CN117307106A - Anti-blowout rotation pumping combined operation pipe column with two anti-blowout and two-time opening and pipe pressing functions and operation method - Google Patents

Abstract

The invention provides a two-time blowout-prevention and two-time opening combined pipe column with a lower pipe and a blowout-prevention rotary pumping operation method, which comprises a rod pump supporting cylinder, a double-layer sliding sleeve switch, a controllable internal blowout preventer and a lower pump plug which are sequentially connected from top to bottom, wherein a communication hole is arranged on the side surface of an upper joint of the double-layer sliding sleeve switch, and an internal sliding sleeve and an external sliding sleeve are respectively and hermetically arranged on the inner side and the outer side of the upper joint of the double-layer sliding sleeve switch, which correspond to the communication hole; the lower end of the upper joint of the blowout preventer is provided with a cover plate valve, the lower end of the outer sleeve is internally provided with a shear pin seat in a sealing way, the holes of the upper joint of the blowout preventer and the shear pin seat are internally provided with a core in a sealing way, the core supports the cover plate valve to enable the cover plate valve to be opened and turned on one side of the outer sleeve, the core is limited by a limiting piece on the shear pin seat, and the rod pump supporting cylinder is provided with a rod pump. The invention can shorten the operation time, improve the well repairing efficiency, reduce or even avoid using well killing liquid, reduce the construction cost and labor intensity, and avoid the risk of pollution injury of the reservoir.

Description

Anti-blowout rotation pumping combined operation pipe column with two anti-blowout and two-time opening and pipe pressing functions and operation method

Technical Field

The invention relates to the technical field of oil and natural gas exploitation, in particular to a blowout-preventing rotary pumping combined operation pipe column with a blowout-preventing and twice-opening pressure lower pipe and an operation method.

Background

Oil and gas fields often produce oil and gas wells with certain formation pressure, and the operation process has so-called self-injection capability of injecting fluids such as oil, gas and water in a shaft out of a wellhead. For example, even if the formation pressure of an oil well is kept low, if a foam fluid is used for sand washing during operation, the well bore fluid is replaced by foam fluid in a short time, so that the density of a liquid column is greatly reduced, and intermittent oil, gas and water blowout at a well mouth is often caused. According to the current safety requirements of well control of an oil gas well, when the blowout phenomenon exists in an oil pipe at a well head, the pipe column is forbidden to be pulled down. The traditional operation is to stop the blowout for a long time, and when the water density of the produced oil gas of the stratum is gradually increased, the construction of the next operation of the lifting pipe is carried out after the release of the foam liquid of the shaft is finished, or the circulating well killing of the shaft is carried out by using the well killing liquid with larger specific gravity until the foam liquid is pressed and does not overflow, and the construction of the next operation of the lifting pipe can be carried out. In this way, firstly, the operation takes up a long time, the well repairing operation efficiency is greatly reduced, secondly, the dosage of well entering liquid is increased, the construction cost and the labor intensity are increased, the risk that the reservoir is polluted and damaged by the well entering liquid is increased, and finally the yield of an oil gas well is reduced. The problems are more prominent for gas wells because of higher formation pressure and more obvious pressure injection of wellbore fluids.

Disclosure of Invention

The invention aims to solve the technical problem of providing a two-time blowout prevention and two-time opening combined pipe column with blowout prevention and rotation pumping and operation method for improving the operation efficiency and avoiding the risk of reservoir pollution injury aiming at the defects in the prior art.

The invention is realized in the following way:

the invention provides a blowout-preventing rotary pumping combined operation pipe column with a blowout-preventing and twice-opening pipe under a pressure, which is characterized in that: the device comprises a rod pump supporting cylinder, a double-layer sliding sleeve switch, a controllable internal blowout preventer and a pump lower blanking plug which are sequentially connected from top to bottom, wherein the double-layer sliding sleeve switch comprises a double-layer sliding sleeve switch upper joint and a double-layer sliding sleeve switch lower joint, a communication hole is arranged on the side surface of the upper joint of the double-layer sliding sleeve switch, an internal sliding sleeve and an external sliding sleeve are respectively and hermetically arranged on the inner side and the outer side of the corresponding communication hole on the upper joint of the double-layer sliding sleeve switch, the internal sliding sleeve and the external sliding sleeve are respectively connected with the upper joint of the double-layer sliding sleeve switch through an internal shear pin and an external shear pin, and the upper end of the internal sliding sleeve is provided with a conical surface configured with a sealing ball; the controllable internal blowout preventer comprises a blowout preventer upper connector, a jacket and a blowout preventer lower connector which are sequentially connected from top to bottom, a cover plate valve is arranged at the lower end of the blowout preventer upper connector, a shear pin seat is arranged in the lower end of the jacket in a sealing manner, a core is arranged in holes of the blowout preventer upper connector and the shear pin seat in a sealing manner, the core supports the cover plate valve to enable the cover plate valve to be opened and turned on one side of the jacket, the core is limited by a limiting piece on the shear pin seat, and a rod pump supporting cylinder is provided with a rod pump.

In some alternative embodiments, an inner hole step chamfer is provided on the inner side of the lower end of the upper joint of the double-layer sliding sleeve switch, and the inner diameter of the inner hole step chamfer is smaller than the outer diameter of the inner sliding sleeve.

In some optional embodiments, the upper end and the lower end of the inner sliding sleeve are respectively arranged in a sealing way through a sealing ring and the inner side wall of the upper joint of the double-layer sliding sleeve switch, and are used for sealing the inner side of the communication hole, the sealing ring at the upper end and the lower end of the inner sliding sleeve respectively correspond to the upper sealing surface of the inner wall of the upper joint of the double-layer sliding sleeve switch and the lower sealing surface of the inner wall of the upper joint of the double-layer sliding sleeve switch, and the distance between the chamfer of the inner hole step and the lower sealing surface of the inner wall of the upper joint of the double-layer sliding sleeve switch is equal to the distance between the upper sealing surface of the inner wall of the upper joint of the double-layer sliding sleeve switch and the lower sealing surface of the inner wall of the upper joint of the double-layer sliding sleeve switch, so that after the inner sliding sleeve falls, the sealing surface at the upper part of the inner sliding sleeve is just on the sealing surface of the inner sliding sleeve and the sealing surface of the inner wall of the upper joint of the double-layer sliding sleeve switch, so as to form a secondary sealing surface.

In some alternative embodiments, a space is arranged between the outer sliding sleeve and the outer side of the upper joint of the double-layer sliding sleeve switch to form an annular space, and a step surface is arranged on the inner side of the lower end of the outer sliding sleeve.

In some alternative embodiments, the communication holes are in an elongated waist circular hole structure or in a multi-group elongated slotted mesh filtering structure.

In some alternative embodiments, the cover plate valve comprises a front support, a rear support and a cover plate, wherein the front support and the rear support are symmetrically arranged at the lower end of an upper joint of the blowout preventer, the cover plate is hinged with the front support through a cover plate supporting leg, a torsion spring is arranged at the hinge joint, one end of the torsion spring is fixedly connected with the cover plate supporting leg, and the other end of the torsion spring is fixedly connected with the rear support.

In some alternative embodiments, a compression spring type rack press-fitting is mounted at one end of the upper joint of the blowout preventer, a gear type connector is provided on the cover plate, one end of the gear type connector is hinged with the cover plate, the other end of the gear type connector is hinged with one end of the upper joint of the blowout preventer, and the gear part of the gear type connector is meshed with the rack part of the compression spring type rack press-fitting, so that the gear type connector and the cover plate form a small-angle hinge movable mechanism.

In some alternative embodiments, the pressure spring type rack press fitting part is installed in a side hole of the upper joint of the blowout preventer in a penetrating manner, the pressure spring type rack press fitting part comprises a rack press rod, a rack part is arranged at the outer end part of the rack press rod, the inner end part is connected with a pressure spring, the gear type connecting part comprises a gear connecting rod, one end of the gear connecting rod is provided with a gear hinge part, the other end of the gear connecting rod is provided with a cover plate hinge part, the gear hinge part is provided with a hinge hole for being hinged with the upper joint of the blowout preventer, and the gear hinge part is provided with a gear tooth for being meshed with the rack part.

In some alternative embodiments, the core is provided with a balance hole which is communicated with an annular space between the core and the outer sleeve, and the inner end of the rack compression rod is provided with a breathing hole along the axis, so that the pressure inside and outside the pressure spring mounting hole on one side of the joint of the blowout preventer are balanced.

The operation method for the blowout-preventing rotary pumping combined operation pipe column with the blowout-preventing and twice-opening under-pressure pipe is characterized by comprising the following steps of: the method comprises the following steps:

s1, lowering the two blowout preventers, opening the pipe blowout prevention rotary pumping combined operation pipe column under the pressure twice to a preset depth in a well, and at the moment, realizing the first closing sealing blowout prevention of the inside of the oil pipe by the blanking plug in the process of lowering the tool string into the well until the pipe string is lowered to the preset depth in the well;

s2, after the pipe is opened twice for two times for blowout prevention and the pipe is pressed down, the blowout prevention rotary pumping combined operation pipe column is put in place, the liquid is filled in the oil pipe, after the liquid reaches the opening pressure value of the pump-down plug, the pump-down plug core falls down, a central flow passage is opened, the first opening flow passage in the oil pipe is realized, and at the moment, the production of blowout in the oil pipe or sand flushing and well flushing can be carried out;

s3, when the production of open-flow in the oil pipe or sand flushing and well flushing are finished, the inside of the shaft is still in a low-pressure open-flow state, a steel ball with small specification is put into the oil pipe at the well head, after the steel ball is seated on the controllable inner blowout preventer, the well head is hydraulically powered, after the steel ball reaches the closing pressure value of the controllable inner blowout preventer, the built-in core of the steel ball shears a pin, the steel ball and the core of the controllable inner blowout preventer fall together, the cover plate valve immediately turns up to close the liquid inlet channel under the combined action of spring force and upward open-flow pressure at the bottom of the well, and at the moment, the controllable inner blowout preventer realizes second sealing and blowout prevention in the oil pipe;

s4, before the rod pump is put into the oil pipe, a large-size steel ball is put into the oil pipe again, the steel ball is placed on the double-layer sliding sleeve switch, hydraulic pressure is not added temporarily, after that, the rod pump is put into the oil pipe to a designed position in a second sealing blowout prevention state, the rod pump is not put into the oil pipe for setting, at this time, the hydraulic pressure is added into the oil pipe, and is conducted to the steel ball of the double-layer sliding sleeve switch through the annular gap of the rod pump and the oil pipe until the sliding sleeve core is knocked out by the hydraulic pressure, the side hole of the double-layer sliding sleeve switch is exposed, so that the second opening overcurrent in the oil pipe is realized, and finally the rod pump turning and pumping functions are completed.

The beneficial effects of the invention are as follows:

1. the invention realizes the first closing sealing blowout prevention in the oil pipe in the process of entering the well by arranging the rod pump supporting cylinder, the double-layer sliding sleeve switch, the controllable inner blowout preventer and the pump lower blanking plug, and the central flow passage is completely opened after the pump lower blanking plug core is knocked off, at the moment, the pump lower blanking plug realizes the first opening flow passage in the oil pipe, the whole oil pipe string can realize the complete flow passage, at the moment, the production of the internal blowout of the oil pipe or the flushing of the sand can be carried out, when the production of the internal blowout of the oil pipe or the flushing of the sand is finished, the well bore still presents a low-pressure blowout state, small-specification steel balls are put into the oil pipe at the well mouth, after the steel balls are seated on the controllable inner blowout preventer, the well mouth is hydraulically pressurized, after reaching the closing pressure value of the controllable inner blowout preventer, the steel balls and the controllable inner blowout preventer core fall together, the cover plate valve immediately turns up to close the liquid inlet passage under the combined action of the spring force and the upward blowout pressure at the bottom, at the moment, and the second sealing blowout prevention in the oil pipe is realized by the controllable inner blowout preventer; before the rod pump is put into, the large steel ball is put into again, the steel ball can be placed on the double-layer sliding sleeve switch, but hydraulic pressure is not added temporarily, then the rod pump is put into the oil pipe to a designed position under the condition of second sealing blowout prevention, the rod pump setting is not carried out firstly, hydraulic pressure is added into the oil pipe at this moment, the hydraulic pressure is conducted onto the steel ball of the double-layer sliding sleeve switch through the annular gap between the rod pump and the oil pipe until the sliding sleeve core is knocked out by the hydraulic pressure, and the side hole of the double-layer sliding sleeve switch is exposed, so that the second opening overcurrent in the oil pipe is realized, and the rod pump turning and pumping function is finally completed. Thus, the operation time is shortened, the well repairing operation efficiency is improved, the use of well killing liquid is reduced or even avoided, the construction cost and labor intensity are reduced, and the risk of pollution injury of a reservoir is avoided.

2. The double-layer sliding sleeve switch that this application provided not only can play traditional sliding sleeve switch effect, carries out the pressure testing to upper portion tubular column and tests the hourglass, opens the oil jacket and even flows through, still increases new function, keeps double-layer sliding sleeve switch top connection side intercommunicating pore to seal all the time before opening the sliding sleeve promptly, prevents scale deposit, prevents that impurity from adhering to get into, reaches the long-time submergence in well liquid and still can satisfy the requirement of normally opening after the production of interior central chamber overflows.

3. According to the invention, the core is arranged in the controllable inner blowout preventer, the core supports the cover plate valve to enable the cover plate valve to be opened and turned over at one side of the outer sleeve, so that the central flow passage in the underground controllable inner blowout preventer is opened, pressurized fluid can be normally and automatically ejected out of the wellhead through the underground tubular column, normal production is ensured, when the flow passage needs to be closed, a steel ball or a bat is thrown into the wellhead, after the steel ball or the bat is seated on the underground controllable inner blowout preventer, the wellhead applies hydraulic pressure with a certain magnitude, the steel ball or the bat falls from the inside of the underground controllable inner blowout preventer together with the ball seat core, falls onto the oil pipe inner catcher at the bottom of the tubular column, the underground controllable inner blowout preventer can be closed at the moment that the ball seat core falls down, and the blowout time of the oil-gas-water well under pressure or the blowout overflow state of the fracturing well can be greatly shortened, the operation occupation time is shortened, the well repairing operation efficiency is improved, the use of well killing liquid is reduced, the construction cost and the labor intensity are reduced, and the risk of pollution and damage of a reservoir is avoided.

4. Through setting up the rack link mechanism cover plate valve of automatic fine setting sealing angle, its structure is compacter, the activity is more nimble, not only increased "automatic fine setting sealing angle, just can realize the function that the cover plate valve was closed completely to close sealing" against the pressure spring elasticity, and rack link mechanism's width and thickness can be littleer, compacter moreover, and can accomplish more easily not only guaranteeing sufficient overflow channel size, guarantee the biggest external diameter of less instrument again simultaneously, this is very important to its use that is used in various little specification sleeve pipes more as uniflow valve or blowout prevention valve, namely the commonality of this novel invention instrument, adaptability are stronger.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic diagram of a dual blowout prevention and dual blowout opening combined pipe string (primary closed state) with blowout prevention and rotation pumping under pressure according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a dual blowout prevention and dual blowout opening pipe under pressure blowout prevention rotary pumping combined operation pipe column in a one-time opening state according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of a two-time blowout prevention and two-time opening of a pipe-under-pressure blowout prevention rotary pumping combined tubular column lower rod pump (a two-time closing state) according to an embodiment of the present invention.

Fig. 4 is a schematic diagram of a two-time blowout prevention and two-time opening of a pipe-under-pressure blowout prevention rotary pumping combined tubular column lower rod pump (a two-time opening state) according to an embodiment of the present invention.

Fig. 5 is a schematic diagram of a dual blowout prevention and dual opening pipe under pressure and blowout prevention rotary pumping combined pipe column, i.e. a setting rotary pumping (secondary opening state), according to an embodiment of the present invention.

Fig. 6 is a schematic diagram of a double-layer sliding sleeve switch structure in a full-path through-flow state according to an embodiment of the present application.

Fig. 7 is a schematic diagram of a double-layer sliding sleeve switch structure for opening a lateral overcurrent state according to an embodiment of the present application.

FIG. 8 is a perspective cross-sectional view (open all-pass state) of a downhole controllable internal blowout preventer provided by an embodiment of the present invention;

fig. 9 is a cross-sectional view A-A of fig. 8.

Fig. 10 is a B-B cross-sectional view of fig. 8.

Fig. 11 is a schematic structural view of a cover plate valve according to an embodiment of the present invention.

FIG. 12 is a half cross-sectional view (start-up closed state) of a downhole controllable internal blowout preventer provided by an embodiment of the present invention.

Figures 13a-13e are schematic representations of various dimensions of a cover plate valve provided in an embodiment of the present invention.

Fig. 14 is a cross-sectional view of a cover plate valve of a rack and pinion mechanism for automatically fine-tuning a sealing angle according to a second embodiment of the present invention.

Fig. 15 is a schematic view showing a state in which a cover plate valve is opened in the second embodiment of the present invention.

Fig. 16 is a schematic structural view of a rack connecting rod in the second embodiment of the present invention.

Fig. 17 to 18 are schematic diagrams of an automatic fine adjustment sealing angle principle of a rack-and-link type cover plate valve in a second embodiment of the present invention.

In the figure: 1-upper joint; 1-a front support; 1-2-a rear bracket; 1-3 parts of an upper joint sealing ring; 1-4, sealing steel rings; 2-coat; 3-a core; 3-1-balance hole; 3-2-core seal ring; 4, a cover plate valve; 4-1-cover plate valve support legs; 5-a pin shaft; 6-torsion spring; 7, a sealing gasket; 8-a shear pin seat; 9-shear pins; 10-lower joint; 10-1, a lower joint sealing ring; 11-steel ball; 12-cotter pin; 13-rack compression bars, 14-gear connecting rods, 15-pin shafts, 16-supporting legs, 17-compression springs, 18-shaft sleeves, 19-cotter pins, 20-cover plates, 20-1-brackets, 21-sealing rings and 22-valve bodies; 23-breathing holes; 24-upper joint, 24-1-communication hole, 25-inner sliding sleeve, 26-outer sliding sleeve, 27-inner shear pin, 28-outer shear pin, 29-inner rubber ring, 30-outer rubber ring, 31-lower joint and 32-steel ball; 33-chamfering the inner hole step; i-an oil pipe string; II-a rod pump support cylinder; III, a double-layer sliding sleeve switch for preventing sand and scale; IV, a controllable internal blowout preventer; v-under pump blanking plug; VI, a sieve tube; VII-sucker rod string; VIII-rod pump.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The features and capabilities of the present invention are described in further detail below in connection with the examples.

Example 1:

as shown in fig. 1-5, the embodiment provides a dual blowout prevention dual-opening pipe-pressing blowout prevention rotary pumping combined operation pipe column, which comprises a rod pump supporting cylinder ii, a double-layer sliding sleeve switch iii, a controllable internal blowout preventer iv, a pump lower blanking plug v and a screen pipe vi which are sequentially connected from top to bottom, wherein all tools are connected through an oil pipe string i. The well string is shown in fig. 1-5, and all tools are connected by 1 whole oil pipe or oil pipe nipple, the oil pipe nipple refers to a shorter oil pipe with the length smaller than that of one whole oil pipe, and the length of the whole oil pipe commonly used in the oil and gas industry is generally 9.4-9.6 meters, so the oil pipe nipple refers to an oil pipe with the length smaller than or equal to 6.0 meters, and the oil pipe nipple in the technical scheme adopted by the invention is generally 0.5-2 meters. Said invented screen pipe VI is also called as internal blocking connector of oil pipe, and is a simple structure downhole tool whose side wall is equipped with hole and bottom is sealed, and its bottom is used for receiving falling material in the oil pipe.

In this embodiment, the rod pump support cylinder ii is configured with a rod pump viii, and the upper end of the rod pump viii is connected with a sucker rod column vii, where the rod pump adopts a structure in the prior art, which is not described herein.

As shown in fig. 6 and 7, the double-layer sliding sleeve switch comprises a double-layer sliding sleeve switch upper joint 24 and a double-layer sliding sleeve switch lower joint 31, communication holes 24-1 for communicating the inner side and the outer side of the double-layer sliding sleeve switch upper joint are formed in the double-layer sliding sleeve switch upper joint, an inner sliding sleeve 25 and an outer sliding sleeve 26 are respectively and hermetically arranged on the inner side and the outer side of the double-layer sliding sleeve switch upper joint corresponding to the communication holes 24-1 on the double-layer sliding sleeve switch upper joint 24, the upper end and the lower end of the inner sliding sleeve 25 are respectively and hermetically arranged on the inner side wall of the double-layer sliding sleeve switch upper joint through sealing rings 29 and are used for sealing the inner side of the communication holes, and the upper end and the lower end of the outer sliding sleeve 26 are respectively and hermetically arranged on the outer side wall of the double-layer sliding sleeve switch upper joint through sealing rings 30 and are used for sealing the outer side of the communication holes. The inner sliding sleeve 25 and the outer sliding sleeve 26 are respectively connected with the upper joint 24 of the double-layer sliding sleeve switch through the inner shear pin 27 and the outer shear pin 28, the upper end of the inner sliding sleeve 25 is provided with a conical surface configured with a sealing ball, and the outer diameter of the lower joint of the double-layer sliding sleeve switch is larger than that of the outer sliding sleeve 26, so that the outer sliding sleeve 26 is limited by the lower joint 31 of the double-layer sliding sleeve switch when sliding down.

In this embodiment, a space is formed between the outer sliding sleeve 26 and the outer side of the upper connector 24 of the double-layer sliding sleeve switch, so as to form an annular space, and a step surface is arranged on the inner side of the lower end of the outer sliding sleeve 26. An inner hole step chamfer 33 is arranged on the inner side of the lower end of the upper joint 24 of the double-layer sliding sleeve switch, and the inner diameter of the inner hole step chamfer 33 is smaller than the outer diameter of the inner sliding sleeve 25, so that the inner sliding sleeve 25 can be supported when falling to the inner sliding sleeve, and a rigid and hard seal is formed. The sealing rings 29 at the upper end and the lower end of the inner sliding sleeve 25 respectively correspond to the upper sealing surface of the inner wall of the upper joint 24 of the double-layer sliding sleeve switch and the lower sealing surface of the inner wall of the upper joint of the double-layer sliding sleeve switch, and the distance between the inner hole step chamfer 33 and the lower sealing surface of the inner wall of the upper joint of the double-layer sliding sleeve switch is equal to the distance between the upper sealing surface of the inner wall of the upper joint of the double-layer sliding sleeve switch and the lower sealing surface of the inner wall of the upper joint of the double-layer sliding sleeve switch, so that after the inner sliding sleeve 25 falls down, the sealing surface at the upper part of the inner sliding sleeve is exactly positioned on the sealing surface of the inner wall of the upper joint of the double-layer sliding sleeve switch where the sealing ring at the lower part of the inner sliding sleeve is knocked down, thereby forming a secondary sealing surface, as shown in fig. 7.

As shown in fig. 7, when the double-layer sliding sleeve switch needs to be opened, a wellhead is put into a sealing ball 32 (steel ball or bat) with corresponding specification, the sealing ball 32 is seated on the inner sliding sleeve 25, the inner sliding sleeve 25 is knocked off after the wellhead is hydraulically pressed to form a pressure-blocking shearing inner shear pin 27, the outer circle of the bottom end of the inner sliding sleeve 25 is formed into a rigid and hard seal with the chamfer 33 surface of the inner hole step of the upper joint of the double-layer sliding sleeve switch, and meanwhile, the upper inner sealing ring of the inner sliding sleeve 25 is exactly positioned on the inner sealing surface of the inner joint of the double-layer sliding sleeve switch where the lower inner sealing ring is positioned before the core is knocked off, so that sealing rings are formed to seal, and the sealing ball 32 is always seated on the inner sliding sleeve 25. That is, the sealing ball 32 is seated on the inner slide 25 and is hit off together to form a secondary seal immediately after being dropped, and thus, the inside of the upper joint 24 of the double slide switch is also secondarily pressurized. The hydraulic pressure is conducted to the outer sliding sleeve 26 through the side communication hole 24-1 of the upper joint 24 of the double-layer sliding sleeve switch, and the outer shear pin 28 is sheared again under the action of the pressure difference between the inside and the outside of the oil pipe, so that the outer sliding sleeve 26 is knocked down and sleeved on the lower joint 31 of the double-layer sliding sleeve switch, and the well cannot fall. And finally, the side communication hole 24-1 of the upper joint of the double-layer sliding sleeve switch is completely exposed, so that oil sleeve continuous through flow is realized. Because the inner sliding sleeve and the outer sliding sleeve completely seal and wrap the communication hole 24-1 on the side surface of the upper joint 24 of the double-layer sliding sleeve switch, the communication hole 24-1 is always protected from being corroded by well fluid before the sliding sleeve is opened, and therefore the performance requirements of preventing scaling or preventing impurities from being attached and entering are achieved.

In this embodiment, before the inner shear pin 27 is sheared and the inner sliding sleeve 25 is removed, the tightness of the pipe column above the double-layer sliding sleeve switch can be verified by holding pressure.

In this embodiment, besides setting the external shear pin 28 at the upper end of the external sliding sleeve 26 as shown in fig. 6 and 7, the external shear pin 28 may be set at a position below the lower sealing ring 30 of the external sliding sleeve 26, when the external sliding sleeve 26 is knocked down and limited to fall on the lower joint 31 of the double-layer sliding sleeve switch, the top opening end of the external sliding sleeve 26 is still slightly higher than the position of the external shear pin hole by a certain height, so that the broken end of the external shear pin 28 falls inside the external sliding sleeve 26 and cannot fall into a wellbore, and the problem of downhole tool clamping is prevented.

In this embodiment, the maximum outer diameter of the outer sliding sleeve 26 is smaller than the maximum outer diameter of the upper connector 24 of the double-layer sliding sleeve switch and smaller than the maximum outer diameter of the lower connector 31 of the double-layer sliding sleeve switch, so as to avoid colliding with the outer sliding sleeve 26 during the well bore tripping process.

In this embodiment, the communicating hole 24-1 on the upper connector 24 of the double-layer sliding sleeve switch can adopt a long-strip waist round large-channel flow hole structure, or can adopt a plurality of groups of long-strip slit sieve pore filtering structures, and can effectively filter impurities such as broken rubber and solid fragments remained in a shaft by adopting the plurality of groups of long-strip slit sieve pore filtering structures, so that the problems of blockage of a pump and the like caused by pumping the impurities into a production pipe column are prevented.

As shown in fig. 8-12, the controllable internal blowout preventer iv comprises a blowout preventer upper connector 1, a jacket 2 and a blowout preventer lower connector 10 which are sequentially connected from top to bottom, a cover plate valve 4 is arranged at the lower end of the blowout preventer upper connector 1, a shear pin seat 8 is arranged in the lower end of the jacket 2 in a sealing manner, a core 3 is arranged in holes of the blowout preventer upper connector 1 and the shear pin seat 8 in a sealing manner, the core 3 supports the cover plate valve 4 to be opened and turned on one side of the jacket, and the core 3 is limited by a limiting piece on the shear pin seat 8.

In this embodiment, a positioning shoulder is disposed in the outer sleeve 2, the upper end and the lower end of the shear pin seat 8 are respectively abutted against the positioning shoulder and the end face of the lower joint of the blowout preventer, and a sealing gasket is disposed at the upper end of the shear pin seat 8. The core 3 is provided with a sealing ring to penetrate into the upper joint 1, the outer sleeve 2 and the shear pin seat 8 of the blowout preventer, and the sealing is realized by the upper sealing ring and the lower sealing ring which are contacted with the inner wall of the steel body. The limiting piece is a shear pin 9, the shear pin 9 is arranged at the bottom end of the core or is penetrated and arranged on the side surface of the core, the end surface of the bottom of the core 3 props against the shear pin 9 or is penetrated by the shear pin 9 from the side surface, and the limiting fixation of the core 3 is realized.

As shown in fig. 8, 11 and 12, the cover plate valve comprises a front support 1-1, a rear support 1-2 and a cover plate 4, wherein the front support 1-1 and the rear support 1-2 are symmetrically arranged at the lower end of an upper joint of the blowout preventer, the cover plate 4 is hinged with the front support 1-1 through a cover plate supporting leg 4-1, the cover plate supporting leg 4-1 is hinged with the two front supports 1-1 through a pin shaft 5, a torsion spring 6 is arranged at the hinged position, one end of the torsion spring 6 is fixedly connected with the cover plate supporting leg 4-1, and the other end of the torsion spring 6 is fixedly connected with the rear support 1-2. Wherein, fix the flat washer of rubber on the apron valve plane in order to strengthen sealed effect, the cotter pin 12 anticreep is penetrated to round pin axle thin head end. Under the natural state, the cover plate valve can be pressed on the sealing steel ring embedded on the end face of the inner hole of the upper joint of the blowout preventer under the action of the elasticity of the torsion spring 6, so that the upward blowout pressure of the shaft fluid is intercepted, and under the action of the upward jacking pressure, the cover plate valve is sealed more reliably. Because the front bracket 1-1 and the rear bracket 1-2 are fixed on one side of the end face of the upper joint 1 of the blowout preventer, the circle center of the cover plate valve and the axis of the upper joint of the blowout preventer are in eccentric positions, and the circle center of the inner hole of the upper joint of the blowout preventer and the circle center of the valve plate of the cover plate valve are coaxial, namely, the inner hole of the upper joint of the blowout preventer is of an eccentric structure, as shown in fig. 8 and 10.

The inner hole of the shear pin seat 8 is coaxial with the inner hole of the core 3 and the inner hole of the upper joint 1 of the blowout preventer, so the inner hole of the shear pin seat 8 is of an eccentric structure as shown in fig. 8 and 9. After the core 3 penetrates the shear pin seat 8 and the blowout preventer upper joint 1 are fixed in place, the core 3 supports the cover plate valve to enable the cover plate valve to be fully opened and turned over on one side of the cavity, the underground controllable internal blowout preventer is in a fully opened state, the inner hole channel of the core 3 completely meets the circulation of oil, gas and water output media, and the well entering liquid can also meet the measures such as fracturing liquid and the like to be injected into a shaft. The core is provided with a balance hole 3-1, and high pressure is discharged into the cavity in the fracturing process, so that the whole underground controllable internal blowout preventer achieves the performance of bearing high pressure.

When the wellhead is in a low-pressure overflow state, steel balls of corresponding specifications are thrown into the wellhead, the steel balls are seated on the sealing conical surface at the top of the core, and then downward hydraulic pressure is applied from the wellhead. When the downward hydraulic force overcomes the upward overflow jacking force and finally reaches the shearing force of the shear pins 9, the pins 9 are sheared, and the steel balls 11 and the cores 3 instantaneously fall from the inner holes of the upper joint 1 of the blowout preventer and the shear pin seat 8 and fall into the ball receiving basket at the bottom of the pipe column. At this time, the cover plate valve loses the core support, and is instantly turned up and flatly pressed on the sealing steel ring embedded on the end face of the inner hole of the upper joint of the blowout preventer under the action of the spring force, so that the overflow pressure of the fluid in the cut-off well is closed, and the state of no pressure in the wellhead oil pipe is realized, as shown in fig. 12.

The under-pump blanking plug V comprises a shell, a blocking device is arranged in the shell in a sealing mode, and the blocking device is fixed on the shell through a pin.

When the well fluid of the oil and gas well has a certain pressure, the well mouth is connected with a long pipeline and a blowout pool or a blowout tank for controlling a blowout valve device to a safe distance in the well control range of the well control safety construction well head pressure, namely in the bearing range of an oil pipe self-sealing blowout preventer (sealing leather cup) of the well head blowout preventer. Under the state that the blowout control of the blowout line at the far end of the sleeve opening is continuous, the pressure bearing at the self-sealing blowout preventer (sealing leather cup) of the oil pipe is low, and the oil pipe can be completely sealed in the dynamic dropping process.

The embodiment also provides a working method for the two-time blowout prevention and two-time opening of the blowout prevention rotary pumping combined operation pipe column with the pressure reduction pipe, which comprises the following steps:

s1, lowering the two-time blowout prevention and two-time opening pipe-pressing blowout prevention rotary pumping combined operation pipe column according to any one of claims 1-9 to a preset depth in a well, wherein a plug under a pump in the process of descending a tool string into the well realizes the first closing, sealing and blowout prevention in an oil pipe until the pipe string is lowered to the preset depth in the well, as shown in figure 1;

s2, after the pipe is opened twice for two times, the pipe is opened twice, the pipe is opened under the pressure, the pipe is rotated, the pumping and the connecting pipe is pulled down in place, the liquid is filled in the oil pipe, after the opening pressure value of the pump-down plug is reached, the core of the pump-down plug falls down, and the central flow passage is completely opened. At this time, the under-pump plug realizes the first opening and the over-flow in the oil pipe, namely the complete over-flow in the whole oil pipe string, and at this time, the production of open flow in the oil pipe or sand flushing can be carried out, as shown in figure 2;

s3, when the open-flow production or sand flushing and well flushing in the oil pipe are finished, the well bore is still in a low-pressure open-flow state, and when the wellhead oil pipe is in open-flow oil-gas-water injection, the rod pump cannot be put into the well head oil pipe to perform self-injection rotary pumping construction. At this time, the oil pipe is not required to be moved, only steel balls with corresponding specifications are needed to be put into the oil pipe at the wellhead, after the steel balls are seated on the controllable internal blowout preventer, hydraulic pressure is applied to the wellhead, after the closing pressure value of the controllable internal blowout preventer is reached, the built-in core of the steel balls shears pins, the steel balls and the core of the controllable internal blowout preventer fall down together, and the cover plate type blowout preventing valve of the controllable internal blowout preventer immediately turns up to close the liquid inlet channel under the combined action of spring force and upward blowout pressure at the bottom of the well. At this time, the controllable internal blowout preventer realizes the second sealing blowout prevention in the oil pipe, as shown in fig. 3;

s4, immediately before the rod pump is put in, a larger steel ball with corresponding specification is put in again, and the steel ball is seated on the sand-scale prevention double-layer sliding sleeve switch, but hydraulic pressure is not added temporarily. And then, under the condition that the second sealing blowout prevention state is realized in the oil pipe, starting to put the rod pump down (as shown in fig. 3) until the rod pump is lowered to the depth of about 10 meters at the upper part of the supporting cylinder, not performing rod pump setting, at this time, conducting hydraulic pressure to the steel ball of the sand-preventing double-layer sliding sleeve switch through the annular gap of the rod pump and the oil pipe until the sliding sleeve core is removed by the hydraulic pressure, and exposing the side hole of the sand-preventing double-layer sliding sleeve switch to realize the second opening overcurrent in the oil pipe, as shown in fig. 4. The rod pump is then seated in the support cylinder, effecting the rod pump pumping function, as shown in fig. 5.

Thus, the purpose of realizing pressurized sealing blowout prevention during the first pipe running is achieved, and the production of open-flow production or sand flushing in the oil pipe is started after the blanking plug under the pump is opened; and then the oil outlet pipe is not started, the controllable internal blowout preventer is closed in advance when the sucker rod is arranged under the sucker rod by the rod pump, the pressurized sealing blowout prevention in the second tripping process is realized, the double-layer sliding sleeve switch for preventing sand and scale is opened before the rod pump is arranged in a sitting and sealing way, the second opening overcurrent in the oil pipe is realized, and the pressurized blowout prevention sucker rod pump rotary pumping well completion is successfully completed.

Example 2:

the present embodiment is basically the same as the first embodiment in structure, except that: the structure of a cover plate valve of the controllable internal blowout preventer. The reason for improving the cover plate valve is as follows: compared with a ball valve type uniflow valve or a blowout prevention valve, the cover plate valve adopted in the embodiment has the advantages of flexible opening and closing of a switch and large flow passage after the valve is completely opened, but the cover plate valve has the following three defects in structural design. On the one hand, in order to ensure that the elasticity of the torsion spring is enough, the total width t and the total thickness h of the upper bracket and the supporting leg of the cover plate valve are larger, and the lateral thickness h' of the cover plate in the vertical state after the cover plate is completely opened is also larger. This results in that if the cover valve is to be secured with a certain size of the inner diameter D2 of the connecting housing (the maximum outer diameter of the housing is also constant), the size of the flow-through path D1 thereof is to be reduced, i.e. the flow-through path is to be reduced; to ensure a sufficiently large dimension of the through-flow path D1, the inner diameter D2 of the connecting housing of the cover plate valve is correspondingly increased, i.e. the maximum outer diameter of the housing is correspondingly increased (the wall thickness of the housing is relatively fixed to ensure the strength of the steel body), as shown in fig. 13a to 13 e. While for smaller inner diameter wellbore casing, the maximum outer diameter of the tool is limited. That is, such conventional rack-mounted cover plate valves are structurally difficult to ensure a sufficient flow passage while at the same time ensuring a small maximum tool outer diameter. On the other hand, the cover plate, the bracket and the supporting legs are all formed by welding or integrally processing and are in an integral rigid connection state. When the cover plate valve cover is closed, the contact size of the cover plate valve cover and the sealing opening part of the flow passage is relatively fixed, once the cover plate valve cover is assembled and fixed, the cover plate valve cover cannot be adjusted, the whole assembly difficulty is high, a sealing gap is often formed after the cover plate is closed, namely, the cover plate valve cover is in an untight closing state under the natural elastic force state of the torsion spring, and the cover plate can be completely sealed only after the cover plate is pressed under the action of hydraulic pressure reaching a certain high value. In the third aspect, if the torsion spring is required to achieve a complete sealing state under the natural elastic state, the diameter of the steel wire of the torsion spring needs to be increased, the rigidity is improved, and the like, so that the torsion spring is easy to break or the service life is shortened when the opening and closing angle of the cover plate reaches about 90 degrees. Simultaneously, increase torsional spring structural design also can lead to simultaneously that the size increases such as support, landing leg, and then the linkage influences D1, D2, h', t equidimension structure, finally leads to this kind of traditional support formula flap valve to be difficult to more in structural design both guarantee sufficient overflow channel size, guarantee the biggest external diameter of less instrument simultaneously again.

Therefore, this embodiment provides one kind and both can guarantee sufficient overflow passageway in structural design to above-mentioned problem, can guarantee the biggest external diameter of less instrument simultaneously again, reduces the whole assembly degree of difficulty moreover, guarantees that the apron valve closes and to close the moment can automatic fine setting seal angle, guarantees only can reach the rack connecting rod mechanism lid valve of tight seam sealing state's that can automatic fine setting seal angle under the spring force effect.

As shown in fig. 14 and 15, the blowout preventer comprises a valve body 22 (corresponding to an upper joint of the blowout preventer in the first embodiment) and a cover plate 20 hinged with the valve body 22, wherein a sealing ring 21 is arranged at the end part of the cover plate matched with the valve body, a pressure spring type rack press fitting member is arranged at one end part of the valve body 22, a gear type connecting member is arranged on the cover plate 20, one end of the gear type connecting member is hinged with the cover plate 8, the other end of the gear type connecting member is hinged with one end part of the valve body 22, and a gear part of the gear type connecting member is meshed with a rack part of the pressure spring type rack press fitting member, so that the gear type connecting member and the cover plate form a small-angle hinge movable mechanism.

In this embodiment, the pressure spring type rack press fitting piece is installed in a hole on one side of the valve body in a penetrating manner, the pressure spring type rack press fitting piece comprises a rack press rod 13, a rack portion is arranged at the outer end portion of the rack press rod 13, and the inner end portion is connected with a pressure spring 17. The bottom end of the rack pressing rod 13 penetrates through the pressure spring 17 and is integrally arranged in a side hole of the valve body, and teeth at the upper end of the rack pressing rod are meshed with teeth of the gear connecting rod to form a gear and rack mechanism.

The gear type connecting piece comprises a gear connecting rod 14, wherein one end of the gear connecting rod 14 is provided with a gear hinge part, and the other end of the gear connecting rod is provided with a cover plate hinge part. The gear hinge part is provided with a hinge hole, the gear hinge part is provided with gear teeth which are meshed with the rack part, the gear teeth are sector gear teeth, in the embodiment, semicircular gear teeth are meshed with rack teeth on the rack compression bar. The valve body 22 is provided with the supporting legs 16, and the pin shaft 19 penetrates through the gear tooth hinge holes and then is penetrated with two symmetrical shaft sleeves 18 to be hinged with the cover plate supporting legs 16, so that a rotating mechanism is formed. The hinge part of the cover plate is hinged with a bracket 20-1 arranged in the center of the cover plate through a pin shaft 15, and forms a small-angle hinge movable mechanism with the cover plate. In this way, in this embodiment, the pressure spring, the rack compression bar, the gear connecting rod, the hinged part of the supporting leg and the hinged part of the cover plate bracket form a cover plate valve of the rack connecting rod mechanism, which can automatically fine-tune the sealing angle.

The compression spring 17 is always in a compressed state, and the gear connecting rod is just in an almost horizontal position when the compression spring is at the top dead center, so that the cover plate valve is forced to be just covered and sealed on the sealing ring 21, namely, the valve body 22 is closed and the flow passage is closed. Because the gear connecting rod penetrates into the cover plate bracket 20-1 through the pin shaft 15 and forms a small-angle hinge movable mechanism with the cover plate, the planes of the gear connecting rod and the cover plate have a small-angle movable included angle of 0-alpha, and the cover plate can realize automatic leveling and sealing under the elastic prying action of the pressure spring at the moment that the cover plate is pressed on the sealing ring, as shown in fig. 17 and 18. When the gear connecting rod is lifted to the complete opening of the cover plate, the compression stroke of the pressure spring reaches the maximum.

In order to ensure the up-and-down movement precision of the rack compression bar in the spring hole, the matching clearance between the cylinder at the lower end of the rack compression bar and the spring hole is very small, so that a breathing hole 23 with a certain sectional area is arranged on the cylinder at the lower end of the rack compression bar along the axis (as shown in fig. 17), thereby ensuring the pressure communication balance between the up-and-down spring hole of the cylinder at the lower end of the rack compression bar and ensuring the free up-and-down movement of the rack compression bar under the action of the pressure spring, as shown in fig. 14 and 15.

Compared with the traditional bracket type cover plate valve introduced in the embodiment 1, the automatic fine-tuning sealing angle type rack and connecting rod mechanism cover plate valve has the advantages that the structure is more compact, the movement is more flexible, the function of 'automatic fine-tuning sealing angle and complete cover sealing of the cover plate valve can be realized by abutting against the elastic force of a pressure spring', and under the certain dimension of D1 and D2, after the gear connecting rod is lifted to the cover plate to be completely opened, the width and the thickness (equivalent to the dimension values of h, h and t) of the rack and connecting rod mechanism can be smaller and more compact. The rack connecting rod mechanism cover plate valve capable of automatically fine-adjusting the sealing angle can ensure the size of a sufficient through-flow channel and the maximum outer diameter of a smaller tool more easily compared with the traditional bracket cover plate valve in structural design, and is very important for being used as a uniflow valve or a blowout prevention valve more commonly used in various small-specification sleeves, namely the novel tool has stronger universality and adaptability.

Compared with the traditional torsion spring, the novel rack-and-link mechanism cover plate valve capable of automatically fine-adjusting the sealing angle can be adjusted to be larger in elasticity by adopting the compression spring, and the service life is longer.

The embodiments described above are some, but not all embodiments of the invention. The detailed description of the embodiments of the invention is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Claims (10)

1. The anti-spraying rotation pumping combined operation pipe column is opened twice for two times with a pressing pipe, and is characterized in that: the device comprises a rod pump supporting cylinder, a double-layer sliding sleeve switch, a controllable internal blowout preventer and a pump lower blanking plug which are sequentially connected from top to bottom, wherein the double-layer sliding sleeve switch comprises a double-layer sliding sleeve switch upper joint and a double-layer sliding sleeve switch lower joint, a communication hole is arranged on the side surface of the upper joint of the double-layer sliding sleeve switch, an internal sliding sleeve and an external sliding sleeve are respectively and hermetically arranged on the inner side and the outer side of the corresponding communication hole on the upper joint of the double-layer sliding sleeve switch, the internal sliding sleeve and the external sliding sleeve are respectively connected with the upper joint of the double-layer sliding sleeve switch through an internal shear pin and an external shear pin, and the upper end of the internal sliding sleeve is provided with a conical surface configured with a sealing ball; the controllable internal blowout preventer comprises a blowout preventer upper connector, a jacket and a blowout preventer lower connector which are sequentially connected from top to bottom, a cover plate valve is arranged at the lower end of the blowout preventer upper connector, a shear pin seat is arranged in the lower end of the jacket in a sealing manner, a core is arranged in holes of the blowout preventer upper connector and the shear pin seat in a sealing manner, the core supports the cover plate valve to enable the cover plate valve to be opened and turned on one side of the jacket, the core is limited by a limiting piece on the shear pin seat, and a rod pump supporting cylinder is provided with a rod pump.

2. The dual blowout prevention and dual opening combined pipe string with blowout prevention and rotary pumping under a pressure pipe of claim 1, wherein an inner hole step chamfer is arranged on the inner side of the lower end of the upper joint of the double-layer sliding sleeve switch, and the inner diameter of the inner hole step chamfer is smaller than the outer diameter of the inner sliding sleeve.

3. The dual blowout-prevention two-time opening pipe-pressing blowout-prevention rotary drawing combined pipe column according to claim 1 or 2, wherein the upper end and the lower end of the inner sliding sleeve are respectively arranged in a sealing way through sealing rings and the inner side wall of the upper joint of the double-layer sliding sleeve switch and are used for sealing the inner side of the communication hole, the sealing rings at the upper end and the lower end of the inner sliding sleeve correspond to the upper sealing surface of the inner wall of the upper joint of the double-layer sliding sleeve switch and the lower sealing surface of the inner wall of the upper joint of the double-layer sliding sleeve switch respectively, and the distance between the chamfer of the inner hole step and the lower sealing surface of the inner wall of the upper joint of the double-layer sliding sleeve switch is equal to the distance between the upper sealing surface of the inner wall of the upper joint of the double-layer sliding sleeve switch and the lower sealing surface of the inner joint of the double-layer sliding sleeve switch, so that after the inner sliding sleeve falls, the sealing surface at the upper part of the inner sliding sleeve is just on the inner sealing surface of the upper joint of the double-layer sliding sleeve switch at the inner sealing surface where the lower sealing ring is located before the inner sliding sleeve is knocked down, thereby forming a secondary sealing surface.

4. The dual blowout prevention and dual opening combined pipe column with blowout prevention and rotary pumping under a pressure pipe according to claim 3, wherein a space is formed between the outer sliding sleeve and the outer side of the upper joint of the double-layer sliding sleeve switch, an annular space is formed, and a step surface is arranged on the inner side of the lower end of the outer sliding sleeve.

5. The dual blowout prevention and dual opening combined pipe column with blowout prevention and rotary pumping under a pressure pipe according to claim 1 or 2, wherein the communication hole adopts a strip waist round hole structure or a multi-group strip slit sieve hole filtering structure.

6. The blowout-preventing and rotation-pulling combined pipe column with the blowout-preventing and twice-opening pressure pipe is characterized in that the cover plate valve comprises a front support, a rear support and a cover plate, wherein the front support and the rear support are symmetrically arranged at the lower end of an upper joint of the blowout preventer, the cover plate is hinged with the front support through cover plate supporting legs, torsion springs are arranged at the hinged positions, one ends of the torsion springs are fixedly connected with the cover plate supporting legs, and the other ends of the torsion springs are fixedly connected with the rear support.

7. The blowout-preventing and twice-opening combined pipe string with blowout-preventing and rotation-pulling functions with a pipe under pressure according to claim 1 or 2, wherein a compression spring type rack press-fitting member is installed at one end of a joint on a blowout preventer, a gear type connecting member is arranged on a cover plate, one end of the gear type connecting member is hinged with the cover plate, the other end of the gear type connecting member is hinged with one end of the joint on the blowout preventer, and a gear part of the gear type connecting member is meshed with a rack part of the compression spring type rack press-fitting member, so that the gear type connecting member and the cover plate form a small-angle hinge movable mechanism.

8. The dual blowout prevention and dual opening combined pipe string with blowout prevention and rotary pulling as set forth in claim 7, wherein the compression spring type rack press fitting member is installed in a side hole of the upper joint of the blowout preventer in a penetrating manner, the compression spring type rack press fitting member comprises a rack press rod, a rack portion is arranged at an outer end portion of the rack press rod, an inner end portion is connected with the compression spring, the gear type connecting member comprises a gear connecting rod, a gear hinge portion is arranged at one end of the gear connecting rod, a cover plate hinge portion is arranged at the other end of the gear connecting rod, a hinge hole for being hinged with the upper joint of the blowout preventer is formed at the gear hinge portion, and a gear tooth for being meshed with the rack portion is arranged at the gear hinge portion.

9. The dual blowout prevention and dual opening combined pipe string with blowout prevention and rotary pumping under pressure as claimed in claim 7, wherein the core is provided with a balance hole, the balance hole is communicated with an annular space between the core and the outer sleeve, and the inner end of the rack compression rod is provided with a breathing hole along the axis, so that the pressure inside and outside the pressure spring mounting hole at one side of the joint of the blowout preventer is balanced.

10. The operation method for the blowout-preventing rotary pumping combined operation pipe column with the blowout-preventing and twice-opening under-pressure pipe is characterized by comprising the following steps of: the method comprises the following steps:

s1, lowering the two-time blowout prevention and two-time opening pipe-pressing blowout prevention rotary pumping combined operation pipe column according to any one of claims 1-9 to a preset depth in a well, wherein a blanking plug realizes the first closing sealing blowout prevention in an oil pipe in the process of descending a tool string into the well until the pipe string is lowered to the preset depth in the well;

s2, after the pipe is opened twice for two times for blowout prevention and the pipe is pressed down, the blowout prevention rotary pumping combined operation pipe column is put in place, the liquid is filled in the oil pipe, after the liquid reaches the opening pressure value of the pump-down plug, the pump-down plug core falls down, a central flow passage is opened, the first opening flow passage in the oil pipe is realized, and at the moment, the production of blowout in the oil pipe or sand flushing and well flushing can be carried out;

s3, when the production of open-flow in the oil pipe or sand flushing and well flushing are finished, the inside of the shaft is still in a low-pressure open-flow state, a steel ball with small specification is put into the oil pipe at the well head, after the steel ball is seated on the controllable inner blowout preventer, the well head is hydraulically powered, after the steel ball reaches the closing pressure value of the controllable inner blowout preventer, the built-in core of the steel ball shears a pin, the steel ball and the core of the controllable inner blowout preventer fall together, the cover plate valve immediately turns up to close the liquid inlet channel under the combined action of spring force and upward open-flow pressure at the bottom of the well, and at the moment, the controllable inner blowout preventer realizes second sealing and blowout prevention in the oil pipe;

s4, before the rod pump is put into the oil pipe, a large-size steel ball is put into the oil pipe again, the steel ball is placed on the double-layer sliding sleeve switch, hydraulic pressure is not added temporarily, after that, the rod pump is put into the oil pipe to a designed position in a second sealing blowout prevention state, the rod pump is not put into the oil pipe for setting, at this time, the hydraulic pressure is added into the oil pipe, and is conducted to the steel ball of the double-layer sliding sleeve switch through the annular gap of the rod pump and the oil pipe until the sliding sleeve core is knocked out by the hydraulic pressure, the side hole of the double-layer sliding sleeve switch is exposed, so that the second opening overcurrent in the oil pipe is realized, and finally the rod pump turning and pumping functions are completed.