RU2712665C1 - Method of automatic control of gas drying process at plants for complex gas treatment in conditions of the north - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to preparation of natural gas for long-distance transport, in particular, to automatic control of gas dehydration at complex gas treatment plants – CGTP in conditions of the North of Russia. Automated control system of technological process – APCS of gas drying performs control of raw gas pressure and temperature, control of pressure, temperature, flow rate and dew point of dried gas, automatic maintenance of regenerated absorbent supply to absorber taking into account of extracted gas flow, control of absorbent mass flow rate. It uses for simulation and control of technological processes parameters controlled by it, which measures with given discreteness in time. Among them also include concentration of water-saturated absorbent and specific amount of extracted moisture as a result of gas drying in absorber.

EFFECT: invention enables to minimize the amount of absorbent supplied to the absorber without reducing the quality of the gas drying process to CGTP; automatically hold the specified dew point temperature, which is the main parameter determining the humidity of the dried gas in the CGTP, providing the gas preparation to the long-distance transport with the specified quality parameters; quickly detecting abnormal situations in the absorber operation, simplifying the adoption of efficient control solutions at process facilities involved in the cycle of gas production, transportation and preparation for long-distance transport.

3 cl, 3 dwg

Description

The invention relates to the field of preparation of natural gas for long-distance transport, in particular, to automatic control of gas dehydration at the integrated gas treatment plants (GPP) in the North of the Russian Federation.

A known method of automatic control of the process of absorption drying of gas, which provides automatic maintenance of the given parameters of technological processes at the gas treatment plant [see, p. 413-416, Isakovich R.Ya., Loginov V.I., Popadko V.E. Automation of production processes in the oil and gas industry. Textbook for high schools. M., "Nedra", 1983, 424 s].

The disadvantage of this method is that in it the supply of a desiccant (absorbent) to the absorber is carried out only taking into account the flow rate and moisture content of the dried gas. At the same time, the concentration of saturated absorbent discharged from the absorber and its entrainment with the drained gas is not controlled in real mode.

All these factors together lead to an unsuitable consumption of the absorbent supplied to the absorber, and to an irretrievable loss of this valuable product. As a result of excessive loss of absorbent material, the energy costs of absorbent regeneration increase, the quality of gas preparation for long-distance transport decreases, i.e. as a whole, the efficiency of the gas dehydration process at the gas treatment facility decreases.

The closest, in technical essence, to the claimed invention is a method for automating an absorption unit that automatically maintains the specified parameters of the gas drying process at a gas treatment plant [see, pp. 352-354, Andreev EB and others. Automation of technological processes for the extraction and preparation of oil and gas. - M., "Nedra-Business Center", 2008. - 399 p.]

Significant disadvantages of this method is that the supply of absorbent to the absorber is carried out only taking into account the flow rate and moisture content of the dried gas. At the same time, the concentration of saturated absorbent discharged from the absorber and its entrainment with the drained gas is not controlled in real mode.

These factors together lead to an optimal consumption of the regenerated absorbent supplied to the absorber and the irretrievable loss of this valuable product. As a result of excessive loss of absorbent material, the energy costs of absorbent regeneration are increased and the quality of the prepared gas for long-distance transport is reduced, i.e. as a whole, the efficiency of the gas dehydration process at the gas treatment facility decreases.

The presence of excess moisture in natural gas causes a number of serious problems during its transportation. Therefore, natural gas in the North is depleted in accordance with the requirements and standards for natural gas of the cold climatic zone in accordance with OST 51.40-93 “Natural combustible gases supplied and transported through gas pipelines” before being supplied to the main gas pipelines.

As a rule, gas treatment of the Cenomanian deposits of oil and gas condensate deposits of the North of the Russian Federation - Urengoy, Yamburg, Zapolyarny, etc. oil and gas condensate fields, is carried out at the gas treatment plant using absorption drying technology. A solution of diethylene glycol (DEG) is used as an absorbent [see p. 106, Bekirov T.M., Lanchakov G.A. Gas and condensate processing technology. - M .: Nedra-Business Center LLC, 1999. - 596 p.].

The purpose of the invention is to improve the accuracy of control of the gas drying process, providing a given quality of gas preparation for long-distance transport with a minimum consumption of absorbent at the gas treatment plant.

Technical results when using the invention are:

- increasing the efficiency of the gas dehydration process at the gas treatment plant with minimizing the amount of regenerated DEG (RDEG) supplied to the absorber;

- automatic maintenance of the required temperature of the dew point of the dried gas;

- operational diagnostics of the absorber, which allows real-time detection and fending off potential emergency situations in its operation.

This problem is solved, and the technical result is achieved due to the fact that the method of automatic control of the gas dehydration process at the gas treatment plant in the North implements an automated process control system - automatic process control system for gas dehydration. It controls the pressure and temperature of the raw gas, controls the pressure, temperature, flow rate and dew point of the dried gas, automatically maintains the supply of the regenerated absorbent to the absorber taking into account the flow rate of the produced gas, and controls the mass flow rate of the absorbent. ACS TP uses for modeling and control of technological processes the parameters controlled by it, which it measures with a given discreteness in time. They also include the concentration of water-saturated absorbent and the specific amount of moisture recovered as a result of gas drying in the absorber.

The automatic process control system calculates the flow rate G _{p of the} regenerated absorbent necessary to dry the current flow rate of produced gas passing through the absorber, and sends a signal of this flow rate G _p to the first input I ₁ of the correction block for the mass flow rate of the regenerated absorbent. The correction signal generated by the PID controller for maintaining the temperature of the dew point of the dried gas based on a comparison of its setpoint value - T _TRZ is fed to the second input I ₂ of the correction unit with the actually measured value of the dew point - T _trf for now. Having received these two signals, the correction unit calculates the correction correction Δ to the value G _{p of the} mass flow rate of the regenerated absorbent calculated by the automated process control system. Calculation of the adjusted value of the flow rate setting G _cor. Absorbent using this correction Δ is based on the following expressions:

if T _trf > _TR then G _cor. = G _p + Δ,

if T _trf = T _tr.s. then G _cor. = G _p ,

if T _trf <T _TR then G _cor. = G _p - Δ.

The obtained value of G _box. fed to the input of the job SP of the PID controller to maintain the flow rate of the regenerated absorbent. At the same time, the feedback signal PV of the same PID controller receives the signal G (t) 3 of the actual consumption of the regenerated absorbent. As a result of processing these two signals, the PID controller for maintaining the flow rate of the regenerated absorbent generates at its output a CV signal for the control valve that controls the supply of the regenerated absorbent to the absorber. At the same time, the automatic process control system monitors the dynamics of the actual consumption rate of the regenerated absorbent G (t) relative to its consumption values G _p (t) continuously calculated for the same time points, which in fact are functions of time. And if the automatic process control system detects that the dynamics of behavior of G (t) and G _p (t) becomes different, then the system generates a message to the operator of the gas treatment unit that there has been an increase in the entrainment of the absorbent from the absorber.

The automated process control system analyzes the dynamics of the behavior of G (t) and G _p (t) by controlling the modulus of the difference of these functions, which must satisfy the inequality ⏐G _p (t) - G (t) ⏐ ≤ Δ _G , where Δ _{G is the} maximum allowable difference between the calculated G _p (t) and the actual G (t) consumption of the regenerated absorbent. At the same time, the automatic process control system controls the behavior of their first derivatives in time. And if the difference of the first derivatives at some point in time t ₁ exceeds the allowable threshold ω _ass. defined by the relation ⏐dG (t) / dt - dG _p (t) / dt⏐> ω _ass. , The automatic process control system fixes the difference in values {G (t ₁ ) - G _p (t ₁ )} = Δ _G (t ₁ ) taking place at time t ₁ and searches for deviations fixed before that in the gas operation mode, such as hydrate formation in loops, removal of water or sand from wells, etc. Having discovered such a deviation, the automatic process control system selects a special, specific process control mode to counter the current situation. This control system of the automatic process control system implements until time t ₂ at which the conditions will be satisfied: выполнятьсяdG (t) / dt - dG (t) / dt⏐ = 0 and Δ _G (t ₁ ) = Δ _G (t ₂ ).

When switching to a special process control mode, the automatic process control system generates a message about this to the installation operator with all the data that determined her choice of the installation process control mode.

The value of Δ _G and ω _ass. for each absorber, the installation personnel selects individually, taking into account its condition and according to the results of hydrodynamic studies of operating wells, and enters them into the ACS TP database.

If the automatic process control system does not find fixed deviations in the gas production mode of operation, and / or there are no parry algorithms in the automatic mode of the current situation, the system generates a message to the operator. Based on this, the operator makes decisions that allow to parry the emergency situation in the operation of the gas treatment plant, for example, by changing the operating mode of the installation, reducing the volume of gas passed through the absorber, etc.

The main apparatus of the drying technology at the gas treatment plant operated in the North is a multifunctional absorber (MPA), consisting of separation, mass transfer and filter sections [see p. 11, Lanchakov G.A., Kulkov A.N., Siebert G.K. Technological processes for the preparation of natural gas and methods for calculating equipment. - M.: Nedra - Business Center LLC, 2000. - 279 p.: Ill.].

In the MFA separation section, preliminary gas separation is carried out, in the mass transfer section is the absorption of moisture that is present in the gas, and in the filtering section, the final gas purification is carried out.

In FIG. 1 is a schematic flow diagram of an MFA; FIG. 2 is a block diagram of an automatic control of the supply of RDEG in an MFA, and in FIG. Figure 3 shows the dynamics of changes in the values of the calculated and actual consumption of RDEG in the process of drying gas on an MFA.

In FIG. 1, the following notation is used:

1 - MFA;

2 - filtering section MFA;

3 - absorption section of the MFA;

4 - input line of raw gas;

5 - crude gas temperature sensor;

6 - crude gas pressure sensor;

7 - line withdrawal of an aqueous solution of an inhibitor (ARI);

8 - separation section MFA;

9 - multi-parameter sensor for measuring the concentration and flow rate of saturated DEG (NDEG);

10 - line removal of NDEG for regeneration;

11 - sensor controlling the mass flow of RDEG;

12 - valve-regulator flow rate RDEG;

13 - supply line RDEG;

14 - temperature sensor of the dried gas;

15 - pressure sensor of the dried gas;

16 - flow sensor of dried gas;

17 - temperature sensor dew point of the dried gas;

18 - outlet line of dried gas

19 - ACS TP UKPG.

In FIG. 2 the following notation is used:

20 - flow signal RDEG coming from the sensor 11;

21 - signal of the calculated value of the mass flow rate of RDEG necessary for drying the gas;

22 - signal from the dew point temperature sensor 17 of the dried gas supplied to the input of the PV PID controller 24;

23 - signal for setting the temperature value of the dew point of the dried gas supplied to the input SP of the PID controller 24;

24 - PID controller for maintaining the temperature of the dew point of the dried gas;

25 - block correction of mass flow rate RDEG;

26 - PID-regulator of maintenance of an expense of RDEG;

27 is a control signal supplied from the output of the CV PID controller 26 to the valve-controller 12 of the RDEG flow.

In FIG. 3 the following notation is used:

28 - values of the actual consumption of RDEG;

29 - calculated values of the consumption of RDEG;

30 - area of detection of emergency situations.

A method for automatically controlling the gas dehydration process at a gas treatment facility in the Far North is implemented as follows.

From the raw gas collector UKPG through the inlet line 4, the produced gas enters the inlet separation section 8 of the MFA 1, where droplet liquid and mechanical impurities are released from it. The liquid released from the raw gas is a VRI, which is sent from the bottom (bottom) part of the MPA 1 through the exhaust line of the VRI 7 to either regeneration or disposal. Gas from the separation part through a half-deaf plate enters the absorption section 3 of MFA 1. An RDEG solution of 98-99% concentration is supplied towards the gas stream. On the contact plates, bubble mass transfer occurs between the oncoming flows of the drained gas and the RDEG (moisture is removed from the gas by absorption, and the 2DEG is saturated with moisture). The amount of RDEG supplied to the dehydration mainly depends on the gas flow through the unit, on its moisture content and the concentration of RDEG.

The NDEG is collected on a half-deaf plate of the mass transfer section of the MFA 1 and is discharged through the exhaust line 10 for regeneration. The dried gas from the mass transfer section enters the filter section, where the DEG solution carried away by the gas is captured. DEG dust particles carried away by gas are coagulated on filter cartridges and flow down on their outer surface to a plate from which the DEG is sent via a remote pipe to a half-blank plate of an absorber or to a line for discharging LDEG from a half-blank plate. The level of DEG on a half-deaf plate acts as a water seal, preventing the passage of gas through the pipeline into the filter part of the absorber.

From MFA 1, the gas drained to a predetermined dew point value is supplied through the outlet line 18 of the dried gas to the drained gas collector UKPG.

The process of gas dehydration at the installation is implemented in real mode within the specified boundaries provided by the technological regulations of the gas treatment plant, by monitoring the main parameters of the process with automatic calculation and real-time supply of the required amount of RDEG in MFA 1.

To determine the amount of RDEG, which must be supplied for gas dehydration in MFA 1, ACS TP 19 with a given discreteness measures the basic parameters:

- temperature and pressure of the raw gas (sensors 5 and 6, respectively);

- concentration of NDEG (multi-parameter flow sensor 9);

- temperature, pressure and flow rate of the dried gas (sensors 14, 15, 16 and 17, respectively).

The amount of RDEG required for filing in MFA 1 is determined by the formula [see p. 111, Bekirov T.M., Shatalov A.T. Collection and preparation for the transport of natural gases. - M .: Nedra, 1986. - 261 p.]:

where G _p is the calculated consumption of RDEG (kg / h);

Q is the flow of drained gas through the MFA 1, thousand m ³ / hour;

ΔW is the specific amount of moisture recovered as a result of gas drying in the MPA 1, kg / 1000 m ³ ;

_Rin W, W _O - moisture content of the incoming dry gas and IPA 1, respectively, kg / 1000 m ^3;

X _RDEG , X _NDEG - the concentration of RDEG and NDEG, respectively,% of the mass.

The values of W _in and W _{out are} determined from the Bukachek formula [see p. 14, Klyusov, V.A. Technological calculations of gas absorption drying systems. Reference manual. Publisher: Tyumen: TyumenNIIgiprogaz. 140 pages 2002]:

where p _I , p _o - gas pressure at the inlet and outlet of the MFA 1, measured by pressure sensors 6 and 15, respectively; T _in , T _out - gas temperature at the inlet and outlet of the MFA 1, measured by temperature sensors 5 and 14, respectively.

The concentration value X of _NDEG in the _industrial control system 19 comes from a multi- _parameter control sensor 9 (as a sensor 10, mass flowmeters from KROHNE from the OPTIMASS series or Micro Motion from Metran can be used).

The value of the concentration X of _RDEG in the _industrial control system 19 comes from the regeneration shop of the gas treatment plant. Maintaining the value of the concentration of DEG, as well as maintaining its temperature within the specified limits provided for by the technological regulations of the gas treatment plant, is provided during regeneration in the regeneration shop of DEG.

Maintaining the set value of the temperature of the dew point T _TRZ drained gas provides a cascade circuit of PID controllers 24 and 26, implemented on the basis of industrial control system 19 of the installation. The PID controller 24 for holding the temperature of the dew point of the dried gas, monitors in real time the deviation of the actual value of the dew point temperature T _trf from a given value of T _TRZ To do this, at the input of the reference SP of the PID controller 24, a signal 23 for setting the dew point temperature T _tr.s. , which is determined by OST 51.40-93. At the same time, the feedback signal PV of the same PID controller receives a signal 22 of the actual dew point temperature T _trf recorded by the sensor 17. Comparing these two signals, the PID controller 24 generates at its output CV the correction value Δ necessary to adjust the calculated mass-flow rate control system of the RDEG according to formula (1). The signal of this correction is fed to the input I ₂ of the correction unit 25 of the mass flow of RDEG, also implemented on the basis of ACS TP 19 UKPG. At the same time, the input of I ₁ of the correction unit 25 is supplied from the automatic process control system by a signal of the value of the mass flow rate of the RDEG calculated according to the formula (1).

Receiving these two signals, block 25 calculates the corrective correction to the calculated mass flow rate of the RDEG using the following expressions:

if T _trf > _TR then G _cor. = G _p + Δ,

if T _trf = T _tr.s. then G _cor. = G _p ,

if T _trf <T _TR then G _cor. = G _p - Δ.

To control the supply of RDEG in MFA 1, a PID controller 26 is used to maintain the RDEG flow, to the input of the reference SP of which a signal of the adjusted value of the RDEG flow G _cor. from the output Q of the correction block 25, and to the feedback input PV of the given PID controller, simultaneously the signal 20 of the actual RDEG flow rate G (t) is supplied from the sensor 11. (The signal G (t) is essentially a function of time). Comparing these two signals, the PID controller 26 at its output CV generates a control signal 27, which is supplied to the valve-controller 12 of the RDEG flow. As a result of this, automatic control of the supply of the required amount of RDEG in the MFA 1 is provided, sufficient for drying the gas to a predetermined dew point temperature.

PID controllers are tuned according to well-known methods described, for example, in the Encyclopedia of APCS, clause 5.5, PID controller, resource http://www.bookasutp.ru/Chapter5_5.aspx#HandTuning.

In the process of technological process control using a sensor 11 monitors the dynamics and quasistatic level of the actual consumption of RDEG G (t) supplied for drying gas in the MFA 1.

To control the quasistatic level of the actual RDEG consumption recorded by the sensor 11, the industrial control system builds the current (actual) consumption G (t) in the form of a graph 28 of the time function (see Fig. 3). In parallel to this graph, the automatic control system builds the time function synchronized with it 29 of the continuously calculated value of the RDEG flow rate G _p (t), determined by the formula (1). If both graphs go in parallel, i.e. their dynamics are the same and the difference in these costs is almost constant, i.e. ⏐G _p (t) - G (t) ⏐≤ Δ _G , where Δ _{G is the} maximum allowable difference between the calculated G _p (t) and the actual G (t) RDEG consumption for each time moment, it can be unambiguously stated that the technological process gas dehydration takes place in normal mode. In this case, the value Δ _{G is} assigned individually for each MPA of the gas treatment facility and is refined after each cycle of gas-dynamic studies of operating wells.

To control the dynamics of the behavior of the actual flow rate G (t) relative to the flow values G _p (t) continuously calculated for the same time instants (which in fact are functions of time t), the automatic process control system analyzes the dynamics of the behavior of G (t) and G _p (t) by control module of the difference of these functions, which must satisfy the inequality ⏐G _p (t) - G (t) ⏐≤ Δ _G. At the same time, the automatic process control system monitors the first time derivatives of the actual dG (t) / dt and the estimated dG _p (t) / dt of the RDEG consumption. If the dynamics of change G _fact. (t) relative to G (t) is absent (the curves run parallel), then the difference of their first derivatives will be zero, i.e. ⏐dG (t) / dt - dG (t) / dt⏐ = 0. If the behavior of G (t) and G _p (t) are different, then the modulus of the difference of their first derivatives will be nonzero. The nature of such a change in these graphs over time is shown in FIG. 3. Then, when the dynamics of the graphs becomes really different, it will be characterized by the fact that the difference of their first derivatives (the difference of the tangents of the slope of these curves) will exceed some predetermined limit ω _ass. This statement is mathematically written as an expression

From this moment, it is necessary to take measures to control the technological process to counter the emergency situation. The implementation of this contingency detection algorithm is easily carried out by automated process control systems using PID controllers, which provide the necessary smoothing of the recorded (actual) G (t) and calculated G _p (t) curves to exclude random emissions from the analysis. That is why ACS TP easily detects the moment of the beginning of a deviation during the technological process (this area in Fig. 3 is designated as the "area for detecting emergency situations" 30).

At this moment, the automatic process control system fixes the difference between the values {G (t ₁ ) - G _p (t ₁ )} = Δ _G (t ₁ ) taking place at time t ₁ and searches for deviations recorded before in the gas operation mode, such as:

- hydrate formation in loops, which ACS TP determines and fixes in accordance with the technologies, see RF patents No. 2229371, No. 2560028, and No. 2573654;

- ASU TP revealed changes in the condition of the wells, see RF patent No. 26077004;

- the system detected the removal of water or sand from the wells, see RF patents No. 2474685, No. 2619602 and No. 260 08141, etc.

Having determined the reason for the deviation in the operating mode of the installation, the automatic process control system parries it as follows:

- at the moment t _{1 of} revealing the differences in the dynamics of the behavior of the functions G (t) and G _p (t), the system remembers the magnitude and sign of the difference between these two functions;

- the system searches for an algorithm to parry the current situation;

- the system switches to the control mode of the plant’s technological processes and begins to change the actual RDEG consumption (to control the actual RDEG consumption) in accordance with the selected algorithm;

- the system generates a message to the installation operator about the reasons and the transition to the process control mode, allowing to parry the current situation;

- the system implements the selected control algorithm of the installation until t ₂ when again the conditions are satisfied:

⏐dG (t) / dt - dG _p (t) / dt⏐ = 0

Δ _G (t ₁ ) = Δ _G (t ₂ ).

The value of Δ _G and ω _ass. for each MFA, the service personnel selects individually, taking into account its condition and based on the results of hydrodynamic studies of operating wells.

If the automatic process control system does not find fixed deviations in the gas production mode of operation, and / or there are no parry algorithms in the automatic mode of the current situation, the system immediately generates a message to the operator for decision making, allowing to parry the emergency situation in the operation of the gas treatment facility. The system also offers the operator to solve the problem, for example, by changing the operating mode of the installation, reducing the volume of gas passed through the absorber, etc.

This situation occurs when:

- there is a volley release of formation water in the wells (above the permissible norm);

- there was a violation in the operation of the MFA - clogged with solid particles and torn mesh mats in the separation section, clogged filter cartridges, etc.

A method for automatically controlling the gas dehydration process at a gas treatment facility operating in the Far North was implemented at the Zapolyarnoye oil and gas condensate field at the UKPG-1C, UKPG-2C and UKPG-3C 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 North of the Russian Federation.

The application of this method allows you to:

- in real time, automatically determine the required amount of RDEG, taking into account the flow rate of the gas to be drained through the absorber, the concentration of LDEG removed from it and the specific amount of moisture recovered as a result of gas drying. Thanks to this, it is possible to minimize the amount of delivered RDEG in the MFA without reducing the quality of the gas dehydration process at the gas treatment facility;

- automatically maintain the set temperature of the dew point, which is the main parameter that determines the moisture content of the dried gas at the gas treatment facility, by supplying the MPA with the required volume of RDEG at the moment, providing gas preparation for long-distance transport with the specified quality parameters;

- quickly identify emerging emergency situations in the operation of MFAs, greatly simplifying the adoption of effective control decisions (changing the operating modes of wells, gas treatment facilities, etc.) at technological facilities involved in the cycle of gas production, transportation and preparation for long-distance transport.

Claims (7)

1. A method for automatically controlling the gas dehydration process at the integrated gas treatment plants - gas treatment plants in the north, including monitoring by means of automated process control systems - automated process control systems for pressure and temperature of the raw gas, monitoring pressure, temperature, flow rate and dew point of the dried gas, automatic maintenance supply of regenerated absorbent to the absorber taking into account the flow rate of the produced gas, control of the mass flow rate of the absorbent, characterized in that the ACS TP, using controlled e its parameters measured with predetermined increments of time, including the concentration of saturated water absorbent and the specific amount of recoverable moisture due to drying gas in the absorber, calculates the flow rate G _p regenerated absorbent required for drying the current flow produced from the gas passing through the absorber, and delivers the signal values of the flow rate G _p to a first input I ₁ of the unit mass flow rate of the regenerated absorbent correction, and to a second input I ₂ correction block correction signal is supplied, form vanny PID maintain the dew point of the dried gas by comparing its setpoint value - T _t.r.z. with the actually measured value of the dew point - T _trf at the moment, and, having received these two signals, the correction unit calculates the correction correction Δ to the calculated value of G _{p of the} mass flow rate of the regenerated absorbent calculated by the automated process control system, using the following expressions: if T _trf > _TR then G _cor. = G _p + Δ, if T _trf = T _tr.s. then G _cor. = G _p , if T _trf <T _TR then G _cor. = G _p - Δ, and gives a signal G _cor. to the input of the job SP of the PID controller for maintaining the flow rate of the regenerated absorbent, the feedback input PV of which simultaneously receives the signal for the actual consumption of the regenerated absorbent G (t), and as a result of processing these two signals, the PID controller for maintaining the flow of the regenerated absorbent generates a CV signal at its output for the control valve that controls the supply of the regenerated absorbent to the absorber, and at the same time, the automated process control system monitors the behavior of the actual consumption of the regenerated abs rbenta G (t) with respect continuously calculated for the same moments of time the value of its flow rate G _p (t), which in fact is also a function of time, and if the PCS detects that the dynamic behavior of G (t) and G _p (t) becomes different, the system generates a message to the operator of the gas treatment unit that there has been an increase in the entrainment of the absorbent from the absorber. 2. The method according to p. 1, characterized in that the automatic process control system analyzes the dynamics of the behavior of G (t) and G _p (t) by controlling the modulus of the difference of these functions, which must satisfy the inequality ⏐G _p (t) - G (t) ⏐ ≤Δ _G , where Δ _{G is the} maximum allowable difference between the calculated G _p (t) and the actual G (t) consumption of the regenerated absorbent, and also controls the behavior of their first derivatives in time, and if the difference of the first derivatives at some point in time t ₁ exceeds the permissible threshold ω _back defined by the relation ⏐dG (t) / dt - dG _p (t) / dt⏐> ω _ass. , The automatic process control system fixes the difference between the values {G (t ₁ ) - G _p (t ₁ )} = Δ _G (t ₁ ) taking place at time t ₁ and searches for deviations fixed before that in the gas operation mode, such as hydrate formation in loops, the removal of water or sand from the wells, etc., and selects a special process control mode to counter the current situation, and this control system of the automatic process control system implements until time t ₂ at which the conditions will be satisfied: ⏐dG (t ) / dt - dG (t) / dt⏐ = 0 and Δ _G (t ₁₎ = Δ _G (t _2), and at the transition to the special control mode protses ohm system generates a message about that plant operator with all the data to determine its mode selection, the value of the quantities Δ _G and ω _ass. for each absorber, the installation staff selects individually, taking into account its condition and according to the results of hydrodynamic studies of operating wells. 3. The method according to p. 2, characterized in that if the automated process control system does not find fixed deviations in the gas production mode of operation, and / or there are no parry algorithms in the automatic mode of the current situation, the system generates a message to the operator for making decisions that allow to parry the emergency situation in the operation of the gas treatment plant, for example, by changing the operating mode of the installation, reducing the volume of gas passed through the absorber, etc.

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