CN111911144B - Double-seal straddle test pipe column - Google Patents

Abstract

The invention relates to a double-seal straddle test pipe column which comprises a first sieve pipe corresponding to a first stratum and a second sieve pipe corresponding to a second stratum, wherein a first pressure gauge support cylinder is screwed below the first sieve pipe, a slip packer, a first lifting nipple and a plug are sequentially arranged above the first sieve pipe, the upper end of the plug is connected with the bottom of the second sieve pipe through an adjusting nipple, and the sieve pipe is sequentially connected with the second pressure gauge support cylinder, the straddle packer, the second lifting nipple, a mechanical lock, a tester, the third lifting nipple and a circulating valve from top to bottom. The straddle packer comprises a bypass mechanism, a setting mechanism is arranged below the bypass mechanism, a shear pin mechanism is arranged below the setting mechanism, and a transposition mechanism for controlling bypass and setting is arranged below the shear pin mechanism. The double-seal straddle test pipe column can be used for continuously testing two well sections in sequence, greatly shortens the test time, improves the test efficiency and has high test accuracy. In the process of going into the well, the packer of the straddle type is ensured not to be set in advance, and the success rate of straddle type testing is improved.

Description

Double-seal straddle test pipe column

Technical Field

The invention relates to an instrument for underground testing, in particular to a double-seal straddle testing tubular column, and belongs to the technical field of petroleum and natural gas testing.

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.

Before formation testing, perforating the testing well section, namely, putting a perforating gun to the testing well section, and perforating a casing of the well section to communicate the formation of the testing well section with the inside of the casing. For single packer cased well testing, a testing tool (a circulating valve, a tester, a slip packer, a pressure gauge and the like) is lowered to a testing well section by using an oil pipe, then the slip packer is set, the space of the testing well section, the annulus and the interior of a testing pipe column (namely the interior of the oil pipe) are not communicated at the moment, then the tester is opened, namely well opening flow enters the testing; and (4) closing the well and recovering after testing, so that the testing well section is not communicated with the interior of the tubular column and the annular space, then lifting the tubular column, unsealing the slip packer, and then finishing the subsequent relevant processes.

When the layer is tested, the upper layer is required to be tested, a cement plug can be arranged between the two strata, the lower layer is plugged, and then the upper stratum is subjected to single sealing test. The following layer has a value for exploitation and the cement plug needs to be drilled after the test is finished.

As cement plug drilling is required to accurately inject cement slurry into the underground, the cement plug needs to wait for 48 hours after grouting is finished, and the sealing property needs to be verified after solidification; after the test is finished, the drilling tool needs to be lowered to drill the cement plug, so that the time required for completing the two-layer test is long, the test efficiency is low, the processes are multiple, and the risk is high.

Disclosure of Invention

The invention aims to overcome the problems in the prior art and provide a double-seal straddle test tubular column which can be used for sequentially and continuously testing two well sections, greatly shortens the test time, improves the test efficiency and ensures the accuracy of the test result.

In order to solve the technical problem, the double-seal straddle test pipe column comprises a first sieve pipe corresponding to a first stratum and a second sieve pipe corresponding to a second stratum, wherein a first pressure gauge support cylinder is screwed below the first sieve pipe, a slip packer, a first lifting nipple and a plug are sequentially arranged above the first sieve pipe, the upper end of the plug is connected with the bottom of the second sieve pipe through an adjusting nipple, and the sieve pipe is sequentially connected with the second pressure gauge support cylinder, the straddle packer, the second lifting nipple, a mechanical lock, a tester, the third lifting nipple and a circulating valve from top to bottom.

As an improvement of the invention, the straddle packer comprises an upper joint, wherein the upper end of the upper joint is provided with a conical female thread, 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 sealed through an O-shaped ring, and the lower end of the lower joint is provided with a conical male thread; 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.

As a further improvement of the invention, 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; and a bypass valve for opening or closing the upper bypass hole flow channel is arranged in the inner cavity of the bypass outer barrel.

As a further improvement of the 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 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 sealing ring and the inner wall at the lower part of the sealing sleeve; 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 invention, the outer diameter of the sealing sleeve is smaller than the inner diameter of the bypass outer cylinder.

As a further improvement of the invention, 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 a lower internal thread of the end face sealing joint, the upper drift diameter gauge is screwed on a lower external thread of the end face sealing joint, a rubber cylinder mandrel external spline is arranged at the lower end of the rubber cylinder mandrel, 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.

As a further improvement of the invention, a plurality of rubber cylinders are stacked on the periphery of the rubber cylinder mandrel, and spacing rings are respectively arranged between the adjacent rubber cylinders.

As a further improvement of the invention, the periphery of the lower part of the lower drift diameter gauge is screwed with a circulating outer cylinder, the inner wall of the upper part of the circulating outer cylinder is provided with a circulating outer cylinder spline groove, the circulating outer cylinder spline groove is matched with an external spline of the rubber cylinder mandrel, lower bypass holes extending vertically are uniformly distributed on the circumference of the middle part of the circulating outer cylinder, and a circulating outer cylinder withdrawal groove is arranged below the circulating outer cylinder spline groove.

As a further improvement of the invention, an annular flow passage is arranged between the inner walls of the end face sealing joint and the rubber cylinder mandrel and the outer wall of the core pipe, the upper end of the annular flow passage is communicated with the inner cavity of the bypass outer cylinder, and the lower end of the annular flow passage is communicated with the inner cavity of the circulation outer cylinder.

As a further improvement of the invention, the shear pin mechanism comprises a short connecting piece screwed on the periphery of the lower end of the circulating outer cylinder, a shear sleeve is arranged in an inner cavity of the short connecting piece, a shear pin is inserted in a counter bore in the middle of the shear sleeve, and the inner end of the shear pin is embedded in the reducing section of the core pipe.

As a further improvement of the invention, the transposition mechanism comprises a reversing outer cylinder which is screwed at the lower end of the connecting short section, inverted J-shaped grooves with downward openings are symmetrically arranged on the circumference of the middle section of the reversing outer cylinder, transposition lugs are symmetrically arranged on the periphery of the core tube and are correspondingly embedded in the inverted J-shaped grooves, the short groove height of the inverted J-shaped grooves is smaller than the height of the reducing section, and the upper end of the lower joint is screwed in the lower end internal thread of the reversing outer cylinder.

As a further improvement of the invention, a plurality of reversing outer cylinder drainage holes are arranged on the circumferential wall below the inverted J-shaped groove, and the reversing outer cylinder drainage holes are communicated with the lower cavity of the reversing outer cylinder.

Compared with the prior art, the invention has the following beneficial effects: 1. after the first stratum is tested according to the traditional test method, if the first stratum is judged to have mining value, the test pipe column is put to a preset position, a channel in the pipe column below the plug is sealed, the pipe column directly enters a second stratum to be tested, the slip packer is firstly set above the first stratum in the sleeve, the annular space below the second stratum is isolated, supporting force is provided for the cross packer, then the cross packer is set, the annular space above the second stratum is isolated, then the tester is opened, the stratum fluid of the second test well section enters the test pipe column from the sieve pipe II, flows upwards through the tester, and the well is opened to flow. The tester is then shut in, and the second test interval is disconnected from both the interior of the string and the annulus, i.e., the well is shut in and recovered. And then lifting the pipe column, unsetting the straddle packer and the slip packer, keeping the second formation fluid in the pipe column, lifting the test pipe column, lifting the oil pipe one by one, and sampling when the second formation fluid in the pipe column is seen. Then, a circulating valve is opened by throwing a rod into the pipe column to enable the inside and the outside of the pipe column to be communicated, and clear water is pumped into the annular space by a pump truck to eject the fluid in the pipe column out of the ground for recycling so as to avoid polluting the environment. And the pressure gauge support cylinder II records a curve of the pressure and the temperature of the whole second stratum along with the change of time, and the curve is explained, so that various parameters of the second testing well section can be obtained.

2. After the first stratum test is finished, the time for drilling the cement plug between the first ground and the second stratum, waiting for setting for 48 hours, checking the sealing performance and the like is saved, and the process for drilling the cement plug after the second stratum test is finished is also saved, so that the test efficiency is greatly improved, the process is shortened, and the test safety is improved.

3. The upper joint of the straddle packer 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. 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.

4. 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.

5. 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.

6. 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.

7. 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.

8. 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.

9. The water drain hole of the reversing outer barrel can drain the stored water in the inner cavity of the lower end of the reversing outer barrel, so that the pressure build-up is avoided.

Drawings

The invention is described in further detail below with reference to the attached drawing figures and the detailed description, which are provided for reference and illustration only and are not meant to limit the invention.

FIG. 1 is a front view of a double seal straddle test string according to the present invention.

FIG. 2 is a front view of a straddle packer of the present invention.

Fig. 3 is a front view of the core tube of fig. 2.

FIG. 4 is a cross-sectional view taken along the cross-section of the indexing lug of FIG. 3.

Fig. 5 is a front view of the cartridge mandrel of fig. 2.

Fig. 6 is a front view of the recycling outer drum of fig. 2.

FIG. 7 is a front view of the coupling sub of FIG. 2.

Fig. 8 is a front view of the shear sleeve of fig. 2.

Fig. 9 is a sectional view of the reversing outer cylinder of fig. 2.

Fig. 10 is a development view and an operation state view of the inverted J-shaped groove of fig. 9.

In the figure: A1. a pressure gauge support cylinder I; A2. a second pressure gauge support cylinder; B1. a screen pipe I; B2. a screen pipe II; C1. a slip packer; D1. lifting the first nipple; D2. lifting the second short section; D3. lifting the third short section; E. plugging with a thread; F. adjusting the short section; G. mechanically locking; H. a tester; J. circulating a valve; C2. a straddle packer; 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, a sealing lip; 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, the double-seal straddle test string comprises a first screen pipe B1 corresponding to a first stratum and a second screen pipe B2 corresponding to a second stratum, wherein a first pressure gauge support cylinder A1 is screwed below the first screen pipe B1, a slip packer C1, a first lifting short section D1 and a plug E are sequentially arranged above the first screen pipe B1, the upper end of the plug E is connected with the bottom of the second screen pipe B2 through an adjusting short section F, and the second screen pipe B2 is upwards and sequentially connected with a second pressure gauge support cylinder A2, a straddle packer C2, a second lifting short section D2, a mechanical lock G, a tester H, a third lifting short section D3 and a circulating valve J.

After the first stratum is tested according to the traditional test method, if the first stratum is judged to have the production value, the test pipe column is put to a preset position, a pipe column inner channel below the plug E is sealed, the pipe column directly enters a second stratum to be tested, the slip packer C1 is firstly set above the first stratum in the sleeve pipe to isolate the annular space below the second stratum and provide the supporting force for the cross packer C2, then the cross packer C2 is set to isolate the annular space above the second stratum, then the tester H is opened, the stratum fluid of the second test well section enters the interior of the test pipe column from the screen pipe B2 and flows upwards through the tester H, and then the well is opened to flow. The tester H is then shut in, and the second test interval is disconnected from both the interior of the string and the annulus, and the well is shut in and recovered. The string is then lifted, the straddle packer C2 and the slip packer C1 are unset, the second formation fluid remains in the string, the test string is raised, the tubing string is raised one by one, and a sample is taken when the second formation fluid in the string is seen. And then, a rod is thrown into the pipe column to open a circulating valve J, so that the inside and the outside of the pipe column are communicated, and clear water is pumped into the annular space by a pump truck to eject the fluid in the pipe column out of the ground for recovery so as to avoid polluting the environment. And the pressure gauge support cylinder II A2 records the pressure and temperature change curve of the whole second stratum along with time, and the curve is interpreted to obtain various parameters of the second test well section.

As shown in fig. 2 to 10, the straddle packer C2 includes an upper joint 1, the upper end of the upper joint 1 is provided with a tapered female thread to be screwed with the upper tubular column, the lower end of the upper joint 1 is screwed with a core tube 2 extending downward, the lower end of the core tube 2 is slidably inserted into the upper port of the 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 the 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 at the lower part of the sealing ring 3a and the inner wall at the lower part of the sealing sleeve 3; 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, the lower end of the rubber cylinder mandrel 6 is provided with a rubber cylinder mandrel external spline 6a, 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 6 e; 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 screwed mode.

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, the channel between the upper bypass hole 5a and the annular space is closed, and the tester H can test conveniently.

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 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 technical solutions formed by adopting equivalent substitutions or equivalent transformations fall within the protection scope of the claims of the present invention. Technical features of the present invention which are not described may be implemented by or using the prior art, and will not be described herein.

Claims (7)

1. The utility model provides a test tubular column is striden to two sealings, includes the screen pipe two that corresponds with first stratum and correspond with second stratum that first stratum, its characterized in that: the lower part of the first sieve tube is rotatably connected with a first pressure gauge support cylinder, a slip packer, a first lifting nipple and a plug are sequentially arranged above the first sieve tube, the upper end of the plug is connected with the bottom of a second sieve tube through an adjusting nipple, and the sieve tube is sequentially connected with a second pressure gauge support cylinder, a straddle packer, a second lifting nipple, a mechanical lock, a tester, a third lifting nipple and a circulating valve in an upward direction;

the straddle packer comprises an upper joint, the upper end of the upper joint is provided with a conical female thread, 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 sealed through an O-shaped ring, and the lower end of the lower joint is provided with a conical male thread; 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; a bypass valve for opening or closing the upper bypass hole flow channel is arranged in the inner cavity of the bypass outer cylinder;

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 sealing ring and the inner wall at the lower part of the sealing sleeve; the lower end internal thread of the bypass outer cylinder is screwed with the middle section external thread of the end face sealing joint, and the upper part of the end face sealing joint is provided with a sealing lip which can be embedded into the annular sealing box; the outer diameter of the sealing sleeve is smaller than the inner diameter of the bypass outer cylinder;

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 larger than the outer diameter of the rubber cylinder in a natural state.

2. The double seal straddle test string of claim 1, wherein: the periphery of the rubber cylinder mandrel is overlapped with a plurality of rubber cylinders, and a spacer ring is arranged between every two adjacent rubber cylinders.

3. The double seal straddle test string of claim 2, 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.

4. The double seal straddle test string of claim 3, 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.

5. The double seal straddle test string of claim 4, 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.

6. The double seal straddle test string of claim 5, 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.

7. The double seal straddle test string of claim 6, wherein: and a plurality of reversing outer barrel drainage holes are formed in the circumferential wall below the inverted J-shaped groove and communicated with the lower cavity of the reversing outer barrel.

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