamic water level-temperature measurement system for geothermal wells. Background technique [0002] The significance of online deep dynamic liquid level-temperature measurement of geothermal water wells is to protect the normal operation of submersible electric pumps, avoid damage to submersible electric pumps due to air pumping, and more importantly, to monitor the liquid level and temperature data of geothermal water wells for a long time. The recharge balance after thermal energy utilization provides reliable dynamic monitoring data to prevent land subsidence and protect the hydrogeological environment. [0003] At present, the liquid level gauge of the water measuring well generally adopts the manual or servo motor off-line method, which cannot achieve the purpose of online measurement; the liquid level measurement based on the principle of ...

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Problems solved by technology

[0003] At present, the liquid level gauge of the water measuring well generally adopts the manual or servo motor off-line method, which cannot achieve the purpose of online measurement; the liquid level measurement based on the principle of silicon pressure sensor makes the measurement 100-200 meters due to the bending of the long-distance atmospheric conduit. Long-distance, 100-meter-wide dynamic liquid level changes cannot be realized. Even if it is realized, the diameter of the sensing wire is very large due to the diameter of the air duct, and because of the high temperature of the geothermal water, the online long-term measurement is based on silicon pressure. The liquid level measurement of the principle of the sensor has very strict requirements on the technical requirements of the sensor transmitter's use environment (high temperature), packaging material (titanium alloy) and packaging technology (high temperature waterproof). At the same time, the entire pressure transmitter must be in the standard The measuring tube (1 inch in diameter) of the geothermal water well is placed in it, so the diameter of the entire pressure sensor transmitter should be less than 15mm

Furthermore, since the pressure sensor transmitter has been placed in high-temperature geothermal water with high salinity for a long time, the casing of the pressure sensor transmitter will quickly foul and block the measurement port, making the pressure sensor transmitter run fail

[0004] The fiber grating pressure and temperature measurement method is not applicable to the water level-temperature of online geothermal wells because of the hydrolysis of the fiber cladding and the limitation of temperature resistance (85 degrees Celsius), and because of the cost of the wavelength demodulator. Measurement

[0005] Although the capacitive water level measurement system (two parallel radiation cross-linked polyethylene encapsulated cables) is resistant to geothermal water corrosion and high temperature, due to the interference of the pump working conditions and the long-distance sounding depth of 200 meters, the measurement data Extremely unstable, deep dynamic geothermal water level measurement is impossible at all

[0006] The accurate measurement range of the bubble water level meter is up to 40 meters, and its measurement value is greatly affected by the density and temperature of the medium, so it is not suitable for deep dynamic water level measurement of geothermal wells

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