RU2744486C1 - Method for determining mass of a gas-liquid medium component - Google Patents

Abstract

FIELD: measuring equipment.

SUBSTANCE: invention relates to measurement equipment and can be used for monitoring of flow rate and determination of mass of gas-liquid medium component (GLM) extracted, for example, from borehole. Essence of the invention is that the method of determining the weight of the gas-liquid medium component is characterized in that periodic identical portions of the amount of heat are periodically created in the cross-section of the channel with the gas-liquid flow, and is measured in points uniformly placed along the second cross-section, absorbed by each component in accordance with its heat capacity amount of heat in form of pulses of different amplitude, then, obtained at each point grouped pulses, which are identical in amplitude, and are determined from sums of the number of pulses of all single-type groups of all cross-sections of the weight fraction of each component of the flow.

EFFECT: simplification of determination of mass of gas-liquid medium component at limited instrumentation of measurement devices, reduction of computational and measuring operations requiring simultaneous execution.

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Description

The invention relates to measuring equipment and can be used to control the flow rate and determine the mass of a component of a gas-liquid medium (GLC), extracted, for example, from a borehole.

Known methods and devices for measuring the multiphase flow rate of multicomponent substances, for example, Zh (PP Kremlevsky. Flowmeters and counters of the amount of substance. St. Petersburg. Polytechnic. 2002. Book 2, p. 245), using several successively installed flowmeters with selective properties (Coriolis, volumetric and thermal), and a computing device that determines the costs of individual components based on the readings of the devices.

The disadvantages of the known solutions are the presence of a variety of devices, the large dimensions of the device and the total large error in measuring the flow rate.

The known method of component-wise measurement of the multiphase flow rate (RU 2428662 C2, 09/10/2011). The proposed flow meter according to the known method contains: a unit for measuring the velocity of a gas-liquid two-phase three-component flow, a unit for measuring the density of this flow and a unit for calculating the flow rate of each phase, while the unit for measuring the density contains a unit for extracting a mixed liquid with a pressure difference generator. Due to the forced mixing, even small bubbles are separated from the mixed liquid into the gas phase. In this case, the density measurement is carried out on the mixed liquid accumulated in the liquid storage tank.

The disadvantages of the known method are a large number of mechanical operations in determining the flow density, a part of the flow is selected for analysis, reducing the reliability of the measurement of the entire flow, and a long phase separation time.

The prototype is the method implemented in the device for determining the flow parameters of a multiphase medium of liquid and gas (RU 2386930 C2, 06/27/2009). Sensors with different dependences of readings on the flow rates of the flow components are placed in the measuring channel. To obtain the dependences of the sensor readings on the measured flow parameters during calibration, the sensor readings are recorded at various combinations of liquid and gas flow rates and sequential interpolation is performed. To determine the flow rates of two mutually insoluble liquids and a gas flow of a three-component mixture, three sensors are used, the dependence of the readings on the flow rates of liquids and gas is different. To determine the flow rates of two mutually insoluble liquids, the gas flow rate and the viscosity of the three-component mixture flow, four sensors are used, the dependence of the readings on the flow rates of liquids, gas and viscosity is different. In a particular case, sensors of the same type are placed in series-connected sections of the measuring channel of different diameters.

The disadvantage of the known method is the complex procedure for measuring and calculating the components of the gas mixture.

The technical result of the invention is to simplify the determination of the mass of a component of a gas-liquid medium with a limited instrumental composition of measuring devices, to reduce computational and measuring operations that require simultaneous execution.

The technical result is achieved by the fact that in the method for determining the mass of a component of a gas-liquid medium, pulsed equal portions of the amount of heat are periodically created in the cross-section of a channel with a gas-liquid flow, and the amount of heat absorbed by each component in the form of pulses of different amplitudes, then the pulses obtained at each point of the same amplitude are grouped and determined by the sums of the numbers of pulses of all groups of the same type of all points of the section of the mass fraction of each component of the flow.

The description of the method for determining the mass of a component of the gas mixture is carried out on the example of determining the flow rate of a three-component two-phase medium (gas, water, oil)

FIG. 1 shows the location along the flow of sections of a pulsed heat source and heat flow measuring sensors.

FIG. 2 shows a diagram of the removal of pulsed portions of the heat flow, from the sensor from various components of the GZhS medium, the dashed lines show their tariff values of the specific heat capacity with _p , 1 - impulses of the "water" group, 2 - impulses of the "oil" group, 3 - impulses of the "gas" group ".

The drawings indicate: 1 - Section of heating the medium, around the circumference of which is a pulsed stabilized energy source; 2 - Sensors, for example, A, B, etc., introduced directly into the flow of gas mixtures; 3 - measuring section with heat flow sensors; 4 - channel; 5 - GZhS flow; 6 - gas phase of the flow; 7 - liquid phase of the flow; 8 - a portion of the GZhM with the received heat impulse; 9 - flow of gas mixtures with a portion of the flow heat given by the components to the sensors; 10 - computing unit.

The principle of operation is based on the difference in the heat capacity of the three components of a two-phase medium, in the method for determining the mass of a component of a gas-liquid medium, which is characterized by the introduction of pulsed portions of the heat flux in the cross section 1 of channel 4, in different absorption of these heat portions by the components of the medium 6, 7, the transfer of the flow of 5 absorbed portions heat flow sensors located at various points in the next downstream section 3 of channel 4, and is based on the fact that electrical signals from absorbed portions by the components are transmitted to the computing unit 10 to determine the mass of the component.

In the computing unit, pulses of the same amplitude obtained at each point of the section are grouped and determined by the sums of the numbers of pulses of all groups of the same type of all points of the section into mass fractions of each component in the controlled flow.

The values of the specific heat capacities for the controlled components are determined in advance in the laboratory or use known data. So for the gas-liquid medium adopted for example (oil-water-gas), the values of the specific heat given in the table can be used.

A pulse stabilized power supply located around the circumference of the cross section 1 of channel 4 periodically sends pulses of thermal energy into the flow to the components 6, 7 of the flow 5 of the liquid-liquid mixture of the medium passing through channel 4. the rate of removal of the received energy of the heat flux from each sensor (previous signal readings).

Since in the zone of the heating section 1, the pulsed portions of the heat flux emitted from the power source are equal to each other and are the same for components of different mass, the absorbed amount of thermal energy will be proportional to the specific heat capacity _{p of} these components.

Further, the responses of the sensors to the perception of these portions of the heat flux from various components 6, 7 of the medium of the stream 5 are obtained with minimal loss of information in time and magnitude. To reduce the time of receiving information from components 6, 7 and significantly reduce the thermal exchange between them, increasing the reliability of the information received, it is desirable to use known sensors with a time constant of the order of 10 ^-5 s.

The masses of the components 6, 7 of the stream 5 pass a certain distance along the path along the flow from section 1 to section 3, with stored portions of thermal energy, the sensors receive thermal energy and transmit information to the receiving unit 10 of the calculator from each sensor.

The response of the sensors to the values of the heat flux from the components 6, 7 will differ depending on the different values of c _{p of the} components, as well as on the magnitude of the mass of the components. In the process of determining the mass of a component composed of GLM has two stages: the first stage - the transfer of thermal energy pulse each component from a pulsed source of thermal energy in accordance with the law of absorption α = F _abs / F _pit where F _pit - a unit portion of thermal energy supplied to the component, Ф _absorption = Ф _к = Кс _р М _к is the portion of the heat flux absorbed (assimilated) by the component. The second stage is the transfer of thermal energy stored by each component to the sensor. In the sensor, the heat flux Ф _{to the} component is converted into emf in the form of a dependence: Ф _к = К ₁ Е _к , where Е _к is the emf generated by the sensor, К and К ₁ are the proportionality coefficients.

The sensor receives the heat flux by periodic pulses that are proportional to the mass M _{K of the} component in the vicinity of the sensor. Further, the value of the heat flux Ф _к is transmitted to the computing unit 10 in the form of emf E _к

Ф _к = К ₁ Е _к = Кс _р М _К , proportional to the mass of each component 6, 7 of stream 5.

From source 1, a unit portion _{Фpit of} thermal energy, which is the same for various components, is given to component 6, 7 in the process of moving along channel 4 from section 1 to section 3. For various components, in this example, the values of Ф _к are designated as Ф _n - oil, Ф _c - water, F _g - gas.

Further, as you move along the channel 4, the components 6, 7 pass through the section 3 with sensors that perceive the heat flux from the masses of the components 6 and 7 of the two-phase medium. The sensors are evenly spaced across the cross section 3 of channel 4 and are in direct contact with the components. All sensors perceive only the flow of thermal energy, regardless of which components of the liquid phase 7 (oil or water) and the gas phase 6. Through each sensor, either oil, or water, or gas components alternately pass in pure form. In the pickup procedure, the same sensor, for example A or B or another, receives the heat flux from the masses of the passing components.

Consequently, for example, sensor A on the diagram with _p = K ₂ E _A / M _K (Fig. 2) may have time data on the values of the pulses F _k from the readings when the mass M _K passes. For example, pulses variable with _{p water} = K ₂ E _Av / M _in the component water mass _M, pulses variable with _{p oil} = K ₂ E _AN / M _n from oil component mass M _n and pulses variable with _{p gas} = K ₂ E _Ar / M _g from a gas component with a mass of M _g . Similarly, data from sensor B and sensors at other points are received. FIG. 2 shows that pure components have passed through sensor A when the impulses are equal to the tariff values adopted from the table, i.e. with _{p water} = 4.2; with _{p oil} = 2.0; with _{p gas} = 1.4.

The sensor converts the received heat flux into emf Ф _к = К ₁ Е _к . Per day at the point A goes _to water mass M _p ≡Σs _water (E _Aw), i.e. sum of all the pulses corresponding to the value of _water with _p = ₂ K _Av E / _M = 4.2, the oil mass M _{n p} ≡Σs _oil (E _En), i.e. the sum of all impulses corresponding to the value with _{p oil} = K ₂ E _An / M _n = 2.0 and the mass of gas M _g ≡∑c _{p gas} (E _Ar ), i.e. the sum of all impulses corresponding to the value of c _{p gas} = K ₂ E _Ar / M _g = 1.4. Similarly at other points. During a day, at point B, a mass of gas passes, a mass of water M _in ≡∑cr _water (E _Bb ), a mass of oil M _n ≡∑cr _oil (E _Bn ), a mass of gas M _g cr _gas (E _Bg ), and also at other points in section 3.

The data on the mass flow rate M of the flow 5 of the medium per day in channel 4 will be summed up separately for all readings of the emf at each point, the sensors in which cover the entire section. For this, it is necessary to have M≡∑c _p (E) of all points. This mass will DSA GLM channel 4. The individual components in their pure form will DSA M _{g, M,} M _n, summed over the specific heat capacity of components in the block 10.

This is the procedure for determining the mass of each component.

Based on the known specific heat capacity of the component with _p (laboratory data or others), the mass of the component in the mixture is calculated in accordance with its value with _p , which is shown by dashed lines in Fig. 2 (for oil, it is taken with _{p oil} = 2.0). In this case, the pulses obtained at each point are grouped with the same amplitude and the mass fractions of each component are determined by the sums of the numbers of pulses of all groups of the same type of all cross-section points.

Sensors receive heat flux regardless of the nature of the component, only on their heat capacity properties. With this method of determining the masses of the gas mixture, there are no special techniques and sensors for water, gas content, etc.

Thus, the problem of determining the mass of a component is solved with a minimum technopark of measuring instruments and computational process; data on the fraction of the density and viscosity of the mixture are not required.

Claims (1)

A method for determining the mass of a component of a gas-liquid medium, characterized in that pulsed equal portions of the amount of heat are periodically created in the cross-section of a channel with a gas-liquid flow, measured at points evenly spaced along the second downstream cross-section, absorbed by each component in accordance with its heat capacity, the amount of heat in the form of pulses of different amplitudes, then the pulses obtained at each point are grouped, which are the same in amplitude, and the mass fractions of each component of the flow are determined by the sums of the numbers of pulses of the same groups of all points of the section.

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