RU217320U1 - CENTRIFUGAL TYPE CENTRIFUGAL ELEMENT METER SEPARATOR - Google Patents

Abstract

The utility model relates to the oil and gas industry and can be used in oil, gas and gas condensate fields to assess the efficiency of separation equipment. The proposed separator of the drop liquid entrainment meter contains a cylindrical body with a cover. The lower part of the separator body has a conical shape. A branch pipe for raw gas inlet, a branch pipe for dried gas outlet are attached to the body on the side, and a branch pipe for draining the separated liquid is attached to the bottom. To prevent direct removal of the mixture from the separator, it is equipped with an internal dividing pipe, in the upper part of which a ring is fixed. The ring diameter is equal to the inner diameter of the separator body. Holes are made in the dividing pipe above the ring. The raw gas inlet pipe is located below the ring, and the dry gas outlet pipe is above the ring. Thus, the ring separates the inlet and outlet of the gas. The technical result consists in creating a simple separator design that provides reduced time and increased accuracy in measuring the entrainment of dropping liquid. 7 ill.

Description

The utility model relates to the oil and gas industry and can be used in oil, gas and gas condensate fields to assess the efficiency of separation equipment.

When extracting natural gas, gas condensate and oil before their further shipment by pipeline transport, there is a need for primary preparation of this raw material at gas and oil treatment plants. The main task in this case is to separate gas from condensate or oil (separation of gas and liquid phases). For these purposes, separators of various designs are widely used. To determine the efficiency of separation equipment at oil and gas production facilities, drop liquid entrainment meters are used.

A device for determining the amount of liquid in a gas sample is known, including a sampling probe tube inserted at one end through a stuffing box into a pipeline with a gas flow under investigation, high-pressure connecting hoses, taps and a control valve, a gas flow meter, a filter for separating liquid drops from a gas sample . The filter device allows periodic weighing of the filter element without removing it from the housing. Weighing is carried out at operating pressure using strain gauges placed in the filter housing [patent RU No. 2422804, IPC G01N 9/36, published 06/27/2011].

The known device has a complex structure.

As the closest analogue, a device for measuring liquid entrainment, developed by TsKBN [Liquid entrainment meter GPR-420.00.000. DOAO TsKBN. https://cyberleninka.ru/article/n/17665799.pdf]. This device measures the volume of dropping liquid and mechanical impurities in a natural gas stream at an operating pressure of 1.0 to 14.4 MPa and a temperature of -30°C to +100°C in pipelines with a diameter of 100 to 400 mm inclusive. The meter structurally consists of:

- a probe, which is mounted to the pipeline for the duration of the measurement and allows you to extract a gas sample from the required depth of the investigated gas flow;

- a separator in which the liquid is separated from the gas;

- gas meter, which is used to set the required flow rate of the test gas by the meter;

- a measuring container in which the separated liquid accumulates and its quantity is recorded;

- connecting hoses;

- instrumentation.

The separation of the studied gas-liquid mixture into gas and liquid occurs in the separator of the meter by filtering the flow of this mixture through a filter, which is a metal cylinder with many holes, covered with a textile permeable material (fabric) on the outside. When passing through this filter, the raw gas flow is dried, leaves the separator, lowers its pressure on the pressure regulator, is measured on the meter and disposed of into the atmosphere to the gas diffusion candle. In this case, the liquid separated in the filter impregnates the filter fabric and, over time, under the action of gravitational forces, flows down to the lower part of the separator, from which it enters a measuring container for accumulation and subsequent measurement of its amount. The saturation time of the filter depends on the amount of liquid phase in the investigated raw gas stream.

One of the disadvantages of the existing device is the significant time spent waiting for the filter to fully saturate before each measurement.

Another drawback of the device is the manifestation of the hydrophobic properties of the textile material of the filter when it is saturated (wetted) with a hydrocarbon phase (gas condensate). Raw natural gas, except for gas condensate, almost always contains water (water phase) in its composition. Therefore, when the fabric is completely saturated with hydrocarbons (gas condensate), the aqueous phase is not absorbed by the filter fabric, penetrates through it and is removed from the separator with the gas flow. As a result, there is a deterioration in the separation efficiency of the entire meter, and a measurement error appears. This fact confirms the presence of water in the gas meter after each measurement.

The problem to be solved by the utility model is to reduce the preparation time of the device before each measurement and increase its accuracy.

This problem is solved by the fact that the centrifugal-type droplet entrainment meter separator, containing a housing with a cover, raw gas inlet pipes, dried gas outlet, separated liquid outlet, is equipped with a cylindrical separating pipe located in the separator body, in the upper part of which a ring is fixed, the diameter of which is equal to the inner diameter of the separator body, holes are made in the separating pipe above the ring, the raw gas inlet pipe is located below the ring, and the dry gas outlet pipe is above the ring, while the geometric dimensions of the separator are selected in the following ranges:

ratio of the internal diameter d of the separation branch pipe to the internal diameter D of the separator body: d/D = 0.52…0.58;

wall thickness n of the separation pipe to its inner diameter d: n/d = 0.05…0.1;

angle of inclination a of the wall of the lower conical part of the separator housing to the vertical axis of the separator housing: α = 23°…27°;

the ratio of the height h of the separation branch pipe to the height H of the cylindrical part of the separator body: h/H = 0.85…0.92. The specified ranges of values are optimal.

A decrease in the value of d/D leads to an increase in the velocity of the ascending gas flow inside the separation pipe, which leads to the rise and removal of liquid drops from the separator along with the gas flow, an increase - to a change in the flow structure and a violation of the integrity of the liquid film on the inner surface of the housing in the annular space of the separator , as well as the possible pickup and removal of liquid droplets from the separator along with the gas flow.

A decrease in the value of n/d leads to a decrease in the strength characteristics of the separation pipe, an increase - to an increase in the mass of the entire product.

A decrease in the angle a leads to an increase in the geometric dimensions of the separator body, an increase - to a possible pickup of liquid drops from the inclined surface of the separator and their further removal along with the gas flow.

A decrease in the value of h/H leads to an increase in the geometric dimensions of the body, an increase - to a change in the flow structure in the annular space of the separator in the region of the lower end of the separation pipe, a possible pickup and removal of the dropping liquid along with the gas flow.

The technical result consists in creating a simple design of the separator, which provides a reduced time for measuring the entrainment of dropping liquid.

The essence of the utility model is illustrated by drawings, where figure 1 shows the separator of the entrainment meter in the section, figure 2 - the principle of operation of the separator, figure 3 - section along A-A in figure 2, figure 4 - section along B -B in figure 2, figure 5 - sketch of the separator with the letter designation of geometric dimensions, figure 6 - photo of the separation pipe, figure 7 - photo of the separator with shut-off devices and devices.

The proposed meter separator contains a cylindrical body 1 with a cover 2. In the lower part, the separator body has a conical shape. A branch pipe 3 for raw gas inlet, a branch pipe 4 for dry gas outlet are attached to the body 1 on the side, and a branch pipe 5 for draining the separated liquid from below. To prevent direct removal of the mixture from the separator, it is equipped with an internal dividing pipe 6, in the upper part of which a ring 7 is fixed. The diameter of the ring 7 is equal to the inner diameter of the separator body 1. Holes 8 are made above the ring 7 in the dividing pipe 6. The raw gas inlet pipe 3 is located below the ring 7, and the dry gas outlet pipe 4 is above the ring 7. Thus, the ring 7 separates the gas inlet and outlet.

When the device is operating, the flow of raw gas (gas-liquid mixture), entering through the nozzle 3 into the separator, is directed to the inner surface of its housing 1, forming a spiral motion (figure 3). The dividing pipe 6 sets the trajectory and speed of the gas flow, ensures the selection of gas from the central part of the separator, where the content of the liquid phase is minimal due to its higher density and dependence on inertia forces. Centrifugal forces and gravitational forces act on the flow of the mixture, which contribute to the separation of the gas and liquid phases. Due to its higher density and viscosity, the liquid phase forms a liquid film on the wall of the housing 1, which, under the influence of gravity through the pipe 5, gradually flows into a measuring container (not shown) for further accumulation and measurement of its volume. The gas phase is released from the liquid film and, due to the lower density and viscosity, as well as the pressure drop between the inlet 3 and outlet 4 pipes of the separator, rises and is discharged from the separator through the outlet pipe 4 (figure 4).

At the same time, the design of the separator does not contain filter elements that require complete saturation (wetting) with the liquid phase, which significantly reduces the preparation time of the meter before measurements.

In addition, the proposed design equally effectively separates both the hydrocarbon and aqueous phases from the raw gas flow, making it possible to determine the actual amount of entrainment of droplet liquid after gas-field separators, which provides a more objective assessment of the efficiency of process equipment in preparing natural gas for transport.

In 2020, the specialists of Gazprom dobycha Urengoy LLC designed, manufactured and tested this separator as part of the meter. When designing, a hydrodynamic calculation of the internal cavity of the separator was carried out. Two-phase flow modeling was carried out using the CAE software package. The problem is solved in a non-stationary, compressible formulation using a three-dimensional RANS approach (Navier-Stokes equations averaged over Reynolds). The VOF (Volume Of Fluid) method was used to simulate the media interface.

Further, the main body parts were manufactured taking into account the expected operating conditions, they were assembled and hydraulically tested to confirm the necessary strength characteristics of the entire product. Later, the meter containing the inventive separator was completed with shut-off and control valves, instrumentation, necessary connecting fittings, hoses, thermal insulation and additional attachments.

In 2021 and 2022, at the production facilities of Gazprom dobycha Urengoy, the separator of the meter, called the Cyclone, was successfully tested in real production conditions, confirming its performance, ergonomics and measurement accuracy.

Claims (1)

Centrifugal-type drip liquid entrainment meter separator, containing a body with a cover, raw gas inlet pipes, dried gas outlet, separated liquid outlet, characterized in that it is equipped with a cylindrical separating pipe located in the separator body, in the upper part of which a ring is fixed, the diameter of which is equal to the inner diameter of the separator body, holes are made in the separating pipe above the ring, the raw gas inlet pipe is located below the ring, and the dry gas outlet pipe is above the ring.

Images