RU2666488C1 - Device and method of the liquid level regulation - Google Patents

Abstract

FIELD: measuring equipment; oil and gas industry.SUBSTANCE: invention relates to the automatic control systems and can be used in the oil industry, oil and gas processing and processing facilities. Unit for adjusting the liquid level comprises a separation container, a gas-liquid mixture inlet manifold, a gas pipe, a liquid pipe, an outlet manifold, and opposite siphons. In this case, the gas pipe in the lower part inside the separation container is divided into sections by several siphons of different sections, located sequentially along the section from the maximum section to the minimum section along the level of the gas pipe from the bottom up. End of each siphon is made by hydrocyclones installed at the level from the bottom up in the drop eliminator, that is installed in the separation container. Invention also includes a method for adjusting the liquid level by means of said device.EFFECT: as a result, the performance, tightness and stability of the liquid level control device are increased.2 cl, 1 dwg

Description

The invention relates to automatic control systems and can be used in the oil industry, in installations for the preparation and processing of oil and gas.

A device for regulating a liquid level comprising a process vessel, a manifold for supplying a gas-liquid mixture, a pipe for removing gas and liquid, a buoy level gauge with a pneumatic transducer, a pneumatic statistical control device, the output signal of which is supplied to a pneumatic actuator and simultaneously to a secondary measuring device, which is the master (Isakovich R.Ya., Popadko V.E. Control and automation of oil and gas production. - M .: Nedra, 1985, p. 100. Fig. 8.2).

For devices that use a pneumatic control system, increased requirements are also set when setting it in order to exclude the delay time between the level change and the control of the actuator. To ensure the operability of the buoy level gauge at low temperatures, it is necessary to use means of heating it, which is associated with an increase in costs. The use of pneumatic secondary devices requires special preparation of compressor air for moisture and oil vapor content. Failure to comply with these requirements leads to premature wear of the pneumatic control system and reduce the reliability of the device.

A device for controlling the liquid level (RU No. 2053537, G05D 9/04, 07/21/1992), including a separation tank with a float placed in it, a manifold for supplying a gas-liquid mixture, pipes for removing gas and liquid, and an actuator. The device is equipped with air tanks separated by a shutter connected by means of rods to the float, while the input of one of the air tanks is connected by means of impulse tubes and a throttle to a compressor, and the output is connected to an actuator, the other capacity being connected via an adjustable throttle to the atmosphere. A disadvantage of the known device is the presence of a mechanical system for regulating the liquid level.

A device for controlling the liquid level (RU 2454263, B01D 19/00, G05D 9/02, 27/27/2012), comprising a separation tank, an inlet of a gas-liquid mixture, a gas pipe, a liquid pipe, an outlet manifold, and wherein the connections of the liquid pipe, the gas pipe and the outlet manifold form a complex of one direct siphon and two opposed siphons, the liquid pipe being connected to the outlet manifold using a direct siphon and the opposed siphon having a common elbow, and the gas pipe is connected to the outlet manifold using a second opposed siphon formed by a gas pipe bend and a liquid pipe bend connected to the outlet manifold.

The disadvantage of the analogue is that at high gas flow rates a hydraulic column of liquid in the gas elbow is not formed, is carried out by the gas and gas does not shut off due to the large hydraulic resistance of the liquid approaching at the point of contact with the gas.

The closest in technical essence and the achieved result to the claimed invention is a device for regulating the liquid level (RU 2525146, G01F 1/00, G05D 9/00, 08/10/2014), containing a separation tank, an inlet of the gas-liquid mixture, a gas pipe, a liquid pipe , an output manifold, direct and opposite siphons, while the separation tank is connected to the output collector through a supply tank, and the connections of the liquid pipe, gas pipe and output collector form a complex of two direct and two opposite x siphons, and the liquid pipe is connected through the supply tank to the output manifold using a direct siphon and the opposite siphon, and the gas pipe is connected to the output manifold using another direct and other opposed siphon, also, and, in addition, both the opposite the siphon and the output collector are connected by a tee, and the lower generatrix of the straight siphon elbow connecting the separation tank to the supply tank is located inside the supply tank.

The disadvantages of the closest analogue is that:

- to the failure of the device leads to the formation of gas plugs in direct siphons in their upper part;

- at high gas flow rates, a large amount of liquid is carried along with the gas;

- when adjusting the liquid level, the hydraulic shutter only in a narrow range of gas flow rates;

- with a sharp pressure drop between the tank and the output manifold, a hydraulic shutter is not formed, and all the liquid from the siphons is carried out to the output manifold.

The closest in technical essence and the achieved result to the claimed one is a method that allows you to adjust the liquid level (RF patent No. 2541991, E21B 47/10, 02/20/2015), comprising supplying a gas-liquid mixture into a separation tank, separating it into liquid and gas phases, dumping the gas phase into the output manifold at the end of the accumulation of the liquid phase to a predetermined level, blocking the discharge of the gas phase and accumulating it and, as a result of the overlap, displacing the liquid phase into the output manifold, and after the liquid phase is displaced, open gas phase throw.

The disadvantages of the closest analogue are:

- the lack of a clear separation of the liquid and gas phases of the measurement, since there is the possibility of passing through the gas meter gas-liquid mixture;

- the presence of errors in a wide range of measurement of the flow rate of the liquid and gas phases of the product in the presence of different flowmeters for liquid and gas.

The objective of the invention is to increase the reliability of the device for controlling the liquid level and the stability of the method of regulating the liquid level.

The technical result is to increase the operational characteristics, tightness, reliability of the device and method of controlling the liquid level.

The problem is solved, and the technical result is achieved in a device for regulating the liquid level containing a separation tank, a gas-liquid mixture inlet manifold, a gas pipe, a liquid pipe, an outlet collector, opposed siphons, according to the invention, the gas pipe in the lower part inside the separation vessel is divided into sections parts by several siphons of different cross-sections, arranged in cross-section sequentially from the maximum cross-section to the minimum cross-section along the level of the gas pipe from bottom to top, and approx The end of each siphon is made by hydrocyclones installed in a level from bottom to top in a drop eliminator, which is installed in a separation tank.

The problem is solved, and the technical result is achieved in a method for regulating a liquid level, including supplying a gas-liquid mixture to a separation vessel, separating it into a liquid and a gas phase, discharging a gas phase into a common collector at the end of accumulation of a liquid phase to a predetermined level, blocking the discharge of the gas phase and its accumulation and, as a result of overlapping, the displacement of the liquid phase into the common collector, and at the end of the displacement of the liquid phase, the opening of the discharge of the gas phase, according to the invention, the regulation of the liquid level springs are produced by shutting off the gas phase discharge by dividing the gas phase stream into several siphon flows of different flow rates and cross-sections, sequentially and alternately shutting them from the maximum flow rate and cross-section to the minimum flow rate and cross-section, through preliminary preparation of the flow rate of each siphon - gas phase flow passage through a hydrocyclone by separating and eliminating droplets of the liquid phase from each gas phase stream and depositing them in the separator after the droplet eliminator hydrocyclone, and with increasing liquid level in the separator, the gas phase is sequentially and sequentially blocked by the liquid phase by mixing the gas phase flow with the liquid phase in each siphon, starting from the maximum flow rate and the siphon cross-section, ending with the minimum gas flow rate and siphon cross-section, after which the subsequent preparation of each gas phase flow is carried out, mixed with a liquid in a gas phase siphon by passing each stream through a hydrocyclone, in which droplets of a liquid phase are separated and excluded from the gas phase by precipitation in sep of the reservoir through the hydrocyclone, and then each siphon is successively filled and closed with the liquid phase, starting from the maximum siphon cross section and the gas phase flow rate, ending with the minimum siphon cross section and the gas phase flow rate until the gas phase is completely blocked by the liquid phase, and the formation of the boundary between the gas and liquid phase, without a gas-liquid phase between them and the beginning of squeezing the liquid phase out of the separation vessel, with a drop in the liquid phase level in the separation vessel and siphons dit gas breakthrough from the separation vessel through a siphon, demister, to a collecting reservoir.

The invention is illustrated in the drawing, which shows a General diagram of the device.

A device for controlling the liquid level contains a separation tank 1, a collector of the inlet 2 of the gas-liquid mixture, a gas pipe 3, a liquid pipe 4 and an output manifold 5, opposed siphons 6, 7, 8. The gas pipe 3 in the lower part inside the separation tank 1 is divided into sections parts with several siphons 6, 7, 8, of different cross-section, arranged sequentially from the maximum cross-section to the minimum cross-section along the level of the gas pipe 3 from bottom to top, and the end of each siphon 6, 7, 8 is made by hydrocyclones 9, 10, 11, installed by level from bottom to top in the entrainment separator 12, which is installed in the separation tank 1.

The device operates to control the liquid level as follows. The gas-liquid mixture enters through the inlet line 2 to the separation tank 1, where the gas-liquid mixture is separated into gas and liquid. During the separation process, liquid accumulates in the lower part in the separation tank 1, and gas collects in the upper part in the separation tank 1. As oil well production arrives in the separation tank 1, the liquid level rises through the liquid pipe 4. As the liquid level reaches the lower edges of the siphon 6 through the hydrocyclone 9, the gas level begins to block the gas passage through the siphon 6, creating local resistance through the siphon 6 to the gas passage and its redistribution the flow rate through siphons 7, 8, which entails an increase in the pressure drop between the separation tank 1 and the output manifold 5, due to a decrease in the gas cross section, which contributes to the increase in the liquid level in the inner cavity of the drop eliminator 12, the filling of the siphon 6 with liquid and its overlap.

Similarly, the process of overlapping siphons 7 and 8 and the complete closure of the gas line 3. The process of overlapping siphons 6, 7, 8 provides a stepwise shutoff of the gas flow through the gas pipe 3, the pressure drop between the separation tank 1 and the output manifold 5, a level increase in the inner cavity of the drop collector 12, quickly filling siphons 6, 7, 8 with liquid and blocking gas pipe 3 with liquid with minimal transient processes.

After filling the siphon 6, the liquid level in the gas pipe 3 rises, through which the siphon 7 is filled with a single stream together with the gas. The joint gas-liquid stream after the siphon 7 is divided into gas and liquid in the hydrocyclone 9, where the liquid falls out in the drop eliminator 12, and the gas leaves through the output collector 5.

The gas-liquid flow in the siphon 7, creating local resistance to the passage of gas, an additional pressure drop between the separation tank 1 and the output manifold 5 abruptly raises the liquid level in the droplet eliminator 12 and the siphon 7 is completely filled with liquid. In this case, the liquid level in the gas pipe 3 rises, the liquid is separated from the gas in the hydrocyclone 12, the siphon 8 is filled with liquid and the gas pipe is completely blocked by the liquid.

As a result, the fluid is squeezed out of the separation tank 1 through the drop eliminator 12.

At the same time, a portion of the liquid is squeezed out to the lower level in siphons 6, 7, 8, where gas breaks through the siphons 6, 7, 8, hydrocyclones 9, 10, 11, drop eliminator 12, and the liquid column from drop eliminator 12 is discharged into separation tank 1, providing the passage of gas into the collecting manifold 5, which ensures the maintenance of the lower liquid level and the continued filling of the separation tank 1 to the upper level.

Then the process of regulating the liquid in the separation tank 1 is repeated.

An example of a specific implementation of the method

The process of regulating the liquid level begins with the receipt of the gas-liquid mixture in the separation tank 1, where there is a separation into liquid and gas. Gas passes through siphons 6, 7, 8, hydrocyclones 9, 10, 11, droplet eliminator 12 into the output manifold 5, while the accumulation of liquid in the separation tank 1 to level H occurs, with simultaneous filling of siphons 6, 7, 8 with liquid, closing the discharge of the gas phase into the outlet manifold with the simultaneous replacement of the gas phase by the liquid and gas squeezing the liquid out of the separation tank 1 into the outlet manifold 5. The gas is squeezed out of the separation vessel 1 by gas up to level h in the separation vessel 1 and in siphons 6, 7, 8, at which about goes breakthrough gas from the separation vessel through siphons 6, 7, 8, hydrocyclones 9, 10, 11, 12 in the demister outlet manifold 5. Next, a process of filling the separating tank 1 and liquid level control process is repeated in the vessel.

The stepwise overlap of the cross section of the gas pipe 3 through successive sequential overlapping of several siphons 6, 7, 8, of different cross sections from the maximum cross section to the minimum cross section, creates a reliable system for regulating the liquid level.

Then the process of regulating the liquid level in the separation tank 1 is repeated.

The use of the invention will improve the operational characteristics, tightness and stability of the device for regulating the liquid level.

The reliability of the design of the device, the work of regulating the liquid level without the use of mechanical control systems will provide widespread application of the invention.

Claims (2)

1. A device for controlling the liquid level, comprising a separation tank, a gas-liquid mixture inlet manifold, a gas pipe, a liquid pipe, an outlet manifold, opposite siphons, characterized in that the gas pipe in the lower part inside the separator is divided into sections by several siphons of different sections, arranged sequentially from the maximum section to the minimum section from the bottom to the top of the gas pipe, and the end of each siphon is made by hydrocyclones installed at the bottom level zu up in the droplet eliminator, which is installed in the separation tank. 2. A method of controlling the liquid level, including the supply of a gas-liquid mixture to the separation tank, its separation into liquid and gas phases, discharge of the gas phase into the output manifold after the accumulation of the liquid phase to a predetermined level, overlapping the discharge of the gas phase and its accumulation and, as a result, overlapping , displacing the liquid phase into the outlet manifold, and at the end of the displacement of the liquid phase, opening the discharge of the gas phase, characterized in that the regulation of the liquid level is performed by shutting off the discharge of the gas phase by separation the gas phase flow into several siphons - flows of different flow rates and cross-sections, sequentially and alternately overlapping them from the maximum flow and cross-sections to the minimum flow and cross-sections, through preliminary preparation of the flow of each siphon - gas flow flows through a hydrocyclone, separating and eliminating from each gas flow the phases of the droplets of the liquid phase and precipitating them in the separation vessel after the hydrocyclone of the droplet eliminator, and with increasing liquid level in the separation vessel, a sequential and sequentially blocking the gas phase with the liquid phase by mixing the gas phase stream with the liquid phase in each siphon, starting from the maximum flow rate and cross section of the siphon, ending with the minimum flow rate and cross section of the gas phase siphon, after which subsequent preparation of each gas phase stream mixed with the liquid in the siphon is carried out of the gas phase by passing each stream through a hydrocyclone, in which droplets of the liquid phase are separated and excluded from the gas phase, by their deposition in a separation vessel through a hydrocyclone, and Next, each siphon is sequentially filled and covered with a liquid phase, starting from the maximum siphon cross section and the gas phase flow rate, ending with the minimum siphon cross section and the gas phase flow rate until the gas phase is completely blocked by the liquid phase, completion of the formation of the boundary between the gas and liquid phases, without a gas-liquid phase between by them and the beginning of extrusion of the liquid phase from the separation vessel, with a decrease in the liquid phase level in the separation vessel and siphons, gas breaks out of the separation vessel through siphons, a drop eliminator to the output collector.

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