CN212837614U - Multi-stage sand-prevention well completion pipe string for oil and gas well - Google Patents

Abstract

The utility model relates to a multistage sand control completion tubular column of oil gas well, including the production tubular column, at least a set of second grade sand control tubular column and one-level sand control tubular column, the production tubular column includes from last to the oil pipe of connecting in proper order down, oil recovery pump and bottom confined tertiary screen pipe, and packer and bottom confined second grade screen pipe are hung including the second grade of being fixed from top to bottom to every group second grade sand control tubular column, a coaxial fixed top confined spiral pipe in the second grade screen pipe, and the outer wall of spiral pipe spirals along its axial and forms the heliciform recess. The first-stage sand control pipe column comprises a first-stage suspension packer and a first-stage sieve pipe with a closed bottom end, wherein the first-stage suspension packer is fixed up and down, and the sand blocking particle size of the first-stage sieve pipe, the second-stage sieve pipe and the third-stage sieve pipe is reduced from bottom to top step by step. The utility model discloses a well completion tubular column can improve the permeability of the outer sand bed of screen pipe, reduces the screen pipe and blocks up the degree, improves sand control effect, extension sand control validity period.

Description

Multi-stage sand-prevention well completion pipe string for oil and gas well

Technical Field

The utility model relates to an oil recovery technology technical field especially relates to a multistage sand control completion tubular column of oil gas well.

Background

Stratum loose sandstone oil and gas reservoirs generally have the problem of stratum sand production in the production process, and matched sand control measures are required to be adopted in order to ensure the normal production of a sand production well. The sand control technology of the sieve tube is the most widely applied sand control technology at present due to simple construction and low cost. The prior screen pipe sand control technology mainly adopts a single-stage sand control mode, namely, a sand control screen pipe is put into an oil interval to prevent formation sand from entering a shaft, and most sand grains are prevented from entering the shaft by designing smaller sand control precision.

However, in an oil layer with poor formation sand separation performance, sand grains with different grain sizes are accumulated on the outer side of the sieve tube, so that a low-permeability mud cake is formed, the circulation of the sand layer is reduced, the yield is reduced, and the effective period of sand prevention is shortened. In addition, in an oil layer with small formation sand, in order to improve the sand control effect, the existing single-stage sieve tube sand control mode requires that high-cost high-quality sieve tubes (such as a sintered screen sieve tube, a sintered particle sieve tube, a metal cotton sieve tube, a gravel pre-packed sieve tube and the like) are arranged in an oil layer section, and the well completion cost is increased. In addition, once the single-stage sand control screen pipe is blocked, the screen pipe needs to be fished out through overhaul, or secondary sand control is carried out after the screen pipe is perforated, and the treatment cost is very high.

Therefore, the inventor provides the multi-stage sand control completion pipe string for the oil and gas well by experience and practice of related industries for many years so as to overcome the defects of the prior art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an oil gas well multistage sand control completion tubular column can improve the permeability of the outer sand bed of screen pipe, reduces the screen pipe and blocks up the degree, improves sand control effect, extension sand control validity period.

The utility model aims at realizing like this, a multistage sand control completion tubular column of oil gas well, include:

the production pipe column comprises an oil pipe, an oil extraction pump and a three-stage sieve pipe with a closed bottom end, which are sequentially connected from top to bottom;

the device comprises a production pipe column, at least one group of secondary sand control pipe columns, a plurality of groups of sand control pipe columns and a plurality of groups of sand control pipe columns, wherein the at least one group of secondary sand control pipe columns are positioned below the production pipe column, each group of secondary sand control pipe columns comprise a secondary suspension packer which is fixed up and down and a secondary screen pipe with a closed bottom end, a spiral pipe with a closed top end is coaxially fixed in the secondary;

and the first-stage sand control pipe column is positioned below the second-stage sand control pipe column and comprises a first-stage suspension packer which is fixed up and down and a first-stage sieve pipe with a closed bottom end, and the sand blocking particle size of the first-stage sieve pipe, the second-stage sieve pipe and the third-stage sieve pipe is gradually reduced from bottom to top.

In a preferred embodiment of the utility model, a baffle is fixed inside the upper end of the second grade sieve tube, the upper end of the spiral tube is fixed with the baffle, and the baffle forms the top end sealing part of the spiral tube; a plurality of overflowing holes are formed in the baffle, and the overflowing holes are distributed around the periphery of the spiral pipe.

The utility model discloses an in the preferred embodiment, be equipped with a set of second grade sand control tubular column altogether.

The utility model discloses an in a preferred embodiment, the fender sand particle diameter of one-level screen pipe is 0.3mm, and the fender sand particle diameter of second grade screen pipe is 0.2mm, and the fender sand particle diameter of tertiary screen pipe is 0.1mm or 0.05 mm.

The utility model discloses an among the preferred embodiment, second grade sand control tubular column is still including connecting the blind stifled second grade of connecting at second grade screen pipe lower extreme, and the blind bottom that blocks up the constitution second grade screen pipe of second grade seals the department.

The utility model discloses an in a preferred embodiment, second grade sand control tubular column still includes the sand setting pipe of connection between second grade screen pipe and second grade blind plug.

The utility model discloses an among the preferred embodiment, the production string is still including connecting the tertiary blind stifled at tertiary screen pipe lower extreme, and one-level sand control tubular column is still including the blind stifled one-level that is located the one-level screen pipe, and tertiary blind stifled and the blind bottom that blocks up and constitute tertiary screen pipe and one-level screen pipe respectively seals the department.

The utility model discloses an in a preferred embodiment, the length of one-level screen pipe is 50 ~ 300m, and the length of second grade screen pipe is 30 ~ 50m, and the length of tertiary screen pipe is 10 ~ 20 m.

In a preferred embodiment of the present invention, the first sieve tube is a slotted sieve tube, the second sieve tube is a sintered sieve tube, and the third sieve tube is a metal wool sieve tube, a sintered particle sieve tube or a gravel pre-packed sieve tube.

In a preferred embodiment of the present invention, the outer diameter of the third sieve tube is smaller than the outer diameter of the second sieve tube, and the outer diameter of the second sieve tube is smaller than the outer diameter of the first sieve tube.

From top to bottom, the utility model provides a well completion tubular column adopts multistage screen pipe combination sand control, utilize the multiple stage filtration principle, through one-level sand control tubular column, the cooperation of at least a set of second grade sand control tubular column and production tubular column, and the fender sand grain diameter of the screen pipe at all levels of control reduces from supreme down step by step, guarantee that every grade of screen pipe all only blocks the sand grain of certain particle diameter scope, and then filter out the sand grain of different particle diameters step by big-to-small, through preventing arranging the combination, make the outer sand bed of screen pipe at all levels pile up not fine and close, keep higher permeability, thereby reduce the degree of blocking up, the sand control effect is improved. Meanwhile, the spiral grooves on the outer wall of the spiral pipe are utilized to enable the fluid to form a rotational flow, so that the blocking degree of the three-stage sieve pipe is further reduced, and the service cycle of the sieve pipe is prolonged. In addition, the third-grade screen pipe and the second-grade screen pipe can be periodically taken out for cleaning or replacement; the first-level sieve tube can be installed in a shaft for a long time, and due to the fact that the sand blocking particle size is large, blockage is not prone to occurring, well repairing operation caused by blockage of the sieve tube can be avoided to a large extent, and the service life of the sieve tube is prolonged.

Drawings

The drawings are only intended to illustrate and explain the present invention and do not limit the scope of the invention. Wherein:

FIG. 1: do the utility model provides a multistage sand control completion tubular column's of oil gas well structural schematic diagram.

FIG. 2: do the utility model provides a production string's structural schematic.

FIG. 3: do the utility model provides a structural schematic diagram of second grade sand control tubular column.

FIG. 4: do the utility model provides a cross-sectional view of second grade sand control tubular column.

FIG. 5: do the utility model provides a structural schematic diagram of one-level sand control tubular column.

The reference numbers illustrate:

1. producing a tubular string; 11. an oil pipe; 12. an oil extraction pump; 13. a third grade sieve tube; 14. third-stage blind plugging;

2. a second-stage sand prevention pipe column; 21. a secondary suspension packer; 22. a second grade sieve tube; 23. a sand setting pipe; 24. secondary blind plugging; 25. a spiral tube; 26. a baffle plate;

3. a first-stage sand control pipe column; 31. a primary suspension packer; 32. a first grade sieve tube; 33. first-stage blind plugging;

4. a sleeve;

5. an oil interval.

Detailed Description

In order to clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in fig. 1 to 5, the present embodiment provides a multistage sand control completion string for oil and gas wells, which comprises a production string 1, at least one set of second-stage sand control string 2 located below the production string 1, and a first-stage sand control string 3 located below the second-stage sand control string 2. The production string 1 comprises an oil pipe 11, an oil extraction pump 12 and a three-stage sieve pipe 13 with closed bottom ends, which are sequentially connected from top to bottom, each group of two-stage sand control string 2 comprises a two-stage hanging packer 21 which is fixed up and down and a two-stage sieve pipe 22 with closed bottom ends, a spiral pipe 25 with closed top end is coaxially fixed in the two-stage sieve pipe 22, and the outer wall of the spiral pipe 25 is spirally wound along the axial direction to form a spiral groove. The first-level sand control pipe column 3 comprises a first-level suspension packer 31 which is fixed up and down and a first-level screen pipe 32 with the bottom end closed, and the sand blocking particle size of the first-level screen pipe 32, the second-level screen pipe 22 and the third-level screen pipe 13 is gradually reduced from bottom to top.

Wherein, second grade hangs packer 21 and first grade and hangs packer 31 and all play the effect of hanging the packer, and specific structure is prior art, and no longer repeated here. When in use, the first-stage sand control pipe column 3 is firstly put in, and is suspended in the casing 4 by the first-stage suspension packer 31 and is positioned at the position of the oil interval 5 of the oil well; then, a secondary sand control pipe column 2 is put in, and is suspended in the casing 4 by a secondary suspension packer 21 and is positioned in the middle of the oil well; and finally, the production pipe column 1 is put in, and the production pipe column is put above the secondary sand control pipe column 2 for a certain distance.

During production, as the sand blocking particle sizes of the first-stage sieve tube 32, the second-stage sieve tube 22 and the third-stage sieve tube 13 are gradually reduced from bottom to top, large-particle sand in fluid is filtered under the sand prevention effect of the first-stage sieve tube 32 after the fluid carries formation sand to enter a shaft; filtering out smaller particle sand while passing through the secondary screen 22; when passing through the three-stage screen 13, smaller sand particles are filtered out, and only the smaller sand particles can pass through and be produced along with the oil production pump 12. In addition, when the fluid passes through the second-level sieve tube 22, the fluid is spirally sprayed out through the spiral grooves on the outer wall of the spiral tube 25 to form a rotational flow, and part of sand grains in the fluid can be separated out under the centrifugal action of the rotational flow, so that the blocking degree of the third-level sieve tube 13 is further reduced.

In the whole production process, the production pipe column 1 and the secondary sand control pipe column 2 can be periodically lifted along with pump checking operation or minor repair operation according to production conditions, and the tertiary screen 13 and the secondary screen 22 are washed or replaced to restore the liquidity of the tertiary screen 13 and the secondary screen 22. For the first-stage sand control tubular column 3, because the sand blocking particle size of the first-stage sieve tube 32 is large, fine sand particles can pass through smoothly, and basically, the blockage can not occur, so that the first-stage sand control tubular column 3 can not be lifted out after being installed in a shaft for a long time, the yield reduction or sieve tube extrusion damage caused by the blockage of the sieve tube can be reduced, the long-time service life can be kept, and the overhaul operation is avoided.

From this, the well completion tubular column in this embodiment adopts multistage screen pipe combination sand control, utilize the multiple stage filtration principle, through one-level sand control tubular column 3, the cooperation of at least a set of second grade sand control tubular column 2 and production tubular column 1, and the fender sand grain size of controlling the screen pipes at all levels reduces from the bottom up step by step, guarantee that each level of screen pipe all blocks the sand grain of certain particle size scope, and then filter out the sand grain of different particle sizes step by step from big to little, through preventing discharging the combination (promptly, prevent that the majority of stratum sand from passing through, only there is few part fine sand along with oil recovery pump 12 discharges), make the outer sand bed of screen pipes at all levels pile up not compactly, keep higher permeability, thereby reduce the degree of blocking, the sand control effect has been improved. Meanwhile, the spiral grooves on the outer wall of the spiral pipe 25 can enable the fluid to form a rotational flow, further reduce the blocking degree of the three-stage sieve pipe 13 and prolong the service life of the sieve pipe. In addition, the tertiary screen 13 and the secondary screen 22 can be periodically pulled out for cleaning or replacement; the first-level sieve tube 32 can be installed in a shaft for a long time, and due to the fact that the sand blocking particle size is large, blockage is not prone to occurring, well repairing operation caused by sieve tube blockage can be avoided to a large extent, and the service life of the sieve tube is prolonged.

In a specific implementation, as shown in fig. 4, a baffle 26 is fixed inside the upper end of the secondary screen 22, the upper end of the spiral pipe 25 is fixed with the baffle 26, and the baffle 26 forms the top end seal of the spiral pipe 25. A plurality of flow holes are formed in the baffle plate 26, and the flow holes are arranged around the periphery of the spiral pipe 25.

The spiral tube 25 may be a solid structure or a hollow structure. Thus, during production, fluid flows through the spiral grooves on the outer wall of the spiral pipe 25 and then flows to the third-stage screen 13 through the overflowing holes on the baffle 26.

In practical application, in order to make the structure simpler and reduce the cost at the same time, as shown in fig. 1, a group of secondary sand control pipe columns 2 is arranged. Of course, other sets of secondary sand control pipe columns 2 may be provided according to actual needs, and this embodiment is only an example.

Further, under the condition that a group of second-level sand control pipe columns 2 are arranged, in order to better ensure the sand control effect, the sand blocking particle size of the first-level sieve pipe 32 is 0.3mm, and coarse sand or medium sand can be prevented from passing through; the sand blocking particle size of the second grade sieve tube 22 is 0.2mm, so that fine sand can be prevented from passing through; the sand blocking particle size of the third grade screen pipe 13 is 0.1mm or 0.05mm, so that fine silt can be prevented from passing through.

During production, the fluid carries formation sand into the wellbore, and under the sand control action of the primary screen 32, coarse sand and medium sand in the fluid are filtered out, and sand grains smaller than 0.3mm are allowed to pass through. Upon passing through the secondary screen 22, the fluid is filtered of fine sand, allowing sand particles smaller than 0.2mm to pass through. While passing through the tertiary screen 13, fine silt in the fluid is filtered out, allowing muddy particles smaller than 0.1mm or 0.05mm to pass through and be produced with the production pump 12. And then realize filtering step by step for the outer sand layer of piling up of screen pipe keeps higher permeability, thereby reduces and blocks up the degree, improves sand control effect.

In more detail, in the petroleum field, from the viewpoint of sand control, formation sands are generally classified into three types according to the particle size range: coarse medium sand (grain diameter is more than 0.25mm), fine sand (grain diameter is more than 0.25mm and more than 0.15mm) and fine silt (grain diameter is more than 0.15mm and more than 0.05 mm). In practice, the formation sand is usually mixed with sand in the three size ranges, and therefore, the design needs to be performed according to the actual size of the formation sand in the existing sand control design.

In the embodiment, the first-stage sieve tube 32, the second-stage sieve tube 22 and the third-stage sieve tube 13 are arranged, the sand blocking particle sizes of the sieve tubes are respectively selected to be 0.3mm, 0.2mm, 0.1mm or 0.05mm, sand grains in the three particle size ranges can be screened out from actual formation sand through the step-by-step filtering of the three sieve tubes, and the sand grains in each range have good uniformity, so that the sand blocking particle sizes of the sieve tubes in different particle size ranges can achieve good sand prevention effect. The pipe column in the embodiment just utilizes the principle and adopts three-stage filtration to screen actual formation sand into sand grains with different grain size ranges step by step, and the sand grains in each grain size range can be well prevented only by using a fixed screen pipe to block the sand grain size.

Therefore, the sand blocking particle size of each grade of sieve tube can be designed into a fixed value, the sand blocking particle size of the sieve tube does not need to be designed for different wells, the workload of sand control design is reduced, and the problem of poor sand control effect caused by unreasonable design is solved.

Further, for convenience of processing and installation, the secondary sand control pipe column 2 further comprises a secondary blind plug 24 connected to the lower end of the secondary sieve pipe 22, and the secondary blind plug 24 forms a bottom end closed part of the secondary sieve pipe 22.

To further slow the plugging of the primary screen 32, the secondary sand control string 2 further includes a sand trap 23 connected between the secondary screen 22 and the secondary blind 24.

Wherein, this sand setting pipe 23 is a cylindric body, and lug connection can collect tertiary spool outside sand grain and earth that falls in the second grade screen pipe 22 lower extreme, can also collect the fluid simultaneously and separate the sand grain under the cyclone centrifugal action of spiral pipe 25, prevents continuation of sand grain and earth from dropping, reduces sand grain and the earth that falls into in the one-level screen pipe 32, further prevents the jam of one-level screen pipe 32, prolongs its live time.

Sand outside the secondary screen 22 falls into the inside of the primary screen 32, and sand deposited inside the primary screen 32 can be washed out by a sand washing operation at the time of later workover. Specifically, the production pipe column 1 and the second-stage sand control pipe column 2 are taken out firstly during later-stage well repair, then an oil pipe is put in, and the first-stage sieve pipe 32 is subjected to sand washing operation through a forward washing sand washing mode of injecting liquid into the oil pipe or a back washing sand washing mode of injecting liquid into an oil sleeve annulus.

Further, in order to facilitate processing and installation, the production string 1 further comprises a third-stage blind plug 14 connected to the lower end of the third-stage sieve tube 13, the first-stage sand control string 3 further comprises a first-stage blind plug 33 located on the first-stage sieve tube 32, and the third-stage blind plug 14 and the first-stage blind plug 33 respectively form the bottom end closed positions of the third-stage sieve tube 13 and the first-stage sieve tube 32.

In practical application, the first-stage sieve tube 32 needs to be arranged corresponding to the position of the oil interval 5 to filter the liquid at the first stage, so that the length of the first-stage sieve tube 32 is generally required to be larger than that of the oil interval 5, and the length of the first-stage sieve tube 32 is 50-300 m for a long well section. The length of the second-grade screen pipe 22 is preferably 30-50 m, and the length of the third-grade screen pipe 13 is preferably 10-20 m.

Because the length of the first-grade screen pipe 32 is longer than that of the second-grade screen pipe 22 and the third-grade screen pipe 13, and the screen pipe consumption is larger, the first-grade screen pipe 32 adopts a slotted screen pipe with good coarse sand prevention and medium sand prevention effects, the second-grade screen pipe 22 adopts a sintered screen pipe with good fine sand prevention effects, and the third-grade screen pipe 13 adopts a metal cotton screen pipe, a sintered particle screen pipe or a gravel pre-packed screen pipe with good fine sand prevention effects.

Therefore, in the embodiment, the characteristics of different screen pipes are utilized to carry out advantage combination, and in the oil layer of fine sand and fine silt, a slotted screen pipe with low price can be adopted to replace a high-grade screen pipe and is installed in the oil layer section 5 (specifically, the first-grade screen pipe 32) with large screen pipe consumption; the high-price high-grade screen pipe is installed in the upper well bore with less screen pipe usage (specifically, the second-grade screen pipe 22 and the third-grade screen pipe 13), and compared with the single-grade screen pipe sand control mode in the prior art, the screen pipe well completion cost can be greatly reduced.

In a possible implementation, the outer diameter of the tertiary screen 13 is smaller than the outer diameter of the secondary screen 22, and the outer diameter of the secondary screen 22 is smaller than the outer diameter of the primary screen 32. Of course, the outer diameter of the sieve tube at each level can be designed according to the requirement, and the utility model discloses do not limit this.

The above description is only exemplary of the present invention, and is not intended to limit the scope of the present invention. Any person skilled in the art should also realize that such equivalent changes and modifications can be made without departing from the spirit and principles of the present invention.

Claims (10)

1. A multi-stage sand control completion string for oil and gas wells, comprising:

the production pipe column comprises an oil pipe, an oil extraction pump and a three-stage sieve pipe with a closed bottom end, which are sequentially connected from top to bottom;

the device comprises a production pipe column, at least one group of secondary sand control pipe columns, a plurality of groups of sand control pipe columns and a plurality of groups of sand control pipe columns, wherein the at least one group of secondary sand control pipe columns are positioned below the production pipe column, each group of secondary sand control pipe columns comprise a secondary suspension packer which is fixed up and down and a secondary screen pipe with a closed bottom end, a spiral pipe with a closed top end is coaxially fixed in the secondary;

and the first-stage sand control pipe column is positioned below the second-stage sand control pipe column and comprises a first-stage suspension packer which is fixed up and down and a first-stage sieve pipe with a closed bottom end, and the sand blocking particle size of the first-stage sieve pipe, the second-stage sieve pipe and the third-stage sieve pipe is gradually reduced from bottom to top.

2. The oil and gas well multistage sand control completion string of claim 1,

a baffle is fixed inside the upper end of the second-stage sieve tube, the upper end of the spiral tube is fixed with the baffle, and the baffle forms the top end sealing part of the spiral tube; a plurality of overflowing holes are formed in the baffle, and the overflowing holes are distributed around the periphery of the spiral pipe.

3. The oil and gas well multistage sand control completion string of claim 1,

a group of secondary sand control pipe columns are arranged.

4. The oil and gas well multistage sand control completion string of claim 3,

the sand blocking particle size of the first-grade sieve tube is 0.3mm, the sand blocking particle size of the second-grade sieve tube is 0.2mm, and the sand blocking particle size of the third-grade sieve tube is 0.1mm or 0.05 mm.

5. The oil and gas well multistage sand control completion string of claim 1,

the second-stage sand control pipe column further comprises a second-stage blind plug connected to the lower end of the second-stage sieve pipe, and the second-stage blind plug forms a bottom end sealing part of the second-stage sieve pipe.

6. The oil and gas well multistage sand control completion string of claim 5,

the second-stage sand control pipe column also comprises a sand setting pipe connected between the second-stage sieve pipe and the second-stage blind plug.

7. The oil and gas well multistage sand control completion string of claim 1,

the production string further comprises a third-stage blind plug connected to the lower end of the third-stage sieve tube, the first-stage sand control string further comprises a first-stage blind plug located on the first-stage sieve tube, and the third-stage blind plug and the first-stage blind plug respectively form the bottom end closed parts of the third-stage sieve tube and the first-stage sieve tube.

8. The oil and gas well multistage sand control completion string of claim 1,

the length of the first-stage sieve tube is 50-300 m, the length of the second-stage sieve tube is 30-50 m, and the length of the third-stage sieve tube is 10-20 m.

9. The oil and gas well multistage sand control completion string of claim 8,

the first-level sieve tube adopts a slotted sieve tube, the second-level sieve tube adopts a sintered filter screen tube, and the third-level sieve tube adopts a metal cotton sieve tube, a sintered particle sieve tube or a gravel pre-filled sieve tube.

10. The oil and gas well multistage sand control completion string of claim 1,

the outer diameter of the third-stage sieve tube is smaller than that of the second-stage sieve tube, and the outer diameter of the second-stage sieve tube is smaller than that of the first-stage sieve tube.

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