CN212716530U

CN212716530U - Casing straddle packer

Info

Publication number: CN212716530U
Application number: CN202021679483.XU
Authority: CN
Inventors: 李江涛; 张红霞; 乔春国; 甘典国; 李彬红
Original assignee: China Petroleum and Chemical Corp; Sinopec Jiangsu Oilfield Co
Current assignee: China Petroleum and Chemical Corp; Sinopec Jiangsu Oilfield Co
Priority date: 2020-08-13
Filing date: 2020-08-13
Publication date: 2021-03-16
Anticipated expiration: 2030-08-13

Abstract

The utility model relates to a casing straddle packer, wherein a core pipe extending downwards is screwed in the internal thread at the lower end of an upper joint, the lower end of the core pipe is inserted in the upper port of a lower joint and is sealed by an O-shaped ring; a bypass mechanism capable of communicating the upper and lower liquid flows of the packer is arranged on the periphery of the core pipe and below the upper joint, a setting mechanism is arranged below the bypass mechanism, a pin shearing mechanism is arranged below the setting mechanism, and a transposition mechanism for controlling bypass and setting is arranged below the pin shearing mechanism; the bypass mechanism comprises a bypass outer cylinder, the bypass outer cylinder is suspended on an outer step of an upper joint convex ring through an inner step at the upper end, the upper joint convex ring is positioned on the periphery of the middle part of the upper joint, and a plurality of upper bypass holes extending vertically are uniformly distributed on the circumference of the middle part of the bypass outer cylinder; the inner cavity of the bypass outer cylinder is provided with a bypass valve for opening or closing the upper bypass hole flow passage. The utility model discloses at the in-process of going into the well, ensure to stride to separate the packer can not sit in advance and seal to effective protection packer packing element improves conscientiously and strides to separate the test success rate.

Description

Casing straddle packer

Technical Field

The utility model relates to a test is with utensil in pit, in particular to packer is striden to sleeve pipe belongs to oil and gas test equipment technical field.

Background

In the process of oil exploration, through rock debris logging, gas logging, core analysis and electrical measurement interpretation data, an oil layer, a gas layer and a water layer can be preliminarily determined, but finally verification is required through oil testing. The formation test is also called a drill stem test, is a key link of scientific oil testing, plays an important role in determining reservoir productivity, liquidity, energy, reservoir seepage characteristics, parameters and the like, and can provide reliable and detailed basis for further exploration and development of a block.

The cased well straddle test is mainly used for cased wells with opened intervals, two packers are arranged in a cased well straddle test pipe column, the lower packer is generally a slip support type packer, a blind joint is arranged at the upper part of the cased well straddle test pipe column, and a tested layer is sealed; the upper packer is typically a bottom supported packer, i.e., a straddle packer, used to seal off the annulus and the zone being tested.

At present, a commonly used straddle packer at home and abroad is generally a shear pin packer, the shear pin packer is matched with a slip packer below for use, and a sieve tube is arranged between the shear pin packer and the slip packer. And after the slip packer is set according to the setting step, continuously increasing a larger compression load, shearing the shear pin of the shear pin packer, and setting the shear pin packer, thereby carrying out the straddle test on the test interval.

The shear pin packer is used as a casing pipe straddle packer for downhole testing, and has the following problems due to the structural influence: 1. if the lower end of the tool meets a block or a block in the drilling process, or the shearing pin has the risk of shearing in advance when the ground is not operated properly, the packer can be caused to be set in advance, the packing element is in a compressed and expanded state in the well descending process, the packing element rubs on the wall of the casing, when the packer is lowered to a preset depth, the shearing pin packer packing element is damaged, an effective packing effect cannot be achieved, and the straddle test operation fails. At present, the success rate of the domestic and foreign crossing test is very low. 2. After the tool is normally seated, the shear pin transversely penetrates through the middle part of the packer, and due to the limitation of the shear pin, the full drift diameter cannot be achieved, and other operations cannot be carried out in the drift diameter of the tool; 3. the tool does not have the function of balancing the upper and lower pressure difference of the rubber cylinder, and needs to be matched with other tools for use.

The oil field site also adopts a spring claw type straddle packer which is matched with a slip packer below for use. And after the lower slip packer is set, the lower slip packer continues to be pressed down to open the spring claw, so that the straddle packer realizes setting and can be unset by lifting. But through ground experiments, the first time of pressing down needs about 10T to be set, and later pressing down 1-2T is set, so that the repeated use requirement is not met.

Disclosure of Invention

An object of the utility model is to overcome the problem that exists among the prior art, provide a sleeve pipe and stride a packer, at the in-process of going into the well, ensure to stride a packer can not sit in advance and seal to effective protection packer packing element improves conscientiously and strides a test success rate.

In order to solve the technical problem, the casing straddle packer comprises an upper joint, wherein a core pipe extending downwards is screwed in an internal thread at the lower end of the upper joint, the lower end of the core pipe is inserted in an upper port of a lower joint and is sealed through an O-shaped ring; a bypass mechanism capable of communicating the upper and lower liquid flows of the packer is arranged on the periphery of the core pipe and below the upper joint, the bypass mechanism comprises a bypass outer cylinder, the bypass outer cylinder is suspended on an outer step of an upper joint convex ring through an inner step at the upper end, the upper joint convex ring is positioned on the periphery of the middle part of the upper joint, and a plurality of upper bypass holes extending vertically are uniformly distributed on the circumference of the middle part of the bypass outer cylinder; a bypass valve for opening or closing the upper bypass hole flow channel is arranged in the inner cavity of the bypass outer cylinder; a setting mechanism is arranged below the bypass mechanism, a pin shearing mechanism is arranged below the setting mechanism, and a transposition mechanism for controlling bypass and setting is arranged below the pin shearing mechanism.

As a further improvement of the present invention, the bypass valve comprises a sealing sleeve and an end face sealing joint which are mutually matched, the sealing sleeve is screwed on the external thread of the lower end of the upper joint, the upper port of the sealing sleeve is positioned below the convex ring of the upper joint, the inner cavity of the lower end of the sealing sleeve is provided with a sealing ring, the upper end face of the sealing ring is pressed against the lower end of the upper joint, the outer flange of the sealing ring at the upper part of the sealing ring is pressed on the inner step of the lower part of the sealing sleeve, and the end face sealing ring is embedded in an annular sealing box between the outer wall of the lower part of the sealing ring; the lower end internal thread of the bypass outer barrel is connected with the middle section external thread of the end face sealing joint in a screwing mode, and the upper portion of the end face sealing joint is provided with a sealing lip which can be embedded into the annular sealing box.

As a further improvement of the present invention, the setting mechanism includes a rubber cylinder mandrel, an upper drift diameter gauge, a rubber cylinder and a lower drift diameter gauge, the rubber cylinder mandrel is located at the periphery of the core pipe, the upper end of the rubber cylinder mandrel is screwed in the lower internal thread of the end face seal joint, the upper drift diameter gauge is screwed on the lower external thread of the end face seal joint, the lower end of the rubber cylinder mandrel is provided with a rubber cylinder mandrel external spline, the rubber cylinder is sleeved at the periphery of the middle part of the rubber cylinder mandrel, the upper end inner edge of the rubber cylinder is abutted against the lower part of the end face seal joint, and the upper end outer edge of the rubber cylinder is abutted against the lower part of the upper drift diameter gauge; the lower end of the rubber cylinder is abutted against the top of the lower drift diameter gauge, and the lower end of the lower drift diameter gauge is positioned above the external spline of the rubber cylinder mandrel; the outer diameters of the upper drift diameter gauge and the lower drift diameter gauge are the same and are larger than the outer diameter of the rubber cylinder in a natural state.

As a further improvement of the utility model, the lower part periphery of latus rectum rule has connect the circulation urceolus soon down, the upper portion inner wall of circulation urceolus is equipped with circulation urceolus spline groove, circulation urceolus spline groove with packing element mandrel external splines cooperatees, evenly distributed has the lower by pass hole along vertical extension on the middle part circumference of circulation urceolus, the below of circulation urceolus spline groove is equipped with circulation urceolus tool withdrawal groove.

As a further improvement, the inner wall of end face seal joint and packing element mandrel with it overflows the passageway to be equipped with the annular between the outer wall of core pipe, the annular overflow the upper end of passageway with the inner chamber of bypass urceolus communicates with each other, the annular overflow the lower extreme of passageway with the inner chamber of circulation urceolus communicates with each other.

As a further improvement, the shear pin mechanism includes to connect soon the connection nipple joint of circulation urceolus lower extreme periphery, the inner chamber of connection nipple joint is equipped with the shearing cover, it has the shear pin to peg graft in the middle part counter bore of shearing cover, the inner end of shear pin inlay in the reducing section of core pipe.

As a further improvement, the transposition mechanism is including connecing soon the switching-over urceolus of connection nipple joint lower extreme, the symmetry is equipped with the decurrent groove of falling J of opening on the middle section circumference of switching-over urceolus, the periphery symmetry of core pipe is equipped with the transposition lug, the transposition lug correspondence inlay in the groove of falling J, the short flute height in the groove of falling J is less than the height of reducing section, the upper end of lower clutch connect soon in the lower extreme internal thread of switching-over urceolus.

Compared with the prior art, the utility model discloses following beneficial effect has been obtained: 1. the upper joint is screwed with the upper tubular column, and the lower joint is screwed with the lower tubular column; the upper joint convex ring provides positioning for the bypass outer barrel, and when the upper joint convex ring abuts against the lower part of the inner step at the upper end of the bypass outer barrel, the rubber barrel is unsealed.

2. The lower end of the core tube can freely slide in the lower joint, and the shear pin limits the relative position of the core tube and the rubber cylinder mandrel within a certain range; the connecting short section not only plays a role in connecting the circulating outer cylinder and the reversing outer cylinder, but also neatly limits each shear pin in a counter bore of the shear sleeve.

3. The inner end of the shear pin is not screwed in the threaded hole any more but is positioned at the reducing section on the periphery of the core pipe, and in the process of going down the well, the transposition lug is embedded at the bottom of the short groove of the inverted J-shaped groove, so that the shear pin is completely free from external force, and the condition that the rubber cylinder is set in advance due to accidental shearing of the shear pin is avoided; the height of the reducing section is greater than the height of the short groove of the inverted J-shaped groove, so that the shear pin cannot be sheared when the transposition lug slides in the short groove of the inverted J-shaped groove; when the transposition lug reaches the long groove of the inverted J-shaped groove, the shear pin can be sheared, namely the original function of the shear pin is kept, and the core pipe always keeps the full path diameter, so that the penetration of instruments in other procedures is facilitated; the shearing value of a single shearing pin is 10KN, 12 shearing pins can be installed in total, and the shearing pins with corresponding quantity can be additionally installed according to different well depths.

4. Because the outer diameter of the rubber sleeve is larger, when the rubber sleeve descends along the inner wall of the casing, the rubber sleeve is easy to generate a pumping effect and huge resistance on the stratum; when the well is lowered, the transposition lug is embedded in the short groove of the inverted J-shaped groove, the end face sealing ring and the sealing lip are in a separated state, liquid in the annular space below the rubber sleeve enters the annular overflowing channel between the rubber sleeve mandrel and the core pipe from the lower bypass hole and then flows out from the upper bypass hole to the annular space above the rubber sleeve, the swabbing effect is avoided, and the well lowering resistance is reduced. The upper bypass hole is a long round hole and extends to the middle section of the sealing sleeve, and the outer diameter of the sealing sleeve is smaller than the inner diameter of the bypass outer barrel, so that the upper bypass hole can be always kept smooth in all holes, and water flow is prevented from being blocked.

5. When the transposition lug reaches the elongated slot of the inverted J-shaped slot, the core tube can drive the sealing sleeve and the sealing ring to move downwards, so that the end face sealing ring and the sealing lip are sealed, the channel between the upper bypass hole and the annular space is closed, and the tester can test conveniently.

6. The outer spline of the mandrel of the rubber cylinder is matched with the spline groove of the circulating outer cylinder and slides along the axial direction, so that the rubber cylinder cannot rotate in the process of being pressed or released; go up the drift diameter gauge and be greater than the natural external diameter of packing element with lower drift diameter gauge, can avoid the packing element to take place to scrape and damage in the process of going into the well, improve the success rate of striding at a distance from the test conscientiously.

7. The rubber cylinder is too long and is easy to generate twist-shaped deformation when being pressed, so that the setting effect is influenced; the rubber tube is divided into a plurality of sections and is separated by the spacer ring, so that deformation similar to beads of an abacus can be ensured to be generated when each section of rubber tube is pressed, and a plurality of reliable seals are formed.

Drawings

The invention will be described in further detail with reference to the drawings and the detailed description, which are provided for reference and illustration purposes only and are not intended to limit the invention.

Fig. 1 is a front view of the packer with a casing straddle according to the present invention.

Fig. 2 is a front view of the core tube of fig. 1.

FIG. 3 is a cross-sectional view taken along the cross-section of the indexing lug of FIG. 2.

Fig. 4 is a front view of the cartridge mandrel of fig. 1.

Fig. 5 is a front view of the recycling sleeve of fig. 1.

FIG. 6 is a front view of the coupling sub of FIG. 1.

FIG. 7 is a front view of the shear sleeve of FIG. 1.

Fig. 8 is a sectional view of the reversing outer cylinder of fig. 1.

Fig. 9 is an expanded view of the inverted J-shaped slot of fig. 8.

In the figure: 1. an upper joint; 1a, an upper joint convex ring; 2. a core tube; 2a, reducing section; 2b, a transposition lug; 3. sealing sleeves; 3a, a sealing ring; 3b, end face sealing ring; 4. an end face seal joint; 4a, sealing lips; 5. bypassing the outer cylinder; 5a, an upper bypass hole; 6. a glue cartridge mandrel; 6a, forming an external spline of the rubber sleeve mandrel; 6b, a lower drift diameter gauge; 6c, a rubber cylinder; 6d, spacer rings; 6e, an upper drift diameter gauge; 7. circulating the outer cylinder; 7a, circulating an outer cylinder spline groove; 7b, a lower bypass hole; 7c, circulating the cutter withdrawal groove of the outer cylinder; 8. connecting short sections; 8a, a shearing sleeve; 8b, shearing pins; 9. a reversing outer cylinder; 9a, inversed J-shaped groove; 9b, reversing an outer cylinder drain hole; 10. and a lower joint.

Detailed Description

As shown in fig. 1 to 9, the casing straddle packer of the present invention comprises an upper joint 1, the upper end of the upper joint 1 is provided with a tapered female thread to be screwed with an upper tubular column, a core tube 2 extending downward is screwed in the lower internal thread of the upper joint 1, the lower end of the core tube 2 is slidably inserted into the upper port of a lower joint 10 and sealed by an O-ring, and the lower end of the lower joint 10 is provided with a tapered male thread to be screwed with a lower tubular column; a bypass mechanism capable of communicating the upper and lower liquid flows of the packer is arranged on the periphery of the core pipe 2 and below the upper joint 1, a setting mechanism is arranged below the bypass mechanism, a pin shearing mechanism is arranged below the setting mechanism, and a transposition mechanism for controlling bypass and setting is arranged below the pin shearing mechanism.

The bypass mechanism comprises a bypass outer barrel 5, the bypass outer barrel 5 is suspended on an outer step of an upper joint convex ring 1a through an inner step at the upper end, the upper joint convex ring 1a is positioned on the periphery of the middle part of the upper joint 1 to provide positioning for the bypass outer barrel 5, and a plurality of upper bypass holes 5a extending vertically are uniformly distributed on the circumference of the middle part of the bypass outer barrel 5; the inner cavity of the bypass outer cylinder 5 is provided with a bypass valve for opening or closing the flow passage of the upper bypass hole 5a.

The bypass valve comprises a sealing sleeve 3 and an end face sealing joint 4 which are matched with each other, the sealing sleeve 3 is screwed on the external thread at the lower end of the upper joint 1, the upper port of the sealing sleeve 3 is positioned below the convex ring 1a of the upper joint, a sealing ring 3a is arranged in the inner cavity at the lower end of the sealing sleeve 3, the upper end face of the sealing ring 3a abuts against the lower end of the upper joint 1, the outer flange of the sealing ring at the upper part of the sealing ring 3a is pressed on the inner step at the lower part of the sealing sleeve 3, and an end face sealing ring 3b is embedded in an annular sealing box between the outer wall; the lower end internal thread of the bypass outer cylinder 5 is screwed with the middle section external thread of the end face sealing joint 4, and the upper part of the end face sealing joint 4 is provided with a sealing lip 4a which can be embedded into an annular sealing box.

The setting mechanism comprises a rubber cylinder mandrel 6, an upper drift diameter gauge 6e, a rubber cylinder 6c and a lower drift diameter gauge 6b, the rubber cylinder mandrel 6 is positioned on the periphery of the core pipe 2, the upper end of the rubber cylinder mandrel 6 is screwed in the lower internal thread of the end face sealing joint 4, the upper drift diameter gauge 6e is screwed on the lower external thread of the end face sealing joint 4, a rubber cylinder mandrel external spline 6a is arranged at the lower end of the rubber cylinder mandrel 6, the rubber cylinder 6c is sleeved on the periphery of the middle part of the rubber cylinder mandrel 6, the inner edge of the upper end of the rubber cylinder 6c abuts against the lower part of the end face sealing joint 4, and the outer edge of the upper end of the rubber cylinder 6c abuts against the lower part of the upper drift diameter gauge; the lower end of the rubber cylinder 6c abuts against the top of the lower drift diameter gauge 6b, and the lower end of the lower drift diameter gauge 6b is positioned above the outer spline 6a of the rubber cylinder mandrel; the outer diameters of the upper drift diameter gauge 6e and the lower drift diameter gauge 6b are the same and larger than the outer diameter of the rubber cylinder 6c in a natural state.

The rubber cylinders 6c are stacked on the periphery of the rubber cylinder mandrel 6, and spacer rings 6d are respectively arranged between the adjacent rubber cylinders 6c. The rubber cylinder is too long and is easy to generate twist-shaped deformation when being pressed, so that the setting effect is influenced; the rubber tube is divided into a plurality of sections and is separated by the spacer ring 6d, so that the deformation similar to the bead shape of the abacus can be ensured to be generated when each section of rubber tube 6c is pressed, and a plurality of reliable seals are formed.

The periphery of the lower portion of the lower drift diameter gauge 6b is rotatably connected with a circulating outer barrel 7, a circulating outer barrel spline groove 7a is formed in the inner wall of the upper portion of the circulating outer barrel 7, the circulating outer barrel spline groove 7a is matched with a rubber barrel mandrel outer spline 6a, lower bypass holes 7b extending vertically are uniformly distributed in the middle of the circulating outer barrel 7, and a circulating outer barrel tool withdrawal groove 7c is formed below the circulating outer barrel spline groove 7a to ensure that the circulating outer barrel spline groove 7a is opened to the bottom. The outer spline 6a of the mandrel of the rubber cylinder is matched with the spline groove 7a of the circulating outer cylinder and slides along the axial direction, so that the rubber cylinder 6c cannot rotate in the process of being pressed or released; go up drift diameter gage 6e and drift diameter gage 6b down and be greater than the natural external diameter of packing element 6c, can avoid packing element 6c to take place to scrape and damage in the process of going into the well, improve the success rate of striding at a distance from the test conscientiously.

An annular overflowing channel is arranged between the inner walls of the end face sealing joint 4 and the rubber sleeve mandrel 6 and the outer wall of the core pipe 2, the upper end of the annular overflowing channel is communicated with the inner cavity of the bypass outer cylinder 5, and the lower end of the annular overflowing channel is communicated with the inner cavity of the circulating outer cylinder 7.

The shear pin mechanism comprises a connecting short section 8 which is screwed at the lower end of the circulating outer cylinder 7, a shear sleeve 8a is arranged in an inner cavity of the connecting short section 8, a shear pin 8b is inserted in a counter bore in the middle of the shear sleeve 8a, the connecting short section 8 neatly limits each shear pin 8b in the counter bore of the shear sleeve 8a, and the inner end of the shear pin 8b is embedded in the reducing section 2a of the core pipe 2.

The reversing mechanism comprises a reversing outer barrel 9 which is connected to the lower end of the connecting short section 8 in a screwed mode, inverted J-shaped grooves 9a with downward openings are symmetrically formed in the circumference of the middle section of the reversing outer barrel 9, transposition lugs 2b are symmetrically arranged on the periphery of the core pipe 2, the transposition lugs 2b are correspondingly embedded in the inverted J-shaped grooves 9a, the short groove heights of the inverted J-shaped grooves 9a are smaller than the heights of the reducing sections 2a, and the upper end of the lower connector 10 is connected to the inner threads of the lower end of the reversing outer barrel 9 in a.

The inner end of the shear pin 8b is not screwed in the threaded hole any longer, but is positioned on the reducing section 2a at the periphery of the core pipe 2, and in the process of going down the well, the transposition lug 2b is embedded at the bottom of the short groove of the inverted J-shaped groove 9a, so that the shear pin 8b is completely free from external force, and the rubber cylinder 6c is prevented from being set in advance due to accidental shearing of the shear pin 8 b; the height of the reducing section 2a is greater than the short groove height of the inverted J-shaped groove 9a, so that the shear pin 8b cannot be sheared when the transposition lug 2b slides in the short groove of the inverted J-shaped groove 9 a; when the transposition lug 2b reaches the long groove of the inverted J-shaped groove 9a, the shear pin 8b can be sheared, namely the function of the original shear pin 8b is kept, and the core pipe always keeps the full diameter, so that the penetration of other process instruments is facilitated; the shearing value of the single shearing pin 8b is 10KN, 12 shearing pins can be installed in total, and the corresponding quantity of shearing pins can be additionally installed according to different well depths.

Because the outer diameter of the rubber cylinder 6c is larger, when the rubber cylinder descends along the inner wall of the casing, the rubber cylinder is easy to generate a pumping effect and huge resistance on the stratum; when the well is lowered, the transposition lug 2b is embedded in the short groove of the inverted J-shaped groove 9a, the end face sealing ring 3b and the sealing lip 4a are in a separated state, liquid in the annular space below the rubber sleeve 6c enters the annular overflowing channel between the rubber sleeve mandrel 6 and the core pipe 2 from the lower bypass hole 7b, then flows out from the upper bypass hole 5a and enters the annular space above the rubber sleeve 6c, the swabbing effect is avoided, and the lowering resistance is reduced.

The outer diameter of the sealing sleeve 3 is smaller than the inner diameter of the bypass outer cylinder 5. The upper bypass hole 5a is a long round hole and extends to the middle section of the sealing sleeve 3, the outer diameter of the sealing sleeve 3 is smaller than the inner diameter of the bypass outer cylinder 5, so that the upper bypass hole 5a can always keep a full-hole smooth, and water flow is prevented from being blocked.

When the transposition lug 2b reaches the elongated slot of the inverted J-shaped slot 9a, the core tube 2 can drive the sealing sleeve 3 and the sealing ring 3a to move downwards, so that the end face sealing ring 3b and the sealing lip 4a are sealed, and a channel between the upper bypass hole 5a and the annular space is closed, thereby facilitating the test of a tester.

A plurality of reversing outer cylinder drainage holes 9b are arranged on the circumferential wall below the inverted J-shaped groove 9a, and the reversing outer cylinder drainage holes 9b are communicated with the lower cavity of the reversing outer cylinder 9. The water discharge hole 9b of the reversing outer cylinder can discharge the water stored in the inner cavity of the lower end of the reversing outer cylinder 9, so that the pressure build-up is avoided.

The utility model discloses a packer is striden to sleeve pipe separates work step when carrying out the stratum test as follows: the method comprises the steps of installing a casing pipe straddle packer and a tester in a pipe column, wherein the tester is positioned above the casing pipe straddle packer;

secondly, the transposition lug 2b of the core pipe 2 is positioned in a short groove of the inverted J-shaped groove 9a, and at the moment, the lower bypass hole 7b is in a communicated state with the upper bypass hole 5a through an annular overflowing channel between the inner wall of the rubber sleeve mandrel 6 and the outer wall of the core pipe 2;

the pipe column drives the sleeve pipe to cross the packer to move downwards, and the transposition lug 2b is embedded in the lower end of the short groove of the inverted J-shaped groove 9 a; liquid in the annular space below the rubber cylinder 6c enters the annular overflowing channel from the lower bypass hole 7b, then flows out from the upper bypass hole 5a and enters the annular space above the rubber cylinder 6 c;

fourthly, after the pipe column is lowered to a preset position of the sleeve, the lower pipe column of the sleeve straddle packer is seated in the sleeve;

lifting the tubular column to drive the core tube 2 to move upwards for a certain distance, so that the transposition lug 2b reaches the upper end of the short groove of the inverted J-shaped groove 9a, and then rotating the tubular column rightly, so that the transposition lug 2b reaches the upper end of the long groove of the inverted J-shaped groove 9 a;

sixthly, moving the upper pipe column together with the core pipe 2 downwards for a certain distance, cutting off a shear pin 8b, moving the sealing sleeve 3 and the sealing ring 3a downwards until a sealing lip 4a at the upper end of the end face sealing joint 4 is embedded into an annular sealing box to compress the end face sealing ring 3b, and closing an upper bypass hole flow passage between the interior of the pipe column and the annulus;

the upper string continues down a distance, the deadweight of the string forces the cement barrel 6c to expand and set in the casing;

opening the tester for testing, and allowing formation fluid to enter the test string and flow upwards through the tester;

the self-supporting closing tester ensures that the test well section is not communicated with the interior of the pipe column and the annulus;

the pipe column is lifted for a certain distance until the convex ring 1a of the upper joint abuts against the inner step of the upper end of the bypass outer cylinder 5, the sealing sleeve 3 moves upwards along with the pipe column, so that the end face sealing ring 3b is separated from the sealing lip 4a at the upper end of the end face sealing joint 4, the flow channel of the upper side bypass hole 5a is communicated, and the pressure of the sleeve pipe across the upper part and the lower part of the packer is balanced;

when the upper joint convex ring 1a is hung on the bypass outer cylinder 5 to move upwards to unseal the sleeve straddle packer, the rubber cylinder 6c is unsealed when the upper joint convex ring 1a abuts against the lower part of the inner step at the upper end of the bypass outer cylinder 5, and the rubber cylinder 6c is recovered;

and continuously lifting the pipe column, taking the stratum fluid in the pipe column out of the well, and sampling and analyzing.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention. In addition to the above embodiments, the present invention may have other embodiments. All the technical solutions formed by adopting equivalent substitutions or equivalent transformations fall within the protection scope claimed by the present invention. The undescribed technical features of the present invention can be realized by or using the prior art, and are not described herein again.

Claims

1. A casing straddle packer comprising an upper joint, characterized in that: a core pipe extending downwards is screwed in the internal thread at the lower end of the upper joint, the lower end of the core pipe is inserted in the upper port of the lower joint and sealed through an O-shaped ring; a bypass mechanism capable of communicating the upper and lower liquid flows of the packer is arranged on the periphery of the core pipe and below the upper joint, the bypass mechanism comprises a bypass outer cylinder, the bypass outer cylinder is suspended on an outer step of an upper joint convex ring through an inner step at the upper end, the upper joint convex ring is positioned on the periphery of the middle part of the upper joint, and a plurality of upper bypass holes extending vertically are uniformly distributed on the circumference of the middle part of the bypass outer cylinder; a bypass valve for opening or closing the upper bypass hole flow channel is arranged in the inner cavity of the bypass outer cylinder; a setting mechanism is arranged below the bypass mechanism, a pin shearing mechanism is arranged below the setting mechanism, and a transposition mechanism for controlling bypass and setting is arranged below the pin shearing mechanism.

2. The casing straddle packer of claim 1, wherein: the bypass valve comprises a sealing sleeve and an end face sealing joint which are matched with each other, the sealing sleeve is screwed on the external thread at the lower end of the upper joint, the upper port of the sealing sleeve is positioned below the convex ring of the upper joint, a sealing ring is arranged in the inner cavity at the lower end of the sealing sleeve, the upper end face of the sealing ring is abutted against the lower end of the upper joint, the outer flange of the sealing ring at the upper part of the sealing ring is pressed on the inner step at the lower part of the sealing sleeve, and an end face sealing ring is embedded in an annular sealing box between the outer wall at the lower part of the; the lower end internal thread of the bypass outer barrel is connected with the middle section external thread of the end face sealing joint in a screwing mode, and the upper portion of the end face sealing joint is provided with a sealing lip which can be embedded into the annular sealing box.

3. The casing straddle packer of claim 2, wherein: the setting mechanism comprises a rubber cylinder mandrel, an upper drift diameter gauge, a rubber cylinder and a lower drift diameter gauge, the rubber cylinder mandrel is positioned on the periphery of the core pipe, the upper end of the rubber cylinder mandrel is screwed in the lower internal thread of the end face sealing joint, the upper drift diameter gauge is screwed on the lower external thread of the end face sealing joint, the lower end of the rubber cylinder mandrel is provided with a rubber cylinder mandrel external spline, the rubber cylinder is sleeved on the periphery of the middle part of the rubber cylinder mandrel, the inner edge of the upper end of the rubber cylinder abuts against the lower part of the end face sealing joint, and the outer edge of the upper end of the rubber cylinder abuts against the lower part of the upper drift diameter gauge; the lower end of the rubber cylinder is abutted against the top of the lower drift diameter gauge, and the lower end of the lower drift diameter gauge is positioned above the external spline of the rubber cylinder mandrel; the outer diameters of the upper drift diameter gauge and the lower drift diameter gauge are the same and are larger than the outer diameter of the rubber cylinder in a natural state.

4. The casing straddle packer of claim 3, wherein: the outer ring of the lower drift diameter gauge is connected with a circulating outer barrel in a rotating mode, a circulating outer barrel spline groove is formed in the inner wall of the upper portion of the circulating outer barrel and matched with an outer spline of the rubber barrel mandrel, lower bypass holes extending vertically are uniformly distributed in the middle of the circulating outer barrel in the circumferential direction, and a circulating outer barrel tool withdrawal groove is formed below the circulating outer barrel spline groove.

5. The casing straddle packer of claim 4, wherein: an annular overflowing channel is arranged between the inner walls of the end face sealing joint and the rubber sleeve mandrel and the outer wall of the core pipe, the upper end of the annular overflowing channel is communicated with the inner cavity of the bypass outer barrel, and the lower end of the annular overflowing channel is communicated with the inner cavity of the circulation outer barrel.

6. The casing straddle packer of claim 5, wherein: the shear pin mechanism comprises a short connecting piece which is connected to the periphery of the lower end of the circulating outer barrel in a screwing mode, a shear sleeve is arranged in an inner cavity of the short connecting piece, a shear pin is inserted into a counter bore in the middle of the shear sleeve, and the inner end of the shear pin is embedded into the reducing section of the core pipe.

7. The casing straddle packer of claim 6, wherein: the transposition mechanism comprises a reversing outer barrel connected to the lower end of the connecting short section in a rotating mode, inverted J-shaped grooves with downward openings are symmetrically formed in the circumference of the middle section of the reversing outer barrel, transposition lugs are symmetrically arranged on the periphery of the core pipe and are correspondingly embedded in the inverted J-shaped grooves, the height of a short groove of each inverted J-shaped groove is smaller than that of the reducing section, and the upper end of the lower connector is connected to an inner thread at the lower end of the reversing outer barrel in a rotating mode.