WO2023077958A1

WO2023077958A1 - Concentric injection-production pipe applied to fractured oil and gas well, central string, and well completion structure

Info

Publication number: WO2023077958A1
Application number: PCT/CN2022/117974
Authority: WO
Inventors: 裴柏林; 吴建昌; 宋晓强
Original assignee: 安东柏林石油科技（北京）有限公司; 裴柏林; 吴建昌; 宋晓强
Priority date: 2021-11-05
Filing date: 2022-09-09
Publication date: 2023-05-11
Also published as: CN216043664U

Abstract

Disclosed is a concentric injection-production pipe applied to a fractured oil and gas well, the concentric injection-production pipe comprising a cylindrical channel pipe (51), wherein a water outlet (511) is formed in the channel pipe (51); the channel pipe (51) is internally provided with a support ring (52), the support ring (52) is generally in the form of a cylindrical structure, a plurality of support points (521) extending outwardly are provided on an outer wall of the support ring (52), and the plurality of support points (521) are attached to an inner wall of the channel pipe (51), so as to form an annular wall-sandwiched cavity (56) which is formed by the inner wall of the channel pipe (51) and the outer wall of the support ring (52) and has two ends in communication with each other; a water outlet channel (522) is further provided at a position on the support ring (52) that corresponds to the water outlet (511) of the channel pipe (51), and the water outlet channel (522) communicates the water outlet (511) with the interior of the support ring (52); and a retaining wall (523) is provided on the periphery of the water outlet channel (522), the retaining wall (523) is attached to the inner wall of the channel pipe (51), such that the water outlet channel (522) is isolated from the wall-sandwiched cavity (56). The concentric injection-production pipe has a water injection channel and a liquid production channel, such that the string can be easily operated in a well, a larger overflow surface is provided, and the working efficiency can thus be improved.

Description

Concentric injection-production pipes, central pipe strings and completion structures applied to fractured oil and gas wells

technical field

The utility model belongs to the technical field of petroleum exploitation, and relates to a concentric injection-production pipe and a central pipe string applied to the injection and production of fractured oil and gas wells in the same well, and a well completion structure using the concentric injection-production pipe and the central pipe string .

Background technique

The same well injection and production technology is mainly used to solve the problems of low matrix permeability and difficult production of oil and gas in fractured oil and gas wells. The same well injection and production process usually uses parallel double pipes to run into the wellbore. Outlet pipes, the water outlets of multiple injection pipes and the oil production ports of multiple production pipes are distributed sequentially in the wellbore, and the wellbore annulus between the water outlets and oil production The fractures corresponding to the nozzles are injection fractures, and the fractures corresponding to the production outlets are production fractures. The working process of this technical scheme is as follows: inject water into the injection fracture through the water outlet of the injection pipe, and the water injected into the fracture will displace the formation oil in the matrix between the injection fracture and the production fracture to the production fracture under the action of pressure difference And flow into the production fracture, and then flow from the production fracture through the oil production port into the production pipe, and finally be mined to the ground. Using the same well injection and production technology with double pipe running can improve the liquid production rate, production efficiency and actual recovery factor of oil and gas wells.

However, there are still two problems in the same-well injection-production process with two pipes running in. In the first aspect, compared with the technical scheme of running single pipes into the wellbore, the construction difficulty of running the double pipes into the wellbore and taking them out is very high, and it is prone to the problem of pipe string stuck, which also leads to the same well injection Mining technology has remained in theoretical concepts for a long time, and has rarely been applied in actual engineering. In the second aspect, since the wellbore is usually a circular cross-section structure, and the double pipes run in are also circular cross-sectional structures, resulting in a small diameter of the double pipes and a low utilization rate of the wellbore cross section. For example, when the diameter of the wellbore is 8 inches, the diameter of the lowered double pipe must be less than 4 inches. At this time, the effective cross-sectional area of the double pipe is less than 8π square inches, which is less than half of the overall cross-sectional area of the wellbore, which is 16π. If the thickness of the pipe wall of the double pipe and the margin to be reserved for the cooperation between the pipe string and the wellbore are considered, the effective flow area of the double pipe is only about one-third of the wellbore. The effective flow area of the double pipe is too small. On the one hand, it will lead to large resistance and low flow rate of water injection and oil production, which will seriously affect the production efficiency; It becomes more difficult to segment the space.

Utility model content

The purpose of the utility model is to overcome the defects of the prior art, and provide a concentric injection-production pipe, central pipe string and well completion structure applied to fractured oil and gas wells.

In order to achieve the above object, the utility model adopts the following technical solutions:

A concentric injection-production pipe applied to fractured oil and gas wells, comprising a cylindrical passage pipe 51, the passage pipe 51 is provided with a water outlet 511; the interior of the passage pipe 51 is provided with a support ring 52, the support The ring 52 has a cylindrical structure as a whole, and the outer wall of the support ring 52 is provided with a plurality of outwardly extending support points 521, and the plurality of support points 521 are attached to the inner wall of the channel pipe 51, thereby forming a The inner wall of the passage pipe 51 and the outer wall of the support ring 52 form an annular cavity 56 with two ends connected through the wall; the position corresponding to the water outlet 511 of the passage pipe 51 on the support ring 52 is also provided with a water outlet Channel 522, the water outlet channel 522 communicates the water outlet 511 with the inside of the support ring 52; fit together, thereby isolating the water outlet channel 522 from the clamping wall cavity 56 .

Further, the water outlets 511 of the channel pipe 51 and the water outlet channels 522 of the support ring 52 are axially arranged in a plurality and evenly distributed in the circumferential direction.

Further, a flow guide layer 53 is provided outside the channel pipe 51 , and the interlayer space between the flow guide layer 53 and the channel pipe 51 communicates with the water outlet 511 .

Further, the two ends of the channel pipe 51 are provided with a first adapter 54 and a second adapter 55 for realizing serial connection between multiple pipe strings.

Further, the first adapter 54 and the second adapter 55 are respectively a male adapter and a female adapter in a threaded connection.

Further, it also includes an insertion sealing tube 6 arranged inside the support ring 52, the insertion sealing tube 6 is a tubular structure, and two sets of sealing rings 61 are arranged in the circumferential direction, and the two sets of sealing rings 61 are located at the ends of the support ring 52. The two sides of the water outlet channel 522 are attached and sealed with the inner wall of the support ring 52; The diversion cavity 57 formed therebetween corresponds to the diversion hole 62 .

Further, the sealing ring 61 of the insertion sealing tube 6 is a rubber ring structure prefabricated on the outer circumference of the insertion sealing tube 6, or a ring structure of a liquid-expandable material.

Further, the two ends of the insertion sealing tube 6 are provided with a third adapter for connecting multiple pipelines in series.

In order to achieve the above object, the utility model also adopts the following technical solutions:

A central pipe string applied to fractured oil and gas wells, comprising concentric injection-production pipes 5 and water control screens 4 arranged at intervals, wherein the concentric injection-production pipes 5 adopt the structure as described above; the water control screens A concentric injection pipe 3 is provided inside the pipe 4; the concentric injection-production pipe 5 and the water control screen 4 are connected end to end in sequence; the insertion sealing pipe 6 of the concentric injection-production pipe 5 is connected with the concentric injection pipe 3 in sequence The wall cavity 56 of the concentric injection-production pipe 5 communicates with the annular cavity formed by the water control screen 4 and the concentric injection pipe 3;

A well completion structure applied to fractured oil and gas wells, the wellbore 2 is provided with the above-mentioned central pipe string, and the wellbore annulus between the central pipe string and the wellbore wall of the wellbore 2 is filled with packing particles 7 .

The utility model is a concentric injection-production pipe, central pipe string and well completion structure applied to fractured oil and gas wells. Compared with the existing double-pipe running process, the channel and liquid production channel are not only more convenient for the downhole operation of the pipe string, and are not easy to be blocked, but also have larger flow surfaces in the water injection channel and liquid production channel, which is conducive to improving work efficiency . The second is that the concentric injection-production pipe and water control screen as the outer pipe, and the insertion seal pipe and concentric injection pipe as the inner pipe can be lowered into the wellbore separately, so that they are fully compatible with the existing well equipment. Third, the wellbore annulus is filled with packing particles as the isolation structure, which is easy to construct and has a good effect in preventing channeling of injected water or produced fluid in the wellbore annulus.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of a well completion structure applied to fractured oil and gas wells in an embodiment of the present invention;

Fig. 2 is a schematic diagram of the axial section structure of a concentric injection-production pipe applied to fractured oil and gas wells adopted in Fig. 1;

Fig. 3 is a schematic diagram of the A-A section structure in Fig. 2 (not including the insertion of the sealing tube);

Fig. 4 is a schematic diagram of the fluid movement directions of the two flow channels of the concentric injection-production pipe shown in Fig. 2 .

Detailed ways

The specific implementation of a concentric injection-production pipe, central pipe string and well completion structure of the present invention applied to fractured oil and gas wells will be further described below in conjunction with accompanying drawings 1 to 4. A concentric injection-production pipe, central pipe string and completion structure of the utility model applied to fractured oil and gas wells are not limited to the descriptions of the following embodiments.

Example 1:

This embodiment provides a concentric injection-production pipe applied to fractured oil and gas wells. As shown in Figures 1 to 3, the overall shape of the concentric injection-production pipe 5 is consistent with the shape of the pipe string lowered into the wellbore during the completion of the existing technology, and can be in any form such as a short joint or a long joint. The concentric injection-production pipe 5 includes at least three layers of cylindrical structures from outside to inside, which are diversion layer 53 , channel pipe 51 and support ring 52 .

Wherein, the cylindrical channel pipe 51 is provided with a water outlet 511; preferably, the water outlet 511 of the channel pipe 51 and the water outlet channel 522 of the support ring 52 are arranged axially and centrally in multiple (for example, 4) ), and distributed uniformly in the circumferential direction.

The channel pipe 51 is provided with a support ring 52 inside, and the support ring 52 has a cylindrical structure as a whole. The outer wall of the support ring 52 is provided with a plurality of outwardly extending support points 521, and the plurality of support points 521 and The inner wall of the channel tube 51 is bonded together to form an annular cavity 56 formed by the inner wall of the channel tube 51 and the outer wall of the support ring 52 with both ends connected; preferably, the support point 521 is set At positions close to both ends, the number is 4, evenly distributed along the axial direction. The position corresponding to the water outlet 511 of the channel pipe 51 on the support ring 52 is also provided with a water outlet channel 522, and the water outlet channel 522 communicates the water outlet 511 with the inside of the support ring 52 (that is, communicates with the inside of the support ring 52 The axial flow channel inside the support ring 52 is connected); the periphery of the water outlet channel 522 is provided with a retaining wall 523, and the retaining wall 523 is attached to the inner wall of the channel pipe 51, thereby connecting the water outlet channel 522 to the Obviously, the retaining wall 523 can also play a supporting role similar to the support point 521 to ensure the structural stability of the clamping wall cavity 56 .

The outside of the channel pipe 51 is provided with a diversion layer 53, and the interlayer space between the diversion layer 53 and the channel pipe 51 communicates with the water outlet 511 for evenly distributing or releasing the injected water discharged from the water outlet 511. to the wellbore annular space corresponding to the concentric injection-production pipe 5, so that the injected water enters the injection fracture 8. At the same time, it is also used to prevent the packing particles in the annulus from entering the central pipe string.

Both ends of the channel pipe 51 are provided with a first adapter 54 and a second adapter 55 for realizing serial connection between multiple pipe strings. Preferably, the first adapter 54 and the second adapter 55 are respectively a male adapter and a female adapter in a threaded connection. Both ends of the concentric injection-production pipe 5 can be connected in series with the water control screen, and of course can also be connected with the concentric injection-production pipe 5, so that two or more shorter concentric injection-production pipes 5 can be connected into a group of longer combination structure.

The inside of the support ring 52 of the concentric injection-production pipe 5 is also provided with an insertion sealing tube 6, the insertion sealing tube 6 is a tubular structure, and two sets of insertion sealing rings 61 are arranged in the circumferential direction, and the two sets of sealing rings 61 are located on the support. The two sides of the water outlet channel 522 of the ring 52 are attached to and sealed with the inner wall of the support ring 52 . Preferably, the sealing ring 61 of the insertion sealing tube 6 is a rubber ring structure prefabricated on the outer circumference of the insertion sealing tube 6 , or is a ring structure of a material that expands in contact with liquid to achieve sealing. A guide hole 62 corresponding to the water outlet channel 522 or the guide cavity 57 formed between the insert seal tube 6 and the support ring 52 is provided in the circumferential direction of the insert seal tube 6 . By setting the insertion sealing pipe 6, two channels are formed inside the concentric injection and production pipe 5, that is, the water injection channel inside the insertion sealing pipe 6, and the channel between the insertion sealing pipe 6 and the channel pipe 51. formed oil channels.

The diversion cavity 57 is surrounded by the outer side of the sealing tube 6, the inner side of the support ring 52, and the sealing rings 61 at both ends of the outer side of the sealing tube 6; the purpose of setting the diversion cavity 57 is to When the sealing pipe 6 is lowered during the construction process, on the one hand, since the length of a single section of the sealing pipe 6 and the length of a single section of the concentric injection-production pipe 5 cannot be very precisely consistent, it may cause that the diversion hole 62 cannot It is completely aligned with the water outlet channel 522 in the circumferential direction; on the other hand, since the two are usually connected in series by threads, it is difficult to completely align the flow guide hole 62 with the water outlet channel 522 in the radial direction. Therefore, by setting the diversion cavity 57 as the diversion channel between the diversion hole 62 and the water outlet channel 522, the accuracy and difficulty of construction can be greatly reduced, and the fault tolerance (positional deviation) between the sealing pipe 6 and the concentric injection-production pipe 5 can be improved. )ability.

Preferably, the two ends of the insertion sealing tube 6 are provided with a third transfer interface for realizing the serial connection of multiple pipelines; of course, the third transfer interface of the insertion sealing tube 6 can be connected in series with the concentric injection tube 3, It can also be serially connected with another or more inserted sealing tubes 6 to form a combined structure.

Example 2:

This embodiment provides a central pipe string applied to fractured oil and gas wells, as shown in Figures 1 to 4, including concentric injection-production pipes 5 and water control screens 4 arranged at intervals, wherein the concentric injection-production pipes 5 using the structure described in Example 1. Of course, the concentric injection-production pipes 5 and the water-controlling screens 4 can be arranged at intervals one by one, or one or several concentric injection-production pipes 5 can be connected in series first, and then one or several water-controlling screens 4 can be connected in series. There can be one or more concentric injection-production pipes 5 and water control screens 4 in each pipe section, and the numbers can be equal or unequal, and should be included in the scope of protection of the claims of this application.

Specifically, the water control screen 4 is provided with a concentric injection pipe 3 (not shown in FIG. 1 ). The concentric injection-production pipe 5 and the water control screen pipe 4 are connected end to end in sequence; the insertion sealing pipe 6 of the concentric injection-production pipe 5 is connected with the concentric injection pipe 3 in sequence; the clamp of the concentric injection-production pipe 5 The wall cavity 56 communicates with the annular cavity formed by the water control screen 4 and the concentric injection pipe 3 ; the insertion sealing pipe 6 communicates with the interior of the concentric injection pipe 3 .

Through the above settings, two flow channels are formed inside the central pipe string, one is a water injection channel, which flows through the concentric injection pipe 3, the insertion sealing pipe 6, the diversion hole 62, the water outlet channel 522, and the outlet water respectively according to the flow direction of the injected water. The water inlet 511, the diversion layer 53, the wellbore annulus corresponding to the concentric injection-production pipe 5, and the injection fracture 8; the other is the oil production channel, which flows through the production fracture 9 and the water control screen 4 corresponding to the Wellbore annulus, water control screen 4, cavity between water control screen 4 and concentric injection pipe 3, cavity between insertion sealing pipe 6 and first adapter 54/second adapter 55, clamping wall cavity 56, and then pass through the last water control screen and the last concentric injection-production pipe 5, and flow upward in sequence until the production wellhead. The specific flow directions of injected water and produced oil are shown in Fig. 4.

Example 3:

This embodiment provides a well completion structure applied to fractured oil and gas wells. As shown in Figure 1, the wellbore 2 includes a setting device 1 arranged near the wellhead, and there are injection fractures 8 and production fractures around the wellbore 2. Out of the crack9. A central pipe string as described in Embodiment 2 is lowered into the wellbore, and the wellbore annulus between the central pipe string and the wellbore wall is filled with packing particles 7 .

For the specific filling method, refer to the existing patented technologies listed in the background technology. By filling the packing particles 7, the isolation inside the wellbore can be realized, and fluid (including injected water, produced oil and gas, etc.) can be prevented from axially channeling in the wellbore annulus. At the same time, it will not hinder the injection water flowing out of the diversion layer 53 of the concentric injection-production pipe 5 from entering the injection fracture 8 through the wellbore annulus corresponding to the concentric injection-production pipe 5, and the fluid produced by the production fracture 9 will not be hindered. The well bore annulus corresponding to the water screen 4 enters the cavity between the water control screen 4 and the concentric injection pipe 3 .

Example 4:

This embodiment provides a method for forming the well completion structure described in Embodiment 3, comprising the following steps:

1. Connect concentric injection-production pipes 5 and water control screens 4 in series at the wellhead and run them into the wellbore until all running operations are completed, forming outer pipes in the vertical well section;

2. According to the serial connection relationship between the concentric injection-production pipe 5 and the water control screen 4, insert the sealing pipe 6 and the concentric injection pipe 3 in series at the wellhead and run them into the outer pipe until all the running operations are completed. The inner layer pipe is formed in the vertical well section; the outer layer pipe and the inner layer pipe together form a central pipe string and then run into the bottom of the well; at this time, it is necessary to ensure that the position of the inserted sealing pipe 6 corresponds to the position of the concentric injection-production pipe 5, and the water control screen 4 Corresponding to the position of the concentric injection pipe 3;

3. Fill the annulus between the central pipe string and the wellbore wall with packing particles to form a continuous packing body for water control.

It should be noted that the "hole" as a fluid passage described in the description and claims of the present invention may be a circular hole, a hole of other shapes, a slit hole, etc., on the premise that it can realize a fluid passage. All belong to the equivalent technical scheme.

The above content is a further detailed description of the utility model in combination with specific preferred embodiments, and it cannot be assumed that the specific implementation of the utility model is only limited to these descriptions. For a person of ordinary skill in the technical field to which the utility model belongs, without departing from the concept of the utility model, some simple deduction or substitutions can also be made, which should be regarded as belonging to the protection scope of the utility model.

Claims

A concentric injection-production pipe applied to fractured oil and gas wells, characterized in that:

It includes a cylindrical channel tube, and the channel tube is provided with a water outlet;

A support ring is provided inside the channel tube, and the support ring has a cylindrical structure as a whole. The outer wall of the support ring is provided with a plurality of outwardly extending support points, and the plurality of support points are connected to the inner wall of the channel tube. adhering, thereby forming an annular cavity formed by the inner wall of the passage tube and the outer wall of the support ring and having two ends connected through the clamping wall cavity;

The position corresponding to the water outlet of the channel pipe on the support ring is also provided with a water outlet channel, and the water outlet channel communicates the water outlet with the inside of the support ring; the periphery of the water outlet channel is provided with a blocking The retaining wall is attached to the inner wall of the channel pipe, thereby isolating the water outlet channel from the clamping wall cavity.
The concentric injection-production pipe applied to fractured oil and gas wells according to claim 1, characterized in that: the water outlet of the channel pipe and the water outlet passages of the support ring are axially arranged in a plurality, and are evenly distributed in the circumferential direction .
The concentric injection-production pipe applied to fractured oil and gas wells according to claim 2, characterized in that: a diversion layer is provided on the outside of the channel pipe, and the interlayer space between the diversion layer and the channel pipe is in contact with the The water outlet is connected.
The concentric injection-production pipe applied to fractured oil and gas wells according to claim 3, characterized in that: the two ends of the passage pipe 51 are provided with a first adapter and a second joint for realizing serial connection between multiple pipe strings. Two adapters.
The concentric injection-production pipe applied to fractured oil and gas wells according to claim 4, characterized in that: the first adapter and the second adapter are respectively a male adapter and a female adapter in a threaded connection.
The concentric injection-production pipe applied to fractured oil and gas wells according to claim 5, characterized in that: it also includes an insertion sealing pipe arranged inside the support ring, the insertion sealing pipe is a tubular structure, and two sets of Sealing rings, the two sets of sealing rings are located on both sides of the water outlet channel of the support ring, and are bonded and sealed with the inner wall of the support ring; the circumferential direction of the insertion sealing tube is provided with the water outlet channel or the The guide hole corresponding to the guide cavity formed between the insertion sealing tube and the support ring.
The concentric injection-production pipe applied to fractured oil and gas wells according to claim 6, characterized in that: the sealing ring inserted into the sealing pipe is a rubber ring structure prefabricated on the outer circumference of the inserted sealing pipe, or is a The ring structure of the inflated material.
The concentric injection-production pipe applied to fractured oil and gas wells according to claim 7, characterized in that: the two ends of the insertion sealing pipe are provided with a third transfer interface for realizing the serial connection of multiple pipelines.
A central pipe string applied to fractured oil and gas wells, characterized in that it includes concentric injection-production pipes and water control screens arranged at intervals, wherein,

The concentric injection-production pipe adopts the structure according to any one of claims 6-8;

The inside of the water control screen is provided with a concentric injection pipe;

The concentric injection-production pipe and the water control screen are connected end-to-end in sequence; the insertion sealing pipe of the concentric injection-production pipe is sequentially connected with the concentric injection pipe;

The wall cavity of the concentric injection-production pipe communicates with the annular cavity formed by the water control screen and the concentric injection pipe; the insertion sealing pipe communicates with the interior of the concentric injection pipe.
A well completion structure applied to fractured oil and gas wells, characterized in that: the central pipe string as claimed in claim 9 is arranged in the wellbore, and the wellbore annular space between the central pipe string and the wellbore wall is filled with Pack particles.