RU2326236C2 - Ratio separator of gas at oil recovery - Google Patents

Abstract

FIELD: oil and gas producing industry.

SUBSTANCE: invention is referred to oil and gas producing industry and intended for separation of gas from oil before a plutonic well pump at an oil recovery. Device contains the cylindrical body, an internal coaxial tube and a turbulizer. According to invention the turbulizer for an influent flow is installed directly in body bottom on a current input in the body. The accumulative coaxial tube for gathering knocked out gas is installed above a turbulizer and it has the flap on its top part. The room over the flap is connected with annular room of a hole by pipe junctions for a gas output. The ring channel between the body and a accumulative tube is connected with a pump intake pipe. Thus before a going into a accumulative tube the central tube is installed with chippers consistently affixed to it in the form of the hollow truncated cones which are placed by smaller diameters towards a accumulative tube.

EFFECT: efficiency upgrading of gas separation at oil recovery and device simplification.

1 dwg

Description

The invention relates to the oil industry and is intended to separate gas from oil in front of a deep well pump for oil production.

Known gas separators for oil production (gas anchors) [Lavrushko NP, Muravyov VM Operation of oil and gas wells. - M .: Subsoil. - 1971. - 368 p.], Where the gas-liquid mixture entering the device sharply changes the direction of motion, as a result of which gas bubbles float up and then are removed into the annulus of the well, bypassing the pump. The efficiency of such separators is low, since due to a change in the direction of motion, only sufficiently large bubbles are separated, and smaller ones are carried along with the liquid into the pump.

A device for separating gas and sand during oil production using a sucker rod pump [RF patent No. 2039228, 1990, ЕВВ 43/28], where the purified liquid is accumulated in an additional tank, the movement of the liquid is controlled by a valve system, and the gas separation is in forward motion when liquid accumulates in an additional tank, it occurs due to a change in the direction of motion of the gas-liquid medium. The gas separation efficiency in such a device is not higher than in the previous one.

A device is known for centrifugal separation of liquid and gas during oil production [US patent No. 4088459, 1978, B01D 53/24], which provides three stages: feeding, swirling using rotating blades (impeller) and a centrifugal separation stage using a rotating centrifuge. Typically, a device is connected to a pump (s) for transporting separated components. The disadvantages of this device are the complexity of the design and operation due to the abundance of moving elements.

Known devices in which to remove the separated gas into the well, the gas pressure is increased by a compressor located inside the separation device and driven by an electric motor [US patent No. 4481020, 1984, B01D 45/00] or a hydraulic turbine [US patent No. 6035934, 2000 city, ЕВВ 43/38]. These devices are complex in design and operation.

The closest in technical essence to the claimed device is a centrifugal separator [USSR patent No. 1619528, 1988, B04C 3/06], designed to purify gas from liquids and solids, containing a cylindrical body with nozzles for entering the gas-liquid mixture, the gas outlet and the liquid and the separation element is a coaxial pipe, at the inlet end of which there is a swirl, and the outlet end is separated from the pipe for gas outlet by an annular gap. In the separation element, the gas-liquid flow is twisted by the inlet swirl, as a result of which centrifugal forces separate: the gas is collected in the axial region of the separation element, and the liquid is forced to the periphery to the wall and exits through the annular gap into the space between the device body and the separation element, and from there - into the annulus of the well, while gas from the central pipe enters the pipe for gas to exit and through it is discharged to the surface. This device is designed to purify gas during its production. It is also possible to use this device to separate gas from oil during its production, but for this it is necessary to equip the well with an additional pipe and a pump to bring oil to the surface, which significantly complicates the design of the well. If oil is brought to the surface through the space between the separation element and the body, then it is necessary to remove gas from the separation element into the well. However, during centrifugal separation of a gas-liquid mixture inside the separation element, the pressure in the gas is lower than in the annulus by the value of the resistance of the swirl and the vacuum created by the swirling flow in the center of the vortex. In order to remove the separated gas into the annulus of the well, additional devices are needed to increase its pressure to a value greater than the pressure in the annulus, which complicates the design and operation of the separator.

The task of the invention is to increase the efficiency of gas separation during oil production and simplify the design of the separator.

The problem is solved in that in a centrifugal separator containing a cylindrical body, a swirl and an internal coaxial tube, the swirl is placed directly at the entrance to the body, an internal coaxial tube installed along the axis of the body is cumulative to collect the separated gas and has a valve in its upper part moreover, the space above the valve is connected to the annulus of the well by gas outlets, and before entering the storage pipe, a central tube is installed with successively chippers connected to it in the form of hollow truncated cones located with smaller diameters in the direction of the storage pipe.

The drawing shows a General view of the device is a centrifugal gas separator during oil production.

The device is a centrifugal gas separator for oil production - contains a swirl unit, consisting of a housing 1 and a swirler 2, which is a tangential channel. The swirl unit is connected to a separation unit, including a housing 3, an accumulation pipe 4, conical chippers 5 and 6 attached to a central tube 7, which is centered in the accumulation pipe 4 and in the adapter 8. The accumulation pipe 4 is centered in the housing 3 of the separation unit. In the upper part there is a valve box consisting of a body 9, a valve body 10, a ball valve 11. The valve body 10 is centered in the valve body 9. The housing 3 of the separation unit is connected to the valve body 9 by a threaded sleeve 12. The valve body 10 is connected to the collecting pipe 4 by a threaded sleeve 13. The nozzles 14 connect the volume above the valve to the annulus of the well.

The upper threaded end of the valve box housing 9 is designed to connect the downhole separator to the downhole pump.

The device operates in conjunction with a submersible sucker rod pump as follows.

During the stroke of the sucker rod pump, the oil and gas mixture is sucked through the lower end of the separator (the lower end of the housing 1 of the swirl block), passes the tangential channels of the swirler 2 and twists. In the cavity of the swirl block due to centrifugal forces, gas and liquid are separated. Gas is collected in the central part of the cavity, and the liquid freed from the gas is pressed against the walls and through the annular gap between the breaker cones 5 and 6 and the wall of the housing 3 enters the annular channel between the housing 3 and the collecting pipe 4, then through the annular channel between the housing 9 valve box and the valve body 10 is sent to a sucker rod pump. The separated gas from the axial zone rises through the internal cavities of the baffle cones 5 and 6 and through the central tube 7 enters the storage pipe 4, where it accumulates in its upper part under the valve 11.

During the reverse (idle) stroke of the sucker rod pump, the suction valve of the sucker rod pump closes, the pressure inside the separator is equalized with the pressure in the annulus of the well, the pressure under the valve becomes higher than the pressure in the annulus of the well by the amount of liquid column displaced by the separated gas accumulated during the working stroke in the accumulation pipe, the valve 11 opens and the accumulated gas is displaced into the annulus of the well through the nozzle 14. Next, a working stroke of the deep rod suck and the process repeats. The volume of the internal cavity of the accumulation pipe 4 should be greater than the volume of the separated gas and depends on the gas content of the liquid at the intake, and the volume of the annular channel between the pipes 3 and 4 should be larger than the volume of the pump.

Using the claimed invention by increasing the fill factor of the cylinder of the sucker rod pump allows you to operate oil wells in a wide range of gas factors (30 ... 500 kilograms of gas per ton of oil). As laboratory tests have shown, the installation of a hollow cone chipper (one or more) with a central tube prevents the entrainment of the separated gas by the liquid and increases the gas separation efficiency from 80-90% to 95-98%.

Claims (1)

A centrifugal gas separator for oil production, containing a cylindrical body, an internal coaxial tube and a swirl, characterized in that the swirl for the inlet flow is installed directly in the lower part of the body at the inlet of the flow into the body, a storage coaxial tube for collecting the separated gas is installed above the swirl and has a valve in its upper part, the space above the valve is connected to the annular space of the well by gas outlet pipes, and the annular channel between the body and the storage pipe is connected n with a suction pipe of the pump, while before entering the storage pipe, a central tube is installed with chippers connected in series in the form of hollow truncated cones located with smaller diameters in the direction of the storage pipe.