RU2547533C1 - Borehole separator - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: borehole separator contains a gas gathering chamber connected with well cavity, a gas pre-separation assembly with spiral winding in form of a screw outside, creating the flow channel connected by holes in the screw body with its axial channel, a flow divider, a fluid drainage branch, a partition, a connecting branch. The device has a parker connected with a stem, in its axial channel a seat is installed. The fluid drainage branch is equipped with support washer and is connected by top end with the flow divider equipped with supply channels hydraulically connected the screw axial channel with the sleeve cavity rigidly connected with the flow divider and installed creating the ring chamber with connecting branch hydraulically connected with the drain channels in the flow divider with the axial channel of the fluid drainage branch. The flow divider is installed inside the connecting branch and is equipped with stem having baffle plates, at its top end the partition and seating head with process groove are installed. The screw axial channel is permanently hydraulically connected by hole in the fluid drainage branch body with its axial channel.

EFFECT: increased efficiency of fluid separation from gas/fluid flow with its discharge to well under was/water boundary.

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Description

The invention relates to the gas industry and is intended to separate the dispersed and droplet liquid from the gas stream with discharge under gas-water contact.

Known gas anchor (see AS No. 1472650, Ml. E21B 43/34, publ. 04/15/1989 Bull. No. 14).

The anchor contains a two-stage housing with receiving holes, the lower turns of which are tightly adjacent to the walls of the lower stage. The upper turn is located in the upper stage of the housing, and the exhaust pipe with a check valve is installed in the upper stage of the larger diameter housing. The auger is made of mesh from a hydrophilic material. The lower turns of the screw form an open axial channel, and the upper turn is a funnel in the form of a truncated cone, the upper smaller base of which is connected to the gas outlet pipe. The diameter of the open axial channel is made conical, with an increase from bottom to top. The design allows for the separation of gas with its outlet through the exhaust gas outlet pipe into the annulus of the wells.

However, such a design cannot be used to separate dispersed and droplet moisture from the gas stream, since the separated gas stream in this case is fed into the annulus of the well. No gas is produced in the annulus due to safety requirements.

Known gas anchor (see RF patent No. 2269649, MKI E21B 43/38, publ. 12/27/2003).

The anchor consists of a nozzle with axial and radial channels with cups placed one above the other, facing up. The radial channels in the nozzle are located at the bottom of each cup, the height of which is determined analytically. The anchor is designed for pipe lift columns in wells operated by sucker rod pumps.

The gas is separated in cups with the release of its bubbles from the reservoir fluid and migration into the annular cavity cavity with subsequent discharge into the field gas collector.

The device provides the separation of relatively small volumes of gas from the reservoir fluid, but cannot separate the droplet and dispersed moisture from the gas stream.

Moreover, the liquid separated from the gas stream cannot be discharged to the bottom of the well below the level of the gas-water contact location.

Known centrifugal separator (see AS No. 41362, Mcl. B01d 45/12, publ. 11/05/1974, Bull. No. 5), consisting of a housing with a throttling device and a check valve provided with a rod with a guide sleeve in in the form of a hollow cylinder. In the upper part of the cylinder is provided with a cover with holes, and in the lower part of the cylinder tangential slots are made. A housing with a cylinder forms a filling chamber. The centrifugal separator is mounted vertically.

The gas stream enters the housing through the inlet pipe. When the locking element is opened, the cylinder with the lid moves downward with the supply of a gas stream from the separator, previously introduced through the tangential channels in the cylinder body into its axial channel. The gas flow swirls, and the droplet liquid is thrown to the cylinder wall and in the form of a film moves to the lid traps with an overflow into the accumulation chamber, from where it is discharged outside the separator through the outlet pipe. The gas flow rate is determined by the position of the locking ball element.

The design of a centrifugal separator is difficult to apply in a gas well due to the small diametrical dimensions of the barrel and the large dimensions of the separator body.

Known double-acting borehole separator (see AS No. 1629507, Mcl. E21B 43/38, publ. 02.23.91, Bull. No. 7), designed for the separation of gas and sand under conditions of increased gas-liquid mixture, adopted for the prototype. The device consists of a housing with connecting nozzles and receiving holes, a container, a multi-chamber gas pre-separation unit with rings installed externally, liquid branch pipes, a flow divider, a combined centrifugal gas separation unit in the form of a screw with perforated holes and a spiral forming a flow channel with a shank . In the body of the flow divider along the generatrix of the cylinder, slotted slots are made that communicate the flow channel of the rod with the annular channel. The total cross-sectional area of the slotted slots is selected from the conditions for ensuring the required field of centrifugal forces.

The annular chamber between the auger shank and the casing is divided by rings into separate chambers connected by receiving holes to the well cavity, openings in the casing with a gas collection chamber and a gravitational gas separation chamber.

A search and analysis of the structures of known technical solutions showed that in A.S. No. 761698, Mcl. Е21В 39/00 - “Gas-liquid separator” (published on September 7, 1980, Bull. No. 33), the principle of twisting a gas-liquid flow due to the tangential execution of outlet openings is implemented.

Also known is the design of a gas anchor (see AS No. 875000, Mcl. E21B 43/34, publ. 10/23/1981, Bull. No. 39), where the use of a screw for swirling a flow with a hollow axial channel for receiving and filing.

The technical result that can be obtained by implementing the invention:

- the ability to ensure the health of the well by preventing its self-jamming;

- the possibility of separation of the droplet and dispersed liquid from the gas-liquid stream with its discharge into the well under the level of the gas-water contact;

- the ability to replace and remove the inside of the device to ensure the supply of geophysical instruments into the well;

- the ability to reinstall the internal part of the device in the axial channel of the screw with the continuation of the operation of the well.

The technical result is achieved by the fact that the downhole separator contains a gas collection chamber, a preliminary gas separation unit in the form of a screw with a spiral winding on the outside, forming a flow channel connected with the holes in its body with its axial channel.

The flow divider is equipped with a nozzle for draining fluid, a sleeve, a rod with baffle plates in the axial channel of the sleeve, on the upper end of which there is a partition and a connecting head.

The device is equipped with a packer with a screw at the lower end with a saddle in the axial channel.

The liquid outlet pipe is equipped with a support washer and is connected at its upper end to a flow divider, in which feed channels are made connecting the screw axial channel with a sleeve cavity forming an annular chamber with a connecting pipe hydraulically connected with the discharge channels in the flow divider body with the axial channel of the liquid drain pipe.

The flow divider is installed inside the connecting pipe with the end interaction of the support washer with the seat in the axial channel of the screw.

The design of the downhole separator is illustrated by drawings, where:

- figure 1 is a cross-sectional separator installed in the axial channel of the casing pipe, with a location in the perforation interval;

- figure 2 - the separator in the context, without an inner part, with a free axial channel of the first separation stage;

- figure 3 is a transverse enlarged section of a flow divider.

The device consists of two parts - a separator of the first stage and an extractable second stage.

The first stage consists of a mechanical packer 1, the upper end of which is equipped with a connecting pipe 2.

From the bottom, to the trunk of the packer 1, a first stage separator is connected, in the form of a screw 3 with spiral winding 4, the turns of which overlap the direct gas-liquid flow to the holes 5 in the body of the screw 3, coming from the perforation holes 6 of the casing 7. The holes 5 in the screw 3 are made tangentially directed towards the axis of the device.

A saddle 9 is installed in the axial channel 8 of the screw 3. The recoverable second stage of the separator consists of a flow divider 10 with inlet channels 11 and outlet channels 12. The flow divider 10 blocks the direct flow of gas-liquid mixture from the axial channel 8 of the screw 3 into the fluid outlet 13 connected to a flow divider 10 and a screw 3 passed into the axial channel 8 and extending beyond it with an arrangement in the area under the gas-water contact (GVK) 14. In the lower part of the fluid outlet pipe 13, a thrust washer 15 is installed with the possibility of support on the seat 9.

The flow divider 10 in the upper part is equipped with a separator of the second stage 16, including a sleeve 17, in the bottom of which the rod 18 is fixed with the formation of an annular chamber 19 with it, in which the baffle plates 20 are located. Above the sleeve 17 on the rod 18 is a partition 21 with a landing head 22 , in the body of which a technological boring 23 is made to provide the possibility of introducing a special landing tool into it and capturing the extracted part of the separator. A lock nut 24 is installed in the upper part of the connecting pipe 2. The annular chamber 25, formed by the inner surface of the connecting pipe 2 and the outer surface of the sleeve 17, is constantly hydraulically connected by the discharge channels 12 in the body of the flow divider 10 with the axial channel 26 of the liquid discharge pipe 13. Axial channel 8 the screw 3 is connected by an opening 27 made in the body of the branch pipe of the fluid outlet 13 above the location of the supporting washer 15, with its axial channel 26.

Device operation

In the annular chamber of the connecting pipe 2, under the lock nut 24, a landing head (not shown in Fig.) Is inserted, which is connected, in turn, with the pipe tubing. Carry out the descent of the device to a predetermined depth with the location of the packer 1 above the roof of the reservoir. The spiral winding 4 of the first stage separator is located above the level of the gas-water contact (GVK) 14.

An operation is performed to close the annular space by packer 1. After this, technological operations are carried out to develop and launch a gas well.

When starting, the gas-liquid flow from the reservoir through the perforation holes 6 enters the axial channel of the well, from where, flowing around the coils of spiral winding 4, it enters with twisting through tangentially directed holes 5 in the body of the screw 3 into its axial channel 8 and through the supply channels 11 in the body the flow divider 10 is fed into the sleeve 17 with the interaction with the baffle plates 20. Next, the gas stream is discharged into the annular chamber 25 with the interaction with the body of the partition 21 and changing the direction of gas flow. Liquid droplets, when interacting with the coils of spiral winding 4 and when twisting the gas-liquid flow, flow down the inner surface of the screw 3 to the support washer 15, and through the hole 27, the liquid flows into the axial channel 26 of the fluid outlet 13 and then is discharged under the GWC 14.

The gas-liquid flow through the supply channels 11 in the body of the flow divider 10 enters the cavity of the sleeve 17 and accumulates in the form of a film on its inner surface, with the gas flow moving up to the edge, and on the outer surface the liquid film flows into the annular chamber 25, from where through the outlet channels 12 passes into the fluid outlet pipe 13 and then into the well cavity under the GWC 14. The separated gas stream with residual dispersed moisture enters the baffle 21, with a decrease in the flow rate. In this case, the separated liquid in the form of droplets is discharged from the surface of the partition 21 into the annular chamber 25 with flow through the outlet channels 12 of the flow divider 10 into the axial channel 26 of the liquid outlet 13 and further under the GWC 14.

The process of separation of liquid from a gas-liquid stream occurs in a constant mode.

After the dispersed moisture is removed from the gas-liquid flow, gas is supplied to the consumer through the pipe string.

Figure 2 shows a device without a removable part. To extract this part, a puller is fed into the axial channel of the pipe tubing string, which is inserted into the technological bore 23, connected through the rod 18 to the flow divider 10. The inner part is pulled upward by pulling it up to the surface. Thus, there is the possibility of free descent into the interval of the reservoir of research equipment. After carrying out the research, the research equipment is removed and installed in the axial channel 8 of the screw 3 of the flow divider 10 with a branch pipe 13.

After re-equipping the inside of the separator of the first stage, namely, introducing into the axial channel 8 of the screw 3 of the flow divider 10 with the fluid outlet 13, the well is put into operation with the continuation of the separation process.

If necessary, the entire device can be removed from the well by introducing into the annular chamber 25 of the connecting pipe 2 of a special fishing device that interacts with the lock nut 24.

Claims (1)

An downhole separator comprising a gas collection chamber connected to the well cavity, a gas pre-separation unit with a spiral winding in the form of a screw on the outside, forming a flow channel between itself, connected by openings in the screw body with its axial channel, a flow divider, a pipe for draining fluid, a baffle, a connecting pipe, characterized in that the device is equipped with a packer associated with a screw, in the axial channel of which a saddle is installed, the liquid pipe is equipped with a support washer and connected in the upper end with a flow divider provided with inlet channels hydraulically connecting the axial channel of the screw with the cavity of the sleeve rigidly connected to the flow divider and installed with the formation of an annular chamber with a connecting pipe hydraulically connected to the outlet channels in the flow divider with the axial channel of the liquid outlet pipe, the divider the flow is installed inside the connecting pipe and is equipped with a rod with baffle plates, on the upper end of which there is a partition and a landing head with technical biological bore, and the axial channel of the screw is constantly hydraulically connected by an opening in the body of the fluid outlet pipe with its axial channel.

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