RU2499247C1 - Device to determine quantity of gases in liquid - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: device comprises a metering vessel (1), an additional vessel (2), a gas analyser (3), a filter (4), a drop collector (5), pneumatic valves (6, 7), a source of carrier gas and pipelines connected to listed process elements. The metering vessel (1) is connected to the drop collector (5), connected via the filter (4) with the gas analyser (3). In the mode of operation "without additional volume" the gas analyser (3) is connected via pneumatic valves (6, 7) with the metering vessel (1). In the mode of operation "with additional volume" the gas analyser (3) is connected via pneumatic valves (6, 7) with the additional vessel (2) to the source of carrier gas connected with the metering vessel (1).

EFFECT: higher efficiency, representativeness and accuracy of gas detection in a liquid, simplified design.

2 cl, 2 dwg

Description

The invention relates to devices for determining the amount of gases in a liquid, which, in particular, are used in direct geochemical methods for searching for oil and gas, for example, in gas logging, in laboratory conditions.

Known thermal vacuum degasser TVD-5M (see website, access mode: http://www.leuza.ru/tvd.htm) containing a sampler, a vessel for heating water with an electric heating element, a vessel for cold water, a vessel of a degasser, gas receiving vessel, pressure vessel, taps, vacuum gauge, vacuum pump, gas sampling unit. The degasser is designed for deep degassing of drilling fluid and sludge samples during geological and technological studies of the well during drilling, and formation fluid samples during testing of formations in order to determine their gas saturation, determine the composition of hydrocarbon gases and the nature of formation saturation.

A disadvantage of the known device is the low representativeness of the sample, low operational reliability in the field, a long degassing time of the sample (15-20 minutes) and the complexity of the design.

A device for sampling and introducing samples of the vapor equilibrium phase into a gas chromatograph (see USSR author's certificate for the invention No. 1659837, IPC G01N 30/16, publ. 06/30/1991), containing a mixer tank, a six-way distributor valve, pipeline connecting the input of the mixer tank to one of the inputs of a six-way tap and equipped with a gas flow regulator, a pipeline connecting the output of the container-mixer to one of the inputs of a six-way tap, a gas inlet pipe to a six-way valve, an equilibrium output pipeline gas-vapor mixture connecting the output of a six-way tap-switch with the entrance of a gas chromatograph. The device is additionally equipped with a liquid dosing device and a pipeline connecting this device with a mixer tank. The outlet pipe for draining the liquid from the mixer is connected to one of the inputs of a six-way switch tap. One of the outputs of the switch tap is used to discharge fluid. In addition, in the pipeline connecting the input of the mixer tank to the gas source, an additional gas flow regulator and an interrupt valve are installed. The same pipeline has an inlet and outlet for a fluid metering device.

A disadvantage of the known device is the low representativeness of the sample, which reduces the accuracy of measuring the concentration of the gas phase in the sample.

The closest technical solution to the proposed invention is a device for controlling the composition of the gas phase of a gas-liquid medium (see RF patent for utility model No. 36742, IPC G21C 17/022, publ. March 20, 2004), containing a measuring vessel, degasser, gas analyzer, a carrier gas source and pipelines attached to the above technological elements with locking elements, while the measuring vessel is made integral with the degasser, equipped with a pressure gauge connected to the gas volume of the vessel, and an indicator of the level of the liquid phase of the sample taken. The device is also equipped with a control unit, a level sensor and a pressure sensor in the gas volume of the vessel, as well as control elements on the locking elements, and the control unit is connected to these sensors and control elements.

However, a disadvantage of the known device for controlling the composition of the gas phase of a gas-liquid medium is the design complexity and the need for a carrier gas.

The problem to which the invention is directed, is to create a simple and reliable device with high representativeness of the sample, short degassing time of the sample (less than 2 minutes), without a source of carrier gas and a deep vacuum in the system.

The technical result achieved by the implementation of the invention is to increase the efficiency, representativeness and accuracy of determining gas in a liquid, as well as simplifying the design.

The specified technical result is achieved by the fact that the device for determining the amount of gases in the liquid, containing a measuring vessel, a gas analyzer, a carrier gas source and pipelines connected to the listed technological elements, according to the invention, is equipped with an additional vessel, a filter, a droplet collector, two pneumatic valves, while the measured the vessel is connected to a drip tray connected through a filter with a gas analyzer, and in the "without additional volume" mode, the gas analyzer is connected through a stump solenoid valves with a measuring vessel, and in the “with additional volume” operating mode, the gas analyzer is connected via pneumatic valves with an additional vessel with a carrier gas source connected to the measuring vessel.

It is advisable that atmospheric air be used as the carrier gas.

The device for determining the amount of gas in a liquid uses atmospheric air as a carrier gas, filling the system until the sample is included in the circuit and deep degassing of the sample is not required. The absence of the need for deep degassing of the sample allows the use of low pressure elements in the pneumatic system, which makes it possible to obtain a compact device. The absence of high temperatures (no heater) allows you to get a more representative sample, since in some cases, gas mixtures can change the composition (decompose) under the influence of high temperatures.

The invention is illustrated by drawings, which depict: in Fig.1 - pneumocircuit device for determining the amount of gas in a liquid (option with a gas analyzer); in FIG. 2 - pneumatic diagram of a device for determining the amount of gas in a liquid (version without a gas analyzer). Positions in the drawings indicate the following: 1 - measuring vessel; 2 - an additional vessel; 3 - gas analyzer; 4 - filter; 5 - drip tray; 6 and 7 - pneumatic valves; 8 - insert of chemical rubber; 9 - pump.

A device for determining the amount of gas in a liquid contains a measuring vessel 1 with a sample of the test fluid (drilling fluid), for example, a plastic bottle of 1.5 l (main volume), an additional vessel 2 (vessel with an additional volume of 0.25 l), gas analyzer 3, comprising a thermostat and a pump, a filter 4, a droplet collector 5, two pneumatic valves 6 and 7 (Fig. 1).

The measuring vessel 1 is connected to a droplet collector 5 connected through a filter 4 to a gas analyzer 3. In the "without additional volume" operating mode, the gas analyzer 3 is connected via pneumatic valves 6 and 7 with a measuring vessel 1, and in the "with additional volume" operating mode, the gas analyzer 3 is connected through pneumatic valves 6 and 7 with an additional vessel 2 with a source of carrier gas connected to the measuring vessel 1 (figure 1). All connections with pneumatic valves 6, 7 and gas analyzer 3 are made of flexible polyurethane tubes.

It is possible to determine the equilibrium state without a gas analyzer 3, but then it is necessary to check the tightness of the system for use in the field. In this case, it is necessary to use the chemical rubber insert 8 with a syringe and pump 9 for bubbling the samples, which are installed in the pneumatic circuit of the device when determining the equilibrium state without a gas analyzer 3. In this case, insert 8 and pump 9 are connected in series between the filter 4 and the pneumatic valve 7 (figure 2).

A device for determining the amount of gas in a liquid is used as follows.

A drilling fluid sample is taken from the reservoir, for example, into a plastic bottle with a capacity of 1.5 l (measuring vessel 1) and hermetically sealed with a plastic stopper. Then, without breaking the tightness, the bottle is opened, during which two tubes are inserted through the holes in the plastic stopper of the bottle, one of which (a long tube) is inserted into the bottom of the bottle and provided with a fitting for connecting the sample bottle to the other end (measuring vessel 1 ) into the measuring circuit with the gas analyzer pump 3 for degassing by means of bubbling (i.e., the principle of operation is based on forced bubbling by means of a pump of a liquid column at different volumes of super-liquid space). The other tube (short tube) at one end is located at the top of the sample bottle and is equipped with a fitting at the other end. Thus, by opening a plastic stopper without breaking the seal, two ports are created for connecting to the measuring circuit: the first port is a long tube located at one end at the bottom of the bottle in the working position with a fitting on the other side; the second port - a short tube located at one end in the upper part of the bottle above the sample, has a fitting on the other side (i.e., the principle of operation is based on the hermetic mechanical opening of the bottle cap with the sample, followed by the implementation of a two-port circuit for connecting the test sample to the measuring circuit).

Then the gas analyzer pump 3 is turned on, after a while the so-called equilibrium state occurs, which is fixed by the gas analyzer included in the measuring circuit (gas readings stop increasing and are set at the same level), after which the results of measuring the concentration of gas-air mixture (DHW) are taken (% by volume is measured ) Then, using two pneumatic valves 6 and 7, an additional vessel 2 (volume 0.25 l) is connected to the measuring circuit. The gas analyzer pump 3 is turned on again and after some time an equilibrium state occurs, but the gas readings of the gas analyzer 3 will be lower due to dilution with atmospheric air located in the additional vessel 2. The results of measuring the DHW concentration are recorded.

The values of the volume of the system that is not filled with the sample, and the volume of the sample, as well as gas readings in the case of “with additional volume” and “without additional volume” are substituted into the well-known formula (see, for example, USSR copyright certificate No. 941887, IPC G01N 7/14, published on 07.07.1982) and the calculation of the volumetric gas content of the sample is performed (i.e., cm ³ / l of the drilling fluid sample is located)

$$q=(Q_{\mathrm{well}}^{n}V\text{'}\text{'}{C}_{\infty }^{\text{'}\text{'}}-Q_{\mathrm{well}}^{\text{'}\text{'}}{V}^n{C}_{\infty }^n)/[Q_{\mathrm{well}}^{\text{'}\text{'}}{Q}_{\mathrm{well}}^n(C_{\infty }^n-C_{\infty }^{\text{'}\text{'}})],$$

- объем первой пробы исследуемой жидкости;Where $$Q_{\mathrm{well}}^{\text{'}\text{'}}$$

- the volume of the first sample of the investigated fluid;

V 'is the volume of gas space for the first sample;

- равновесная концентрация компонента для первой пробы; $${\mathrm{FROM}}_{\infty }^{\text{'}\text{'}}$$

- the equilibrium concentration of the component for the first sample;

- объем второй пробы исследуемой жидкости; $$Q_{\mathrm{well}}^n$$

- the volume of the second sample of the investigated fluid;

V ⁿ is the volume of gas space for the second sample;

- равновесная концентрация компонента для второй пробы. В устройстве выбраны одинаковые объемы проб жидкости $$(Q_{ж}^{\text{'}}=Q_{ж}^n)$$

при разных объемах газового пространства, что приводит к частному случаю реализации способа определения количества газов в жидкости. $${\mathrm{FROM}}_{\infty }^n$$

is the equilibrium concentration of the component for the second sample. The device selected the same volume of fluid samples $$(Q_{\mathrm{well}}^{\text{'}\text{'}}=Q_{\mathrm{well}}^n)$$

with different volumes of gas space, which leads to a special case of the implementation of the method for determining the amount of gas in a liquid.

It is possible to determine the equilibrium state without a gas analyzer 3, but then it is necessary to check the tightness of the system for use in the field. In this case, you will need an insert 8 of chemical rubber for sampling with a syringe for the operating modes "with additional volume" and "without additional volume" for feeding into gas analysis equipment, as well as a pump 9 for bubbling the sample (figure 2).

Claims (2)

1. A device for determining the amount of gas in a liquid, containing a measuring vessel, a gas analyzer, a carrier gas source and pipelines connected to the listed technological elements, characterized in that it is equipped with an additional vessel, a filter, a droplet collector, two pneumatic valves, while the measuring vessel is connected to a droplet collector connected through a filter with a gas analyzer, and in the “without additional volume” operating mode, the gas analyzer is connected through pneumatic valves with a measuring vessel, and in the “with additional volume "the gas analyzer is connected via pneumatic valves with an additional vessel with a carrier gas source connected to the measuring vessel. 2. The device according to claim 1, characterized in that atmospheric air is used as the carrier gas.

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