CN216950311U

CN216950311U - Packer and well completion structure for improving axial packing effect of continuous packing body along shaft

Info

Publication number: CN216950311U
Application number: CN202121446497.1U
Authority: CN
Inventors: 裴柏林; 崔洪琪; 宋晓强; 吴建昌
Original assignee: Anton Bailin Oilfield Technology Beijing Co ltd
Current assignee: Anton Bailin Oilfield Technology Beijing Co ltd
Priority date: 2021-06-28
Filing date: 2021-06-28
Publication date: 2022-07-12
Anticipated expiration: 2031-06-28

Abstract

The utility model provides a packer, a method and a well completion structure capable of improving the axial packing effect of a continuous packing body along a shaft, wherein the whole packer is of a cylindrical structure, a central mounting hole for mounting a central pipe column is arranged at the axial position of the packer, one or more annular first grooves are respectively arranged at the two ends of the outer side of the packer, and expandable media are arranged in the first grooves; one or more annular second grooves are arranged in the middle of the outer side of the packer. The utility model makes the flow control pipe column and the well wall form a continuous packer by installing the packer with the expandable function in the well and filling packing particles in the annular space. The expandable medium expands to extrude packing particles to generate a high-density continuous packing body which is better attached to the well wall, so that a better packing effect is realized, and the flow-by of produced water in the well shaft annulus is reduced; the diameter of the packer is reduced, more packers are put into the same shaft, blocking is not easy to occur, and a better packing effect is further obtained.

Description

Packer and well completion structure for improving axial packing effect of continuous packing body along shaft

Technical Field

The utility model belongs to the technical field of oil and gas well exploitation, and relates to a packer capable of improving the axial packing effect of a continuous packing body in a shaft along the shaft, a method capable of improving the axial packing effect of the continuous packing body in the shaft along the shaft, and a well completion structure capable of improving the axial packing effect of the continuous packing body in the shaft along the shaft.

Background

In the oil and gas well exploitation technical field, the shaft of the oil and gas well generally penetrates through a plurality of sections of stratums, because the permeability of each section of stratum is usually inconsistent, and the viscosity of the stratum water is far less than that of the crude oil to be exploited, under the same bottom hole pressure difference, a large amount of stratum water is often produced from the local stratum with high permeability. The common water control method is to put a flow control pipe column with balanced flow into the well to control water or to control water by a water control pipe column. When the flow control pipe column is arranged in the shaft for controlling water and increasing oil, the formation water axially flows in the shaft annulus along the shaft annulus, so that the flow control of the flow control pipe column is ineffective. By sealing the shaft annulus, the production of formation water is controlled, and the channeling of the formation water in the shaft annulus is reduced, so that the method is an effective method for improving the crude oil recovery ratio. The existing method for realizing water control by packing shaft annulus mainly comprises two modes of expanding packer water control and continuous packing body water control.

The expansion packer is applied to a certain extent due to simple structure and low cost. However, this device has the following disadvantages when in use: in the first aspect, since the diameter of the device is larger than the diameter of the central pipe string (or close to the diameter of the well bore), the pipe string formed by connecting a plurality of central pipe strings is very easy to generate the phenomenon of well descending blockage when the well is descended. To solve the downhole choke problem, it is necessary to reduce the number of expansion packers placed on the string, for example one per 50-100 meter interval, to isolate the wellbore into multiple separate isolated units of 50-100 meters in length. However, inside each separation unit, the wellbore annulus is still connected, and the problem of cross flow in the wellbore still exists, which leads to the oil production of the unit being not optimal; in extreme cases, if there is a large water outlet area inside the separation unit (e.g. by fracture communication with the ground bottom water), the oil recovery of the separation unit will become even lower. In the second aspect, the expansion packer is a prefabricated part generally, cannot perfectly adapt to complex well conditions such as inconsistent well diameters, non-centered central pipe columns, uneven well wall surface and the like, cannot ensure that the expansion material can cling to the well wall and realize complete sealing after being completely expanded, and thus formation water channeling among different separation units cannot be thoroughly stopped. In a third aspect, for example, two adjacent units in a downhole production zone that are sealed by a packer that swells in the presence of fluid are located on the left unit in the water production zone and on the right in the oil production zone. The water outlet section can form high pressure due to the large flow limiting resistance of the water control sieve tube; the oil outlet section has low pressure due to the small flow restriction resistance of the water control sieve tube. Therefore, pressure difference is formed at two ends of the packer when the packer is expanded in the presence of liquid, so that water in the water outlet section seeps into the oil outlet section, and sand in the shaft is driven to fall off to form earthworm holes.

The continuous packer water control is a new oil-gas well water control method in recent years. Referring to chinese utility model patent CN2009102507912, CN2014100135988, CN2019100846588, CN2019104892759, etc., the basic principle of the method is to fill packing particles into the shaft to form a continuous packing body, micro-channels inside the continuous packing body formed by micro-pores between the packing particles have a channeling-preventing effect on produced liquid, and further reduce the production of formation water, and can meet the actual application requirements under various well conditions (for example, the shaft diameter is irregular, the shaft has a leak, deformation, cement ring channeling, there is an annulus outside the old screen pipe, there is an annulus outside the perforated pipe, etc.). However, this method still has some disadvantages in application: on one hand, because the continuous packer is bound to have a micro-channel for oil gas to pass through, in order to ensure the smooth production of the oil gas, the resistance of the micro-channel to the flow of produced liquid is not too small, so as to ensure the flow of the produced liquid; on the other hand, because the mobility of water is much higher than that of oil, for a scene that the interval between each section of stratum is small (for example, 2-5 meters), the produced water of a high-water stratum of a local well section in the shaft still flows to the well section of an adjacent stratum structure along the shaft annulus through the micro-channel in the continuous packer body when the flowing water quantity is large. That is, there is still a significant cross-flow of produced water in the wellbore, which may not optimize oil recovery. Specifically, the conventional range of use of packer particles is 16-100 mesh (particle size range 0.15-1.18mm), corresponding to continuous packers with a permeability of 20D-300D, even 20D permeability is still high relative to the formation permeability. For example, a 6-in multi-layer vertical well is run in a 3-1/2in water control screen, filled with continuous packer particles with a permeability of 40D, and a 2 meter long continuous packer annulus (i.e., the continuous packer corresponding to the blind section between two screens) has a flow rate of 29 square/day at a production pressure of 1 MPa. And a flow control screen pipe of 5-1/2in is arranged in a certain horizontal well of 8-1/2in, continuous packer particles with the permeability of 20D are filled, and the flow rate of the continuous packer rings of 2 meters in length is 45 square/day under the production pressure difference of 1 MPa. Therefore, even if the continuous packer is used for controlling water, the interlayer axial channeling flow in the annular space of the well casing is still large, and the packing effect is necessary to be further improved.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects of the prior art, and provides a packer and a packing device which have simple structure, convenient operation, high reliability and good effect of preventing channeling, do not influence the filling of particles of a continuous packing body in a production section and can improve the axial packing effect of the continuous packing body in a shaft along the shaft, a method for improving the axial packing effect of the continuous packing body in the shaft along the shaft, and a well completion structure which can improve the axial packing effect of the continuous packing body in the shaft along the shaft.

In order to realize the purpose, the utility model provides the following technical scheme:

the packer can improve the axial packing effect of a continuous packing body in a shaft along the shaft, is integrally of a cylindrical structure, and has the outer diameter smaller than the diameter of the shaft, so that an annular space formed by the packer and a shaft wall is used as a particle filling channel of the continuous packing body; the axial center of the packer is provided with a center mounting hole for mounting a center pipe column, the outer side of the packer, which is close to two ends, is respectively provided with one or more annular first grooves, and expandable media are arranged in the first grooves; and one or more annular second grooves are formed in the middle of the outer side of the packer.

Furthermore, the middle part of the outer side of the expandable medium bulges upwards and is firstly contacted with the well wall, the contact surface is gradually unfolded to drive the particles to move towards the two ends, and finally, the shape with a high middle part and low two sides is formed. After the expansion medium is completely expanded, the expansion medium can directly contact the well wall, so that particles are hardly generated between the well wall and the expansion medium, and the packing effect is better.

Further, the shape of the upward bulge in the middle of the outer side of the expandable medium is one or more of a triangle, an arc, a semicircle or a trapezoid.

Furthermore, two or more than two first grooves are formed in the outer side of the packer and close to the two ends of the packer; the time for completing expansion of the expandable medium arranged in the first grooves at the outer sides of the two ends is earlier than the time for completing expansion of the expandable medium arranged in the first grooves at the inner sides of the two ends.

In order to achieve the purpose, the utility model also provides the following technical scheme:

the packer device capable of improving the axial packing effect of the continuous packer in the shaft along the shaft comprises the packer and the central pipe column; the central pipe string penetrates through a central mounting hole of the packer and is fixedly connected with the packer.

Furthermore, the packer and the central pipe column are connected and fixed in one or more modes of welding, bolt fixing or clamping piece fixing.

Furthermore, the central pipe column is a short-section blind pipe, and flow control filter pipe strings are installed at two ends of the short-section blind pipe.

a method for improving the axial packing effect of a continuous packer in a shaft along the shaft is provided, wherein the packer is adopted, and comprises the following steps: (1) determining the number and the positions of packers to be set in a shaft; (2) completing the assembly of the packers and the central pipe column according to the number and the positions of the packers determined in the step (1); running a pipe string provided with the packer and the central pipe string into the shaft; (3) filling packing particles into the shaft to form a continuous packing body; (4) expandable media in first grooves, close to two ends, on the outer side of the packer begin to expand, and packing body particles in an expansion area are extruded towards two sides; (5) and after the expandable medium is expanded, the second groove of the packer and the annular space outside the packer form a high-density continuous packer.

a method for improving the packing effect of a continuous packing body in a shaft along the axial direction of the shaft is adopted by the packing device, and the method comprises the following steps: (1) determining the number and the positions of packing devices to be set in a shaft; (2) according to the number and the positions of the packing devices determined in the step (1), lowering a pipe string provided with the packing devices into a shaft; (3) filling packing particles into the shaft to form a continuous packing body; (4) expandable media in first grooves, close to two ends, on the outer side of the packer begin to expand, and packing body particles in an expansion area are extruded towards two sides; (5) and after the expandable medium is expanded, the second groove of the packer and the annular space outside the packer form a high-density continuous packer.

a well completion structure capable of improving the axial packing effect of a continuous packing body in a shaft along the shaft comprises a plurality of central pipe columns which are arranged in the shaft in an end-to-end manner, wherein the continuous packing body is arranged in an annular space between the central pipe columns and the wall of the shaft, and one or more central pipe columns are provided with the packer; and high-density continuous packer bodies are arranged in the second groove of the packer and in the annular space outside the packer.

a well completion structure capable of improving the axial packing effect of continuous packing bodies in a shaft along the shaft comprises a plurality of central pipe columns which are arranged in the shaft in an end-to-end manner, wherein the continuous packing bodies are arranged in an annular space between the central pipe columns and the wall of the shaft, and one or more central pipe columns are the packing devices; and high-density continuous packer bodies are arranged in a second groove of a packer of the packing device and in the annular space outside the packer.

a well completion structure capable of improving the axial packing effect of a continuous packing body in a well bore along the well bore is formed by adopting the method.

The utility model relates to a packer, a method and a well completion structure capable of improving the axial packing effect of a continuous packing body along a shaft.A packer with an expandable function is arranged in the shaft, packing particles are filled before an expandable medium is completely expanded, after the expandable medium is expanded, a gap possibly exists between the expandable packer and the shaft after the expandable packer is completely expanded due to the irregularity of the inner diameter of the shaft of an open hole, but the continuous packing body is filled in the annular space of the packer and the shaft, and the packing particles are extruded after the expandable medium is expanded, so that the generated high-density continuous packing body can be better attached to the wall of a well, thereby realizing better packing effect and reducing the channeling of produced water in the annular space of the shaft; and because the whole annular space is filled with continuous packer particles, no space is left in the annular space for storing the silt generated by the earthworm holes, so that the earthworm holes cannot be formed at two ends of the packer, and the problems of well wall collapse, silt migration and the like cannot be caused. Meanwhile, the diameter of the packer is reduced, more packers can be put into the same shaft, and blocking is not easy to occur; further obtaining better packing effect.

Drawings

FIG. 1 is a schematic cross-sectional view of the overall structure of an initial state of a packer in a wellbore for improving the axial packing effect of a continuous packer along the wellbore in an embodiment of the utility model;

FIG. 2 is a schematic cross-sectional view of the overall structure of a packer for improving the axial packing effect of a continuous packer along a wellbore in an embodiment of the utility model after the packer is expanded in the wellbore in the presence of a fluid;

FIG. 3 is a schematic cross-sectional view of another embodiment of the packer of the present invention showing an overall configuration to enhance the axial packing of the continuous packer along the wellbore;

FIG. 4 is a schematic cross-sectional shape of an expandable medium in an embodiment of the present invention;

FIG. 5 is a schematic cross-sectional view of another embodiment of the packer of the present invention configured to increase the axial packing of a continuous packer along a wellbore;

FIG. 6 is a schematic diagram showing the specific structural dimensions of a packer for increasing the packing effect of a continuous packer along the axial direction of a wellbore in an embodiment of the utility model;

FIG. 7 is a schematic cross-sectional view of an overall configuration of a completion configuration for enhancing the axial packing effect of a continuous packer along a wellbore in an embodiment of the utility model.

Detailed Description

The following further describes specific embodiments of a packer, a method and a completion structure for improving the packing effect of a continuous packer along the axial direction of a wellbore according to the present invention with reference to fig. 1 to 6. It should be noted that the drawings in the specification are only used for visually showing the whole or partial specific features of the technical scheme disclosed in the embodiment, and the proportion or the dimensional structure is not drawn according to the actual product, so that the technical scheme disclosed in the embodiment cannot be specifically limited; the packer, method and completion structure of the present invention for improving the packing effect of a continuous packer along the axial direction of a wellbore are not limited to the description of the following embodiments.

Example 1:

the embodiment provides a packer capable of improving the packing effect of a continuous packer in a shaft along the axial direction of the shaft. As shown in fig. 1, the packer 1 is of a cylindrical structure as a whole, and the axial direction of the cylinder is consistent with the axial direction of a shaft; a central mounting hole 11 for mounting a central pipe column is formed in the axial center of the packer 1; one or more annular first grooves 12 are respectively arranged at positions, close to two ends (namely the upper plane and the lower plane of the cylinder), of the outer side (namely the outer arc surface position of the cylinder) of the packer 1. Specifically, as shown in fig. 1, the cross section of the first groove 12 is rectangular, but may be other shapes, such as triangle, semicircle, trapezoid, etc., or other irregular shapes, as long as the expandable medium 13 can be accommodated and installed, and the present invention is considered to fall within the protection scope of the present invention. One or more first grooves 12 are arranged at two ends of the packer 1, and the number of the first grooves 12 arranged at the two ends can be equal or unequal.

An expandable medium 13 (such as an oil/liquid expandable medium, etc.) is disposed in each first groove 12. Preferably, the bottom (i.e. the position fitting the bottom of the first groove 12) and the side (i.e. the position fitting the side of the first groove 12) of the expandable medium 13 are fitted with the bottom and the side of the first groove 12, so as to ensure that the expandable medium 13 can be firmly and reliably prefabricated in the first groove 12; the outer side (i.e. the side opposite to the bottom) of the expandable medium 13 is flush with or lower than the notch of the first groove 12, so that the expandable medium 13 is prevented from rubbing against the well wall to damage or lose when the packer 1 is used in a well; of course, as an equivalent solution, the outside of the expandable medium 13 may also be slightly higher than the notch of the first groove 12.

One or more annular second grooves 14 are provided in the middle of the outside of the packer 1, i.e. between the first grooves 12 at both ends of the packer 1. The second groove 14 may or may not be located centrally outside the packer 1.

The working process and principle of the packer 1 described in this embodiment are as follows:

after the packer 1 is put into the shaft 2, the shaft 2 is filled with packing particles to form a continuous packer 3. Then, the expandable medium 13 of the packer starts to expand, and packing particles in an expansion area (i.e., a space position occupied by the expanded expandable medium) are extruded to both sides along the axial direction of the shaft. The structure after the expansion is completed is as shown in fig. 2, the expandable medium 13 is extruded on the well wall 21 or the packing particles outside the expandable medium are extruded on the well wall 21, so that a good packing effect is formed; meanwhile, the annular space inside and outside the second groove 14 is filled with packing particles, and more packing particles are squeezed in, so that a high-density packing body 3 with a more compact structure is formed, and the packing effect is further enhanced; the two aspects act together to play a better role in preventing the produced liquid in the annular space of the well casing from flowing along the axial direction 2 of the well casing.

Example 2:

the present embodiment provides another packer capable of improving the packing effect of continuous packer in the well along the axial direction of the well, and as shown in fig. 3, the present embodiment is an improvement of the technology described in embodiment 1, and is different from embodiment 1 in that the middle of the outer side of the expandable medium 13 of the packer 1 is bulged upwards. The advantage of providing the elevations is that on the one hand the elevations may be more favorable for pressing the packing particles to both sides in the axial direction of the wellbore; on the other hand, during the expansion process of the expandable medium, the top of the bulge is firstly contacted with the well wall, so that the packing particles in the extrusion area can further move towards two sides and are stacked, and the structure of the continuous packing body 3 formed by the packing particles filled in the second groove 14 and the annular space outside the second groove is tighter.

The shape of the upward bulge in the middle of the outer side of the expandable medium 13 can be one or more of a triangle, an arc, a semicircle, an ellipse, a trapezoid or an approximate shape, and the expandable medium 13 can directly contact the well wall after being completely expanded, so that packing particles between the well wall and the expandable medium 13 are tighter or almost have no packing particles; the protuberances may be symmetrical structures such as standard semi-circles, trapezoids, etc.; non-symmetrical structures are also possible, such as asymmetrical arcs, right or non-equilateral triangles, right or non-isosceles trapezoids, etc. The smaller the slope (i.e., the angle relative to the axial direction of the wellbore) provided toward the second groove 14, the more packing particles can be squeezed toward the second groove.

Specifically, as shown in the first row shape in fig. 4, the shape in which the outer side of the expandable medium 13 is upwardly bulged includes a semicircular shape, an arc shape, an isosceles trapezoid shape, a triangular shape, a right trapezoid shape, and the like. The ridge can be the whole outer side surface is upward and the middle ridge is highest (as shown in the first row of fig. 4); or only the lateral surface is locally raised (as shown in the second row of fig. 4); alternatively, a plurality of protuberances may be provided on the outer side (as shown in the second row 2, 4 of fig. 4). It should be understood that the specific shape illustrated in fig. 4 is only a specific embodiment provided for explaining the technical idea of the present invention in detail, and should not be construed as a specific limitation of the present invention. It is considered to fall within the scope of the present invention that a slope having a certain slope (whether the slope section is a straight line or a curved line) is provided toward the second groove 14.

Example 3:

the embodiment provides another packer capable of improving the axial packing effect of a continuous packer in a wellbore along the wellbore, as shown in fig. 5, the embodiment is an improvement of the technology described in

embodiment

1 or 2, and is different from embodiment 1 or 2in that two or more first grooves 12 are respectively arranged at positions, close to two ends, outside the packer 1; the time for completing expansion of the expandable medium (first expansion medium 13-1) disposed in the first grooves (first expansion grooves 12-1) at the outer side positions of both ends of the packer 1 (i.e., the first grooves closer to the axial end surfaces (i.e., the upper plane and the lower plane) of the cylinder, which may be one or more grooves) is earlier than the time for completing expansion of the expandable medium (second expansion medium 13-2) disposed in the first grooves (second expansion grooves 12-2) at the inner side positions of both ends (i.e., the first grooves farther from the axial end surfaces of the cylinder, which may be one or more grooves).

This has the advantage that after the swelling of the swellable medium (first swelling medium 13-1) in the first recess (first swelling first recess 12-1) at positions outside the two ends of the packer 1 is completed, the corresponding annulus (including the annulus corresponding to the unexpanded first recess 12 and the annulus corresponding to the second recess 14) and the second recess 14 of the packer 1 can be sealed; then the expandable medium (post-expansion medium 13-2) in the first grooves 12 arranged at the inner side of the two ends begins to expand, and can further press the packing particles in the expansion area to move to the area near the second groove 14, so that the structure of the continuous packing body 3 formed by the packing particles filled in the annular space inside and outside the second groove 14 is tighter.

Example 4:

the embodiment provides a specific structural size of a packer which is used for a 5.5-inch wellbore and can improve the packing effect of continuous packer in the wellbore along the axial direction of the wellbore. As shown in fig. 6, the dimensions marked in the figure are in millimeters and the maximum outer diameter of the packer is 102 millimeters. The diameter of the packer used in this embodiment is significantly reduced compared to the inflatable packers described in the background. For example, if a conventional swell packer is used, its diameter is typically no less than 115 millimeters; the diameter of the packer is only 102 mm by adopting the packer disclosed by the utility model. The reason is that the packer adopted by the embodiment simultaneously adopts the expandable medium and the high-density continuous packer body for sealing, and the sealing effect of the packer is still far higher than that of the traditional large-diameter expandable packer on the premise of greatly reducing the diameter of the packer.

Another benefit of reducing the diameter of the packer is that the probability of plugging during downhole is effectively reduced, allowing more packers to be run into the wellbore. Optimally, one packer can be installed between every two screens, thereby achieving the best packing effect.

Example 5:

the embodiment provides a packing device capable of improving the axial packing effect of a continuous packing body in a shaft along the shaft, wherein the packing device comprises a packer and a central string as described in any one of embodiments 1 to 3; the central pipe column penetrates through the central mounting hole of the packer and is fixedly connected with the packer. Specifically, the packer and the central pipe column are connected and fixed in one or more of welding, bolt fixing or clamping piece fixing modes. Preferably, the central pipe column is a blind pipe with a common length or a short blind pipe.

The advantage of this embodiment is that directly with the packer and the preformed shape of center tubular column described in any of embodiments 1-3 above, can directly assemble in the cluster when using on the spot, the operation is more convenient.

Example 6:

the embodiment provides a method for improving the axial packing effect of a continuous packer in a wellbore along the wellbore, wherein the packer disclosed by any one of embodiments 1 to 3 is adopted, and the method comprises the following steps:

(1) determining the number and the positions of packers to be set in a shaft;

(2) completing the assembly of the packers and the central pipe column according to the number and the positions of the packers determined in the step (1); a pipe string provided with the packer and a central pipe string is put into the shaft (the pipe string refers to an oil production channel which is put into the shaft and consists of a plurality of central pipe strings, and the central pipe string comprises a blind pipe, a sieve pipe and the like);

(3) filling packing particles into a shaft to form a continuous packing body;

(4) expandable media in first grooves at positions, close to two ends, on the outer side of the packer begin to expand, and packing body particles in an expansion area are extruded towards two sides along the axial direction of the packer; wherein the swelling area is an additional volume of space within the wellbore after completion of swelling of the swellable medium relative to an unexpanded state.

(5) And after the expandable medium is expanded, the second groove of the packer and the annular space outside the packer form a high-density continuous packer.

This embodiment has the benefit that the packing particles can be compressed by the expandable medium to form a high density continuous packing body; through the combined action of the expanded expandable medium and the high-density continuous packing body, a better water control effect can be realized.

Example 7:

the embodiment provides a method for improving the packing effect of a continuous packing body in a shaft along the axial direction of the shaft, wherein the packing device according to the embodiment 5 is adopted, and the method comprises the following steps:

(1) determining the number and the positions of packing devices to be set in a shaft;

(2) according to the number and the positions of the packing devices determined in the step (1), a pipe string provided with the packing devices is lowered into a shaft;

(3) filling packing particles into a shaft to form a continuous packing body;

(4) expandable media in the first grooves at the positions, close to the two ends, of the outer side of the packer begin to expand, and particles of the packing body in an expansion area are extruded towards the two sides;

The benefit of this embodiment is that the packing particles can be compressed by the expandable medium to form a high density continuous packing body; through the combined action of the expanded expandable medium and the high-density continuous packing body, a better water control effect can be realized.

Example 8:

the embodiment provides a well completion structure capable of improving the packing effect of continuous packing bodies in a shaft along the axial direction of the shaft, as shown in fig. 7, and comprises a plurality of center pipe columns 4 which are arranged in the shaft 2in an end-to-end mode, and flow control filter pipe strings are arranged at two ends of each center pipe column 4. A continuous packer 5 is arranged in an annular space between the central pipe column 4 and the well wall 21 of the well shaft 2; the one or more central tubular columns 4 are provided with packers 1 as described in any of embodiments 1 to 3; and a high-density continuous packer body 3 is arranged in the second groove 14 of the packer 1 and in the annular space outside the packer 1.

Example 9:

the embodiment provides another well completion structure capable of improving the axial packing effect of continuous packing bodies in a shaft along the shaft, as shown in fig. 7, the well completion structure comprises a plurality of center pipe columns 4 which are arranged in the shaft 2 end to end, and continuous packing bodies 5 are arranged in an annular space between the center pipe columns 4 and a wall 21 of the shaft 2; the one or more central tubular strings are the packoff of embodiment 3; and a high-density continuous packer body 3 is arranged in the second groove 14 of the packer 1 of the packing device and in the annular space outside the packer 1.

Example 10:

this embodiment provides another well completion structure for improving the axial packing effect of the continuous packing in the wellbore, as shown in fig. 7, and the formation process of the well completion structure adopts the method as described in embodiment 6 or 7.

In embodiments 8 to 10, compared to the conventional inflatable packer, the packer (or packing device) used in this embodiment can achieve the features of smaller diameter, less possibility of blockage, etc. while ensuring the packing effect, so that more packers (or packing devices) can be arranged in the string, for example, one packer is arranged between every two screens, thereby dividing the wellbore into a plurality of units with the length close to that of the screens; and the adjacent units do not have a cross flow phenomenon, so that the oil recovery rate of the oil-gas well can be ensured to be optimal.

The utility model relates to a packer, a method and a well completion structure capable of improving the axial packing effect of a continuous packing body along a shaft, which have the following contents and effects of a utility model:

1. the packer occupies a certain wellbore section, but is not permeable by itself;

2. the packer and the continuous packer technology are used together, so that the problem that some packers cannot completely pack the cross section of the shaft is solved;

3. the packer is used independently to form the earthworm hole, the packer and the continuous packer technology are used together, and the continuous packer particles can fill the annular space, so that mud and sand generated by the earthworm hole have no space to be stored, and the earthworm hole cannot be generated;

4. the shape of the expansion medium of the packer can be one or more of triangle, arc, semicircle or trapezoid, and the middle part of the expansion medium can be firstly contacted with the well wall to form a conical structure. Along with the continuous expansion of the expansion medium on the two sides of the conical structure, most of continuous packer particles on the two sides of the conical structure are pushed away between the expansion medium and the well wall, so that the expansion medium of the packer is completely extruded onto the well wall, and the axial channeling is eliminated.

The foregoing is a more detailed description of the utility model in connection with specific preferred embodiments and it is not intended that the utility model be limited to these specific details. For those skilled in the art to which the utility model pertains, several simple deductions or substitutions can be made without departing from the spirit of the utility model, and all shall be considered as belonging to the protection scope of the utility model.

Claims

1. The utility model provides a can improve packer that continuous packer body packed the effect along pit shaft axial in the pit shaft which characterized in that: the whole packer is of a cylindrical structure; a central mounting hole for mounting a central pipe column is formed in the axial center of the packer; one or more annular first grooves are respectively formed in the outer side of the packer close to the two ends, and expandable media are arranged in the first grooves; and one or more annular second grooves are formed in the middle of the outer side of the packer.

2. The packer for improving the packing effect of the continuous packer in the shaft along the axial direction of the shaft as claimed in claim 1, wherein: the middle of the outer side of the expandable medium bulges upward.

3. The packer capable of improving the packing effect of the continuous packer in the shaft along the axial direction of the shaft as claimed in claim 2, wherein: the shape of the upward bulge in the middle of the outer side of the expandable medium is one or more of a triangle, an arc, a semicircle or a trapezoid.

4. The packer for improving the packing effect of the continuous packer in the shaft along the axial direction of the shaft as claimed in claim 1, wherein: two or more first grooves are formed in the outer side of the packer and close to the two ends of the packer; the time for completing expansion of the expandable medium arranged in the first grooves at the outer sides of the two ends is earlier than the time for completing expansion of the expandable medium arranged in the first grooves at the inner sides of the two ends.

5. The utility model provides a can improve packing device that continuous packer separates effect along pit shaft axial in the pit shaft which characterized in that: comprising the packer of any one of claims 1 to 4 and a central string; the central pipe string penetrates through a central mounting hole of the packer and is fixedly connected with the packer.

6. The packing device for improving the axial packing effect of a continuous packing body in a shaft along the shaft according to claim 5, wherein: the packer and the central pipe column are connected and fixed in one or more modes of welding, bolt fixing or clamping piece fixing.

7. The packing device for improving the axial packing effect of a continuous packing body in a shaft along the shaft according to claim 5, wherein: the central pipe column is a short blind pipe.

8. The utility model provides a can improve well completion structure of continuous packer along pit shaft axial packing effect in pit shaft, including setting up a plurality of tubular core of end to end in the pit shaft, be equipped with continuous packer in the annular space between the wall of a well of tubular core and pit shaft, its characterized in that: the packer as claimed in any one of claims 1 to 4 is arranged on the one or more central pipe columns; and high-density continuous packer bodies are arranged in the second groove of the packer and in the annular space outside the packer.

9. The utility model provides a can improve well completion structure of continuous packer along pit shaft axial packing effect in pit shaft, includes a plurality of tubular center posts of end to end that set up in the pit shaft, be equipped with continuous packer in the annular space between the wall of a well of tubular center post and pit shaft, its characterized in that: the one or more centre strings being packing devices according to any one of claims 5 to 7; and high-density continuous packer bodies are arranged in a second groove of a packer of the packing device and in the annular space outside the packer.