CN112012708B - Sand jam prevention soluble bridge plug fracturing process pipe column and construction method thereof - Google Patents

Abstract

The invention relates to a sand jam prevention soluble bridge plug fracturing process pipe column and a construction method thereof, wherein the process pipe column comprises a pipe column body, a perforation part, a setting part, a soluble bridge plug and a soluble displacement sand washing tool, wherein the soluble displacement sand washing tool comprises a soluble rubber plug, a soluble impeller structure and a soluble nozzle which are sequentially connected from the soluble bridge plug to a free end; the soluble rubber plug is used for scraping off residual sand in the well and replacing the residual sand into fracturing cracks; the soluble impeller structure is rotatably connected with the soluble rubber plug and is used for generating vortex to push the sand-carrying liquid; the soluble nozzle is fixedly connected with the soluble impeller structure and used for spraying displacement fluid into the well to wash settled sand; the soluble nozzle, the soluble impeller structure and the soluble rubber plug are all composed of soluble material units. According to the invention, the soluble displacement sand washing tool is used for realizing less displacement liquid amount and high displacement efficiency, ensuring that the soluble bridge plug is smoothly lowered and set, avoiding the influence of the flow conductivity and providing guarantee for obtaining good fracturing effect in the later period.

Description

Sand jam prevention soluble bridge plug fracturing process pipe column and construction method thereof

Technical Field

The invention relates to the technical field of petroleum industry, in particular to a sand jam prevention soluble bridge plug fracturing process pipe column and a construction method thereof.

Background

The conventional oil-gas field horizontal well soluble bridge plug segmented transformation process comprises the steps of putting a soluble bridge plug tool string in a well after well flushing and deeper operation, correcting depth in real time by a magnetic locator, setting the soluble bridge plug, and performing perforation of each cluster in a first section and fracturing construction of an optical sleeve; then, cleaning sand setting in the casing through the displacement fluid, and completing perforation of other sections and fracturing of the optical casing; after fracturing, open flow is carried out, and the remaining parts of the soluble bridge plug are discharged out of the ground; and finally, putting a production string and completing the well.

In the conventional displacement operation process, if the displacement liquid amount is too much, the settled sand near the shaft is pushed to the deep part of the crack, so that the pressure is reduced, the crack near the shaft is closed, and the phenomenon of dumpling making is caused, thereby reducing the productivity of the fracturing well; if the displacement liquid amount is too small, a part of residual sand is slowly deposited in a shaft, and the bridge plug sand blocking accident is easily caused.

Therefore, the inventor provides a sand-block-preventing soluble bridge plug fracturing process pipe column and a construction method thereof by virtue of experience and practice of related industries for many years, so as to overcome the defects in the prior art.

Disclosure of Invention

The invention aims to provide a sand jam prevention soluble bridge plug fracturing process tubular column and a construction method thereof, which can avoid the problems of reduced flow conductivity, sand jam and the like when the displacement fluid volume is too much, realize less displacement fluid volume and high displacement efficiency through a soluble displacement sand flushing tool, ensure the smooth descending and setting of a soluble bridge plug, avoid the influence of flow conductivity and provide guarantee for obtaining good fracturing effect in the later period.

The invention aims to realize the purpose, and the sand blocking prevention soluble bridge plug fracturing process pipe column comprises a pipe column body, a perforation part, a setting part, a soluble bridge plug and a soluble displacement sand washing tool which are sequentially connected, wherein the soluble displacement sand washing tool comprises a soluble rubber plug, a soluble impeller structure and a soluble nozzle which are sequentially connected from the soluble bridge plug to a free end; the soluble rubber plug is used for scraping off residual sand in the well and replacing the residual sand into fracturing cracks; the soluble impeller structure is rotatably connected with the soluble rubber plug and is used for generating vortex to push the sand-carrying fluid; the soluble nozzle is fixedly connected with the soluble impeller structure and used for spraying a displacing liquid into the well to wash settled sand; and a displacement liquid channel is arranged in the soluble rubber plug, the soluble impeller structure and the soluble nozzle in a run-through manner, and the soluble nozzle, the soluble impeller structure and the soluble rubber plug are all formed by soluble material units.

In a preferred embodiment of the present invention, one end of the soluble nozzle, which is away from the soluble impeller structure, is arranged in a closed manner, a nozzle central hole with one open end is axially arranged on the soluble nozzle, a plurality of spray holes are arranged at intervals on a side wall of the nozzle central hole, the spray holes are tangentially arranged along the side wall of the nozzle central hole, the displacement liquid channel is communicated with the spray holes, and the displacement liquid is sprayed into the well through the displacement liquid channel and the spray holes.

In a preferred embodiment of the present invention, the soluble impeller structure includes an impeller body, and a plurality of blades are disposed on an outer wall of the impeller body.

In a preferred embodiment of the present invention, an axially fixed impeller rotating shaft is rotatably disposed in the impeller body, one end of the impeller rotating shaft, which is away from the soluble nozzle, is located at an outer side of the impeller body and forms a connection end, and the connection end is fixedly connected to the soluble rubber plug; and a rotating shaft center hole for passing liquid is axially arranged on the rotating shaft of the impeller.

In a preferred embodiment of the present invention, the connection end of the impeller rotation shaft is hermetically connected with a connection shaft sleeve, the connection shaft sleeve is sleeved with the soluble rubber plug, and the outer wall of the soluble rubber plug is provided with scraping teeth which are obliquely arranged.

In a preferred embodiment of the present invention, the tubular column body is a weighted drill rod, one end of the weighted drill rod, which is far away from the perforation portion, is provided with a magnetic locator, and the magnetic locator is connected with a wellhead power supply through a cable joint and a cable.

In a preferred embodiment of the invention, the perforating part comprises a perforating gun, a first igniter is arranged between the perforating gun and the tubular column body, and the first igniter is connected with a wellhead power supply through a cable joint and a cable.

In a preferred embodiment of the invention, the setting part comprises a setting tool, a second igniter is arranged between the setting tool and the perforation part, and the second igniter is connected with a wellhead power supply through a cable joint and a cable.

In a preferred embodiment of the present invention, the soluble bridge plug comprises a bridge plug body having a side wall provided with bridge plug slips.

The object of the invention can also be achieved by a construction method using the sand-block-prevention soluble bridge plug fracturing process pipe column, which comprises the following steps:

step a, completing first-stage perforation and casing fracturing construction by using a conventional soluble bridge plug fracturing process pipe column;

b, putting the sand-blocking-preventing soluble bridge plug fracturing process pipe column into the well, pumping a displacement fluid, and flushing and displacing the settled sand by the displacement fluid through a soluble displacement sand flushing tool;

step c, after the displacement is finished, pushing the soluble displacement sand washing tool to the tail end of the shaft for natural dissolution;

d, setting the setting part after the soluble bridge plug is put down to reach a preset position, and performing second-stage perforation and casing fracturing construction;

e, after the second-stage fracturing operation is completed, repeating the steps b to d, and continuing the next-stage perforation and casing fracturing construction;

f, after fracturing is completed completely, performing open flow, and discharging fragments of the soluble displacement sand washing tool and the soluble bridge plug tool back to the ground;

and g, putting a subsequent production tool into the well, and completing the well.

In a preferred embodiment of the present invention,

from the above, the sand-block-prevention soluble bridge plug fracturing process pipe column and the construction method thereof provided by the invention have the following beneficial effects:

in the sand jam prevention soluble bridge plug fracturing process tubular column provided by the invention, a soluble displacement sand washing tool is used for carrying out displacement operation, the required displacement liquid amount is small, the displacement efficiency is high, and the influence of an over-displacement phenomenon on the fracturing effect is avoided, so that the yield of an oil-gas well can be effectively improved; the soluble nozzle, the soluble impeller structure and the soluble rubber plug are all formed by soluble material units, can be naturally dissolved in well fluid, and can be used for discharging the residual fragments of the soluble displacement sand washing tool to the ground through open flow after fracturing construction is finished, so that the construction efficiency is high, and the smooth and unimpeded production channel of the sleeve can be ensured; the soluble displacement sand washing tool can ensure that the soluble bridge plug can be smoothly lowered and set, thereby avoiding the influence of the flow conductivity and providing guarantee for obtaining good fracturing effect in the later period; the construction method of the fracturing process pipe column using the sand-blocking-preventing soluble bridge plug is simple, high in construction efficiency and beneficial to popularization and implementation.

Drawings

The drawings are only for purposes of illustrating and explaining the present invention and are not to be construed as limiting the scope of the present invention. Wherein:

FIG. 1: is a schematic diagram of the sand-control soluble bridge plug fracturing process string of the invention.

FIG. 2: is an isometric view of a soluble displacement sand washout tool of the present invention.

FIG. 3: is a side view of the soluble displacement sand wash tool of the present invention.

FIG. 4: is a cross-sectional view a-a in fig. 3.

FIG. 5: is a cross-sectional view B-B in fig. 4.

In the figure:

100. fracturing a process pipe column by using a sand blocking prevention soluble bridge plug;

1. a soluble displacement sand wash tool;

11. a soluble rubber plug; 111. a connecting shaft sleeve; 112. scraping teeth; 113. clamping the convex teeth; 114. connecting a central hole of the shaft sleeve;

12. a soluble impeller structure; 121. an impeller body; 122. a blade; 123. an impeller shaft; 124. a central hole of the rotating shaft;

13. a soluble nozzle; 130. a nozzle central bore; 131. spraying a hole;

2. a soluble bridge plug; 21. a bridge plug body; 22. a bridge plug slip;

3. a setting part; 31. setting a tool; 32. a second igniter;

4. a perforation portion; 41. a perforating gun; 42. a first igniter;

5. a tubular column body;

61. a magnetic locator; 62. a cable joint; 63. and (3) a cable.

Detailed Description

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

The specific embodiments of the present invention described herein are for the purpose of illustration only and are not to be construed as limiting the invention in any way. Any possible variations based on the present invention may be conceived by the skilled person in the light of the teachings of the present invention, and these should be considered to fall within the scope of the present invention. It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "mounted," "connected," and "connected" are to be construed broadly and may include, for example, mechanical or electrical connections, communications between two elements, direct connections, indirect connections through intermediaries, and the like. As used herein, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are for purposes of illustration only and do not denote a single embodiment.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As shown in fig. 1 to 5, the present invention provides a sand-seizing prevention soluble bridge plug fracturing process tubular column 100, which comprises a tubular column body 5, a perforation part 4, a setting part 3, a soluble bridge plug 2 and a soluble displacement sand-washing tool 1 which are connected in sequence, wherein the soluble displacement sand-washing tool 1 comprises a soluble rubber plug 11, a soluble impeller structure 12 and a soluble nozzle 13 which are connected in sequence from the soluble bridge plug 2 to a free end; the soluble rubber plug 11 is used for scraping off residual sand in the well and replacing the residual sand into fracturing cracks; the soluble impeller structure 12 is rotatably connected with the soluble rubber plug 11, and the soluble impeller structure 12 is used for generating vortex to push the sand-carrying liquid; the soluble nozzle 13 is fixedly connected with the soluble impeller structure 12, and the soluble nozzle 13 is used for spraying displacement fluid to wash settled sand in the well; the soluble rubber plug 11, the soluble impeller structure 12 and the soluble nozzle 13 are internally provided with a displacement liquid channel in a through mode, and the soluble nozzle 13, the soluble impeller structure 12 and the soluble rubber plug 11 are all composed of soluble material units. The soluble material unit is a soluble alloy material and is generally prepared by adopting smelting and hot extrusion processes; the structural member made of the soluble alloy material has good solubility, high strength and certain plasticity. The soluble alloy materials have different compositions and different mechanical properties and dissolution rates, and specific materials can be determined according to actual requirements. In a specific embodiment of the invention, the soluble material unit resists the pressure of 80MPa and resists the temperature of 50-120 ℃, and can be completely dissolved after being soaked in the fracturing fluid at the temperature of 90 ℃ for 15 days, and the dissolved residue is granular or flocculent solid phase substances.

In the sand jam prevention soluble bridge plug fracturing process tubular column provided by the invention, a soluble displacement sand washing tool is used for carrying out displacement operation, the required displacement liquid amount is small, the displacement efficiency is high, and the influence of an over-displacement phenomenon on the fracturing effect is avoided, so that the yield of an oil-gas well can be effectively improved; the soluble nozzle, the soluble impeller structure and the soluble rubber plug are all formed by soluble material units, can be naturally dissolved in well fluid, and can be used for discharging the residual fragments of the soluble displacement sand washing tool to the ground through open flow after fracturing construction is finished, so that the construction efficiency is high, and the smooth and unimpeded production channel of the sleeve can be ensured; the soluble displacement sand washing tool can ensure that the soluble bridge plug can be smoothly lowered and set for sealing by displacement operation, thereby avoiding the influence of the flow conductivity and providing guarantee for obtaining good fracturing effect in the later period.

Further, as shown in fig. 2, 4, and 5, one end (i.e., a free end) of the soluble nozzle 13 away from the soluble impeller structure 12 is disposed in a closed manner, a nozzle center hole 130 with one end open is axially disposed on the soluble nozzle 13, a plurality of nozzle holes 131 are disposed at intervals on a sidewall of the nozzle center hole 130, the nozzle holes 131 are tangentially disposed along the sidewall of the nozzle center hole 130, a displacement fluid channel (the nozzle center hole 130 belongs to a part of the displacement fluid channel) is disposed in communication with the nozzle holes 131, and the displacement fluid is injected into the well through the displacement fluid channel and the nozzle holes 131. In one embodiment of the present invention, 8 orifices 131 are spaced on the sidewall of the soluble nozzle 13. The displacing liquid can be uniformly sprayed into the well through the plurality of spray holes 131 to uniformly wash the settled sand of the casing.

Further, as shown in fig. 2 and 4, the soluble impeller structure 12 includes an impeller body 121, and a plurality of blades 122 are provided on an outer wall of the impeller body 121. In the present embodiment, a nozzle female screw is provided at one end of the soluble nozzle 13, and an impeller male screw capable of being hermetically connected to the nozzle female screw is provided on an outer wall at one end of the impeller body 121.

Further, as shown in fig. 2 and 4, an impeller rotating shaft 123 fixed axially is rotatably disposed in the impeller body 121, one end of the impeller rotating shaft 123 far away from the soluble nozzle 13 is located outside the impeller body 121 and forms a connecting end, and the connecting end is fixedly connected with the soluble rubber plug 11; the impeller shaft 123 is provided with a shaft center hole 124 for passing liquid along the axial direction. The soluble rubber plug 11 is mainly used for axially scraping off residual sand in a well and replacing the residual sand into a fracturing crack, and the movement of the soluble rubber plug is axial movement; the soluble impeller structure 12 generates vortex under the impact of liquid in the well to push sand-carrying liquid, the movement of the soluble impeller structure is mainly circumferential rotation, and the impeller rotating shaft 123 can realize the relative rotation between the soluble impeller structure 12 and the soluble rubber plug 11.

Further, as shown in fig. 2 and 4, the connection end of the impeller rotation shaft 123 is connected with a connection shaft sleeve 111 in a sealing manner, the connection shaft sleeve 111 is sleeved with a soluble rubber plug 11, and the outer wall of the soluble rubber plug 11 is provided with a scraping tooth 112 which is arranged in an inclined manner. The soluble rubber plug 11 is mainly used for axially scraping off residual sand in a well and replacing the residual sand in a fracturing crack, the movement of the soluble rubber plug is axial movement, the connecting shaft sleeve 111 is connected with the impeller rotating shaft 123, the impeller rotating shaft 123 can be kept circumferentially immobile, and the impeller body 121 can rotate relative to the impeller rotating shaft 123 under the liquid flow impact effect, so that the relative rotation of the soluble impeller structure 12 relative to the soluble rubber plug 11 is realized.

In this embodiment, as shown in fig. 2 and 4, the outer wall of the connecting shaft sleeve 111 is provided with a convex clamping convex tooth 113, the inner wall of the soluble rubber plug 11 is provided with a clamping groove capable of being clamped on the clamping convex tooth 113, and the soluble rubber plug 11 is connected to the outer wall of the connecting shaft sleeve 111 through the clamping groove and the clamping convex tooth.

Further, as shown in fig. 2 and 4, the connecting bushing 111 is provided with a connecting bushing central hole 114 which is axially penetrated, and the connecting bushing central hole 114 is used for the circulation of the displacement fluid; one end of the central hole 114 of the connecting sleeve, which is close to the soluble impeller structure 12, is provided with a connecting sleeve internal thread, and the connecting end of the impeller rotating shaft 123 is provided with a connecting end external thread matched with the connecting sleeve internal thread.

Further, as shown in fig. 2 and 4, a nozzle center hole 130 is axially provided in the soluble nozzle 13, and an impeller structure center hole is axially provided to penetrate through the soluble impeller structure 12, in this embodiment, the rotating shaft center hole 124 constitutes an impeller structure center hole; the inner part of the soluble rubber plug 11 is provided with a central rubber plug hole in a through manner along the axial direction, and in the embodiment, the inner cavity of the soluble rubber plug 11 is communicated with the central connecting shaft sleeve hole 114 to form a central rubber plug hole; the central hole of the rubber plug, the central hole of the impeller structure and the central hole of the nozzle are communicated to form a displacement liquid channel.

Further, as shown in fig. 1, the pipe column body 5 is a weighted drill rod, one end of the weighted drill rod, which is far away from the perforation part 4, is provided with a magnetic locator 61, the magnetic locator 61 is connected with a wellhead power supply (prior art) through a cable joint 62 and a cable 63, and the magnetic locator is used for performing real-time depth correction on the underground well to ensure that the setting position is accurate. The weight per unit length of weighted drill pipe, which is a heavy pipe wall body with elongated joints, is moderate for components on a drill string. The weighted drill pipe has an outer diameter as large as a standard drill pipe to facilitate operation of the drilling machine. The weighted drill pipe is characterized by being capable of bearing pressure like a drill collar. One unique characteristic of the weighted drill rod is that the middle part of the drill rod is provided with a wear-resistant belt. The wear-resistant belt can play the role of a stabilizer, the rigidity of the weighted drill rod in a drill string is improved, and well deviation is reduced.

Further, as shown in fig. 1, the perforating part 4 comprises a perforating gun 41, a first igniter 42 is arranged between the perforating gun 41 and the tubular column body 5, and the first igniter 42 is connected with a wellhead power supply through a cable joint 62 and a cable 63.

Further, as shown in fig. 1, the setting part 3 comprises a setting tool 31, a second igniter 32 is arranged between the setting tool 31 and the perforation part 4, and the second igniter 32 is connected with a wellhead power supply through a cable connector 62 and a cable 63. The setting tool may be an existing tool that is set by firing.

Further, as shown in fig. 1, the soluble bridge plug 2 includes a bridge plug body 21, and bridge plug slips 22 are provided on the side wall of the bridge plug body 21. In a specific embodiment of the invention, the bridge plug slips 22 are made of ceramic materials, the bridge plug body 21 is made of soluble material units, the soluble material units resist pressure of 80MPa and resist temperature of 50-120 ℃, and can be completely dissolved after being soaked in 90 ℃ fracturing fluid for 15 days, and the dissolved residues are granular or flocculent solid-phase substances.

The invention also provides a construction method for fracturing a process string 100 by using the sand-control soluble bridge plug, which comprises the following steps:

step a, completing first-stage perforation and casing fracturing construction by using a conventional soluble bridge plug fracturing process pipe column (the prior art);

specifically, after a well is flushed and deeper operation is carried out, a conventional soluble bridge plug fracturing process pipe column is put into the casing, the bridge plug of the conventional soluble bridge plug fracturing process pipe column is set, the pressure test of the bridge plug is 40MPa, the pressure is stabilized for 20min, then perforation is carried out, after the perforation is finished, the rest tool strings (cables, conventional pipe columns, perforating guns and the like) are released and taken out of a well mouth, fracturing fluid is injected into the casing, and fracturing operation is carried out.

B, lowering the sand blocking prevention soluble bridge plug fracturing process pipe column 100 into the well, pumping a standard amount of displacement fluid, and flushing and displacing the settled sand by the displacement fluid through a soluble displacement sand flushing tool 1;

specifically, the displacement fluid passes through the displacement fluid channel and then is sprayed out through a soluble nozzle 13 at the front end (the front end in the present text refers to the direction of the free end of the soluble nozzle in fig. 1) to flush the settled sand in the casing; the soluble impeller structure 12 positioned in the middle drives the soluble nozzle 13 at the front end to rotate under the flushing of the displacement liquid, generates vortex in the sleeve and pushes the sand-carrying liquid; the soluble rubber plug 11 positioned at the rear end pushes the sand-carrying liquid in the casing, scrapes off the residual sand in the casing, pushes the residual sand in the casing into the stratum and prevents the residual sand from depositing at the bottom of the well to form sand blocking;

step c, after the displacement is finished, pushing the soluble displacement sand washing tool 1 to the tail end of the shaft for natural dissolution;

d, after the soluble bridge plug 2 is lowered to a preset position, setting the setting part 3, and performing second-stage perforation and casing fracturing construction;

specifically, the soluble bridge plug 2 is smoothly put into a preset position through the flushing and the displacing of the settled sand by the soluble displacement sand flushing tool 1, the second igniter 32 is ignited, the setting tool is set, and the soluble bridge plug 2 can be smoothly set; and (3) testing the pressure of the soluble bridge plug 2 at 40MPa, stabilizing the pressure for 20min, lifting the cable 63 to enable the perforating gun 41 to reach a preset position and correcting the depth, igniting the first igniter 42, perforating the perforating gun 41, releasing the perforating gun 41 and the parts above to be out of a well mouth after perforating is finished, injecting fracturing fluid into the sleeve, and performing fracturing operation.

E, after the second-stage fracturing operation is completed, repeating the steps b to d, and continuing the next-stage perforation and casing fracturing construction;

f, after fracturing is completed completely, performing open flow, and discharging fragments of the soluble displacement sand washing tool and the soluble bridge plug tool back to the ground;

and g, putting a subsequent production tool into the well, and completing the well.

From the above, the sand-block-prevention soluble bridge plug fracturing process pipe column and the construction method thereof provided by the invention have the following beneficial effects:

in the sand jam prevention soluble bridge plug fracturing process tubular column provided by the invention, a soluble displacement sand washing tool is used for carrying out displacement operation, the required displacement liquid amount is small, the displacement efficiency is high, and the influence of an over-displacement phenomenon on the fracturing effect is avoided, so that the yield of an oil-gas well can be effectively improved; the soluble nozzle, the soluble impeller structure and the soluble rubber plug are all formed by soluble material units, can be naturally dissolved in well fluid, and can be used for discharging the residual fragments of the soluble displacement sand washing tool to the ground through open flow after fracturing construction is finished, so that the construction efficiency is high, and the smooth and unimpeded production channel of the sleeve can be ensured; the soluble displacement sand washing tool can ensure that the soluble bridge plug can be smoothly lowered and set, thereby avoiding the influence of the flow conductivity and providing guarantee for obtaining good fracturing effect in the later period; the construction method of the fracturing process pipe column using the sand-blocking-preventing soluble bridge plug is simple, high in construction efficiency and beneficial to popularization and implementation.

The above description is only an exemplary embodiment of the present invention, and is not intended to limit the scope of the present invention. Any equivalent changes and modifications that can be made by one skilled in the art without departing from the spirit and principles of the invention should fall within the protection scope of the invention.

Claims (8)

1. The anti-sand-blocking soluble bridge plug fracturing process pipe column is characterized by comprising a pipe column body, a perforation part, a setting part, a soluble bridge plug and a soluble displacement sand washing tool which are sequentially connected, wherein the soluble displacement sand washing tool comprises a soluble rubber plug, a soluble impeller structure and a soluble nozzle which are sequentially connected from the soluble bridge plug to a free end; the soluble rubber plug is used for scraping off residual sand in the well and replacing the residual sand into fracturing cracks; the soluble impeller structure is rotatably connected with the soluble rubber plug and is used for generating vortex to push the sand-carrying fluid; the soluble nozzle is fixedly connected with the soluble impeller structure and used for spraying a displacing liquid into the well to wash settled sand; a displacement liquid channel is arranged in the soluble rubber plug, the soluble impeller structure and the soluble nozzle in a run-through manner, and the soluble nozzle, the soluble impeller structure and the soluble rubber plug are all formed by soluble material units;

the soluble impeller structure comprises an impeller body, and a plurality of blades are arranged on the outer wall of the impeller body;

the impeller body can be rotatably provided with an axially fixed impeller rotating shaft in a penetrating manner, one end of the impeller rotating shaft, which is far away from the soluble nozzle, is positioned on the outer side of the impeller body and forms a connecting end, and the connecting end is fixedly connected with the soluble rubber plug; and a rotating shaft center hole for passing liquid is axially arranged on the rotating shaft of the impeller.

2. The sand control soluble bridge plug fracturing process string as recited in claim 1, wherein an end of the soluble nozzle, which is far away from the soluble impeller structure, is arranged in a closed manner, a nozzle center hole with an open end is axially arranged on the soluble nozzle, a plurality of spray holes are arranged on a side wall of the nozzle center hole at intervals, the spray holes are tangentially arranged along the side wall of the nozzle center hole, the displacement fluid channel is communicated with the spray holes, and the displacement fluid is sprayed into the well through the displacement fluid channel and the spray holes.

3. The fracturing process string of claim 1, wherein the connection end of the impeller rotating shaft is hermetically connected with a connection shaft sleeve, the connection shaft sleeve is sleeved with the soluble rubber plug, and the outer wall of the soluble rubber plug is provided with scraping teeth in an inclined manner.

4. The sand control soluble bridge plug frac process string as recited in claim 1 wherein said string body is a weighted drill pipe, said weighted drill pipe having a magnetic locator disposed at an end thereof remote from said perforation, said magnetic locator connected to a wellhead power source via a cable connection and a cable.

5. The sandcard resistant soluble bridge plug frac process string of claim 1, wherein said perforating section comprises a perforating gun, said perforating gun being positioned between said perforating gun and said string body, said first igniter being connected to a wellhead power supply by a cable connection, a cable.

6. The sand control soluble bridge plug fracturing process string of claim 1, wherein the setting section comprises a setting tool, a second igniter is arranged between the setting tool and the perforation section, and the second igniter is connected with a wellhead power supply through a cable joint and a cable.

7. The sand control soluble bridge plug frac process string as recited in claim 1 wherein said soluble bridge plug comprises a bridge plug body having a side wall on which is disposed a bridge plug slip.

8. A method of construction using a sand control soluble bridge plug frac process string according to any one of claims 1 to 7, comprising the steps of:

step a, completing first-stage perforation and casing fracturing construction by using a conventional soluble bridge plug fracturing process pipe column;

b, putting the sand-blocking-preventing soluble bridge plug fracturing process pipe column into the well, pumping a displacement fluid, and flushing and displacing the settled sand by the displacement fluid through a soluble displacement sand flushing tool;

step c, after the displacement is finished, pushing the soluble displacement sand washing tool to the tail end of the shaft for natural dissolution;

d, setting the setting part after the soluble bridge plug is put down to reach a preset position, and performing second-stage perforation and casing fracturing construction;

e, after the second-stage fracturing operation is completed, repeating the steps b to d, and continuing the next-stage perforation and casing fracturing construction;

f, after fracturing is completed completely, performing open flow, and discharging fragments of the soluble displacement sand washing tool and the soluble bridge plug tool back to the ground;

and g, putting a subsequent production tool into the well, and completing the well.

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