Process pipe column capable of throwing and fishing underground oil-water separator

Abstract

The invention discloses a process pipe column capable of throwing and fishing an underground oil-water separator. Comprising an outer sleeve; a perforated pipe is arranged at the lower end of the central oil pipe; the lower end of the bridge type channel is connected with the upper end of the central oil pipe, and a first channel and a second channel are respectively arranged in the bridge type channel; the reinjection oil pipe is arranged above the bridge type channel, and the lower end of the reinjection oil pipe is communicated with the upper end of the first channel; the lower end of the lower working barrel is connected with the upper end of the reinjection oil pipe; a right lower interface of the Y joint is connected with the upper end of the lower working barrel; the electric submersible pump unit is arranged in the outer sleeve and located on one side of the lower working barrel. The lower end of the upper working barrel is connected with an upper interface of the Y joint; the lifting oil pipe is fixed in the external sleeve through a packer; a stopper; and the underground oil-water separator can be thrown and fished. The underground oil-water separation and reinjection device has the beneficial effect that the underground oil-water separation and reinjection process is realized under the condition that a tubular column is not moved during conventional commingling production.

Description

Technical Field

[0001] The invention relates to the technical field of petrochemical industry, in particular to a process pipe column for a downhole oil-water separator that can be cast and salvaged. Background Art

[0002] With the continuous exploitation of offshore oil fields, the problem of high water content in production oil fields is becoming increasingly serious. Various forms of water control technologies are constantly emerging. Among them, although downhole oil-water separation technology can effectively solve the problem of high water content in oil fields, there are problems such as the lack of suitable reinjection layers and difficulties in well and layer selection. It cannot be promoted and applied on a large scale, which restricts the effective implementation of this technology.

[0003] At present, there are many combined production and injection wells. In the injection wells, there are still high-yield oil layers that need to continue to produce oil, and other layers are injected. The pipe string has problems such as wellhead modification and high difficulty in double-pipe safety control. Downhole oil-water separation and reinjection technology pipe strings can be used to replace the original combined production and injection and other one-well multi-purpose pipe strings to reduce the oil content of reinjection water. However, since the pipe string needs to be moved and the downhole oil-water separation and reinjection pipe string needs to be re-inserted, the operation and supporting tool costs are high and the economic benefits are poor. Summary of the invention

[0004] The object of the present invention is to provide a throwable downhole oil-water separator process tubing string, which is provided with a perforated pipe, a central oil pipe, an insert seal, a bridge channel, a reinjection oil pipe, a lower working cylinder, a Y-joint, an upper working cylinder, a lifting oil pipe and a packer in sequence from the lower right to the upper part of the outer casing. By throwing in a plug during separate production and throwing in a throwable downhole oil-water separator during reinjection, the downhole oil-water separation and reinjection process can be realized without moving the tubing string during conventional combined production.

[0005] To achieve the above object, the present invention adopts the following technical solutions, including:

[0006] External casing;

[0007] A central oil pipe, which is arranged inside the outer casing by inserting a seal, and a perforated pipe is provided at the lower end of the central oil pipe;

[0008] A bridge channel, the lower end of which is connected to the upper end of the central oil pipe, and a first channel and a second channel are respectively provided in the bridge channel; the lower end of the second channel is connected to the central oil pipe, and the upper end of the second channel is connected to the annulus between the central oil pipe and the external casing; the lower end of the first channel is connected to the annulus between the central oil pipe and the external casing;

[0009] an oil return pipe, which is arranged above the bridge channel, the lower end of which is communicated with the upper end of the first channel, and a slidable sleeve is provided on the oil return pipe, and the sleeve can open / close the water hole on the oil return pipe; and

[0010] A lower working cylinder, the lower end of which is connected to the upper end of the oil return pipe;

[0011] A Y-joint, the lower right interface of which is connected to the upper end of the lower working cylinder;

[0012] An electric submersible pump unit is arranged in the outer casing and located on one side of the lower working cylinder, and the electric submersible pump unit is connected to the lower left interface of the Y-joint;

[0013] An upper working cylinder, the lower end of which is connected to the upper interface of the Y-joint;

[0014] A lifting oil pipe, which is fixed in the outer casing through a packer, and the lower end of the lifting oil pipe is connected to the upper end of the upper working cylinder;

[0015] A plugging device, which is used to be put into the lower right interface during combined mining to achieve blocking of the lower right interface;

[0016] The downhole oil-water separator can be put into the lower right interface during reinjection to separate the oil and water in the produced liquid from the electric submersible pump unit.

[0017] Preferably, a downhole safety valve is provided on the upper portion of the lifting oil pipe.

[0018] Preferably, the packer is a cable packer.

[0019] Preferably, a positioning bypass is provided on the periphery of the bridge channel for connecting with the second channel of the bridge channel.

[0020] Preferably, a locking groove is provided in the lower right interface for cooperating with a lock core on the outer periphery of the castable downhole oil-water separator to fix the castable downhole oil-water separator.

[0021] Preferably, positioning steps and sealing surfaces are respectively provided in the upper working cylinder and the lower working cylinder, which cooperate with the retrievable downhole oil-water separator respectively to achieve positioning and sealing connection between the retrievable downhole oil-water separator and the upper working cylinder and the lower working cylinder respectively.

[0022] The beneficial effects of the present invention are as follows: a perforated pipe, a central oil pipe, an insert seal, a bridge channel, a reinjection oil pipe, a lower working cylinder, a Y-joint, an upper working cylinder, a lifting oil pipe and a packer are arranged in sequence from the lower right to the upper right in the outer casing; a plugging device is put into the well during separate production, and a salvageable downhole oil-water separator is put into the well during reinjection, so that downhole oil-water separation and reinjection technology can be realized without moving the pipe string during conventional combined production. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of a process pipe string for a downhole oil-water separator according to the present invention Figure 1 (Joint mining status).

[0024] Figure 2 A schematic diagram of a process pipe string for a downhole oil-water separator according to the present invention Figure 2 (Re-injection status).

[0025] Figure 3 Schematic diagram of the Y connector in the present invention.

[0026] Figure 4 It is a schematic diagram of the upper working cylinder in the present invention. DETAILED DESCRIPTION

[0027] The invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement it according to the description.

[0028] It should be understood that terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or other elements or combinations thereof.

[0029] like Figure 1-4 As shown, a process pipe string 1 for a downhole oil-water separator that can be cast and salvaged according to the present invention comprises:

[0030] External sleeve 110;

[0031] A central oil pipe 120, which is arranged inside the outer casing 110 by inserting a seal 121, and a perforated pipe 122 is provided at the lower end of the central oil pipe;

[0032] The lower end of the bridge channel 130 is connected to the upper end of the central oil pipe 120, and a first channel 131 and a second channel 132 are respectively provided in the bridge channel 130; the lower end of the second channel 132 is connected to the central oil pipe 120, and the upper end of the second channel 132 is connected to the annulus between the central oil pipe 120 and the outer casing 110; the lower end of the first channel 131 is connected to the annulus between the central oil pipe 120 and the outer casing 110;

[0033] A return oil pipe 140 is disposed above the bridge channel 130 , the lower end of the return oil pipe 140 is connected to the upper end of the first channel 131 , a slidable sleeve 141 is provided on the return oil pipe 140 , and the sleeve 141 can open / close the water hole 142 on the return oil pipe 140 ; ​​and

[0034] A lower working cylinder 151, the lower end of which is connected to the upper end of the oil return pipe;

[0035] The Y-joint 160, whose lower right interface 161 is connected to the upper end of the lower working cylinder;

[0036] The electric submersible pump unit 170 is arranged in the external casing and located on one side of the lower working cylinder. The electric submersible pump unit is connected to the lower left interface 162 of the Y-connector; the electric submersible pump unit 170 is electrically connected to the surface device through a power cable 171.

[0037] The upper working cylinder 152, the lower end of which is connected to the upper interface 163 of the Y-joint;

[0038] A lifting oil pipe 180, which is fixed in the outer casing through a packer 181, and the lower end of the lifting oil pipe is connected to the upper end of the upper working cylinder;

[0039] A plug 191 is used to be put into the lower right interface during combined mining to block the lower right interface;

[0040] The downhole oil-water separator 192 can be put into the lower right interface during reinjection to separate the oil and water from the produced liquid from the electric submersible pump unit.

[0041] During use, when combined production is performed, both the A layer and the B layer are oil-producing layers, and the plug 191 is put into the lower right interface to seal the lower right interface 161; the production fluid of the A layer enters the casing annulus along the combined central oil pipe 120 and the second channel 132, and the production fluid of the B layer enters the casing annulus from the water hole 142 along the combined first channel 131 and the reinjection oil pipe 140; the production fluid of the A layer and the production fluid of the B layer are then lifted by the electric submersible pump unit 170 and enter the lifting oil pipe 180 through the Y joint 160 to achieve combined production. When the water content of the produced fluid increases, the A layer can be changed into a reinjection layer, and the water after oil and water separation can be reinjected into the formation. The plug 191 is fished out by wire operation, the sleeve 141 is closed, and the salvageable downhole oil-water separator 192 is put into the Y-joint 160. At this time, the production fluid of the B layer enters the central oil pipe 120, enters the oil casing annulus through the second channel 132, and is lifted to the Y-joint 160 by the submersible pump unit 170, and enters the salvageable downhole oil-water separator 192 laterally. The production fluid entering the salvageable downhole oil-water separator 192 is separated under the action of centrifugal force, and the water is close to the outer shell of the salvageable downhole oil-water separator 192. The oil gathers in the center to form an oil core, which is lifted upward under the action of pressure, and a large amount of water flows down to the reinjection oil pipe 140 through the first channel 131 to the water injection layer A layer.

[0042] In another embodiment, a downhole safety valve 182 is provided on the upper portion of the lifting oil pipe 180 .

[0043] In another embodiment, the packer 181 is a cable packer.

[0044] In another embodiment, a positioning bypass 133 is provided on the periphery of the bridge channel 130 for connecting with the second channel of the bridge channel.

[0045] In another embodiment, a locking groove 161a is provided in the lower right interface 161 for cooperating with a lock core on the outer periphery of the castable downhole oil-water separator 192 to fix the castable downhole oil-water separator.

[0046] In another embodiment, a positioning step 153 and a sealing surface 154 are respectively provided in the upper working cylinder 152 and the lower working cylinder 151, which respectively cooperate with the retrievable downhole oil-water separator 192 to achieve the positioning and sealing connection of the retrievable downhole oil-water separator 192 with the upper working cylinder 152 and the lower working cylinder 151 respectively.

[0047] In summary, the present invention provides a throwable downhole oil-water separator process string 1, in which a perforated pipe, a central oil pipe, an insert seal, a bridge channel, a reinjection oil pipe, a lower working cylinder, a Y-joint, an upper working cylinder, a lifting oil pipe and a packer are arranged in sequence from the lower right to the upper part of the external casing. By throwing in a plug during separate production and throwing in a throwable downhole oil-water separator during reinjection, the downhole oil-water separation and reinjection process can be realized without moving the string during conventional combined production.

[0048] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A process string for a downhole oil-water separator that can be cast and salvaged, characterized in that: include: External casing; A central oil pipe, which is arranged inside the outer casing by inserting a seal, and a perforated pipe is provided at the lower end of the central oil pipe; A bridge channel, the lower end of which is connected to the upper end of the central oil pipe, and a first channel and a second channel are respectively provided in the bridge channel; the lower end of the second channel is connected to the central oil pipe, and the upper end of the second channel is connected to the annulus between the central oil pipe and the external casing; the lower end of the first channel is connected to the annulus between the central oil pipe and the external casing; an oil return pipe, which is arranged above the bridge channel, the lower end of which is communicated with the upper end of the first channel, and a slidable sleeve is provided on the oil return pipe, and the sleeve can open / close the water hole on the oil return pipe; and A lower working cylinder, the lower end of which is connected to the upper end of the oil return pipe; A Y-joint, the lower right interface of which is connected to the upper end of the lower working cylinder; An electric submersible pump unit is arranged in the outer casing and located on one side of the lower working cylinder, and the electric submersible pump unit is connected to the lower left interface of the Y-joint; An upper working cylinder, the lower end of which is connected to the upper interface of the Y-joint; A lifting oil pipe, which is fixed in the outer casing through a packer, and the lower end of the lifting oil pipe is connected to the upper end of the upper working cylinder; A plugging device, which is used to be put into the lower right interface during combined mining to achieve blocking of the lower right interface; The downhole oil-water separator can be put into the lower right interface during reinjection to separate the oil and water in the produced liquid from the electric submersible pump unit.

2. The process pipe string for a downhole oil-water separator that can be cast and salvaged according to claim 1 is characterized in that: A downhole safety valve is arranged on the upper part of the lifting oil pipe.

3. The process pipe string for a downhole oil-water separator that can be cast and salvaged according to claim 1 or 2, characterized in that: The packer is a cable packer.

4. The process pipe string for a downhole oil-water separator that can be cast and salvaged according to claim 1 is characterized in that: A positioning bypass is provided on the periphery of the bridge channel for connecting with the second channel of the bridge channel.

5. The process pipe string for a downhole oil-water separator that can be cast and salvaged according to claim 1 is characterized in that: A locking groove is provided in the lower right interface for cooperating with a lock core on the outer periphery of the castable downhole oil-water separator to fix the castable downhole oil-water separator.

6. The process pipe string for a downhole oil-water separator that can be cast and salvaged according to claim 6 is characterized in that: Positioning steps and sealing surfaces are respectively provided in the upper working cylinder and the lower working cylinder, which cooperate with the retrievable downhole oil-water separator respectively to realize the positioning and sealing connection between the retrievable downhole oil-water separator and the upper working cylinder and the lower working cylinder respectively.

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