RU2565611C1 - Control method of removal of liquid and gaseous phases from well fluid separator reservoir - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: removal of liquid and gaseous phases from a well fluid separator reservoir is controlled via two separate measuring channels, with provision of flow measurements of quantitative parameters as to liquid and gas, with further combination of these flows into one flow for further conveying. A flow regulator installed in a gas line maintains within the specified limits the excess pressure in the separator reservoir over pressure in a phase mixing chamber based on the data on change of pressure difference of media contained in the separator reservoir and in the phase mixing chamber while level of liquid in the separator reservoir is maintained by the flow regulator in the liquid line based on the data on changes in level of liquid in the separator reservoir.

EFFECT: providing effective maintenance of boundary level of media in the separator reservoir at simultaneous maintenance within the specified limits of excess pressure in the separator reservoir over pressure in the liquid and gas mixing chamber.

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Description

FIELD OF THE INVENTION

The invention relates to the oil and gas industry, in particular to the field of technical arrangement of oil production, and can be used to provide the necessary conditions for the rapid determination of the content of the main phases and components in the oil and gas fluid coming from the well, in-line measurements of quantity and quality indicators.

State of the art

The prior art method for controlling the selection of media from the separator according to the patent [1] (RU 2232528, published on 10/20/2005), including controlling the selection of one component (water) depending on the pressure of the hydrostatic column of liquids in the separator, comparing it with a given value. And the selection of another component (oil) is not regulated (all excess oil flowing through the separation wall is selected); however, the pressure of the oil at the outlet is not controlled or regulated (oil drains with a free pressureless jet), which is a significant drawback of this method.

The prior art device for controlling the process of separation of the oil-water mixture according to the patent [2] (RU 2275414, published 04/27/2006), which also regulates the selection of water, but depending on the position of the interface between the components of the oil-water. The disadvantage of this device is that the selection of oil is also not regulated.

Separation plants according to the patents [3] (RU 2238783, published on 10.27.2004) and [4] (RU 2296609, published on 08.20.2006), in which the fluid is divided into three components: oil, water and gas, are known from the prior art. However, the constructive scheme with which these methods are inextricably linked is not applicable when there is a wide variation in flow rates and component composition of the gas-liquid mixture (which often occurs when measuring well fluid) because of the inability to constantly maintain a given level of the interphase boundary.

The closest analogue of the claimed invention is a method for controlling the level of the oil-water phase separation in sealed flow tanks and a device for its implementation [5] (RU 2328518, published July 10, 2008), in which the level of the interface between the media (oil and water) in the tank is regulated by changing the flow rate of one of the components (water) - depending on the differences in hydrostatic pressure between three preset control points located in the tank at different levels, on both sides of the interface. The disadvantage of this analogue, with respect to the objective of the present invention, is the inability to control the excess pressure in the separator tank over the pressure in the mixing chamber.

SUMMARY OF THE INVENTION

The problem solved by the claimed invention is to maintain the level of the interphase boundary in the separator and maintaining within specified limits the excess pressure in the separator tank over the pressure in the mixing chamber of the liquid and gas (after phase measurements).

The technical result of the invention is to provide effective maintenance of the level of the interface of the media (liquid-gas) in the separator tank while maintaining, within specified limits, the excess pressure in the separator tank over the pressure in the mixing chamber of the liquid and gas.

The specified technical result is achieved due to the independent regulation of the removal of the liquid phase from the separator tank, keeping the liquid level in the separator tank and the gaseous phase within the specified limits, maintaining the pressure in the separator tank above the pressure in the liquid and gas mixing chamber within the specified limits.

Brief Description of the Drawings

FIG. 1 is a flow chart of the regulation of the removal of liquid and gaseous phases from the reservoir capacity of the well fluid separator.

The positions indicated in figure 1:

1 - separator capacity;

2 - level gauge,

3, 14 - pressure sensors;

4 - gas measuring channel;

5 - measuring fluid channel;

6, 7 - shutoff valves:

8, 9 - flow controllers;

10, 11 - flowmeters;

12 - in-line hydrometer;

13 - phase mixing chamber.

Disclosure of invention

The method for controlling the removal of liquid and gaseous phases from the reservoir capacity of the well fluid separator is illustrated in the flow diagram of FIG. 1 and is carried out as follows.

The borehole fluid is fed for gas-liquid separation into the capacity of the separator 1. The liquid level in the separator is controlled using a level gauge 2; the pressure of the media in the separator - using a pressure sensor 3. The measurement results are transmitted to the measuring and computing complex (IVC). The selection of gas and liquid from the separator is carried out separately - through the gas 4 and liquid 5 measuring channels, according to the instructions of the IVK, depending on the values of the measured indicators of the liquid level and pressure in the capacity of the separator 1, using shutoff 6, 7 and control valves 8, 9 ( flow controllers). In this case, the flow regulator 8 fulfills the changes in gas withdrawal from the separator tank to ensure a given differential pressure of the media between the separator 1 and the mixing chamber 13. And the flow regulator 9 changes the fluid withdrawal to maintain a given level of liquid in the separator tank. According to the readings of in-line measuring devices (IVC), namely, flowmeters 10, 11 and in-line moisture meters 12, the flow rates of the amount of gas and liquid flowing through the corresponding measuring channels are determined, as well as the relative content of water in the liquid flowing through the liquid measuring channel.

Next, the gas and liquid phase 4, 5 are fed into the mixing chamber 13, after which the gas-liquid mixture is sent to the process pipeline. In the process of mixing the media in the chamber 13, the pressure in it is monitored using a pressure sensor 14. The predetermined pressure difference between the separator 1 capacity and the phase mixing chamber 13, necessary to ensure the technological transport of the measured media, is maintained automatically, based on the settings entered in the IVK.

The given implementation of the claimed method provides effective maintenance of the level of the interface of the media (liquid - gas) in the separator tank while maintaining, within specified limits, the excess pressure in the separator tank over the pressure in the liquid and gas mixing chamber.

Claims (1)

The method of regulating the removal of liquid and gaseous phases from the reservoir capacity of the well fluid separator through two separate measuring channels, providing flow measurements of quantitative indicators for liquid and gas, followed by combining these flows into one for further transportation, characterized in that the flow regulator installed in the gas the lines maintain, within specified limits, the excess of pressure in the separator tank over the pressure in the phase mixing chamber, based on data on the change in the pressure difference of the medium Contained in the separator vessel and a phase mixing chamber, while the liquid level in the separator tank supports the flow regulator in fluid line based on the data about changes in the liquid level of the separator vessel.