RU2661500C1 - Method of inhibitor supply automatic control for prevention of the hydrates formation in gas gathering tails of gas condensate deposits located in the far north regions - Google Patents

Abstract

FIELD: gas industry.

SUBSTANCE: invention relates to the field of natural gas production and can be used to prevent hydrates formation and hydrates destruction in gas gathering tails (GGT) located in the Far North regions. Method comprises the hydrates formation inhibitor supply automatic system. System contains the electrically driven pump unit and the inhibitor take-off line from the reservoir, providing the inhibitor supply to the beginning of the GGT. After the produced fluid exit from GGT, the inhibitor aqueous solution is separated from it in the separator and its supply to the inhibitor regeneration shop. During this process, performing the continuous control over the inhibitor concentration in the aqueous solution of C_{2 act.}, entering to the regeneration, and in the regenerated inhibitor C_{1 act.}, supplied to the GGT, by means of concentration sensors, as well as the regenerated inhibitor flow rate F_{inhib_act.}, supplied to the GGT, which value is controlled by the regenerated inhibitor flow rate sensor. Regenerated inhibitor flow rate F_{ingib_fac.} signal is supplied to the PV feedback input to the regenerated inhibitor flow rate maintaining in the GGT PID regulator, which, with the help of the regulator valve located downstream of the pump unit in the inhibitor to the GGT supply pipeline, enables automatic maintaining of the preset inhibitor concentration in the entering to the regeneration aqueous solution. At this PID controller SP setting input, supplying the corrected regenerated inhibitor flow rate F_{inhib_calc_corr.}, which is determined taking into account the calculated by the APCS with a given discreteness of the regenerated inhibitor mass flow calculated value F_{inhib_calc.}. Regenerated inhibitor mass flow calculating algorithm F_{inhib_calc.} takes into account the regenerated inhibitor actual concentration C_{1 act.}, calculated is C_{2 calc.} and the actual C_2act value of the inhibitor concentration in the entering the regeneration aqueous solution.

EFFECT: technical result is increase the hydrocarbon field development efficiency and safety by eliminating of the hydrates formation in the GGT with the minimum possible inhibitor consumption.

5 cl, 4 dwg

Description

The invention relates to the field of natural gas production, in particular to the prevention of hydrate formation and destruction of hydrates in gas gathering plumes (GSSh) located in the Far North.

A device is known for automatically controlling the process of supplying a hydrate inhibitor to natural gas pipelines [see Auth. testimonial. USSR No. 526864, publ. 1976]. It includes: a regulator of the ratio of gas flow rates and inhibitor associated with the actuator supplying the inhibitor through a pipeline equipped with a bypass line, and a gas flow regulator. In order to increase reliability in operation, the device is equipped with a two-position regulator, the input of which is the output of the gas flow regulator, and a shut-off element connected to a two-position regulator installed on the bypass line.

The disadvantage of this device is cumbersome due to the presence of two control valves and a bypass line, the latter is a source of energy loss spent on the message unused pressure to the bypassed amount of inhibitor in the system.

The closest in technical essence and the achieved result to the claimed invention is a comprehensive automated system for the distribution and dosage of a hydrate inhibitor [see RF patent No. 2376451, publ. 2009], which contains:

- electric driven pumping unit, pressure manifold, inhibitor withdrawal pipelines from the collector;

- independent pressure stabilization circuits, one of which is formed by a pressure sensor in the pressure head manifold, the output of which is connected to the automatic controller of the frequency converter, and the output of the latter is connected to the electric drive of the pump unit, the second pressure stabilization circuit forms a direct-acting pressure regulator block included in the group of selective devices between pressure manifold and actuators;

- the pressure regulator "after itself", which forms, together with the actuators, one controlled group of devices that supply the inhibitor to the protected points of the technological equipment according to a given algorithm and program;

- a group of actuators providing direct controlled programmatic supply of an inhibitor to well clusters from a common reservoir;

- adjustable devices located on each inhibitor supply pipe to the bush, which ensure the distribution of the inhibitor flow between the wells in the bush in accordance with the individual settings for each well and automatically maintain the specified ratio of pressure drops.

Significant disadvantages of this system are the lack of the ability to quickly determine the concentration of the inhibitor supplied to the HSS and in the spent solution that comes from the HSS, which can lead to a significant overspending or insufficient supply of the inhibitor to the system, and if volley releases of formation water occur, the automated system will be unable to prevent possible hydrate formation in the GSS. In addition, the use of this system to prevent hydrate formation in the GSH does not allow to diagnose its operation, which excludes the prompt detection of abnormal situations in the work of the plume or well and significantly complicates the adoption of effective decisions to control the work of the plume and well.

The listed factors ultimately make it inappropriate to use this automated inhibitor supply control system to prevent hydrate formation in the GSS in the Far North.

The problem to which the present invention is directed is to increase the efficiency and safety of developing a hydrocarbon field by eliminating hydrate formation in the HSS with the lowest possible inhibitor consumption.

Technical results achieved by the implementation of this invention are:

- automatic real-time determination of the amount of inhibitor necessary to prevent hydrate formation in the GSH. At the same time, its concentration in the regenerated (initial) and spent aqueous solution is taken into account;

- automatic prevention of hydrate formation in the HSS by maintaining a given concentration of inhibitor in the spent aqueous solution, providing the necessary reduction in the temperature of hydrate formation in the loop;

- diagnostics of the GSH operation, which allows to quickly identify emergency situations in its work, which greatly simplifies the adoption of effective decisions on the management of the loop and well.

This problem is solved, and the technical result is achieved due to the fact that the automatic process control system (ACS TP) of the complex / preliminary gas treatment unit (UKPG / UPPG) with the help of two proportional-integral-differentiating (PID) regulators integrated into its structure supports the concentration of the inhibitor in the spent aqueous solution, providing a specified decrease in the temperature of hydrate formation in the loop. And also it provides the supply of the required amount of regenerated inhibitor to the HSS to prevent hydrate formation, taking into account its concentration in the regenerated (initial) and spent aqueous solution, which is measured using concentration sensors in real time.

A method for automatically controlling the supply of an inhibitor to prevent hydrate formation in the gas collection lines of the gas supply system of gas condensate fields located in the Far North includes an automatic system for supplying a hydrate inhibitor. The system contains a pumping unit with an electric drive and an inhibitor withdrawal pipe from the collector, ensuring the supply of the inhibitor to the start of the main compressor train. After the produced fluid leaves the HSS, the aqueous solution of the inhibitor is separated from it in the separator and the aqueous solution is supplied to the inhibitor regeneration workshop.

During this process, using an automatic process control system, the plants continuously monitor the concentration of the inhibitor in an aqueous solution of C _{2 ph.} entering the regeneration, and the concentration of the regenerated inhibitor With _{1 fak.} supplied to the GSH, using concentration sensors, as well as the flow rate of the regenerated inhibitor F _{inhib_fak.} supplied to the GSH, the value of which is monitored by the flow sensor of the regenerated inhibitor. The signal flow rate of the regenerated inhibitor F _{inhib_fak.} fed to the feedback input PV of the PID controller to maintain the flow rate of the regenerated inhibitor in the HSS, which, with the help of the control valve located after the pump unit in the supply pipe of the inhibitor in the HSS, automatically maintains a given concentration of the inhibitor in the aqueous solution supplied to the regeneration. At the input of the SP job of this PID controller, a corrected flow rate value of the regenerated inhibitor F _{inhib_calc_core is supplied.} , determined taking into account the calculated ACS TP with a given discreteness of the calculated value of the mass flow rate of the regenerated inhibitor F _{inhib_calc.} . The algorithm for calculating the mass flow rate of the regenerated inhibitor F _{inhib_calc.} takes into account the actual concentration of C _{1 fact.} regenerated inhibitor calculated - C _{2 calc.} and the actual - With _{2 fact} values of the concentration of the inhibitor in the aqueous solution supplied to the regeneration. Simplified calculated mass flow rate of the regenerated inhibitor F _{inhib_calc.} determined from the ratio:

,

,

where F _gas is the value of the gas flow rate in the main gas supply system, which comes from the gas flow sensor installed at the beginning of the loop; G is the specific consumption of the inhibitor introduced into the gas stream to prevent hydrate formation, which is determined by the formula:

,

,

where ΔW is the amount of liquid water contained in the gas; q _g - the equilibrium content of methanol contained in the incoming gas.

The signal for setting the flow rate of the regenerated inhibitor to the input of the SP task of the PID controller for maintaining the flow rate of the regenerated inhibitor in the HSS is implemented by the second PID controller for maintaining the required concentration of the inhibitor in the aqueous solution coming from the HSS, and a block for correcting the mass flow rate of the regenerated inhibitor. To do this, the signal of the calculated ACS TP value of the concentration of inhibitor in an aqueous solution of C _{2 races is} fed to the input of the SP task of the second PID controller _. providing a predetermined decrease in the temperature of hydrate formation, and the actual concentration С _{2 ph.} signal is fed to the feedback input PV of this PID controller _. measured by a sensor of the concentration of inhibitor in an aqueous solution withdrawn from the separator for regeneration. Using these parameters, the PID controller generates at its output CV the correction value Δ for the calculated ACS TP of the flow rate of the regenerated inhibitor F _{inhib_calc.} , and applies the correction Δ to the input of the inhibitor mass flow correction block. The signal of the calculated flow rate of the regenerated inhibitor F _{inhib_calc} is supplied to the second input of the mass flow rate correction block of the inhibitor _. . Using the signals supplied to the mass flow rate correction block of the inhibitor, it calculates the adjusted value of the flow rate of the regenerated inhibitor F _{inhib_calc_core.} At the moment, observing the following conditions:

if C _{2 calc.} <C _{2 ph.} , then F _{inhibit_calc_core.} = F _{inhibition_calc.} - Δ

if C _{2 calc.} > C _{2 ph.} , then F _{inhibit_calc_core.} = F _{inhibition_calc.} + Δ,

if C _{2 calc.} = C _{2 fact.} , then F _{inhibit_calc_core.} = F _{inhibition_calc.}

The obtained value of F _{inhib_calc_core.} the mass flow rate correction block of the inhibitor supplies the input of the SP task of the PID controller to maintain the flow rate of the regenerated inhibitor in the GSH.

The proportional, integral and differential coefficients, as well as the dead zones of the PID controllers, are set up by the UKPG / UPPG service personnel at the time the system is launched into operation under specific production conditions specified by the geological service, taking into account the inertia of the system and the signal delay time.

To detect salvo bursts of produced water in the main water supply, the calculated value of the inhibitor concentration in an aqueous solution is C _{2 calc.} providing a predetermined decrease in the temperature of hydrate formation, build in the form of a graph of the time function. A synchronized time function of the actually measured concentration value of C _{2 fak} is applied to this graph _. inhibitor in aqueous solution. And if both of these graphs go in parallel, i.e. their dynamics are the same and the difference C _{2 calc.} - With _{2 ph.} approximately constant, then volley releases of formation water in the main water supply does not occur. But as soon as the dynamics of change With _{2 calc.} and C _{2 ph.} becomes different, i.e. their difference begins to change in time, a message is immediately generated automatically to the maintenance personnel to make a decision - either to change the well operating mode to reduce water occurrence, or to stop the well for repair.

In order to control the specific consumption of the inhibitor according to the norm established by the regulatory plan of the Enterprise to prevent hydrate formation in the GSS, the calculated values of the specific consumption of the inhibitor G are plotted as a graph of the time function. And if the specific consumption of the inhibitor is in the permissible zone, according to the regulatory plan of the Enterprise, this GSH is operated. But if it turns out that the value of the specific consumption of the inhibitor has exceeded the limits of the permissible restriction zone, a message is immediately automatically generated for the maintenance personnel to make a decision - either to change the well operating mode to reduce water occurrence, or to stop the well for subsequent repair.

In FIG. 1 shows a schematic flow diagram of the supply of an inhibitor to the GSH.

In FIG. Figure 2 shows an enlarged block diagram of the automatic control of the supply of an inhibitor to the GSH.

In FIG. Figure 3 shows the dynamics of changes in the calculated and actual concentration of the inhibitor, which provides a given decrease in the temperature of hydrate formation in the HSS.

In FIG. 4 shows the dynamics of changes in the specific consumption of the inhibitor in the prevention of hydrate formation in GSH.

In FIG. 1 the following notation is used:

1 - gas well;

2 - pressure sensor installed at the beginning of the GSH;

3 - a temperature sensor installed at the beginning of the GSH;

4 - gas flow sensor, installed at the beginning of the GSH;

5 - GSH;

6 - inhibitor supply pipe;

7 - valve-regulator flow rate of the inhibitor;

8 - gas flow control valve;

9 - pressure sensor installed at the end of the GPS;

10 - a temperature sensor installed at the end of the GSH;

11 - flow sensor of the regenerated inhibitor supplied to the GSH;

12 - pumping unit supplying the regenerated inhibitor to the GSH;

13 - concentration sensor of the regenerated (initial) inhibitor;

14 - buffer capacity of the regenerated (initial) inhibitor;

15 - gas separator;

16 - sensor concentration of an aqueous solution of the inhibitor;

17 - ACS TP UKGG / UPPG.

In FIG. 2 the following notation is used:

18 - input signal from the flow sensor of the regenerated inhibitor 11;

19 - input signal calculated mass flow rate of the regenerated inhibitor F _{inhib_calc} ;

20 - input signal corresponding to the calculated value of the concentration of the inhibitor With _2calc ;

21 - input signal from a concentration sensor 16 of an aqueous solution of the inhibitor - C _2fact ;

22 - proportional-integral-differentiating (PID) regulator of maintaining the concentration of inhibitor in an aqueous solution coming from the HSS;

23 - block correction of the mass flow rate of the regenerated inhibitor;

24 - PID controller to maintain the flow rate of the regenerated inhibitor in the GSH;

25 is a control signal to the valve-regulator 7 of the flow of the inhibitor.

In FIG. 3 the following notation is used:

26 - the calculated total concentration of the inhibitor in the aqueous solution, providing a given decrease in the temperature of hydrate formation in the HSS;

27 - the actual total concentration of the inhibitor in an aqueous solution, providing a given decrease in the temperature of hydrate formation in the HSS;

28 - area of detection of volley emissions of produced water in the main water supply.

In FIG. 4, the following notation is used:

29 - the rate of specific consumption of the inhibitor in the enterprise;

30 - specific consumption of the inhibitor according to GSH.

A method for automatically controlling the supply of an inhibitor to prevent hydrate formation in gas-condensate fields of gas condensate fields located in the Far North is implemented as follows.

The gas coming from well 1 (for simplicity, we assume that only one well is connected to the GSS) passes through the GSS 5, equipped with pressure sensors 2, temperature 3 and flow 4 installed at its beginning, and pressure sensors 9 and temperature 10 installed at its end.

Next, the gas through the flow control valve 8, which is used to regulate gas production, enters the inlet of the separator 15. In the separator 15, the gas is cleaned of mechanical impurities, dropping liquid and the aqueous solution of the inhibitor is separated, which is discharged to the bottom of the separator 15 for regeneration through a pipeline equipped with an inhibitor concentration sensor 16. From the output of the separator 15, gas purified from mechanical impurities and dropping liquid is either supplied to the gas treatment plant of the gas treatment plant for further operation ears, or to the exhaust manifold UPPG for further transportation to the GPP.

To supply the inhibitor, a separate inhibitor supply pipe 6 was laid at the beginning of the secondary compressor station 5, which is equipped with an inhibitor flow sensor 11 and a control valve 7. The necessary pressure in the inhibitor pipe 6 is created by the inhibitor supply unit 12. The pump unit 12 is connected by an inlet pipe equipped with a concentration sensor 13 regenerated inhibitor, with a buffer capacity of 14.

Using the telemetry system, which is one of the subsystems of the ACS TP UKPG / UKPPG, measure the pressure (sensor 2), temperature (sensor 3) and gas flow (sensor 4) at the start of the main compressor station 5. At the same time, using the automatic control system UKPG / UPPG measure the pressure (sensor 9) and the temperature of the produced fluid (sensor 10) at the end of the GSH. Also, with the help of ACS TP UKPG / UPPG with a given discreteness, the actual concentration of the regenerated inhibitor (sensor 13) and the inhibitor in an aqueous solution is measured (sensor 16). ACS TP UKPG / UPPG, upon detection of the onset of hydrate formation in the HSS, for example, as described in the patent for the invention of the Russian Federation No. 23239371, begins to calculate the amount of inhibitor that must be submitted to the HSS to prevent hydrate formation.

Methanol is usually used as an inhibitor to prevent hydrate formation in gas-condensate fields in gas condensate fields located in the Far North. Therefore, we consider below the determination of the amount of inhibitor necessary to prevent hydrate formation in HSS, using methanol as an example. For this purpose, with the help of ACS TP UKPG / UPPG 17, the following values are calculated:

a) the concentration of the inhibitor in an aqueous solution that provides a predetermined decrease in the temperature of hydrate formation, which is determined by the converted Hammerschmidt formula [see, for example, page 6, Instructions for calculating methanol consumption standards for use in calculating maximum permissible or temporarily agreed methanol discharges for OAO facilities Gazprom, WFD 39-1. 13-010-2000]:

where 32 is the molecular weight of methanol; 1295 - Hammerschmidt constant; Δt is the required decrease in the temperature of hydrate formation at the end of the GSS. In turn, Δt is determined from the following expression:

,

,

where t _K.GSSH is the gas temperature at the end of the GPS, the value of which comes from sensor 10; t _hydr - hydrate formation temperature, which depends on pressure. For Cenomanian gas, which is produced in the fields of the Far North, t _hydr is determined from the following expression [see, for example, page 22, Instructions for calculating methanol consumption standards for use in calculating maximum permissible or temporarily agreed methanol discharges for Gazprom facilities , WFD 39-1. 13-010-2000]:

,

,

where P is the value of the gas pressure at the end of the GSH, which comes from the pressure sensor 9.

b) the specific consumption of the inhibitor introduced into the gas stream to prevent hydrate formation is determined by the formula [see, for example, page 23, Instructions for calculating methanol consumption standards for use in calculating maximum permissible or temporarily agreed methanol discharges for Gazprom facilities , WFD 39-1. 13-010-2000]:

where C ₁ is the concentration of the regenerated inhibitor injected into the main stream (usually 90 ... 95% wt.), the value of which comes from the sensor 13 to the input of the mass flow correction block of the inhibitor 23; q _g is the equilibrium methanol content contained in the incoming gas; ΔW is the amount of liquid water contained in the gas, the value of which is determined from the expression [see, for example, page 9, Instructions for the calculation of methanol consumption standards for use in calculating maximum permissible or temporarily agreed methanol discharges for Gazprom facilities, WFD 39 -one. 13-010-2000]:

,

,

where W ₁ and W ₂ is the moisture content of the gas at the beginning and end of the HSS, which can be determined from the Bukachek formula [see, for example, p. 88, E. B. Accountant. Methanol and its use in the gas industry. M., Nedra, 1986, 238 pp.]:

,

,

where p is the gas pressure value coming from the pressure sensors 2 and 9 for W ₁ and W ₂ ; t is the gas temperature value coming from temperature sensors 3 and 10 for W ₁ and W ₂ . The equilibrium methanol content in the gas in contact with the water-methanol solution is determined from the expression [see, for example, page 6, Instructions for calculating methanol consumption standards for use in calculating maximum permissible or temporarily agreed methanol discharges for Gazprom facilities, WFD 39 -one. 13-010-2000]:

,

,

where M ₀ is the solubility of methanol in gas in the methanol-natural gas system, the value of which is determined by processing the graph shown in Fig. 2 on page 8 Instructions for the calculation of methanol consumption standards for use in the calculation of maximum permissible or temporarily agreed methanol discharges for Gazprom facilities, WFD 39-1. 13-010-2000.

c) the mass flow rate of the inhibitor is F _{inhibition_calc} , which is determined from the following expression:

where F _gas is the value of the gas flow rate in the secondary gas supply, which comes from the flow sensor 4.

Also using ACS TP UKPG / UPPG 17 control the following parameters:

d) volley releases of produced water that may occur in the secondary water supply, the value of the inhibitor concentration in the aqueous solution is C _{2 calc.} providing a given decrease in the temperature of hydrate formation, which is determined by the formula (1), is built in the form of a graph of the time function (see Fig. 3, line 26). A synchronized time function of the actually measured concentration value of C _{2 phak} is plotted on the same graph _. inhibitor using a sensor 16 in an aqueous solution (see Fig. 3, line 27). If both graphs go parallel, i.e. their dynamics are the same and their difference (C _{2 calculation} - C _{2 ph.} ) is approximately constant, then volley releases of produced water from the well does not occur. As soon as the dynamics of change With _{2 calc.} and C _{2 ph.} becomes different, i.e. the difference (C _{2 calculation} - C _{2 ph.} ) begins to change in time (in Fig. 3 this area is designated as the “detection area of saline water burst emissions in the main water supply”, line 28), the operator is immediately informed about this for him to make a decision.

d) the consumption of the inhibitor supplied to the HSS, the value of the specific consumption of the inhibitor, determined by the formula (2), is also plotted as a graph of the time function (see Fig. 4). If the specific consumption of the inhibitor is line 30 in FIG. 4, be in the permissible zone (below lines 29 in Fig. 4) according to the regulatory plan of the enterprise, this cable continues to be operated. But if it turns out that the value of the specific consumption of the inhibitor exceeded the permissible limit (above line 29 in Fig. 4), this is immediately reported to the maintenance personnel of the gas treatment plant / gas treatment plant for making the necessary decision.

As with the detection of volley emissions of produced water, and with an increased specific consumption of the inhibitor, maintenance personnel can make one of two decisions. First of all, change the mode of operation of the well, which is connected to the GSH, to reduce water occurrence. But if this does not lead to a positive result, then stop the well for repair work.

Also, with the help of ACS TP UKPG / UPPG 17, the values of the following parameters are maintained:

e) the concentration of the inhibitor in an aqueous solution that provides a given decrease in the temperature of hydrate formation in the HSS. To do this, use the PID controller 22 to maintain the inhibitor concentration in the aqueous solution coming from the GSH, which is implemented on the basis of the ACS TP UKPG / UPPG. Using this PID controller, the deviation of the calculated concentration value of the inhibitor C _{2 calc is} constantly monitored _. from its actual value - C _2fact . In this case, the signal With _{2 calc.} applied to the input of the reference SP 20, and the signal C _2fak . comes from the concentration sensor of the aqueous solution of the inhibitor 16 to the feedback input PV 21 of this PID controller. As a result, at the output of the CV of the PID controller 22, maintaining the inhibitor concentration in the aqueous solution coming from the GSS, the necessary correction value Δ is formed for the calculated mass flow rate of the regenerated inhibitor F _{inhib_calc} ., Which is fed to the input of block 23 and is corrected using the following expression:

if C _2calc. <C _{2 fact.} , then F _{inhibition_calc_core} = F _{inhibition_calc.} - Δ

if C _2calc. > C _{2 fact.} , then F _{inhibition_calc_core} = F _{inhibition_calc} + Δ,

if _C2calc = _{C2 fact} , then F _{inhibition_calc_core} = F _{inhibition_calc} ,

where F _{inhibition_calc.} - the calculated value of the mass flow rate of the inhibitor, which is determined by the formula (3); F _{inhib_calc_corr} is the adjusted mass flow rate of the regenerated inhibitor. The correction block for the mass flow rate of the regenerated inhibitor 23 is also implemented on the basis of ACS TP UKPG / UPPG.

g) the mass flow rate of the regenerated inhibitor F _{ingi_calc} . To do this, use the PID controller 24 to maintain the mass flow rate of the inhibitor in the GSH, which is also implemented on the basis of ACS TP UKPG / UPPG. At the input of the SP job of this PID controller, the calculated corrected mass flow rate of the regenerated inhibitor F _{ingi_calc_corr} from correction block 23 is supplied, and the actual value F _{inhib_fac} is fed to its feedback input PV _. from the flow sensor of the regenerated inhibitor 11 (input 18), as a result, at the output of the CV of the PID controller 24, a control signal 25 is generated, which is fed to the flow control valve of the inhibitor 7. As a result, the required amount of inhibitor will be automatically supplied to the GSH, sufficient to prevent hydrate formation.

PID controllers are tuned by the operating personnel at the time the system is put into operation under specific production conditions determined by the geological service, taking into account the inertia of the system and the signal delay time, according to the method described, for example, in the Encyclopedia of industrial control systems, clause 5.5, PID controller. Resource http://www.bookasutp.ru/Chapter5_5.aspx#HandTuning.

The method of regulating the automatic control of the inhibitor supply to prevent hydrate formation in the gas and gas condensate field located in the Far North regions was implemented at the Zapolyarnoye oil and gas condensate field at UKPG 1C, UKPG 2C and UKPG 3C of Gazprom dobycha Yamburg PJSC Gazprom. The results of operation have shown its high efficiency. The claimed invention can be widely used in other existing and newly developed gas condensate fields of the Far North of the Russian Federation.

The application of this method allows you to:

- in real time, automatically determine the amount of inhibitor necessary to prevent hydrate formation in the GSH;

- automatically prevent hydrate formation in the HSS by maintaining a given concentration of inhibitor in the spent aqueous solution, which provides the necessary decrease in the temperature of hydrate formation in the loop;

- diagnose the work of the GSH, allowing you to quickly identify abnormal situations in its work, which greatly simplifies the adoption of effective decisions on the management of the loop and well;

- optimize the flow of the inhibitor to prevent hydrate formation in the GSH, which ultimately will lead to an increase in the efficiency of production and preparation of well products.

Claims (9)

1. A method for automatically controlling the supply of an inhibitor to prevent hydrate formation in gas gathering plumes (GSS) of gas condensate fields located in the Far North, including an automatic hydrate inhibitor supply system comprising an electrically driven pumping unit, a pressure manifold, an inhibitor withdrawal pipe from the collector, providing an inhibitor supply to the start of the HSS and the subsequent separation of the aqueous solution of the inhibitor in the separator from the produced fluid and feeding it to the workshop reg an inhibitor, characterized in that the automatic process control system (ACS TP) of a complex gas pre-treatment unit (UKPG / UPPG) continuously monitors the concentration of the inhibitor in an aqueous solution of C _{2 ph.} entering the regeneration, and in the regenerated inhibitor With _1fak. supplied to the GSH, using concentration sensors, as well as the flow rate of the regenerated inhibitor F _{inhib_fak.} supplied to the GSH, the value of which is monitored by the flow sensor of the regenerated inhibitor and sends a signal to the feedback input PV of the PID controller (proportional-integral-differentiating regulator) to maintain the flow rate of the regenerated inhibitor in the GSH, which, with the help of the control valve, is located after the pump unit in the inhibitor supply line to the HSS provides automatic maintenance of a given concentration of the inhibitor in the aqueous solution supplied to the regeneration, and to the input of the SP task of this PID controller submit the adjusted value of the flow rate of the regenerated inhibitor F _{inhib_calc_corr.} , determined taking into account the calculated ACS TP with a given discreteness of the calculated value of the mass flow rate of the regenerated inhibitor F _{inhib_calc.} , the actual concentration of C _1fact. regenerated inhibitor calculated - With _2calc. and the actual - С _2fact value of the inhibitor concentration in the aqueous solution supplied to the regeneration. 2. The method according to claim 1, characterized in that to generate a signal for setting the flow rate of the regenerated inhibitor for the PID controller to maintain the flow rate of the regenerated inhibitor in the HSS, use the PID controller to maintain the required concentration of the inhibitor in the aqueous solution coming from the HSS and a mass correction block flow rate of the regenerated inhibitor, for which the signal of the calculated ACS TP value of the concentration of the inhibitor in an aqueous solution of C _{2ras is} fed to the input of the SP task of this PID controller _. , which provides a predetermined decrease in the temperature of hydrate formation, and the actual concentration С _2fac signal is fed to the PV feedback feedback of this PID controller _. measured by the sensor of the concentration of the inhibitor in the aqueous solution withdrawn from the separator for regeneration, using which the PID controller generates at its output CV the correction value Δ for the calculated ACS TP of the flow rate of the regenerated inhibitor F _{inhib_calc.} taking into account its calculated C _2calc and the actual C ₂ concentration concentration, and applies the Δ correction to the input of the mass flow rate correction block of the inhibitor, the second input of which receives the signal of the calculated flow rate of the regenerated inhibitor F _{inhib_calc.} using which, the inhibitor mass flow correction block calculates the corrected flow rate value of the regenerated inhibitor F _{inhib_calc_core.} At the moment, observing the following conditions: if C _2calc. <C _{2 ph.} , then F _{inhibit_calc_core.} = F _{inhibition_calc_} -Δ, if C _2calc. > C _{2 ph.} , then F _{inhibit_calc_core.} = F _{inhibition_calc_} + Δ, if _C2calc = _{C2 fact} , then F _{inhibition_calc_core} = F _{inhibition_calc} , and submits the obtained value of F _{inhib_calc_core.} at the input of the job SP of the PID controller to maintain the flow rate of the regenerated inhibitor in the GSH. 3. The method according to claim 1, characterized in that the proportional, integral, and differential coefficients, as well as the dead zones of the PID controllers, configure the GPP staff at the time the system starts up to work under specific production conditions, the inertia of the system, and the signal delay time. 4. The method according to claim 1, characterized in that for the detection of volley emissions of produced water in the water supply system, the calculated value of the concentration of inhibitor in aqueous solution C_{2 times}, providing a predetermined decrease in the temperature of hydrate formation, they are built in the form of a graph of the time function, and a synchronized time function of the actually measured concentration value C is applied to this graph_2fact. inhibitor in aqueous solution, and if both schedules go in parallel, i.e. their dynamics are the same and the difference C_{2 times} - FROM_2fact approximately constant, then volley releases of formation water in the main water supply does not occur, but as soon as the dynamics of change C_{2 calc.} and C_2fact becomes different, i.e. their difference begins to change in time, a message is immediately generated automatically to the maintenance personnel to make a decision - either to change the well operating mode to reduce water occurrence, or to stop the well for repair. 5. The method according to claim 1, characterized in that to control the specific consumption of the inhibitor according to the norm established by the regulatory plan of the enterprise to prevent hydrate formation in the GSS, the obtained calculated values of the specific consumption of the inhibitor G are built in the form of a graph of the time function, and if it turns out that the specific consumption of the inhibitor is in the permissible zone, according to the regulatory plan of the enterprise, this GSH is operated, and if it turns out that the value of the specific consumption of the inhibitor is outside the permissible zone tions, it just automatically generated message service personnel to make a decision - either to change the mode of operation of the well to reduce water seepage, or to stop the well for repairs.

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