RU2580909C2 - System for compounding sour crude oil in multiple directions of pumping mixed flows - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to automation and can be used in pipeline transportation during oil intake from one pipeline or from several branches in several common lines by which mixture of oils is transported to consumer. Distinctive feature of invention is introduction of into the system structure of following units for control over oil compounding: coefficients calculator of oil flow rate ratio in each transported flow and in mixed flow, calculator for oil density ratios in each transported flow and in mixed flow, real time calculator for required compounding efficiency value in direction of transfer, required for plan execution monitoring. Inputs of said calculators are connected to flow and density sensors, and outputs of calculators are connected to inputs of control unit.

EFFECT: technical result is provision in automatic mode of different at certain quality indicators oil grades compounding with simultaneous or sequential transfer of mixed flow via several main pipelines.

4 cl, 2 dwg

Description

The invention relates to automation and can be used in pipeline transport when pumping oil from one pipeline or from several branches into several common highways through which a mixture of oils is transported to the consumer. Moreover, the number of trunk directions for a mixed flow may be several: two or more.

The system is designed to control and regulate the compounding process - the rational mixing of several oil flows in order to ensure the necessary quality characteristics of mixed oil flows in several directions of pumping, to monitor the implementation of the compounding plan in each direction and in general, to ensure the safety and consistency of the piping system in the compounding process .

A well-known automated system for controlling the quality indicators of a fluid flow obtained by mixing oil streams flowing through pipelines to a mixing tank, comprising a flow control device, a control unit, the control output of which is interconnected with the flow control device, units for measuring the parameters of the flow of sour crude oil, a meter sour oil flow rate and mixed flow meter, while outputs of high sulfur flow parameter measurement unit istoy oil and meter sour oil flow, mixed flow rate meter are interconnected with the respective information inputs of the control unit, the measurement quality indicators mixed stream provided analyzer sulfur, flow control device designed to control the pressure and sour crude oil flow rate and is provided with a pressure regulator and flow. (Patent RU 2158437 G05D 11/02, 06/25/1999). The specified system is selected as the closest analogue.

The known system allows you to maintain the specified quality indicators of compounded oil (sulfur content or density) by continuously monitoring the quality indicators of this flow and regulating the flow rate of the oil stream with high sulfur content, ensuring pressure control in the pipeline with sour crude oil entering the main line, with the aim of maintaining the pressure in this pipeline is higher than the pressure corresponding to the evaporation mode — the cavitation threshold, accounting for the amount of oil, my customer based on the total amount of backbone and sour crude.

However, this system cannot function when the oil flow from one pipeline or from its branches, the quality of which needs to be improved by some indicators (for example, sulfur content or density) is pumped simultaneously or alternately into different main oil pipelines, i.e. in several directions.

The objective of the invention is the provision in the automatic mode of compounding of multi-grade oils according to some quality indicators while simultaneously or alternately pumping a mixed stream through several main pipelines. The system selects (approves) the pumping of oil to a particular pipeline depending on the availability of quality margin in the pipeline in this direction according to compounded indicators and ensures safe (to avoid exceptions to work on a closed gate valve of a pumping station (NS) pumping the oil flow for compounding) switching oil flow from one direction of pumping to another in automatic mode, when in one direction of pumping the sulfur content reaches a predetermined value, and in another direction Compounding is not carried out at this time and the sulfur content in oil of this direction is less than the specified value, i.e. there is a stock of quality. Another objective of the invention is to control and ensure the implementation of the compounding plan in automatic mode in each direction and, in general, the implementation of the overall compounding plan.

The problem is solved in that the oil compounding process control system, comprising two or more directions of transportation, containing an oil flow meter, a flow meter, an oil density meter, and an oil flow control means installed in each of the pipelines in each direction for transporting oil, is installed in each pipeline for a mixed flow, an oil flow meter, a density meter, a sulfur content meter, the outputs of these soybean meters dinene with the inputs of the control unit, the outputs of which are connected with means for regulating oil consumption, according to the invention contains a calculator of the coefficients of the ratio of oil consumption in each transported stream and in the mixed stream, a calculator of the coefficients of the ratio of the density of oil in each transported stream and in the mixed stream, a calculator of the required performance real-time compounding in the directions of pumping necessary to control the implementation of the plan, inputs of the indicated subtracts divisors are connected to the flow meter and density, and the outputs of calculators connected to inputs of the control unit.

The system contains quality reserve calculators in each direction of the mixed flow, the inputs of the calculators are connected to the calculators of the flow ratio, the sulfur content meters, and the outputs of each calculator are connected to the input of the common control unit (quality reserve controller), the outputs of which are connected to the corresponding dampers. When the flow ratio reaches the maximum allowable value of the flow ratio, the controller gives a control signal to close the damper on this flow, and if necessary, after opening, according to the results of comparing quality stocks, the damper on the flow, where there is more quality stock, i.e. provides, if necessary, safe switching of flows (full opening of the damper on one thread and full closing of the damper on another thread in automatic mode).

The pipelines of the incoming flows to the compounding are hydraulically interconnected, i.e. are branches of one common thread.

The system contains a common total calculator of the required planned performance in real time in all directions, the inputs of which are interconnected with calculators of the required planned performance in real time in the directions, flow meters, the outputs of the calculator are interconnected with the input of a common control unit (plan controller), outputs which are associated with the corresponding dampers, according to the results of the comparison, the plan controller gives a control signal to turn off (full close e) or inclusion (full opening) of the corresponding damper.

The system provides a record of the amount of sour oil pumped for compounding in real time, calculates the required volume and average compounding capacity for the remaining time of the planning period and in case of lagging behind the plan, opens the damper on the sour oil stream to ensure the necessary performance, and if at the same time open shutter does not achieve the required performance, it turns off the swap for compounding in a different direction, to which is not a priority, which will lead to an increase in flow rate in the first direction, and if after that the required flow rate is not achieved, then a light and sound alarm is given, and a recommendation to the dispatcher on changing the mode (flow rate) of NS high-sulfur oil and mixed flow rate in this direction.

It is known that when mixing liquids (mutually insoluble), quality indicators (the content of quality parameters characterizing the physicochemical properties) obey the law of additivity.

G ₂ S ₂ + G ₁ S ₁ = G _CM S _CM , (one) G _CM = G ₂ + G ₁ , (2)

where G _CM , G ₂ , G ₁ - the mass flow rates of mixed oil, sour and sulphurous oil, respectively;

S _SM , S ₂ , S ₁ - mass sulfur content in mixed, sour and sulfur oil, respectively.

From relations (1), (2), we obtain

S _CM = S ₁ + G ₂ / G _CM (S ₂ -S ₁ ) (3)

Thus, from relation (3) it can be seen that the regulation of the sulfur content S _SM can be carried out by changing the ratio of costs.

In those cases when the sulfur content in the incoming sulphurous oil stream increases and approaches the set S _ass value (lack of quality margin), the automation system closes the dampers on the sour oil stream and the compounding stops. From relation (3) it follows that for

S _CM = S ₁ = S _{CM back} G ₂ / G _{CM =} 0, i.e. G ₂ = 0.

Conclusion: regardless of the sulfur content in the sour crude oil stream, compounding can be carried out if the condition is met: the sulfur content in the incoming stream is less than the specified value G ₂ > 0, i.e. in this case, G ₂ > 0.

Formula (3) is expressed with respect to S ₁

$$S_{\mathrm{one}}=\frac{S_{\mathrm{from}m}-S_2\frac{G_2}{G_{\mathrm{from}m}}}{\mathrm{one}-\frac{G_2}{G_{\mathrm{from}m}}}\text{(four)}$$

The sulfur content in the mixed stream is determined continuously by the content analyzer in the stream. Regulation is carried out according to the ratio of costs. It is known that the range of changes in the sulfur content in the sour crude oil stream is in practice observed from 2% to 3.5%. The set value of the sulfur content in the mixed stream will accept 1.35% or 1.4%. The solution of the example using the relation (4), provided that after compounding, S _СМ = [S _{СМ back} ] is supported, allows us to draw the following conclusion (Appendix 1).

By changing the ratio of the costs of the regulatory system, we can estimate how much the sulfur content in the input stream

sulphurous oil and approaches the specified (maximum permissible) value of sulfur content in the stream of compound (mixed) oil. According to the above calculations, it can be seen that, with sufficient accuracy for practical calculations, it is possible to take the limit value of the flow ratio G ₂ / G _СМ = А, for example, G ₂ / G _СМ = 0.02, while the margin of quality of the incoming stream in terms of sulfur content will be small from 1.5 to 3.3%, or the absolute value of the difference between the specified value of the sulfur content and sulfur content in the input stream will be in the range from 0.02 to 0.04 % . When the cost ratio reaches A, it is necessary to make a decision to stop compounding (pumping sour crude oil) or to switch the flow of sour oil to another pipeline (to a different pumping direction), where there is a margin of quality. This conclusion can be used to switch the pumping of sour flow from one pipeline to another in the automatic control system.

In FIG. 1 is a schematic flow diagram of an oil pumping station (NPS) for compounding high-sulfur oils in several directions for pumping a mixed stream on offer. In FIG. 2 is a functional diagram of oil compounding control. The diagram shows tanks 1, pump 2 for pumping compounded oil, quality measuring unit 3 (BIC), oil metering unit 4 (UON), sulphurous oil pipeline 5, sulphurous oil pipelines 6, and sulphurous oil piping 6.

The pipeline for pumping sour crude oil, the quality of which must be changed by compounding, contains a pumping unit (HC) -7 (Fig. 2), equipped with centrifugal pumping units; a quality measuring unit (BIC) -7v is placed on the common line after the pumping unit, which contains a standard set sensors, for example, densitometer, moisture meter, pressure and temperature sensors and others (not shown in the diagram). Further, the stream branches into several streams in the directions of transportation of the mixed stream, for example, the direction of transportation of compound oil can be two or more. Pipelines, on each branch of sour crude oil, contain 6 _v1 , 6 _v2 , 6 _v3 flow meters, dampers for regulating the flow rate and flow pressure of 10 _v1 , 10 _v2 , 10 _v3 .

Each pipeline for pumping sulfur dioxide (directions for pumping mixed oil after compounding) contains a booster pump, respectively 12 ₁ , 12 ₂ , 12 ₃ , a mixing tank 4, which uses a receiving manifold of a booster pump, flow meters 6 _{1 cm} , 6 _{2 cm} , 6 _3cm , density meters 7 _1cm , 7 _2cm , 7 _3cm , sulfur content meters 8 _1cm , 8 _2cm , 8 _3cm , main pumping 13 ₁ , 13 ₂ , 13 ₃ , automatic mode control system (ATS), not shown in the ATS diagram. The control unit for each direction of pumping the mixed stream contains a calculator of the ratio of the flow rate of sour oil to the flow rate of the mixed flow of WU 14i (where i = 1, 2, 3 are the serial numbers of the directions of pumping), a calculator of the ratio of the density of sour oil to the density of the mixed flow of WU 15i, a calculator Wu 16i the necessary current performance of pumping sour crude oil for the implementation of the compounding plan, calculator WU 17i stock quality by compounding indicator. The inputs of VU 14i, 15i calculators are connected to the corresponding outputs of the flow and density meter, the inputs of the By 16i calculator are connected to the corresponding outputs of the flow meter, the value of the planned compounding volume is entered into the memory cell of the calculator, the inputs of the VU 17i calculator are connected to the outputs of the VU 14i and sulfur content meters, in the memory cell of the calculator is entered values S _ass , S ₂ .

The outputs of the calculators WU 14i, 15i, 16i are connected to the input of the controller of the corresponding direction K 20i, the output of which gives a control signal to change the position of the shutter 10vi, i.e. this changes the ratio of costs.

To coordinate the operation of control units in the directions (BUN) of mixed flows in the pumping directions, there is a common compounding control unit (BUo) - controllers K23 and K25. Information from the calculators 14i, 15i, 17i is fed to the input of the common controller, the sulfur content values in the mixed flow of each direction from the 8icm meters. Data on the limit value of the flow ratio for each direction is entered into the controller’s memory cell, upon reaching which the compounding in this direction should stop and the shutter is completely closed if compounding is being carried out in other directions. And if compounding is carried out in only one direction, in which compounding should cease due to the lack of quality margin, then the controller safely switches the flow to another direction, where there is a quality margin in the compounding indicator, i.e. First, the flap of the connected direction opens and only after that the flap on the flow closes, where the compound stops. Formula (5) is proposed for determining the quality margin Z _c .

Quality margin is the ratio of the difference between the values of a given value of sulfur content in a mixed stream and the current value of sulfur content in the incoming stream to the value of a given value. Given the value of S ₁ in relation (4), we have:

$$3_{\mathrm{to}}=\frac{\mathrm{one}-\frac{S_{\mathrm{FROM}M}}{S_{s\mathrm{but}d}}+\frac{G_2}{G_{\mathrm{FROM}M}}\left(\frac{S_2}{S_{s\mathrm{but}d}}-\mathrm{one}\right)}{\mathrm{one}-\frac{G_2}{G_{\mathrm{FROM}M}}}\left(5\right)$$

The computing device VU 17i continuously calculates the quality margin in each direction, the information is fed to the input of the controller K23. This value of the quality margin is used to select the direction of switching the flow, for example, from two possible options, the switch is made to the flow, where the value of the quality margin is greater. In cases where compounding ceases due to a lack of quality margin in the input stream, this leads to a failure to comply with the compounding plan in the direction, as well as the compounding plan for the total amount of sour crude oil as a whole for the LPS. Therefore, in the claimed system in the control unit, a function has been introduced to monitor the implementation of the planned tasks of compounding high sulfur oil in the directions of pumping and flow control to fulfill the plan. The real-time recording of the amount (volume) of pumped sour oil in each direction is kept. The volume is determined by integrating the flow rate of oil flowing through the flow transducer (counter) over time

$$V_{\mathrm{at}it}={\displaystyle \underset{0}{\overset{t}{\int }}{Q}_{\mathrm{at}i}(t)dt,\left(6\right)}$$

where V _vit , Q _vit - volume and flow rate in the i-th direction of pumping high sulfur oil for the current time t, respectively;

t - period of time from the beginning of the reporting period (two hours, shifts, etc.)

, гдеor $$V_{\mathrm{at}it}={\displaystyle \sum _i{q}_i\cdot \Delta t_i}$$

where

q _i is the instantaneous value of the flow rate for the i-cycle of measurement (scan);

Δt _i is the scanning period.

(A.Sh. Fathutdinov, MA Slepyan, N.I. Khanov and others. “Automated accounting of oil and oil products in the extraction of transport and processing.” Moscow, Nedra. 2002, p. 10.)

The average pumping flow for each pumping direction is calculated, which is necessary to maintain the T-t planning period for the remaining time in order to fulfill the planned compounding volume.

$$Q_{\mathrm{at}io\mathrm{from}t}=\frac{V_{\mathrm{at}iPl}-{\displaystyle \underset{0}{\overset{t}{\int }}{Q}_{\mathrm{at}i}(t)dt}}{T-t}\left(7\right)$$

When Q _viost ≥Q _Bi, the system enhances performance by opening the valve if there is a stock quality, i.e. S ₁ <S _back

There may be cases when the damper is fully open, and the flow rate remains less than the required flow rate for the implementation of the plan. Then the microprocessor of the compounding system analyzes the implementation of the plan in other directions. For example, in other directions pumping is ahead of schedule, then the control system reduces the flow rate in these directions by covering the shutter. When this occurs, the redistribution of flow rates

$$Q_{\mathrm{at}\mathrm{one}}+Q_{\mathrm{at}2}+Q_{\mathrm{at}3}=Q_{\mathrm{at}},\left(8\right)$$

where Q _in - the working capacity of the pumping station when pumping sour oil.

If, even after regulation, the pumping flow is less than the necessary volume for fulfilling the plan Q _vi <Q _viost , a decision is made to stop compounding in a direction that is not currently priority, for example, in direction 3. Then the sour oil will be pumped in two directions 1 and 2. This will be

$$Q_{\mathrm{at}\mathrm{one}}+Q_{\mathrm{at}2}=Q_{\mathrm{at}}\left(9\right)$$

And if, even after the adjustment in two directions is Q _c1 <Q _viost then disconnected pumping more in one direction and the compounding is carried out only in one direction. In this case, there will be maximum swap consumption

$$Q_{\mathrm{at}\mathrm{one}}=Q_{\mathrm{at}}\left(10\right)$$

And if, at the same time, Q _b1 = Q _at <Q _viost , it is not possible to provide a pumping mode for fulfilling the plan, then the dispatcher is notified (an audible and visual alarm is given) and it is recommended to change the NS mode for pumping sour oil and the mode in the direction of pumping the mixed stream.

Thus, the WU 16i computing device provided in the control unit, in real time, calculates the required pumping capacity of the amount of sour crude oil in order to monitor the implementation of the compounding plan for each oil pipeline, as well as the WU24 computing device as a whole in a hydraulically connected common flow. The K20i controller, connected via information channels to the VU 16i calculator, regulates the performance (cost ratio) by opening the shutters to establish the necessary performance in each direction, which allows the daily plan to be fulfilled (subject to the sulfur content S _Сi ≤ [S _{СМi back} ], and the controller K25 disables the flows for which the plan is executed, or the direction at the moment is not priority from the point of view of the plan.

The system operates as follows.

Consider the general compounding scheme when it is possible to compound and pump mixed oil through three main oil pipelines. Cases depending on the sulfur content are possible:

$$\begin{array}{l}\mathrm{one})S_{\mathrm{one}}<[S_{\mathrm{FROM}M\mathrm{one}s\mathrm{but}d}]\left(\mathrm{eleven}\right)\\ S_2<[S_{\mathrm{FROM}M2s\mathrm{but}d}]\\ S_3<[S_{\mathrm{FROM}M3s\mathrm{but}d}]\end{array}$$

compounding can be carried out through three oil pipelines, i.e. in directions 1, 2, 3.

$$\begin{array}{l}2)S_{\mathrm{one}}\ge [S_{\mathrm{FROM}M\mathrm{one}s\mathrm{but}d}]\left(12\right)\\ S_2<[S_{\mathrm{FROM}M2s\mathrm{but}d}]\\ S_3<[S_{\mathrm{FROM}M3s\mathrm{but}d}]\end{array}$$

compounding can be carried out in directions 2, 3

$$\begin{array}{l}3)S_{\mathrm{one}}\ge [S_{\mathrm{FROM}M\mathrm{one}s\mathrm{but}d}]\left(13\right)\\ S_2\ge [S_{\mathrm{FROM}M2s\mathrm{but}d}]\\ S_3<[S_{\mathrm{FROM}M3s\mathrm{but}d}]\end{array}$$

compounding can be done in direction 3

$$\mathrm{four})S_{\mathrm{one}}\ge [S_{\mathrm{FROM}M\mathrm{one}s\mathrm{but}d}]\left(\mathrm{fourteen}\right)$$

$$\begin{array}{l}{S}_2<[S_{\mathrm{FROM}M2s\mathrm{but}d}]\\ S_3\ge [S_{\mathrm{FROM}M3s\mathrm{but}d}]\end{array}$$

compounding can be carried out in direction 2

$$\begin{array}{l}5)S_{\mathrm{one}}<[S_{\mathrm{FROM}M\mathrm{one}s\mathrm{but}d}]\left(\mathrm{fifteen}\right)\\ S_2\ge [S_{\mathrm{FROM}M2s\mathrm{but}d}]\\ S_3\ge [S_{\mathrm{FROM}M3s\mathrm{but}d}]\end{array}$$

compounding can be done in direction 1

$$\begin{array}{l}6)S_{\mathrm{one}}<[S_{\mathrm{FROM}M\mathrm{one}s\mathrm{but}d}]\left(16\right)\\ S_2\ge [S_{\mathrm{FROM}M2s\mathrm{but}d}]\\ S_3<[S_{\mathrm{FROM}M3s\mathrm{but}d}]\end{array}$$

compounding can be carried out in the direction of 1, 3

$$\begin{array}{l}7)S_{\mathrm{one}}<[S_{\mathrm{FROM}M\mathrm{one}s\mathrm{but}d}]\left(17\right)\\ S_2<[S_{\mathrm{FROM}M2s\mathrm{but}d}]\\ S_3\ge [S_{\mathrm{FROM}M3s\mathrm{but}d}]\end{array}$$

compounding can be carried out in the direction 1, 2

$$\begin{array}{l}8)S_{\mathrm{one}}\ge [S_{\mathrm{FROM}M\mathrm{one}s\mathrm{but}d}]\left(\mathrm{eighteen}\right)\\ S_2\ge [S_{\mathrm{FROM}M2s\mathrm{but}d}]\\ S_3\ge [S_{\mathrm{FROM}M3s\mathrm{but}d}]\end{array}$$

compounding cannot be carried out in any direction.

In the case of compounding in three or two directions at the same time (cases 11, 12, 16, 17), when the flow ratio in one direction reaches the limit value A, the damper on this line closes and the compounding stops. Compounding remains on 2 lines, if previously it was carried out on 3 lines, and on the 1st line, if before this compounding was carried out on 2 lines. In this case, the control signal to close the dampers is given by the K23 controller.

The most dangerous from the point of view of pumping station operation for a closed gate valve are when compounding is carried out in one direction of pumping, i.e. cases 13, 14, 15. In these cases, compounding is carried out in one direction of pumping, but in others it is not, i.e. dampers (gate valves) on the sour oil pumping lines are closed in the other two directions.

In the claimed system, the control unit provides the ability to automatically switch flows of sour oil from one direction of pumping to another direction for the above cases.

The switching system works as follows:

when passing a batch of sulphurous oil in the inlet stream with sulfur content S ₁ ≥ [S _СМ1зад ], the damper on the sour oil pumping line will close. Compounding stops when the flow ratio reaches A. If the situation has changed and there is a margin of quality in other directions, in order not to stop the pumping of sour oil from the pumping station (HC) (to avoid operation with a closed valve), in the compounding control system in automatic mode, the switching program provides for the opening of a pre-shutter on the sour oil pumping line, at least in one pumping direction, where there is a margin of quality. At the same time, the switching of the sour oil flow supplied to the compounding from one direction to another direction of transportation is carried out in automatic mode with the corresponding time settings, i.e. first, the damper opens on the sour oil connection line, and then the damper closes on the line where compounding stops.

, эта информация поступает в блок сравнения контроллера К23, микропроцессор контроллера К23 на основании анализа информации по запасу качества, поступающих с вычислительного устройства ВУ 17i, выбирает поток, где больше Зк≥B и контроллер К23 дает управляющий сигнал на переключение потоков, где больше запас качества. Если ситуация изменяется и появляется запас качества в направлении, которое было отключено, то контроллер 23 дает управляющий сигнал на открытие заслонки и компаундирование возобновляется. Если запас качества по всем линиям (направлениям) меньше значения Зк<B, то дается звуковая и световая сигнализация и оперативный персонал останавливает насосную станцию.When calculator 14i reaches a cost ratio $$\frac{G_2}{G_{\mathrm{FROM}M}}=A$$

, this information goes to the comparison block of controller K23, the microprocessor of controller K23, on the basis of the analysis of information on the quality stock coming from the computing device VU 17i, selects a stream where there is more Зк≥B and controller K23 gives a control signal for switching flows, where there is more quality stock . If the situation changes and there is a margin of quality in the direction that was turned off, then the controller 23 gives a control signal to open the damper and compounding resumes. If the quality margin in all lines (directions) is less than the value Зк <B, then sound and light alarms are given and the operating staff stops the pumping station.

In the event that the situation (18) is established when compounding cannot be carried out in any direction, the pumping of sour oil directed to compounding stops.

The considered combinations of the work of pumping sour crude oil in the pumping directions, determined by the sulfur content, can take place not only in the sulfur content, but also by the decision of the dispatcher, for example, in cases where there is no compounding plan for some pumping directions or the daily plan for the pumping direction has already been completed and the gate valve on the sour oil pumping line will be in the closed position.

Consider a situation where compounding in the pumping directions is carried out alternately. In this case, the priority will be the control circuit for sulfur content. Information about the sulfur content in the mixed stream is continuously supplied to the controller K20 and compared with a given value of sulfur content. If the sulfur content in the mixed flow is less than the set value, the controller gives a control signal to open the damper slightly and increase the flow rate, and vice versa, if the sulfur content is greater than the set value, the shutter closes and the flow ratio decreases, i.e. the system seeks to maintain a given value of sulfur content in the mixed stream. There may be cases when the valve is fully open, and the sulfur content is less than the specified value, and if the compounding plan is not followed, then the sound and light signals are given to the dispatcher about the advisability of increasing the pump station's mode (flow rate) for pumping high-sulfur oil. The system monitors the implementation of the compounding plan. The operator enters the value of the plan into the memory of the K20i controller at the beginning of the day. According to relation (7) is calculated Q value _viost and compared with the current flow rate value Q _Bi, Q if _viost ≥Q _Bi, then on slave calculator 16i K20i information enters a controller which provides a control signal to the valve slightly open, and the sulfur content is verified. The condition [S _CM ] ≤ [S _{CM back} ] must always be fulfilled. If the compounding plan is not fulfilled when the shutter is fully open and the sulfur content in the mixture is also less than the set value, then a light and sound alarm is given and the dispatcher is given a recommendation on changing the HC mode and increasing the flow rate. If the compounding plan is exceeded, i.e. Q _viost ≤Q _Bi, then covered and the flap ratio decreases costs.

Consider the situation when compounding is carried out simultaneously along two or three pipelines (pumping directions) from the point of view of ensuring the implementation of the compounding plan.

Based on the daily compounding plan (route telegrams), we determine the volume of dosed pumping of sour crude oil in each direction of pumping, i.e. compounding volume for each oil pipeline.

$$V_{\mathrm{at}Pl}=V_{\mathrm{at}\mathrm{one}Pl}+V_{\mathrm{at}2Pl}+V_{\mathrm{at}3Pl},gde\left(19\right)$$

V _v1pl , V _v2pl , V _v3pl - compounding volume (plan) for the planning period (day, month) through the oil pipelines 1, 2, 3, respectively.

$$Q_{\mathrm{at}Pl}=Q_{\mathrm{at}\mathrm{one}Pl}+Q_{\mathrm{at}2Pl}+Q_{\mathrm{at}3Pl},gde\left(\mathrm{twenty}\right)$$

Q _v1pl , Q _v2pl , Q _v3pl - average planned productivity of pumping sour crude oil through the pipelines 1, 2, 3, respectively.

Let us denote by the symbols V _cm1pl , V _cm2pl , V _cm3pl and Q _cm1pl , Q _cm2pl , Q _cm3pl - planned pumping volumes and average pumping capacities through the oil pipelines 1, 2, 3, respectively.

Compounding Control Algorithm:

NA 1. Mode for pumping sour crude oil is set for the planned volume of compounding - Q _IDPs

$$Q_{\mathrm{at}Pl}=Q_{\mathrm{at}\mathrm{one}Pl}+Q_{\mathrm{at}2Pl}+Q_{\mathrm{at}3Pl},\left(21\right)$$

Since the flow redistribution occurs due to the increase in local resistance on the damper when regulating the performance of pumping sour oil with shutters, the following assumptions can be made:

1) For the case when on any two lines the valves are fully open, and on the other line the shutter is closed when adjusting the sulfur content, there is a redistribution of flows and at the same time with a small error it can be accepted that:

Q _in1 <Q _in1pl on the regulation line;

Q _B2 > Q _B2pl ; Q _B3 > Q _B3pl

on other lines and at the same time the total swap volume changes slightly and we can accept

$$Q_{\mathrm{at}Pl}\approx Q_{\mathrm{at}\mathrm{one}}+Q_{\mathrm{at}2}+Q_{\mathrm{at}3}=Q_{\mathrm{at}Pl}-const\left(22\right)$$

2) For the case when the valve is fully open on one line, and on the other two lines, the shutters are covered when adjusting the sulfur content, redistribution of flows occurs, and at the same time it will be observed:

Q _c1 <Q _v1pl Q _e2 <Q _v2pl on regulation lines;

Q _v3 > Q _v3pl - on the line where flow control is not carried out

At the same time, it can also be assumed with a small error that the total value of the swap volume changes insignificantly and we can accept

_IDPs ≈Q Q + Q _{c1 c2 c3} + Q = Q _IDPs -const

3) For the case when the shutters on all three lines are covered (or when two lines are operating on these two lines) when controlling the sulfur content, the pumping capacity is reduced, and the ratio

$$Q_{\mathrm{at}\mathrm{one}}<Q_{\mathrm{at}\mathrm{one}Pl};Q_{\mathrm{at}2}<Q_{\mathrm{at}2Pl};Q_{\mathrm{at}3}<Q_{\mathrm{at}3Pl}{Q}_{\mathrm{at}}<Q_{\mathrm{at}Pl}\left(23\right)$$

2. A certain ratio of costs is established.

, $$\frac{Q_{б2пл}}{Q_{см2}}$$

, $$\frac{Q_{б3пл}}{Q_{см3}}$$

из расчета выполнения суточного объема компаундирования по каждому направлению перекачки смешанного потока с учетом выполнения условия (18). $$\frac{Q_{b\mathrm{one}Pl}}{Q_{\mathrm{from}m\mathrm{one}}}$$

, $$\frac{Q_{b2Pl}}{Q_{\mathrm{from}m2}}$$

, $$\frac{Q_{b3Pl}}{Q_{\mathrm{from}m3}}$$

based on the calculation of the daily volume of compounding for each direction of pumping a mixed stream, taking into account the fulfillment of condition (18).

A predetermined ratio is maintained for each pipeline

$$\frac{Q_{\mathrm{at}i}}{Q_{\mathrm{FROM}Mi}}PR\mathrm{and}\mathrm{at}sP\mathrm{about}lnen\mathrm{and}\mathrm{and}\mathrm{at}\mathrm{from}l\mathrm{about}\mathrm{at}\mathrm{and}\mathrm{I\; am}{S}_{\mathrm{FROM}Mi}\le [S_{\mathrm{FROM}Mis\mathrm{but}d}]\left(24\right)$$

Moreover, in the case of a change in the sulfur content in one stream upwards, when this leads to a violation of condition (24) for the mixture, i.e. S _cmi > [S _SMizad ], the shutter will be covered on the line where the sulfur content has increased, causing a redistribution of flow rates (case 1) and relation (22). For example, the damper on the UCN unit at one branch of the pipeline (UCN) of sour oil is covered when regulating the sulfur content in the case when

по данному направлению уменьшается. Или в случаях, когда значение содержания серы во входящем потоке сернистой нефти больше, чем заданное значение для смешанного потока S₁≥[S_СМiзад], по этому направлению компаундирование прекращается и компаундирование ведется только по двум нефтепроводам или по одному трубопроводу.S _CMi > [S _CMizad ], the ratio $$\frac{Q_{\mathrm{at}i}}{Q_{\mathrm{FROM}Mi}}$$

in this direction decreases. Or in cases when the sulfur content in the incoming sulphurous oil stream is greater than the set value for the mixed stream S ₁ ≥ [S _Сmi-back ], in this direction compounding stops and compounding is carried out only through two oil pipelines or through one pipeline.

Due to the fact that the piping system is hydraulically connected, this causes an increase in the flow rate for another branch of the pipeline (UCN) of sour crude oil. The automation system checks the sulfur content in the direction of transportation, in which the pumping capacity of high sulfur oil has increased, if the condition S _СMi ≤ [S _CMiad ] is _fulfilled , the damper opens and a new flow rate is established. If in this case it turns out S _СМi > [S _CMiad ], then the shutter is _closed . This may lead to failure to comply with the compounding plan.

In the case of a change in the sulfur content in all three streams, or when working in two directions on two streams, when this leads to a violation of condition (24) for each pipe, the control system, by changing the position of the dampers, will set the sour oil productivity values lower than planned (case 3) and relations (23). In this case, this will also lead to the failure of the compounding plan. Thus, when control units (BUN) in each direction of pumping operate independently, there is a need to coordinate their work in terms of controlling the compounding process and implementing the plan for the volume of compounded oil.

нельзя выполнить план компаундирования (из-за ограничения по условию S_СМi>[S_CMiзад]), то при увеличении производительности смешанного потока Q_СМi устанавливается другое соотношение расходов, позволяющее выполнить план при соблюдении условия S_СМi≤[S_СМiзад].Therefore, the claimed system provides for the installation of computing devices VU 16i, which constantly calculate the volume of compounded oil for each pipeline in real time, determines the necessary performance for the implementation of the plan for each pipeline, as well as in a hydraulically connected common flow. Carries out the regulation of productivity (ratio of costs) by opening the shutters to establish the necessary performance, which allows to fulfill the daily plan (subject to the sulfur content S _СMi ≤ [S _CMiad ]). If the steady-state flow rate in the direction is not enough to fulfill the plan, then the K25 microprocessor based on the information received from the VU24 computing device analyzes other pumping directions and reduces the pumping flow by decreasing the degree of opening of the shutters, if necessary, turns off the flow, which is currently not a priority . If the regulation of the shutters (when their position is fully open) and turning off non-priority flows of sour crude oil does not allow achieving the performance necessary to fulfill the compounding plan, the control unit provides recommendations to the dispatcher on changing the operating mode of the pumping of sour crude oil or through mixed flow pipelines 1, 2 , 3 depending on the direction in which the compounding plan is not being implemented. That is, when with the established ratio $$\frac{Q_{\mathrm{at}i}}{Q_{\mathrm{FROM}Mi}}$$

if the compounding plan cannot be fulfilled (due to the restriction under the condition S _СМi > [S _CMiad ]), then with an increase in the productivity of the mixed flow Q _СМi , a different cost ratio is established that allows the plan to be fulfilled if the condition _{С СМi} ≤ [S _Сmiad ] is _met .

и $$\frac{Q_{в3}}{Q_{СМ3}}$$

, и в случае, когда S_СМ2>[S_СМ2зад], S_СМ3>[S_CM3зад], заслонка прикрывается и установится новый расход Q_в2 и Q_в3, меньший, чем суточный план Q_в2<Q_в2пл, Q_в3<Q_в3пл, что приведет к невыполнению суточного плана компаундирования по каждому направлению и в целом по НПС. Вычислитель ВУ 16₂ определяет объем ожидаемого невыполнения плана и пересчитывает необходимую среднюю производительность подкачки Q_в2ост, которую необходимо поддерживать за оставшееся время для выполнения суточного плана. Объем компаундированной нефти за время t будет, например, для направления 2:For example, consider the case 1) S _CMI> [S _CMizad] Let i = 1, in this case the command BU1 flap on LMD covered and reduced pumping rate Q _B1, the directions 2 and 3 increase rate Q _e2 and Q _B3 and the ratio $$\frac{Q_{\mathrm{at}2}}{Q_{\mathrm{FROM}M2}}$$

and $$\frac{Q_{\mathrm{at}3}}{Q_{\mathrm{FROM}M3}}$$

, and in the case when S _СМ2 > [S _СМ2ad ], S _СМ3 > [S _CM3ad ], the shutter is _closed and a new flow rate Q _в2 and Q _{в3 is established} , smaller than the daily plan Q _в2 <Q _в2пл , Q _в3 <Q _в3пл , which will lead to failure to fulfill the daily compounding plan in each direction and in general for the NPS. The calculator WU 16 ₂ determines the amount of expected non-fulfillment of the plan and recounts the necessary average swap performance _Q2ost , which must be maintained for the remaining time to complete the daily plan. The volume of compounded oil over time t will be, for example, for direction 2:

$$V_{\mathrm{at}2t}={\displaystyle \underset{0}{\overset{t}{\int }}{Q}_{\mathrm{at}2}(t)dt}$$

Remaining amount to complete the plan $$V_{\mathrm{about}\mathrm{from}t\mathrm{at}2}=V_{\mathrm{at}2}-{\displaystyle \underset{0}{\overset{t}{\int }}{Q}_{\mathrm{at}2}(t)dt}$$

The average productivity of pumping sour crude oil necessary to fulfill the plan in direction 2 over time -

(T-t) is:

$$V_{\mathrm{at}2\mathrm{about}\mathrm{from}t}=\frac{V_{\mathrm{about}\mathrm{from}t\mathrm{at}2}}{T-t}$$

If Q _B2 <Q _B2ost regulates the productivity (cost ratio) by opening the dampers to establish the necessary performance, which allows to fulfill the daily plan (subject to the sulfur content S _cm2 ≤ S _cm2set ). If the shutter is not fully operational when the shutter is fully open, i.e. Q _B2 <Q _B2ost , then the K25 controller can disable the non-priority direction of pumping, which will allow to increase the pumping flow Q _B2 . If the regulation of the shutters (when their position is fully open) does not allow achieving the performance necessary to complete the compounding plan, then the dispatcher is given an alarm and it is recommended to maintain _Q2ost mode to execute the plan or to increase the pumping capacity in general in direction 2.

Similarly for the first compounding stream (direction)

$$V_{\mathrm{about}\mathrm{from}t\mathrm{at}\mathrm{one}}=V_{\mathrm{at}\mathrm{one}}-{\displaystyle \underset{0}{\overset{t}{\int }}{Q}_{\mathrm{at}\mathrm{one}}(t)dt}$$

$$V_{\mathrm{at}\mathrm{one}\mathrm{about}\mathrm{from}t}=\frac{V_{\mathrm{about}\mathrm{from}t\mathrm{at}\mathrm{one}}}{T-t}$$

If Q _in1 <Q _in1ost carries out the regulation of productivity (cost ratio) by opening the shutters to establish the necessary performance, which allows you to complete a daily plan (subject to the sulfur content S _SM ≤S _ass ).). If the shutter is not fully operational when the shutter is fully open, i.e. Q _in1 <Q _in1ost , then the K25 controller can turn off the non-priority direction of pumping, which will allow to increase the pumping flow Q _in1 . If the regulation of the shutters (when their position is fully open) does not allow achieving the performance necessary to fulfill the compounding plan, an alarm is issued to the dispatcher and a recommendation on changing the _operating mode and in general through the direction 1 oil pipeline to maintain _{Q1ost mode} in order to fulfill the plan. Similarly, in the third direction of pumping.

It is also possible in the VU24 calculator to monitor the overall implementation of the overall compounding plan

V _in = V _in1 + V _in2 + V _in3

$$\frac{V_{\mathrm{about}\mathrm{from}t\mathrm{at}\mathrm{one}}+V_{\mathrm{about}\mathrm{from}t\mathrm{at}2}+V_{\mathrm{about}\mathrm{from}t\mathrm{at}3}}{T-t}=Q_{\mathrm{at}\mathrm{about}\mathrm{from}t}$$

If Q _east <Q _in , it regulates the performance (cost ratio) by opening the shutters in the directions, according to the established priorities, to establish the necessary performance that allows you to complete the daily plan (subject to the sulfur content S _Сi ≤ S _СМi back). If the regulation of the shutters (when their position is fully open) does not allow achieving the performance necessary to fulfill the compounding plan, an alarm is issued to the dispatcher and a recommendation on changing the mode for the pumping of sour crude oil and / or in general for transportation directions 1, 2, 3 Q _east in order to fulfill the plan. Moreover, in each of the streams, the sulfur content should be less than a specified value

S _CMi <[S _SMizad ].

In this case, you can set the goal of fulfilling the total volume of compounding, and in the direction of transportation there may be less than the plan in the direction in the direction, and in the other more than the plan in this direction of transportation.

Claims (4)

1. An oil compounding process control system, comprising two or more directions of transportation, containing an oil flow meter, an oil meter, an oil density meter and an oil flow control device installed in each oil pipeline for mixed transport installed in each of the oil pipelines in each direction for oil transportation flow meter oil flow meter, density meter, sulfur content meter, the outputs of these meters are connected to the inputs of the control unit, you the moves of which are associated with means for regulating oil consumption, characterized in that it contains a calculator of the coefficients of the ratio of oil consumption in each transported stream and in the mixed stream, a calculator of the coefficients of the ratio of oil density in each transported stream and in the mixed stream, the calculator of the value of the required compounding capacity in real the time mode in the directions of pumping necessary to control the implementation of the plan, the inputs of these computers are connected to meters flow rate and density, and the outputs of calculators connected to inputs of the control unit. 2. The system according to p. 1, characterized in that it contains quality stock calculators in each direction of the mixed flow, the inputs of the calculators are connected to the flow rate calculators, the sulfur content meters, and the outputs of each calculator are connected to the input of the common control unit - the quality stock controller, outputs which are associated with the corresponding dampers. 3. The system according to any one of paragraphs. 1 or 2, characterized in that the pipelines of the incoming flows to the compounding are hydraulically interconnected, i.e. are branches of one common thread. 4. The system according to any one of paragraphs. 1 or 2, characterized in that it contains a common total calculator of the required planned performance in real time in all directions, the inputs of which are interconnected with calculators of the required planned performance in real time in the directions, flow meters, the outputs of the calculator are interconnected with the input of the common block control - the controller of the plan, the outputs of which are connected with the corresponding dampers.