Unconventional natural gas content automatic measuring apparatus and measuring method thereof

Abstract

The invention discloses an unconventional natural gas content automatic measuring apparatus. The apparatus comprises a gas collection measuring cylinder (3), a balancing measuring cylinder (4), a liquid storage tank (5), a data acquisition and control system (6), a host computer (7) and a lifting device (12) for driving the motion of the gas collection measuring cylinder (3) and the balancing measuring cylinder (4) relative to the liquid storage tank (5), each of the lower ports of the gas collection measuring cylinder (3) and the balancing measuring cylinder (4) is placed below the liquid level of the liquid storage tank (5), a precipitation tank (1) is placed in a constant temperature water-bath box (2), a gas guide tube A (18) is communicated with the precipitation tank (1) and the gas collection measuring cylinder (3), and a gas guide tube B (19) is communicated with the balancing measuring cylinder (4) and outside air. According to the invention, a photoelectric non-contact closed loop measurement and control method is adopted to realize the constant-pressure equal-volume automatic continuous measurement of the content of the natural gas in an unconventional natural gas reservoir sample, and the apparatus has the advantages of simple structure, reliable measurement and analysis results, simple operation, and high measurement precision.

Description

technical field [0001] The invention relates to a natural gas content measuring device, in particular to an automatic unconventional natural gas content measuring instrument and a measuring method. Background technique [0002] At present, the measurement of the natural gas content contained in natural gas reservoir samples at home and abroad refers to the collection of natural gas in the sample analysis tank under the conditions of a certain temperature (simulated reservoir temperature) and pressure (usually atmospheric pressure) within the specified measurement time. (that is, a closed container with constant volume) is the capacity of natural gas contained in a certain weight sample. At home and abroad, the micro pressure sensor gas volume measurement method and the gas flow meter measurement method are mainly used. The micro pressure sensor gas volume measurement method is that when the natural gas enters the closed metering tube from the analytical tank, the micro pres...

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Problems solved by technology

The micro pressure sensor gas volume measurement method is that when the natural gas enters the closed metering tube from the analytical tank, the micro pressure is increased, and the pressure makes the liquid level in the metering cylinder drop from the upper limit value. The measurement of the natural gas content is to read and record the measurement The capacity value corresponding to the scale change value after the liquid level in the tube drops to the lower limit value. At the same time, the vertical height of the liquid storage balance tube (that is, the end of the U-shaped tube connected to the atmosphere) must be changed manually so that the liquid level in the metering tube is in line with the The liquid level in the liquid storage balance tube is kept equal (that is, the micro pressure difference is zero), so as to ensure the accuracy of the gas content measurement; close the gas outlet valve of the desorption tank, open the gas outlet valve of the metering cylinder, adjust the height of the liquid storage pipe and make the metering cylinder and the storage tank The liquid level in the liquid pipe reaches the upper limit again; after closing the gas outlet valve of the metering cylinder and opening the gas outlet valve of the analytical tank, the next constant volume gas content measurement can be started. This method requires manual real-time observation and recording, human operation and reading errors The gas flow measurement method is to directly connect the gas flow meter at the outlet of the sample analysis tank to measure and automatically record the volume of natural gas precipitated by the sample. The measurement accuracy of this method depends on the The selected flowmeter, but because the analyzed natural gas contained in the reservoir sample is not a continuous constant flow flow, it affects the measurement accuracy of this method

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