CN114718473A - Fracturing sand prevention integrated process pipe column capable of preventing erosion and deep backwashing well and operation method thereof - Google Patents

Abstract

The invention provides a fracturing sand control integrated process pipe column capable of preventing erosion and deep backwashing and an operation method thereof. The invention can realize fracturing and self-spraying production once by one time of the pipe column, and can greatly reduce the construction cost; the invention prevents blowout accidents caused by erosion damage of the valve clack of the safety valve in the fracturing process by using a special safety valve protection mechanism, realizes the backwashing of the whole tubular column by adopting a deep backwashing device, and reduces the risk of sand blocking of the tubular column to the maximum extent.

Description

Fracturing sand prevention integrated process pipe column capable of preventing erosion and deep backwashing well and operation method thereof

Technical Field

The invention relates to the technical field of petroleum and natural gas exploitation, in particular to a fracturing sand prevention integrated process pipe column capable of preventing erosion and deeply backwashing a well and an operation method thereof.

Background

For low-permeability non-loose oil reservoirs, fracturing is a common production increasing mode, sand is not produced mostly after fracturing, for wells with higher formation pressure coefficients, a proppant is embedded into the formation after fracturing, the formation permeability is greatly improved, and the production of a self-injection well after fracturing is a production increasing mode frequently selected by the wells.

The conventional fracturing string can only perform fracturing, and the fracturing string is lifted out and then put into a production string after fracturing, namely the fracturing string and the production string are carried out in two times. For the fracturing production process, in order to prevent blowout, a production pipe column is connected with a safety valve and a packer which has a locking structure and can seal the oil sleeve annulus, because the inner diameter of the safety valve is smaller than the inner diameter of an oil pipe, the diameter of the safety valve is reduced in the pipe column, the reduced diameter part is strongly eroded by fracturing fluid in the large-discharge fracturing construction process, the sand ratio concentration in the fracturing fluid is higher and can reach 50 percent at most, under the erosion of the fracturing fluid with high sand ratio, a valve clack of the safety valve is seriously damaged and destroyed, the sealing with a valve seat is lost, and in the later-stage production process, if blowout occurs, the well control failure can be caused by the sealing failure of the safety valve, so that accidents are caused. On the other hand, the fracturing production string is provided with a backwashing valve above the packer, when the string encounters a sand jam, a well can be backwashed, the backwashing valve of the existing string can only wash the string above the topmost packer of the string, the string below the packer cannot be washed, especially, sand between the layered packer and the sand blaster cannot be washed, the outer diameter of each layer of packer is the maximum outer diameter of the whole string, sand and the sand jam are most easily accumulated at the position, if the packer cannot be washed, the string is easily jammed by the sand, and once the sand jam occurs, the success rate of releasing the jam only by the backwashing well is lower.

In view of the above problems, there is an urgent need for a fracturing production string that can prevent the safety valve from being eroded during the fracturing process, and can deeply flush the outside of the string by backwashing the well when the string is stuck.

Disclosure of Invention

The invention overcomes the defects in the prior art, and the problems that the safety valve is easy to erode, the pipe column cannot go deep into a backwashing well when being blocked and the outer side of the pipe column cannot be completely flushed exist in the conventional fracturing sand prevention integrated pipe column, so that the fracturing sand prevention integrated process pipe column capable of preventing erosion and deeply backwashing the well and the operation method thereof are provided, and the fracturing sand prevention integrated process pipe column can realize fracturing and self-spraying production in one time and greatly reduce the construction cost; the invention prevents blowout accidents caused by erosion damage of the valve clack of the safety valve in the fracturing process by using a special safety valve protection mechanism.

The purpose of the invention is realized by the following technical scheme.

The integrated fracturing sand control process pipe column capable of preventing erosion and deep backwashing comprises a well control part, an erosion prevention part, a deep backwashing part and a layered fracturing part, wherein the well control part comprises a safety valve with a valve clack, an upper hydraulic anchor and an annular packer, the erosion prevention part comprises an upper sealing barrel, a hollow insertion pipe and a lower sealing barrel, the deep backwashing part comprises a deep flushing valve, a flushing differential pressure rupture disc, a flushing water outlet and an inserted seal in an oil pipe, and the layered fracturing part comprises a Y344 packer, a ball throwing and sand blasting sliding sleeve, a normally open sand blasting sliding sleeve, a lower hydraulic anchor and a check valve ball seat;

the upper part of the safety valve with the valve clack is connected with the upper sealing cylinder, the lower part of the safety valve with the valve clack is connected with the lower sealing cylinder, a hollow insertion pipe limiting step is formed on the inner wall of the upper sealing cylinder, the hollow insertion pipe is inserted into the upper sealing cylinder, the safety valve with the valve clack and the lower sealing cylinder from top to bottom, a limiting reducing section is formed on the upper part of the outer wall of the hollow insertion pipe, the limiting reducing section and the hollow insertion pipe limiting step are utilized to realize the position limitation of the hollow insertion pipe inserted into the upper sealing cylinder, namely the hollow insertion pipe cannot move downwards relative to the upper sealing cylinder and can only move upwards, the upper hydraulic anchor and the deep well washing valve are sequentially installed on the lower sealing cylinder from top to bottom, a well washing through hole is formed on the outer wall of the upper part of the deep well washing valve, and the well washing differential pressure breaking disc is installed at the well washing through hole, the tail end of the deep well-flushing valve forms a large-size connecting thread and a small-size connecting thread, the small-size connecting thread is positioned on the inner side of the large-size connecting thread, the large-size connecting thread is connected with the annular packer through a tubing string, the well-flushing water outlet is formed on the oil pipe string below the annular packer, the small-size connecting thread is inserted into the oil pipe through the small oil pipe and is connected with the oil pipe in a sealing manner, the Y344 packers are uniformly arranged in an annular space between the tubing string and the casing pipe below the insertion seal in the tubing from top to bottom to divide the annular space into a plurality of fracturing layers, the normally open sand blasting sliding sleeves are arranged on the oil pipe string positioned on the lowest fracturing layer, the ball throwing sand blasting sliding sleeves are arranged in the layer positions above the normally open sand blasting sliding sleeves, the lower hydraulic anchor and the check valve ball seat are sequentially arranged on the oil pipe string below the normally-open sand blasting sliding sleeve from top to bottom.

O-shaped rings are arranged on the outer walls of the head end and the tail end of the hollow insertion tube to realize the matching and sealing of the hollow insertion tube and the upper sealing cylinder as well as the lower sealing cylinder.

And a sealing module is arranged on the outer side of the insertion seal in the oil pipe, and the insertion seal in the oil pipe is matched with the inner wall of the oil pipe string to realize sealing through the sealing module.

Along with the increase of the number of fracturing layers, the quantity of the ball throwing sand blasting sliding sleeves correspondingly increases, and the inner diameters of the ball throwing sand blasting sliding sleeves arranged from top to bottom are reduced in sequence.

The check valve ball seat consists of a ball seat and a soluble ball.

The operation method of the fracturing sand control integrated process pipe column capable of preventing erosion and deep backwashing well comprises the following steps:

step 1, putting the fracturing sand prevention integrated process pipe column into the underground, setting an annular packer in a rotating and pressing mode, and performing upper annular pressing and seal checking;

2, putting the soluble ball into the fracturing sand prevention integrated process pipe column, and enabling the soluble ball to fall onto a check valve ball seat so as to seal a plurality of fracturing layers;

step 3, performing sand fracturing on the fracturing layer at the lowest layer through a normally-open sand blasting sliding sleeve, wherein during fracturing, because the pressure in the oil pipe string is higher than the pressure in the sleeve, each Y344 packer is in a setting state, so that fracturing of the target layer is realized, and other layers are not fractured;

step 4, throwing balls into the fracturing sand prevention integrated process pipe column, enabling the balls to fall into a ball throwing sand blasting sliding sleeve, throwing hydraulic pressure into the fracturing sand prevention integrated process pipe column, and starting a ball throwing sliding sleeve type sand blaster;

step 5, performing sand blasting fracturing on the fracturing layer above the lowest layer, wherein the pressure in the oil pipe string is higher than the pressure in the sleeve during fracturing, at the moment, each Y344 packer still plays a layering role, and repeating the steps 4-5 until all fracturing layers are subjected to sand blasting fracturing;

step 6, fishing the safety valve inner protective sleeve with the valve clack by killing well, and carrying out open flow and self-flow production;

step 7, after the self-injection production is finished, hydraulic pressure is applied to the annulus above the annulus packer, a well-flushing differential pressure rupture disc of the deep backwashing valve is opened, at the moment, the pressure in the oil pipe string is no longer far greater than the pressure of the casing pipe, the Y344 packer is in an unset state, the annulus between the oil pipe string and the casing pipe is no longer sealed, deep backwashing operation is carried out, and the fracturing sand control integrated process pipe column is taken out after the backwashing operation is finished;

and 8, lowering a well completion string and an electric submersible pump production string.

The invention has the beneficial effects that: the invention can realize fracturing and self-spraying production once by one time of the pipe column, and can greatly reduce the construction cost; the invention prevents blowout accidents caused by erosion damage of the valve clack of the safety valve in the fracturing process by using a special safety valve protection mechanism.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic structural view of the deep backwash well of the present invention;

in the figure: 1 is a wellhead; 2 is a tubing string; 3 is an upper sealing cylinder; 4 is a hollow cannula; 5 is a safety valve with a valve clack; 6 is a lower sealing cylinder; 7 is a water feeding anchor; 8 is a deep well-flushing valve; 9 is a well-flushing differential pressure rupture disc; 10 is an annular packer; 11 is a well-flushing water outlet; 12, inserting a seal into the oil pipe; 13 is a Y344 packer; 14, a ball throwing and sand blasting sliding sleeve; 15, fracturing to form cracks; 16 is a normally open type sand blasting sliding sleeve; 17 is a lower hydraulic anchor; 18 is a check valve ball seat; and 19 is a sleeve.

For a person skilled in the art, other relevant figures can be obtained from the above figures without inventive effort.

Detailed Description

The technical solution of the present invention is further illustrated by the following specific examples.

The fracturing sand control integrated process pipe column capable of preventing erosion and deep backwashing comprises a well control part, an erosion prevention part, a deep backwashing part and a layered fracturing part, wherein the well control part comprises a safety valve 5 with a valve clack, an upper hydraulic anchor 7 and an annular packer 10, the erosion prevention part comprises an upper sealing barrel 3, a hollow insertion pipe 4 and a lower sealing barrel 6, the deep backwashing part comprises a deep flushing valve 8, a flushing differential pressure rupture disc 9, a flushing water outlet 11 and an oil pipe inserted seal 12, and the layered fracturing part comprises a Y344 packer 13, a ball throwing and sand blasting sliding sleeve 14, a normally open sand blasting sliding sleeve 16, a lower hydraulic anchor 17 and a check valve ball seat 18;

the upper part of a safety valve 5 with a valve clack is connected with an upper sealing barrel 3, the lower part of the safety valve 5 with the valve clack is connected with a lower sealing barrel 6, a hollow insertion pipe limiting step is formed on the inner wall of the upper sealing barrel 3, the hollow insertion pipe 4 is inserted into the upper sealing barrel 3, the safety valve 5 with the valve clack and the lower sealing barrel 6 from top to bottom, a limiting reducing section is formed at the upper part of the outer wall of the hollow insertion pipe 4, the limiting reducing section and the hollow insertion pipe limiting step are utilized to limit the position of the hollow insertion pipe 4 inserted into the upper sealing barrel 3, namely the hollow insertion pipe 4 cannot move downwards relative to the upper sealing barrel 3 and can only move upwards, and because liquid is injected into the stratum in the fracturing process, the hollow insertion pipe 4 is limited by the upper sealing barrel 3 and cannot move downwards, and meanwhile, because of being sealed with the upper sealing barrel 3 and the lower sealing barrel 6, the fracturing liquid is prevented from entering the inside of the safety valve 5 with the valve clack, so that the safety valve 5 with the valve clack cannot be eroded and damaged;

an upper hydraulic anchor 7 and a deep well-flushing valve 8 are sequentially arranged on a lower sealing barrel 6 from top to bottom, a well-flushing through hole is formed on the outer wall of the upper part of the deep well-flushing valve 8, a well-flushing differential pressure rupture disc 9 is arranged at the well-flushing through hole, a large-size connecting thread and a small-size connecting thread are formed at the tail end of the deep well-flushing valve 8, the small-size connecting thread is positioned on the inner side of the large-size connecting thread, the large-size connecting thread is connected with an annular packer 10 through a tubing string 2, a well-flushing water outlet 11 is formed on the tubing string 2 below the annular packer 10, the small-size connecting thread is connected with an insertion seal 12 in the tubing through a small tubing string, when a well needs to be backflushed, annular pressure is firstly suppressed, the well-flushing differential pressure rupture disc 9 is crushed, well-flushing liquid enters the annular packer 10 from the well-flushing differential pressure rupture disc 9 and enters an annulus between the insertion seal 12 in the tubing, and finally flows out from a water outlet hole 11 of the well-flushing valve, flushing the shaft below the annular packer 10, and performing deep backwashing according to the principle shown in FIG. 2, wherein the deep flushing valve 8 and the inner part of the inserted seal 12 in the oil pipe are through holes, so that a channel for injection and production is provided for fracturing and production;

y344 packers 13 are uniformly arranged in an annular space between an oil pipe string 2 below an inserted seal 12 in an oil pipe and a sleeve 19 from top to bottom, the annular space is divided into a plurality of fracturing layers, a normally open type sand blasting sliding sleeve 16 is installed on the oil pipe string 2 positioned on the lowermost fracturing layer, the normally open type sand blasting sliding sleeve 16 is used as a sand blasting sliding sleeve of the lowermost fracturing layer and can be used for directly carrying out fracturing construction, ball throwing and sand blasting sliding sleeves 14 are installed in layers above the normally open type sand blasting sliding sleeve 16, and a hydraulic anchor 17 and a check valve ball seat 18 are sequentially arranged on the oil pipe string 2 below the normally open type sand blasting sliding sleeve 16 from top to bottom.

The tubular column technology needs to carry out self-blowing production after pressure construction, in the production process, if a blowout accident occurs, the safety valve 5 with the valve can seal the pressure in the oil pipe string 2, the annular safety valve 10 can seal the pressure in the oil sleeve space, finally, liquid in a well is prevented from gushing out of a shaft, safe production is guaranteed, the hydraulic anchor 7 is connected with the annular packer 10 for use, and the purpose is to prevent the annular packer 10 from being mistakenly unsealed due to the fact that the oil pipe string 2 is jacked up when the pressure is below the annular packer 10, and well control failure is caused.

O-shaped rings are arranged on the outer walls of the head end and the tail end of the hollow insertion tube 4, so that the hollow insertion tube 4 is matched and sealed with the upper sealing cylinder 3 and the lower sealing cylinder 6.

And a sealing module is arranged on the outer side of the inserted seal 12 in the oil pipe, and the inserted seal 12 in the oil pipe is matched with the inner wall of the oil pipe string 2 to realize sealing through the sealing module.

Along with the increase of the number of fracturing layers, the number of the ball-throwing sand-blasting sliding sleeves 14 is correspondingly increased, the inner diameters of the ball-throwing sand-blasting sliding sleeves 14 arranged from top to bottom are sequentially reduced, the ball-throwing sand-blasting sliding sleeves 14 are arranged before throwing balls, sand-blasting holes are blocked by the sliding sleeves, and when the balls are thrown and pressed to cut off shear nails, the sand-blasting holes are exposed, so that fracturing construction of the layer can be carried out; if the number of fracturing layers increases, the inner diameter of the ball throwing and sand blasting sliding sleeve 14 on each layer is sequentially reduced from top to bottom, so that the ball throwing is performed for multiple times in the later period, and except for fracturing of the fracturing layer at the lowest part, the other layers are all thrown with balls once, the fracturing layer is one layer, the balls on the layer are thrown, the upper layer is fractured, and the like.

The check valve ball seat 18 is composed of a ball seat and a soluble ball, the check valve ball seat 18 plugs the whole string, fracturing fluid is prevented from leaking out of the bottom of the string when fracturing, production fluid can push the soluble ball to enter the string to a wellhead when production is carried out, and a production channel is more smooth after the soluble ball is dissolved.

The operation method of the fracturing sand control integrated process pipe column capable of preventing erosion and deep backwashing well comprises the following steps:

step 1, putting the fracturing sand prevention integrated process pipe column into the underground, setting an annular packer 10 in a rotary pressing mode, and performing upper annular pressing and seal checking;

2, putting the soluble ball into the fracturing sand prevention integrated process pipe column, and enabling the soluble ball to fall onto the check valve ball seat 18 so as to seal a plurality of fracturing layers;

step 3, performing sand fracturing on the fracturing layer at the lowest layer through the normally-open sand blasting sliding sleeve 16, wherein the pressure in the oil pipe string 2 is higher than the pressure in the sleeve 19 during fracturing, at the moment, each Y344 packer 13 is in a setting state, so that fracturing of the target layer is realized, and other layers are not fractured;

step 4, throwing balls into the fracturing sand prevention integrated process pipe column, enabling the balls to fall into the ball throwing sand blasting sliding sleeve 14, throwing hydraulic pressure into the fracturing sand prevention integrated process pipe column, and starting a ball throwing sliding sleeve type sand blaster;

step 5, performing sand blasting and fracturing on the fracturing layer above the lowest layer, wherein the pressure in the oil pipe string 2 is higher than the pressure in the sleeve 19 during fracturing, at the moment, each Y344 packer 13 still plays a role in layering, and repeating the steps 4-5 until all the fracturing layers are subjected to sand blasting and fracturing;

step 6, fishing the protective sleeve in the safety valve 5 with the valve clack, and performing open flow and self-flow production;

step 7, after the self-injection production is finished, hydraulic pressure is applied to the annulus above the annulus packer 10, a well-flushing differential pressure rupture disc 9 of the deep backwashing valve 8 is opened, at the moment, the pressure in the oil pipe string 2 is no longer far greater than the pressure in the casing pipe 19, the Y344 packer 13 is in an unset state, the annulus between the oil pipe string 2 and the casing pipe 19 is no longer sealed, deep backwashing operation is carried out, and the fracturing and sand prevention integrated process pipe string is taken out after the backwashing operation is finished;

and 8, lowering a well completion pipe column and an electric submersible pump production pipe column.

Spatially relative terms, such as "upper," "lower," "left," "right," and the like, may be used in the embodiments for ease of description to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that the spatial terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "lower" can encompass both an upper and a lower orientation. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

Moreover, relational terms such as "first" and "second," and the like, may be used solely to distinguish one element from another element having the same name, without necessarily requiring or implying any actual such relationship or order between such elements.

The present invention has been described in detail, but the above description is only a preferred embodiment of the present invention, and is not to be construed as limiting the scope of the present invention. All equivalent changes and modifications made within the scope of the present invention shall fall within the scope of the present invention.

Claims (6)

1. Can prevent erosion and degree of depth backwash well's fracturing sand control integration technology tubular column, its characterized in that: the well control part comprises a safety valve with a valve clack, an upper hydraulic anchor and an annular packer, the erosion prevention part comprises an upper sealing barrel, a hollow insertion pipe and a lower sealing barrel, the deep backwashing part comprises a deep flushing valve, a flushing differential pressure rupture disc, a flushing water outlet and an insertion seal in an oil pipe, and the layered fracturing part comprises a Y344 packer, a ball throwing and sand blasting sliding sleeve, a normally open sand blasting sliding sleeve, a lower hydraulic anchor and a check valve ball seat;

the upper part of the safety valve with the valve clack is connected with the upper sealing cylinder, the lower part of the safety valve with the valve clack is connected with the lower sealing cylinder, a hollow insertion pipe limiting step is formed on the inner wall of the upper sealing cylinder, the hollow insertion pipe is inserted into the upper sealing cylinder, the safety valve with the valve clack and the lower sealing cylinder from top to bottom, a limiting reducing section is formed at the upper part of the outer wall of the hollow insertion pipe, the limiting reducing section and the hollow insertion pipe limiting step are utilized to limit the position of the hollow insertion pipe inserted into the upper sealing cylinder, the upper hydraulic anchor and the deep well washing valve are sequentially installed on the lower sealing cylinder from top to bottom, a well washing through hole is formed on the outer wall of the upper part of the deep well washing valve, the well washing differential pressure breaking disc is installed at the well washing through hole, and a large-size connecting thread and a small-size connecting thread are formed at the tail end of the deep well washing valve, small-size connecting thread is located jumbo size connecting thread's inboard, jumbo size connecting thread pass through tubing string with annular packer links to each other, in annular packer below form on the tubing string wash the well delivery port, small-size connecting thread pass through little tubing with insert sealed linking to each other in the tubing, insert sealed below in the tubing the annular between tubing string and the sleeve pipe in evenly set up from top to bottom Y344 packer divide into a plurality of fracturing layers with above-mentioned annular, installs on being located the tubing string on below fracturing layer the normal open type sandblast sliding sleeve all installs in the horizon that is located normal open type sandblast sliding sleeve top the ball blasting sliding sleeve, in normal open type sandblast sliding sleeve below the tubing string sets gradually from top to bottom down under the hydraulic anchor with the single current valve ball seat.

2. The integrated fracturing sand control process string capable of preventing washout and deep backwash as claimed in claim 1, wherein: o-shaped rings are arranged on the outer walls of the head end and the tail end of the hollow insertion tube to realize the matching and sealing of the hollow insertion tube and the upper sealing cylinder and the lower sealing cylinder.

3. The integrated fracturing sand control process string capable of preventing washout and deep backwash as claimed in claim 1, wherein: and a sealing module is arranged on the outer side of the insertion seal in the oil pipe, and the insertion seal in the oil pipe is matched with the inner wall of the oil pipe string to realize sealing through the sealing module.

4. The integrated fracturing sand control process string capable of preventing washout and deep backwash as claimed in claim 1, wherein: along with the increase of the number of fracturing layers, the quantity of the ball throwing sand blasting sliding sleeves correspondingly increases, and the inner diameters of the ball throwing sand blasting sliding sleeves arranged from top to bottom are reduced in sequence.

5. The integrated fracturing sand control process string capable of preventing washout and deep backwash as claimed in claim 1, wherein: the check valve ball seat consists of a ball seat and a soluble ball.

6. The method for operating the fracturing sand control integrated process string capable of preventing erosion and deep backwash as claimed in any one of claims 1 to 5, wherein: the method comprises the following steps:

step 1, putting the fracturing sand prevention integrated process pipe column into the underground, setting an annular packer in a rotating and pressing mode, and performing upper annular pressing and seal checking;

2, putting the soluble ball into the fracturing sand prevention integrated process pipe column, and enabling the soluble ball to fall onto a check valve ball seat so as to seal a plurality of fracturing layers;

step 3, performing sand fracturing on the fracturing layer at the lowest layer through a normally-open sand blasting sliding sleeve, wherein during fracturing, because the pressure in the oil pipe string is higher than the pressure in the sleeve, each Y344 packer is in a setting state, so that fracturing of the target layer is realized, and other layers are not fractured;

step 4, throwing balls into the fracturing sand prevention integrated process pipe column, enabling the balls to fall into a ball throwing sand blasting sliding sleeve, throwing hydraulic pressure into the fracturing sand prevention integrated process pipe column, and starting a ball throwing sliding sleeve type sand blaster;

step 5, performing sand blasting fracturing on the fracturing layer above the lowest layer, wherein the pressure in the oil pipe string is higher than the pressure in the sleeve during fracturing, at the moment, each Y344 packer still plays a layering role, and repeating the steps 4-5 until all fracturing layers are subjected to sand blasting fracturing;

step 6, fishing the protective sleeve in the safety valve with the valve clack in the well killing process, and performing open flow and self-flow production;

step 7, after the self-injection production is finished, hydraulic pressure is applied to the annulus above the annulus packer, a well-flushing differential pressure rupture disc of the deep backwashing valve is opened, at the moment, the pressure in the oil pipe string is no longer much larger than the pressure of the casing, the Y344 packer is in an unsealing state, the annulus between the oil pipe string and the casing is no longer sealed, deep backwashing operation is carried out, and the fracturing and sand prevention integrated process pipe string is taken out after the backwashing operation is finished;

and 8, lowering a well completion string and an electric submersible pump production string.

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