RU2655866C1 - Plant for measuring production rate of gas condensate wells - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil and gas industry and can be used for the operational metering of production rates of gas condensate deposits and studies of the operation of multiphase flowmeters on a real gas mixture, formation water and unstable gas condensate produced directly from the well. Plant comprises a separator, a liquid flow meter installed in a liquid line, a gas flowmeter and a sampler with an additional separation unit installed in a gas line. In this case, gas discharge line from the separator contains the main and additional metering and control units. Separator is equipped with a gas-liquid flow distributor and centrifugal separation elements, made without a condensate collector and connected to a horizontal two-section separator of liquid immiscible phases with separation of liquid phases due to their different specific gravity and light phase transfusion through the separation wall, the compartments of which are equipped with lines for the discharge of formation water and unstable condensate, equipped with one main and one additional metering and control unit, while formation gas-liquid mixture injection line into the separator is additionally equipped with piping for the serial connection of a flow-through multiphase flowmeter for the study of the features of its operation on the flow of a real formation gas-liquid mixture in the well conditions. Gas-liquid mixture discharge line from the plant contains two static mixers, the first of which combines flows from the main gas metering and control units, formation water and unstable condensate, and creates a flow of gas-liquid mixture with the possibility of regulating the total production rate and the ratio of the phases in the mixture, and the second one combines excess gas streams from the separator and formation water and unstable condensate from the separator from the additional metering and control units with the flow created at the first static mixer, to discharge the combined mixture from the plant to the well flow piping, as well as piping for sequential connection of the flowing multiphase flowmeter under study on the flow with the specified production rate and phase ratios in the mixture, and additional separation unit for monitoring and metering the unseparated drip liquid in the separation gas is additionally equipped with a mobile probe with a pointed tip, a mass flowmeter, a regulating valve to ensure isokinetic sampling by controlling the flow rate of a sample by the signal from the mass flowmeter, a recuperative heat exchanger to cool the sample gas stream and a heating cable to heat the sample gas flow to ensure isothermal sampling.

EFFECT: measurement of well production rates of gas and gas condensate fields with a small error on the flow of formation gas-liquid mixture without accumulation of phases for measurement purposes, and also research of features of operation of existing and perspective types of instruments for in-line measurement of multiphase production rates of gas condensate wells in field conditions and on real working mixtures with an unstable liquid content.

5 cl, 2 dwg

Description

The invention relates to the oil and gas industry and can be used for operational accounting of production rates of gas condensate fields and studies of the operation of multiphase flow meters in a real mixture of gas, produced water and unstable gas condensate obtained directly from the well.

Determining the flow rate of a well, the product of which is a reservoir gas-liquid mixture of GHS (reservoir mixture, reservoir fluid, fluid), which is under significant overpressure and contains a significant amount of unstable gas condensate (hereinafter NC), is a difficult engineering task.

The source of reservoir GHS is the production of gas or gas condensate wells in the fields.

Currently, existing methods for determining the flow rate of multiphase flows with the content of an unstable liquid phase are either poorly studied or do not give reliable and metrologically confirmed results. A standard reproducing multiphase flow with the content of an unstable liquid phase does not exist in industry to verify emerging multiphase flow meters.

For this reason, samples produced by industry are tuned and tested on multi-phase flow test benches, where oil, oil or other hydrocarbon liquids that are stable (non-boiling or low boiling) under normal conditions are used as the liquid hydrocarbon phase. They can even be used with an unstable liquid, for example, industrial refrigerant refrigerant isobutane, the boiling point of which, like any one-component liquid, is expressed by a clear curve in the classical phase diagram used in thermodynamics. This component under thermobaric conditions of measurements of the MPF will be either liquid or gaseous, that is, in fact, although unstable in atmospheric conditions, it will be strictly stable under given measurement conditions.

However, the difficulty lies in the fact that the gas-unstable gas condensate system of gas fields is quasistable. In it, the liquid - condensate - is a homogeneous mixture of various components - hydrocarbon monomers and isomers (ethane, propane, butane, etc.), and gas, except methane, contains gaseous ethane, a small amount of propane and vanishingly small amounts of higher components (isobutane , butane, etc.). That is, with any, even insignificant, change in temperature and pressure, a small amount of “heavy” gas components, such as propane and ethane, can condense, or vice versa, a small amount of “light” gas condensate components can boil and pass into the gas phase. The main amount of these components that are easily passing from one phase state to another, both in gas and in condensate, are the same ethane and propane. They are “heavier” than the main “light” component of methane gas, which practically does not condense, and “lighter” than the “heavy” components of condensate, isobutane, butane, isopentane, pentane, etc., which generally do not boil within the pressure range, taking place in the flow part of the MFR. This feature, as a rule, is taken into account by the MFR algorithm, but should be verified in real operation.

In the process of any gas-dynamic studies of wells, including measuring the flow rate of a well, it is necessary to take samples of gas and liquids. The selection of representative samples of PV, NK, and in particular the gas of separation, is a difficult task. In practice, despite the perfection of the developed methods and equipment, because of their complexity, the percentage of low-quality gas samples is high. The sample may also be spoiled in the laboratory due to incorrect actions in preparation for the analysis or due to insufficient equipment of the laboratory. The most difficult are the sampling and processing of gas samples.

Currently, a number of methods are known for accounting for the flow rates of gas condensate and oil wells and installations for their implementation.

The technical result of the known solutions is aimed at ensuring high-quality separation of formation fluid (reservoir GHS) into phases and accurate measurement of the amount of separated liquid and gas with the possibility of sampling.

Known methods for measuring the liquid flow rate of wells based on measuring the volume or weight of the fluid accumulated in the separation tank for the measured time and recalculating the received information about the amount of fluid and the time of its accumulation in the daily flow rate of the well. In particular, there are known installations for measuring the flow rate of oil wells of the "Sputnik-A", "Sputnik-A-40" type, where the production of the measured well is directed to a hydrocyclone separator, in which free gas is separated and goes into the gas manifold, and the fluid flow rate is measured by short-term passes through a turbine meter of liquid accumulating in the separator and recording volumes on an individual meter in the local automation unit (BMA), liquid accumulation in the lower separator vessel to a predetermined upper level and its release to the lower level is carried out with the help of a float regulator and a gas line damper (Reference book on oil production, edited by Doctor of Technical Sciences Sh. K. Gimatudinova. M., "Nedra", 1974, p. 487- 489).

The well-known "Method and installation for measuring production rates of gas condensate and oil wells" according to the patent of the Russian Federation No. 2532490 from 06/20/2013, publ. November 10, 2014

The method for measuring the production rates of gas condensate and oil wells consists in feeding the product in the form of a gas-liquid mixture to a hydrocyclone separator with a condensate collector, preliminary accumulating liquid in a condensate collector, separating the gas-liquid mixture into a liquid and gas in a hydrocyclone separator, followed by supplying gas to a gas pipeline line containing a flow meter gas, and supplying liquid to a liquid pipeline line containing a liquid flow meter, determining a gas and liquid flow rate with with the help of gas and liquid flow meters, and at the same time, the separation of the gas-liquid mixture in the hydrocyclone separator and the gas and liquid flow to the gas and liquid flow meters in the gas and liquid pipelines are carried out continuously, a gas sample is taken from the gas pipeline using a sampling probe, the condensate content in the sample is analyzed gas using an additional separation unit and determine the production rate of the well, taking into account the condensate content in the gas according to the additional separation unit.

The apparatus for measuring the production rate of oil wells contains a hydrocyclone separator with a condensate collector, a liquid pipeline connected to a condensate collector and a gas pipeline connected to a hydrocyclone separator, a liquid flow meter installed in the liquid pipeline, a gas flow meter installed in the gas pipeline it is equipped with at least one inlet in the gas pipeline line and an additional separation unit made oh with the ability to determine the content of condensate in the gas, (adopted as a prototype)

The disadvantage of this method (according to the prototype) and the used device for implementing the method is that it:

- effective separation of the gas phase is not ensured;

- not provided for the possibility of continuous separation of a mixture of liquid immiscible phases (PV and NK), their continuous withdrawal and accounting separately without prior sedimentation;

- representativeness of gas sampling for continuous determination of the residual content of the dispersed phase is not ensured, since sampling can only be carried out from the near-wall region of the gas pipeline, without observing the isokinetics of the sampling, with distortions in the concentration of dispersed particles, phase transitions due to non-compliance with the thermobaric parameters during sampling.

The objective of the invention is the creation of a production line that allows you to continuously divide the reservoir GHS into single-phase flows (PV, NK, Gas) and work in two modes: to determine the flow rate of the reservoir fluid of the wells of gas and gas condensate fields and to study the operation of multiphase flow meters in the flow of a gas mixture of the reservoir water and unstable gas condensate obtained by mixing these phases at the outlet of the installation in predetermined proportions.

The technical result is the measurement of the flow rates of gas and gas condensate fields with a small error on the flow of the reservoir GHS without phase accumulation for measurement purposes, as well as the study of the features of the existing and promising types of devices for in-line measurement of multiphase flow rates of gas condensate wells in the field and on real working mixtures containing unstable liquids.

The technical result is achieved by the fact that the installation for measuring the production rate of gas condensate wells, comprising a separator, a liquid flow meter installed in the liquid pipe line, a gas flow meter and a sampler with an additional separation unit installed in the gas pipeline line, while the gas outlet line from the separator contains the main and additional metering and control units, the separator is equipped with a gas-liquid flow distributor and centrifugal separation elements, It is without condensate collector and connected to a horizontal two-section separator of liquid immiscible phases with separation of liquid phases due to their different specific gravity and transfusion of the light phase through the separation wall, the compartments of which are equipped with production water and unstable condensate discharge lines equipped with one main and one additional metering unit and regulation, while the line for entering the reservoir gas-liquid mixture into the separator is additionally equipped with a strapping for serial connection of the flow a multiphase flow meter for investigating in the well conditions the features of its operation on the flow of a real reservoir gas-liquid mixture, the gas-liquid mixture withdrawal line from the installation contains two static mixers, the first of which combines flows from the main metering and control units of gas, formation water and unstable condensate, and creates a flow gas-liquid mixture with the ability to control the total flow rate and phase ratio in the mixture, and the second combines the flow of excess gas from the separator and produced water and is unstable about condensate from the separator from additional metering and control units with a stream created on the first static mixer for outputting the combined mixture from the installation to the downhole loop, as well as a strapping for sequential connection of the flow multiphase flow meter under study with a given flow rate and phase ratios in the mixture , and an additional separation unit for monitoring and accounting for unseparated dropping liquid in the separation gas is additionally equipped with a mobile probe with an attacking tip a nozzle, a mass flow meter, a control valve to ensure sampling isokinetics by adjusting the sample flow rate according to the mass flow meter signal, a recuperative heat exchanger to cool the gas sample stream, and a heating cable to heat the gas sample stream to ensure isothermal sampling.

The source of reservoir GHS is the production of gas or gas condensate wells. After separation of the mixture in the separator and separator, the flow rates of single-phase flows are measured: gas phase - wet natural gas, hereinafter referred to as "gas"; aqueous solution - water, water-methanol solution, produced water (PV) with the content of salts and methanol, hereinafter referred to as “produced water” or “PV”; a liquid hydrocarbon phase that does not form chemical compounds, solutions, stable suspensions, emulsions or foam — unstable gas condensate (NK), a mixture of stable, unstable condensate, hereinafter referred to as “unstable condensate” or “NK” with water or aqueous solutions.

The inventive device is presented in the drawings:

FIG. 1 is a general view of a production line.

FIG. 2 - the relative position of the separator and the separator, shown on a fragment of the production line, including the separator and the separator of liquid phases.

The installation consists of the following nodes and elements:

1) The unit for connecting to the cluster strapping 1 (Fig. 1), including flexible high-pressure hoses, fittings for connecting the unit to fountain fittings and auxiliary networks (horizontal flare unit, drainage tank, mobile steam generator unit, etc.), as well as an electric shut-off device fittings for remote and local control of the flow of formation fluid through the installation or bypassing it, as well as devices for remote and local measurement of the temperature and pressure of the reservoir GHS at the inlet and outlet of the installation.

2) Connection node multiphase flowmeter 2 for research in thermobaric conditions of the well. It includes a strapping that allows passing the flow of formation fluid (reservoir GHS) through the instrument under study or bypassing it. The harness includes instruments for measuring temperature and pressure of the medium.

3) Harness 3 for connecting a mobile metering device (MZU), designed to measure the flow rate of the wells by the method of selecting part of the flow, to study the operation of this device in the conditions of the well.

4) Vertical gas separator 4, equipped with pressure and temperature measuring instruments.

The separator contains three stages of separation:

The first is a gas-liquid flow distributor 6 (Fig. 2) at the inlet 5, which provides for the separation of large drops of liquid and evenly distributes the gas stream over the entire cross section of the apparatus.

In the middle part of the separator, the cross section of the apparatus is blocked by two sheets 7 and 8 with centrifugal separation elements (ECS) installed on them — the second and third separation stages.

The gas stream rises up and leaves the separator 4 through the outlet nozzle 9.

The vertical gas separator 4 does not contain a liquid storage (condensate collector), which reduces its height for placement on a car trailer, also simplifies the process control of the continuous removal of liquid from the separator. The liquid from the separator is removed by gravity through the pipe 10 into a horizontal separator 11 located in close proximity.

5) The horizontal separator 11 is equipped with a separation section for intensifying the process of separation of liquid immiscible phases, equipped with pressure and temperature measuring devices.

The horizontal separator 11 has two compartments 12 and 13, separated by a vertical partition 14. Compartment 12 is designed to receive and separate a heterogeneous mixture of liquid immiscible phases: an aqueous solution of salts and alcohols (produced water) and liquid hydrocarbons (unstable condensate), as well as the removal of excess formation water through the fitting 16.

In compartment 12 of separator 11, an internal device 15 is installed over the entire cross section of the apparatus, which degasses the mixture of liquid phases with high efficiency and high performance and separates it into PV (produced water) and NK (unstable condensate) due to their different specific gravity. NK, occupying the upper layer, is transferred through a vertical wall 14 into the second compartment 13 of the separator 11. The output of an excessive amount of unstable gas condensate from the compartment 13 of the separator 11 is carried out through the fitting 17.

The separator 11 comprises a level gauge for the general liquid level and a liquid phase separation level 18 and a level gauge for measuring the level of unstable gas condensate 19. (FIG. 1).

To equalize the pressure in the separator 4 and the separator 11, an equalization line 20 is provided.

The output of produced water from compartment 12 of the separator 11 is carried out along line 21, and the withdrawal of oil from compartment 13 is carried out along line 23. Line 21 is equipped with fittings for sampling produced water 22, and line 23 is equipped with fittings for sampling unstable gas condensate 24.

6) The filter block of line 25, in which two filters are provided: a working one and a reserve one, as well as stop valves for switching them and devices for remote and local monitoring of filter contamination by the pressure drop across them.

7) The unit for regulating the flow and measuring parameters of PV 26, including valves, a mass flow meter with a density measurement function, an automatic valve-regulator of flow with an electric actuator, a check valve.

8) Block for level control and measurement of parameters of PV 27, including valves, a mass flow meter with a density measurement function, an automatic valve-regulator with an electric actuator that maintains the level of PV in compartment 12, a non-return valve.

9) Filter block 28 of line 23, in which a filter is provided, as well as shut-off valves providing the ability to turn off the filter and work without it, and a device for remote and local monitoring of filter contamination by the pressure drop across it.

10) Flow control and parameter measurement unit NK 29, including valves, a mass flow meter with a density measurement function, an automatic flow control valve with an electric actuator, a check valve.

11) The unit for level control and measurement of parameters of NK 30, including shutoff valves, a mass flow meter with density measurement function, an automatic valve-regulator with an electric actuator that maintains the level of NK in compartment 13, a non-return valve.

12) Drain line 31, equipped with shutoff valves, which allows you to remove the MF and NK from the separator 11 to complete work and maintenance.

13) The block of safety valves 32 mounted on the equalization line 20 to protect against overpressure of the separator 4 and the separator 11.

14) The gas outlet line 33 from the separator 4.

15) Sampling probe 34 with a device for its automatic movement and extraction, installed in line 33.

16) The measurement unit 35 of the content of the dispersed phase in the gas (ISDF).

17) The unit for controlling the flow and measuring gas parameters 36 includes: a mass flow meter or a volumetric flow meter with direct sections before and after it, gas temperature and pressure measuring instruments, a valve for pouring the hydrate inhibitor in the line after the flow meter, an automatic electric flow control valve, check valve.

18) The unit for regulating the flow and measuring gas parameters 37 includes: a mass flow meter or a volumetric flow meter with direct sections before and after it, gas temperature and pressure measuring instruments, a valve for introducing a hydration inhibitor into the line after the flow meter, an automatic electric flow control valve, check valve.

19) A block of a static or ejection mixer 38, designed to mix the gas entering after block 36, PV after block 26, NK after block 29, also equipped with an output line with installed temperature and pressure measuring instruments.

20) Tying 39 for connecting a mobile metering device (MZU), designed to measure the flow rate of wells by the method of selecting a part of the flow, to study the features of this device in the full range of flow rates of GHS and the ratios of gas, liquid hydrocarbon phase and aqueous solutions in the mixture.

21) A unit for connecting a multiphase flow meter 40 for studies in the full range of GHS flow rates and the ratios of gas, liquid hydrocarbon phase and aqueous solutions in the mixture. It includes a strapping that allows passing the flow of formation fluid through the instrument under study or bypassing it. The harness includes instruments for measuring temperature and pressure of the medium.

22) A static mixer or an ejection mixer 41, designed to mix the gas entering after block 37, PV after block 27, NK after block 30 and GHS after block 38.

23) High-speed valve 42 for depressurizing and blowing gas from the separator 4, line 34 and blocks 36, 37 onto the torch.

24) High-speed valve 43 to relieve pressure and relieve medium and purge piping to the torch.

25) The information processing unit (BOI) in the cabinet (not shown in Fig.).

26) Semi-trailer (not shown in FIG.). Cargo truck semi-trailer of standard size. It is retrofitted with a front rolling trolley, thanks to which it is transformed into a trailer.

27) An operator station as part of a separate self-propelled transport-utility vehicle (not shown in FIG.).

The implementation of the invention

Installation can work in two modes:

Mode 1 - determining the flow rate of the reservoir GHS and the creation of GHS from pre-separated phases with arbitrarily set parameters in a wide range to study the operation of the multiphase flow meter in the full range of GHS flow rate and the content of the mixture components (the blocks indicated in Fig. 2 are additionally involved in the work , 3, 27, 30, 37, 39, 40).

Mode 2 - determining the flow rate of the reservoir GHS in the well conditions (the blocks indicated in Fig. 2, 3, 27, 30, 37, 39, 40 are not involved in the work).

Installation operation in mode 1

By means of flexible hoses equipped with quick disconnect couplings (BRS) provided as part of the connection unit to the well 1, the installation is connected to the fountain fittings of the well or bypass fittings of the loop pipe of the well bush so that the full flow of the reservoir GHS passes through the installation.

The input group of valves with remote control (the diagram shows full bore ball electric valves, but any valves, gates, valves, valves can be used), which is part of the connection unit to the bush 1, serves for automatic emergency shutdown of the installation and smooth switching of the flow back to the loop Bypassing Installation.

At the entrance of the reservoir GHS to the installation, a connection unit for a multiphase flow meter is provided to study the features of its operation on the reservoir GHS and in the thermobaric conditions of the well or plume 2. In the strapping, means for controlling the temperature and pressure of the flow, as well as straight sections before and after the flow meter under study, are provided. In the study of MPF in this case, the flow rate and the content of NK and PV in the reservoir GHS can be measured within narrow limits determined by the limited possibilities of regulating the source of reservoir fluid (GHS).

Further downstream, also to study the features of work, using strapping 3, a mobile metering device (MZU) can be connected, described in STO Gazprom 3.1-2-008-2008, which is a nozzle artificially introduced into the stream, which due to a significant narrowing the cross section of the stream accelerates and homogenizes it. At the nozzle exit, an insignificant part of the flow is taken by a sampling probe under conditions of conservation of speed, pressure, and temperature. The selected sample is divided into homogeneous phases in a miniature separator, the amount of each phase is taken into account. The flow rate is determined proportionally to the selected part of the flow.

Next, the reservoir GHF flow enters the separator 4, in which gas and liquid phases are separated with high efficiency.

The separator 4 is made vertical and contains three stages of separation.

The first is a highly efficient distributor of gas-liquid flow 6 (Fig. 2) at the inlet 5, which ensures the separation of large drops of liquid and evenly distributes the gas stream over the entire cross section of the apparatus. The part of the liquid separated at the distributor 6 falls to the bottom of the separator 4, and the gas stream containing finely divided drops of liquid rises.

In the middle part of the separator, the cross section of the apparatus is blocked by two sheets 7 and 8 with centrifugal separation elements (ECS) installed on them — the second and third separation stages. The gas flow passes sequentially through the ECS of the second (pos. 7) and third (pos. 8) stages. ECS effectively separate small drops of liquid from the gas stream. The separated liquid accumulates on the canvases and flows to the bottom of the apparatus.

The liquid flowing to the bottom of the separator is a heterogeneous mixture of immiscible liquids: produced water, which is an aqueous solution of salts and / or alcohols, and an unstable condensate, which is a homogeneous mixture of liquid hydrocarbons. Liquid is removed from the separator by gravity to a horizontal separator 11 located in close proximity. To equalize the pressure in the separator 4 and the separator 11, an equalization line 20 is provided.

The liquid level in the separator 4 is determined by the height of the vertical septum 14 of the separator 11, provided that the level of NK is not higher than the upper limit level of NK in the compartment of the NK, which should be below the level of the vertical partition. The relative position of the separator 4 and the separator 11, as well as the separation elements of the separator 4, is selected so that the maximum liquid level in the separator 4 does not reach the gas-liquid flow distributor 6.

In compartment 12 of separator 11, an internal device 15 is installed over the entire cross section of the apparatus, which degasses a heterogeneous mixture of liquid phases from separator 4 with high efficiency and high performance and separates it into PV and ND due to their different specific gravity. NK, occupying the upper layer, overfills compartment 12 and merges through the separation wall 14 into compartment 13.

Excessive amount of PV and NK from the separator 11 is constantly automatically displayed by lines 21 and 23, respectively. The PV and NK levels should not fall below the lower limit levels indicated in FIG. 2. The first compartment (compartment for receiving and separating the mixture into PV and NK) of the separator 11 in operation should be filled to the edge of the vertical partition 14, and the level of the NK in the compartment 13 should be maintained below the edge of the vertical partition.

The use of separator 4 without a condensate collector and the use of a separate separator 11 tank for liquid collection purposes allows to reduce the overall height and to eliminate instrumentation and automation tools designed to automatically maintain the liquid level in separator 4, compared to the classical scheme of strapping a gas separator with a condensate collector in the bottom part .

Wet gas without the content of dropping liquid is removed from the separator 4 by line 33 and divided into blocks 36 and 37. Lines 36 and 37 are equipped with gas temperature and pressure measuring instruments, gas flow meters (mass flow meters with the function of measuring density or volume type), as well as automatic valves regulators and check valves. Also, after measuring the gas with flow meters, the introduction of a hydrate inhibitor using auxiliary valves is provided. This ensures the stable operation of the control valves during throttling of moist natural gas, which often causes freezing of saddle pairs. The full gas flow rate is divided between lines 36 and 37, based on the specified gas flow rate necessary for the study of the MZU installed in node 39, and / or the MPF installed in node 40. The instantaneous flow rate necessary for the study is supplied through line 36, and from line 37 from separator 4 discharges excess gas.

The quality of gas separation in the separator 4 can be determined using the ISDF 35 unit. The ISDF includes a sampling probe, a separator equipped with a filter cartridge and a measuring device for the separated liquid from the gas, a gas flow control valve, a container with an inhibitor and an inhibitor supply valve to the flow control valve gas filter cartridge for collecting mechanical impurities from gas, and also contains a device for automatically moving a sampling probe over the cross section of the studied pipeline, a differential pressure transducer between the sampling line and the studied gas-dispersed flow, designed to perform isokinetic sampling due to the automatic control valve installed at the outlet of the sampling line, of the zero pressure difference between the sampling line and the studied gas-dispersed flow, thermostatic control, mass flow meter to account for the amount of separated liquid a measuring device containing a level gauge, while the valve actuator is included in the control circuit by a sensor signal pressure difference.

A sampling probe 34 ISDF 35 is introduced into the gas outlet line 33 from the separator 4. The meter of the content of the dispersed phase 35 determines the amount of droplet liquid contained in the gas, which is a quantitative characteristic of the efficiency of gas separation. ISDF 35 also provides for the possibility of taking a representative gas sample for analysis in the laboratory.

The residual contents of the droplet liquid PV and NK in the gas, determined by ISDF, can be automatically summed up with the quantities determined by the Installation according to the readings of flow meters installed in lines 26, 27, 29, 30.

Means for sampling 22 and 24, respectively, filter blocks 25 and 28, respectively, for mechanical cleaning of liquids to protect valves, are provided in the pumping lines PV 21 and NK 23.

Automatically dosed by the control valves and taken into account by flowmeters as part of the flow control unit and measure the parameters of the air conditioner 26 and the flow control and measurement unit of the air conditioner 29 the instantaneous flow rate of the air conditioner and air conditioner required to create current GHS parameters required by the conditions of the study blocks 39 or 40, respectively. Overfilling of the compartments 12 and 13 of the separator 11 is eliminated by the fact that surplus airflow and low voltage are removed by means of a level control unit and measure parameters of air conditioner 27 and the level control and measurement unit of air conditioner 30 containing automatic control valves and flow meters that take into account the number of removed air and air conditioners.

Gas along the line after block 36, PV after block 26 and NK after block 29 are supplied to the mixer 38, where they are mixed. Mixing of flows without a special mixer is also allowed. The supply of phases is ensured by the mutual regulation of pressures after the control valve in each line automatically.

The GHS obtained in mode 1 from pre-separated phases of gas, PV and NK and with known parameters of instantaneous flow, temperature and pressure passes through the studied multiphase flow measuring instruments, connected in series, and enters the output manifold, where it is combined on the second mixing unit 41 with homogeneous phases (gas, PV and NK) coming from blocks 27, 30 and 37, respectively. The combined flow, which is a reservoir GHS, is output into the loop by means of a flexible high-pressure hose as a part of the connection unit to the cluster piping 1. Changes in the temperature and pressure of the formation fluid as a result of its passage through the installation are evaluated by the readings of the instruments installed at the inlet and outlet of the connection unit to the bush 1.

The quality of the separation of liquid phases in the separator 11 is indirectly determined by the readings of the level gauges, as well as by measuring the densities of the PV and NK using mass flowmeters with density determination function as part of blocks 26, 27, 29, 30. For control, the possibility of sampling into sealed cylinders with preservation of sampling pressure, delivered to the laboratory with preservation of temperature, is provided.

The measured quantities of single-phase flows are used to determine the flow rate of a well or a cluster of wells. The exact dosage of each flow makes it possible to artificially reproduce on the site for connecting the investigated _multigas well gas station with a given total flow rate in the range from zero to Q _{well gas} and a given phase ratio, where Q well gas is the current gas flow rate of the well. The amount of PV and NK in the mixture can be set independently from each other in the range from zero to Q _{well SP} (current well flow rate for produced water) and Q _{well NK} (current well flow rate for unstable condensate), respectively. Briefly, due to the phase volume separator accumulated in the tank, the amount of PV and NK in the mixture can be set to more than Q _{borehole PV} and Q _{borehole NK} in the range up to Q _{borehole PV} (upper limit for measuring the flow meter in the line of airflow) and Q _{borehole. NK} (the upper limit of the flow meter in the NK line), respectively. This is relevant when studying multiphase flow meters under conditions of gas condensate with a low condensate factor, when the flow rates of the liquid phases of the well do not allow achieving all the necessary phase and flow ratios in the mixture being created.

Investigations of the operation of MZU and MFR in a real reservoir GHS of a gas condensate field are required to confirm the applicability of these instruments for measuring the flow rate of a mixture containing a liquid phase that is quasi-stable under measurement conditions. This is not achievable in the factory, where the manufacturer of the instruments carries out their adjustment, or in the conditions of a calibration bench at which metrological centers carry out their calibration and verification.

The behavior of a quasi-stable (component-wise boiling) multicomponent homogeneous liquid mixture in the flow part of the MPF is difficult to model and significantly differs from the flow of a fluid stable under these conditions, even if it is unstable under atmospheric conditions. The flow of a mixture of gas and a heterogeneous mixture of two immiscible liquids is simulated even more complicated, one of which is quasistable - a heterogeneous liquid mixture of produced water and unstable gas condensate.

In mode 2 - determining the flow rate of the reservoir GW.

This mode of operation is chosen if there is no need for a detailed study of the work of the MFR or MZU, but it is necessary to measure the flow rate of the well.

In this mode, the blocks and units shown in FIG. 1 under numbers 2, 3, 26, 29, 36, 39, 40.

2 - Connection node multiphase flow meter for research in thermobaric conditions of the well;

3 - Harness for connecting a mobile metering device (MZU), designed to measure the flow rate of the wells by the method of selecting part of the flow, to study the operation of this device in the conditions of the well;

26 - Block flow control and measurement of airflow parameters;

29 - Flow control unit and measuring the parameters of the tax code;

36 - flow control unit and gas parameters measurement;

39 - Harness for connecting a mobile metering device (MZU), designed to measure the flow rate of the wells by the method of selecting part of the flow, to study the features of this device in the full range of flow rates of GHS and the ratios of gas, liquid hydrocarbon phase (NK) and aqueous solutions (PV) in mixtures;

40 - Connection unit for a multiphase flow meter for studies in the full range of GHS flow rates and gas, liquid hydrocarbon phase (HC) and aqueous solutions (PV) ratios in the mixture. It includes a strapping that allows passing the flow of formation fluid (reservoir GHS) through the instrument under study or bypassing it. The harness includes instruments for measuring temperature and pressure of the medium.

The total costs of gas, PV and NK are output to the loop and are taken into account in blocks 27, 30, 37.

27 - Unit for level control and measurement of parameters of the air conditioner;

30 - Unit for regulating the level and measuring NK parameters;

37 - Block flow control and measurement of gas parameters.

In mode 2, ISDF block 35 is used similarly to mode 1. In addition, in mode 2 of the unit operation, gas samples are taken using the ISDF method for gas analysis in the laboratory. During the study of one well or one well cluster, several gas samples are taken (several samplers are filled).

Also, to confirm the safety of the gas sample during its transportation and preparation for analysis in the laboratory, a set of samples taken at each well is provided with the results of a full-scale low-temperature separation experiment.

The experiment is carried out in the ISDF unit, for which a gas sample is chilled with a counter flow of the spent gas sample in a recuperative heat exchanger, which is included in the device. After the heat exchanger, the amount of gas is measured by the standard mass flowmeter of the ISDF device and the gas flow pressure at the standard valve of the device is significantly reduced, during which the sample temperature is significantly reduced. A deeply cooled gas sample stream is fed to a standard ISDF small-sized separator, where a low-temperature separation process takes place, which differs from sample separation when measuring the content of the dispersed phase in that there is a deep dehydration of wet gas. The spent gas sample is discharged onto the candle through a recuperative heat exchanger, where it cools the incoming gas sample stream. The result of the experiment is the amount of condensate measured during the experiment that precipitated during the low-temperature separation process and is related to the total amount of gas from which the condensate was separated.

Confirmation of the safety of a gas sample during its transportation and preparation for analysis in the laboratory is carried out by comparing the results of a full-scale experiment and laboratory analysis, in which the experiment is essentially similar by other technical means.

An installation that implements both modes is placed on a vehicle-sized semi-trailer and transported by a tractor on public roads. The technological piping of the Unit is ready for use immediately after placing the trailer in the immediate vicinity of the fountain or bypass fittings on the loop pipe of the wellbore.

Transportation of the Unit can be carried out both as a part of a road train with a truck tractor, and as a part of a road train with a transport-household self-propelled operator’s car as part of the Installation as a towing vehicle.

Thermal insulation of apparatuses and pipelines, as well as cable heating of pipelines and apparatuses that can be filled with PV are provided.

Pipelines and fittings, including automated ones, are provided for emergency and regular emptying and discharge to a horizontal flare unit (HFC).

The advantages of the proposed technical solution:

- The installation allows you to effectively divide the reservoir GHS into single-phase flows: gas, produced water, liquid hydrocarbons, with parameters suitable for measuring their flow rates and accurate dosage.

- Equipping the gas separator with three stages of separation significantly increases the efficiency of gas separation, widens the range of effective separation, expands the range of sizes of dispersed particles in the gas stream that separator effectively separates, reduces the gas pressure loss on the separator compared to the design of the hydrocyclone separator used in the prototype.

- Due to the use of a separator with a highly efficient internal device and two separate lines for output and metering of PV and NK, it was possible to realize continuous separation and metering of homogeneous liquids of PV and NK without their preliminary accumulation, settling and sequential withdrawal and metering.

- Due to the use of separate devices of the separator and the separator of a simple cylindrical shape, in comparison with the prototype, it was possible to significantly improve maintainability, ease of maintenance, process efficiency.

- Through the use of a special ISDF sampling probe, as well as a method for ensuring representative gas samples, it was possible to provide representative gas samples for analysis in the laboratory and for continuous determination of the residual content of the dispersed phase directly in the work.

- The installation allows the study of the features of the existing or advanced instruments for measuring multiphase flow rates. The study consists in evaluating the results of the operation of a multiphase flow meter according to the indications of serial single-phase flow meters used in the installation: gas, produced water, unstable condensate.

- The installation allows you to conduct research on the operation of existing or promising instruments for measuring multiphase flow rates directly on the reservoir fluid flow (reservoir GHS) without changing its thermobaric parameters. The GHS consumption and the content of the mixture components in it depend on the well, cannot be changed during the study, and are measured by the installation after the instrument under study.

- The installation allows you to conduct research on the operation of existing or advanced instruments for measuring multiphase flow rates in a wide range of flow rates and contents of the mixture components. At the same time, the flow rate of the GHS mixed in the installation and the content of the mixture components in it are independent of the well, can vary during the study and are measured by the installation up to the device under study.

- The installation allows you to save the reservoir fluid of the well for further targeted use by returning to the plume of the field cluster with a slight pressure loss.

- Due to the use of the design of the semitrailer and the elimination of the separator liquid accumulator in the gas separator, it was possible to keep the Unit in the transport envelope, due to which it is in a high degree of readiness and significantly reduces the deployment time “from the wheels” compared to the prototype, in which non-compliance with the transport dimension, it is necessary to disassemble the sealed apparatus and part of the strapping, which entails constant work to check the tightness after assembly.

- The installation allows you to verify the safety of the gas sample during its transportation and preparation for analysis in the laboratory by comparing the results of a full-scale experiment on changing the thermobaric parameters of the separation gas and laboratory analysis, in which the experiment is essentially similar by other technical means.

Installation for measuring the production rate of gas condensate wells

Items in the drawings

1 - node connection to the cluster harness;

2 - node connection multiphase flow meter;

3 - harness for connecting a mobile metering device (MZU);

4 - a vertical gas separator equipped with pressure and temperature measuring instruments;

5 - input fitting (Fig. 2);

6 - distributor of gas-liquid flow at the inlet fitting 5;

7, 8 - cloths with centrifugal separation elements (ECS) of the separator installed on them;

9 - output fitting from the separator 4;

10 - line output of unstable fluid from the separator to the separator;

11 - horizontal separator;

12 - compartment for receiving and separating a heterogeneous mixture of liquid phases of produced water and unstable condensate;

13 - compartment for receiving unstable condensate;

14 - vertical partition;

15 - internal device for intensifying the separation of liquid phases and degassing of NK;

16 - fitting for the output of produced water;

17 - fitting for the output of unstable gas condensate;

18 - level gauge of the general liquid level (PV) and the level of the separation of liquid phases (PV and NK);

19 - level sensor measuring NK;

20 - leveling line;

21 - line output PV from the separator;

22 - fittings for sampling formation water;

23 - line output NC from the separator.

Installation for measuring the production rate of gas condensate wells

24 - fittings for sampling NK;

25 - block filter line 21 (PV);

26 - block flow control and measurement of airflow parameters;

27 - unit for level control and measurement of the parameters of the air supply;

28 - block filter line 23 (NK);

29 - flow control unit and measuring the parameters of the tax code;

30 - block level control and measurement of parameters of the tax code;

31 - drainage line;

32 - block safety valves;

33 - gas outlet line from the separator 4;

34 - sampling probe with a device for its automatic movement and extraction, installed in line 33;

35 is a block for measuring the content of the dispersed phase in the gas (ISDF);

36 - flow control unit and measuring gas parameters;

37 - flow control unit and measuring gas parameters;

38 - mixer unit;

39 - harness for connecting a mobile metering device (MZU);

40 - connection node multiphase flow meter;

41 - mixer;

42 - high-speed valve;

43 - high-speed valve.

Claims (5)

1. Installation for measuring the production rate of gas condensate wells, comprising a separator, a liquid flow meter installed in the liquid pipeline, a gas flow meter and a sampler with an additional separation unit installed in the gas pipeline, characterized in that the gas outlet line from the separator contains the main and additional metering and regulation units, the separator is equipped with a gas-liquid flow distributor and centrifugal separation elements, made without a condensate collector and connected to a horizontal two-section separator of liquid immiscible phases with separation of liquid phases due to their different specific gravity and transfusion of the light phase through the separation wall, the compartments of which are equipped with output lines of produced water and unstable condensate, equipped with one main and one additional metering and regulation unit, with the line for entering the reservoir gas-liquid mixture into the separator is additionally equipped with a strapping for sequential connection of a flow multiphase flow meter for research in the well conditions of the features of its operation on the flow of a real reservoir gas-liquid mixture, the gas-liquid mixture withdrawal line from the installation contains two static mixers, the first of which combines flows from the main units of gas metering and regulation, formation water and unstable condensate, and creates a gas-liquid mixture flow with the ability to control the total flow rate and phase ratio in the mixture, and the second combines the flows of excess gas from the separator and produced water and unstable condensate from the separator from additional metering and control units with a flow created on the first static mixer to withdraw the combined mixture from the installation to the downhole plume loop, as well as a piping for sequentially connecting the studied flow multiphase flow meter in the flow with the given flow rate and phase ratios in the mixture, and an additional separation the installation for monitoring and accounting for unseparated droplet liquid in the separation gas is additionally equipped with a mobile probe with an attacking pointed tip, mass a flow meter, a control valve to ensure isokinetic sampling by regulating the flow rate of the sample by the signal of the mass flow meter, a recuperative heat exchanger for cooling the gas sample stream and a heating cable to heat the gas sample stream to ensure isothermal sampling. 2. Installation for measuring the production rate of gas condensate wells according to claim 1, characterized in that for the protection of the control valves from hydrate formation in the main and additional gas metering and control units, additional hydrate formation inhibitor filling valves are provided. 3. Installation for measuring the production rate of gas condensate wells according to claim 1, characterized in that the horizontal two-section separator of liquid immiscible phases contains sensors for measuring the level of formation water and unstable condensate in the first compartment and measuring the level of unstable condensate in the second compartment. 4. Installation for measuring the production rate of gas condensate wells according to paragraphs. 1-3, characterized in that the additional separation unit for monitoring and accounting for the unseparated droplet liquid in the separation gas is additionally equipped with a sample pressure control valve with a pour line and metering of the hydration inhibitor installed upstream of the separator, which allow changing the pressure and pressure separation parameters to establish the safety of the gas sample in the process of its transportation and preparation for laboratory analysis by comparing the results of a full-scale experiment on measuring the condensation of bone when changing parameters of temperature and pressure gas and a similar experiment in the laboratory. 5. Installation for measuring the production rate of gas condensate wells according to claim 1, characterized in that in the main and additional units for metering and controlling the flow of unstable condensate in front of the mass flow meters, valves are provided in the upper part of the pipeline to blow off gas bubbles that have arisen directly in the pipeline.

Images