Switchable intelligent fracturing sliding sleeve system based on intelligent tag and coiled tubing control

Abstract

A switchable intelligent fracturing sliding sleeve system based on an intelligent tag and coiled tubing control, relating to the technical field of oil and gas exploration and development. An intelligent key tag (A6) for initially opening an intelligent fracturing sliding sleeve (A4) is pumped from the ground surface and conveyed downhole by means of a casing; during water shutoff in a production process, the intelligent fracturing sliding sleeve (A4) is opened and closed using an intelligent switching tool (A3); and coiled tubing (A1) carries the intelligent switching tool (A3) connected to a cable (A0) to perform opening or closing operations. The intelligent fracturing sliding sleeve system can allow for repeated opening or closing control of the intelligent fracturing sliding sleeve (A4) corresponding to a production zone without altering physical properties of the formation and the inner diameter of the casing, and when combined with a profile control process, achieves flexible control over water detection and shutoff in the production zone, thereby significantly reducing the operation complexity and cost.

Description

Switchable intelligent fracturing sliding sleeve system based on intelligent tag and coiled tubing control TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas exploration and development, and more particularly to a switchable intelligent fracturing sliding sleeve system based on intelligent tag and coiled tubing control. BACKGROUND

[0002] For the development of low-permeability reservoirs by hydraulic fracturing, in order to further improve the development effect, on the one hand, it is necessary to realize dense and uniform fracture creation in the horizontal section to maximize the single-well production, and on the other hand, it is necessary to realize the repeated switch control after the development of the water-producing layer in the later stage and the treatment of the production layer, so as to ensure the controllable transformation and development of the whole life cycle of the oil and gas well.

[0003] To solve the above problems, since the traditional fracturing technology has many inherent defects, it is difficult to improve the traditional fracturing technology, and as an improved technology, the fracturing system based on intelligent tag (intelligent key tag) has more advantages than the traditional fracturing technology and has a larger improvement space. SUMMARY

[0004] The present application provides a switchable intelligent fracturing sliding sleeve system based on intelligent tag and coiled tubing control, which can realize unlimited level and efficient and accurate fracturing transformation of unconventional oil and gas wells, and has the functions of mechanical and chemical water shutoff operation in the production stage, and through the switchable intelligent fracturing sliding sleeve pre-installed in the completion string, the intelligent switch tool is carried by the coiled tubing to realize the repeated switch control of the production layer without changing the internal diameter of the completion string and throttling the production liquid, which greatly improves the flexibility of the oil and gas reservoir from the initial development to the later stable oil control stage.

[0005] The above object is achieved by the following technical solutions:

[0006] An intelligent switch tool, comprising: a tubing connector, an electric control cavity detachably connected to the lower end of the tubing connector, a connector detachably connected to the lower end of the electric control cavity, a jaw guard detachably connected to the lower end of the connector, and a guide piece detachably connected to the lower end of the jaw guard;

[0007] The oil pipe connector, the electric control cavity and the connector form a cavity, the electric control cavity is fixedly connected with a motor and an electric control system for controlling the motor in the cavity, a screw rod is fixedly connected to an output shaft of the motor, the screw rod is rotatably connected in the connector, a pressing sleeve is fixedly connected to a lower end of a screw rod pressing cover, a transmission rod is screw driven on the screw rod, a key groove is formed in an inner wall of the pressing sleeve along an axial direction, a key is fixedly connected to the transmission rod and matched in the key groove, a first end cover is threadedly connected to a lower end of the transmission rod, a claw mounting body is fixedly connected to an upper end of the first end cover, and a claw is arranged on an upper side of the claw mounting body; when the claw mounting body moves upward, the claw is pushed to move away from the axis of the supporting screw rod and open.

[0008] The claw comprises a claw body, two mirror-symmetrical and radially extending guide grooves are arranged on the claw body, a guide block matched with the first guide groove is fixedly connected to a lower end of the claw guard, so that the claw body can slide radially along the claw guard; a second wedge surface is formed at an inner end of the claw body, a distance of the second wedge surface from the axis of the screw rod increases from top to bottom, a protruding strip extending along the second wedge surface is fixedly connected to the inner end of the claw body, a third wedge surface is arranged on an outer circumferential surface of the claw mounting body, a distance of the third wedge surface from the axis of the screw rod increases from top to bottom, a second guide groove extending along the third wedge surface is arranged on the claw mounting body, and the protruding strip is matched in the second guide groove.

[0009] A signal detection system is fixedly connected to the electric control cavity.

[0010] An intelligent key tag for a first opening intelligent fracturing sliding sleeve comprises an electric control cavity with an open upper end, an actuator is fixedly connected in the electric control cavity, a connecting shaft is fixedly connected to an output shaft of the actuator, a transmission rod is fixedly connected to the connecting shaft, a first pressing cover is slidably connected to a lower part of the electric control cavity, the first pressing cover is screw driven with the transmission rod, a sealing element is arranged between the first pressing cover and the electric control cavity, an inner hole wedge surface I is arranged at a lower end of the sealing element, a protrusion I matched with the inner hole wedge surface I is arranged at an upper end of the first pressing cover, the sealing element can move radially relative to the first pressing cover, an inner hole wedge surface II is arranged on an inner circumferential surface of the sealing element, a first wedge surface is arranged on an outer circumferential surface of the electric control cavity, a distance of the first wedge surface from an axis of the electric control cavity increases from bottom to top, so that when the sealing element moves upward along the first wedge surface, the sealing element is pushed by the first wedge surface, the diameter of the sealing element continuously expands, and when the sealing element moves downward along the first wedge surface, the diameter of the sealing element continuously reduces; a pressing cover channel is arranged on the first pressing cover, a liquid passing pipe is fixedly connected in the electric control cavity, an electric control cavity channel is arranged on the electric control cavity, a second end cover is detachably connected to an upper end of the electric control cavity, an end cover channel is arranged on the second end cover, a central pipe is fixedly connected to the electric control cavity and the second end cover, the pressing cover channel, the liquid passing pipe, the electric control cavity channel, the central pipe and the end cover channel are communicated to form a back flushing channel, a fracturing ball for plugging the back flushing channel is arranged in the end cover channel, a second pressing cover is threadedly connected to an upper part of the second end cover, the fracturing ball and the second pressing cover form a sealing cavity in the end cover channel.

[0011] The electric control cavity is internally provided with a mounting hole I, and an induction device is mounted in the mounting hole I.

[0012] The intelligent fracturing sliding sleeve comprises a sliding sleeve upper joint, a flow hole is arranged on the sliding sleeve upper joint, a sliding sleeve inner core is inserted into the sliding sleeve upper joint, the outer wall of the sliding sleeve inner core has a reduced diameter section, two inner core grooves are arranged on the outer wall of the sliding sleeve inner core and are located on the upper and lower sides of the reduced diameter section, the sliding sleeve inner core can slide in the sliding sleeve upper joint, a necked portion is formed on the upper side of the inner wall of the sliding sleeve upper joint to form a sliding sleeve upper joint shoulder, the sliding sleeve upper joint shoulder can block the sliding sleeve inner core from moving upward further, a sliding sleeve lower joint is detachably connected to the lower end of the sliding sleeve upper joint, a second identification ring mounting groove is arranged on the outer wall of the sliding sleeve lower joint, and a second identification ring is fixedly connected in the second identification ring mounting groove; the inner wall of the lower end of the sliding sleeve upper joint is connected with the sliding sleeve lower joint through thread cooperation, and the second identification ring is located between the sliding sleeve upper joint and the sliding sleeve lower joint.

[0013] The downhole pipe string comprises an identification short joint and an intelligent fracturing sliding sleeve, the identification short joint comprises a short joint upper joint, a short joint lower joint is detachably connected to the lower end of the short joint upper joint, a first identification ring mounting groove is arranged on the outer periphery of the upper part of the short joint lower joint, and a first identification ring is fixedly connected in the first identification ring mounting groove; the identification short joint and the intelligent fracturing sliding sleeve are connected through a casing pipe.

[0014] The switchable intelligent fracturing sliding sleeve system based on intelligent tags and coiled tubing control comprises an intelligent switch tool and a downhole pipe string, or an intelligent key tag for first opening of the intelligent fracturing sliding sleeve and the downhole pipe string, or the intelligent switch tool, the intelligent key tag for first opening of the intelligent fracturing sliding sleeve and the downhole pipe string.

[0015] When the switchable intelligent fracturing sliding sleeve system based on intelligent tags and coiled tubing control is used for switching a single target intelligent fracturing sliding sleeve, a battery-powered self-identification switch control system is adopted, and the battery-powered self-identification switch control system comprises a serial communication circuit, an induction module, a first microcontroller, a first state display circuit, a power supply circuit, a first driver circuit and a first execution mechanism.

[0016] When multiple-layer intelligent fracturing sliding sleeves need to be opened or closed, a coiled tubing built-in cable power supply and communication switch control system is adopted, and the coiled tubing built-in cable power supply and communication switch control system comprises a carrier wave ground controller and an intelligent switch tool circuit; the carrier wave ground controller comprises an industrial computer, a second microcontroller, a carrier wave communication circuit, a carrier wave power supply circuit and a carrier wave communication cable; the intelligent switch tool circuit comprises a carrier wave communication circuit, an induction unit, a third microcontroller, a second state display circuit, a carrier wave power supply circuit, a second driver circuit and a second execution mechanism.

[0017] A fracturing method, the switchable intelligent fracturing sliding sleeve system based on intelligent tags and coiled tubing control, comprises the following steps: using the intelligent key tag for first opening of the intelligent fracturing sliding sleeve when the intelligent fracturing sliding sleeve is first opened, and using the intelligent switch tool for opening and closing of the intelligent fracturing sliding sleeve when water plugging occurs in the production process.

[0018] The beneficial effects of the switchable intelligent fracturing sliding sleeve system based on intelligent tags and coiled tubing control are as follows:

[0019] In the early stage of reservoir reconstruction, the intelligent key tag with automatic positioning recognition and variable diameter function is used as an opening tool, and the opening and fracturing operation of the intelligent fracturing sliding sleeve at each level in the well can be completed by only pumping after automatic delivery at the wellhead, which realizes full-bore and efficient dense fracturing of the whole well section, and avoids measures such as explosives and cables. In the later stage of reservoir development, without mechanical water plugging tool and chemical water plugging operation, the intelligent switch tool is carried by the coiled tubing, which can repeatedly close or open the intelligent fracturing sliding sleeve corresponding to the production layer without changing the formation properties and the inner diameter of the casing, and in combination with the profile control process, the flexible control of water plugging in the production layer is realized, and the operation complexity and cost are greatly reduced. BRIEF DESCRIPTION OF DRAWINGS

[0020] Fig. 1 is a schematic diagram of the switchable intelligent fracturing sliding sleeve system based on intelligent tags and coiled tubing control in the initial opening state according to the present application;

[0021] Fig. 2 is a schematic diagram of a short-circuit structure;

[0022] Fig. 3 is a schematic diagram of the closed state of the intelligent fracturing sliding sleeve;

[0023] Fig. 4 is a schematic diagram of the open state of the intelligent fracturing sliding sleeve;

[0024] Fig. 5 is a schematic diagram of the initial state of the intelligent key tag for first opening of the intelligent fracturing sliding sleeve;

[0025] Fig. 6 is a schematic diagram of the working state of the intelligent key tag for first opening of the intelligent fracturing sliding sleeve;

[0026] Fig. 7 is a partial enlarged view of P in Fig. 3;

[0027] Fig. 8 is a partial enlarged view of K in Fig. 3;

[0028] Fig. 9 is a schematic diagram of the battery-powered self-identification switch system according to the present application;

[0029] Fig. 10 is a schematic diagram of the coiled tubing built-in cable power supply and communication switch system according to the present application;

[0030] Fig. 11 is a schematic diagram of the claw in the working state;

[0031] Figure 12 is a schematic diagram of the dog in the initial state;

[0032] Figure 13 is a schematic diagram of the dog structure;

[0033] Figure 14 is a schematic diagram of the battery-powered self-identification switch control system;

[0034] Figure 15 is a schematic diagram of the coiled tubing built-in cable power supply and communication switch control system;

[0035] Figure 16 is a schematic diagram of the different number of intelligent fracturing sliding sleeve flow holes that can be used in the present application;

[0036] Figure 17 is a schematic diagram of the different phases of intelligent fracturing sliding sleeve flow holes that can be used in the present application;

[0037] Figure 18 is a schematic diagram of the different diameters of intelligent fracturing sliding sleeve flow holes that can be used in the present application.

[0038] In the figure: cable A0; coiled tubing A1; identification short circuit A2; short circuit upper connector 1b; first identification ring 2b; short circuit lower connector 3b; intelligent switch tool A3; tubing connector 1; electric control cavity 2; signal detection system 3; connector 4; sealing sleeve 5; screw rod gland 6; pressure sleeve 7; screw rod 8; dog guard 9; transmission rod 10; sealing sleeve 11; dog 12; dog mounting body 13; first end cover 14; guide 15; motor 16; electric control system 17; intelligent fracturing sliding sleeve A4; sliding sleeve upper connector 1C; sliding sleeve inner core 2C; second identification ring 3C; sliding sleeve lower connector 4C; pin gland 5C; spring 6C; bolt 7C; locking pin 8C; sealing cover 9C; structure with sand blasting hole 10C; Nth intelligent fracturing sliding sleeve A5; intelligent key tag for the first time opening of the intelligent fracturing sliding sleeve A6; first gland E1; transmission rod E2; electric control cavity E3; actuator fixing part E4; sealing part E5; rigid connection shaft E6; sensing device E7; jackscrew E8; actuator E9; liquid passage pipe E10; central pipe E11; second end cover E12; fracturing ball E13; second gland E14; serial communication circuit 3-1; sensing module 3-2; first microcontroller 3-3; first state display circuit 3-4; power supply circuit 3-5; first driver circuit 3-6; first execution mechanism 3-7; industrial computer 5-1; second microcontroller 5-2; carrier wave communication circuit 5-3; carrier wave power supply circuit 5-4; carrier wave communication cable 5-5; carrier wave communication circuit 6-1; sensing unit 6-2; third microcontroller 6-3; second state display circuit 6-4; carrier wave power supply circuit 6-5; second driver circuit 6-6; second execution mechanism 6-7. DETAILED DESCRIPTION

[0039] The switchable intelligent fracturing sliding sleeve system based on intelligent tags and coiled tubing control, referring to FIGS. 1, 9 and 10, includes a cable A0, a coiled tubing A1, a downhole string, a ground control system, an intelligent switch tool A3 and an intelligent key tag A6 for first opening of the intelligent fracturing sliding sleeve;

[0040] The intelligent key tag A6 for first opening of the intelligent fracturing sliding sleeve is used in cooperation with a battery-powered self-identification switch system, and the cable A0 is not required. The intelligent switch tool A3 is used in cooperation with a coiled tubing built-in cable power supply and communication switch control system, and the cable A0 is required.

[0041] The downhole string includes an identification short circuit A2, an intelligent fracturing sliding sleeve A4 and an Nth intelligent fracturing sliding sleeve A5. According to the reservoir fracturing position corresponding to the construction design, the identification short circuit A2 and the intelligent fracturing sliding sleeve A4 are connected through a casing, and the intelligent fracturing sliding sleeves A4 are also connected through casings.

[0042] The identification short circuit A2, referring to FIG. 2, includes a short circuit upper joint 1b, an inner thread is arranged at the lower end of the short circuit upper joint 1b, an outer thread is arranged at the upper end of a short circuit lower joint 3b, the short circuit upper joint 1b and the short circuit lower joint 3b are connected through thread cooperation, a first identification ring installation groove is arranged on the outer periphery of the upper part of the short circuit lower joint 3b, and a first identification ring 2b is fixedly connected in the first identification ring installation groove;

[0043] The intelligent fracturing sliding sleeve A4 and the Nth intelligent fracturing sliding sleeve A5 have the same structure, referring to FIG. 3. The intelligent fracturing sliding sleeve A4 includes a sliding sleeve upper joint 1C, a flow-through hole is arranged on the sliding sleeve upper joint 1C, the axis of the flow-through hole is perpendicular to the axis of the sliding sleeve upper joint 1C, a sand-blasting hole structure 10C is connected in the flow-through hole through thread cooperation, a sealing cover 9C covering the sand-blasting hole structure 10C is arranged in the flow-through hole, a sealing ring abutting against the inner wall of the flow-through hole is arranged on the outer periphery of the sealing cover 9C, a sliding sleeve inner core 2C is inserted into the sliding sleeve upper joint 1C, the outer wall of the sliding sleeve inner core 2C has a reduced diameter section, two inner core grooves are arranged on the outer wall of the sliding sleeve inner core 2C, the two inner core grooves are respectively located on the upper and lower sides of the reduced diameter section, the sliding sleeve inner core 2C can slide along the axis of the sliding sleeve upper joint 1C in the sliding sleeve upper joint 1C, the upper side of the inner wall of the sliding sleeve upper joint 1C is necked to form a sliding sleeve upper joint shoulder, the sliding sleeve upper joint shoulder can block the further upward movement of the sliding sleeve inner core 2C, a sliding sleeve lower joint 4C is connected to the inner wall of the lower end of the sliding sleeve upper joint 1C through thread cooperation, a second identification ring installation groove is arranged on the outer wall of the sliding sleeve lower joint 4C, a second identification ring 3C is fixedly connected in the second identification ring installation groove, the second identification ring 3C is located between the sliding sleeve upper joint 1C and the sliding sleeve lower joint 4C;

[0044] The outer periphery of the sliding sleeve inner core 2C is provided with three sliding sleeve inner core sealing rings abutting against the inner wall of the sliding sleeve upper joint 1C, two of which are located on the upper and lower sides of the two inner core grooves, and the other is located on the uppermost side, and when the sliding sleeve inner core 2C abuts against the shoulder of the sliding sleeve upper joint, the uppermost sliding sleeve inner core sealing ring is located on the upper side of the flow hole.

[0045] The outer wall of the sliding sleeve lower joint 4C is provided with a diameter expansion section to form a sliding sleeve lower joint shoulder, and the sliding sleeve lower joint abuts against the lower end of the sliding sleeve upper joint 1C, and a sealing ring is arranged between the second identification ring 3C and the shoulder.

[0046] Regarding the functions of the sealing cover 9C and the sandblasting hole structure 10C:

[0047] Before the fracturing process is performed, the sandblasting hole structure 10C is in the sealing cavity composed of the sealing cover 9C, the sliding sleeve upper joint 1C and the sliding sleeve inner core 2C, and when the fracturing starts, the sliding sleeve inner core 2C first moves downward to the maximum distance, and the intelligent fracturing sliding sleeve A4 is opened, which is the ground fracturing continues to pressurize, and the pressure is first transmitted to the sealing cover 9C through the central hole of the sandblasting hole structure 10C, and the sealing cover 9C is separated from the sliding sleeve upper joint 1C under the action of pressure, at this time the pressure acts on the bottom layer until the fracturing of the bottom layer is completed, and after fracturing the sandblasting hole structure 10C is completely dissolved in a short time after being soaked in well fluid, and finally the flow passage area is increased during production, so as to increase the production.

[0048] The main function of the sandblasting hole structure 10C is that the diameter of the central hole is relatively small, which is more beneficial to the initiation of fracturing, and the improvement of the extension and uniformity of the fracture under the same displacement and pressure.

[0049] Further explanation, regarding the positioning of the sliding sleeve inner core 2C:

[0050] The sliding sleeve upper joint 1C is provided with a mounting hole, and a positioner is mounted in the mounting hole. The positioner comprises a pin press cover 5C inserted into the mounting hole. An end of the pin press cover 5C towards the sliding sleeve inner core 2C is provided with a press cover groove. A spring 6C in a compressed state is arranged in the press cover groove. In FIG. 4, the upper end of the spring 6C is fixed to the pin press cover 5C, and the lower end of the spring 6C is fixed with a clamping pin 8C. The clamping pin 8C is inserted into the press cover groove to slide up and down. The pin press cover 5C is fixed to the sliding sleeve upper joint 1C by a bolt. The number of positioners can be increased according to actual conditions, so as to improve the temporary positioning capacity of the sliding sleeve inner core 2C. The number of positioners corresponds to the number and position of the inner core grooves one by one. When the sliding sleeve inner core 2C abuts against the sliding sleeve upper joint shoulder, the sliding sleeve inner core 2C blocks the overflow hole, and the overflow hole is in a closed state. At this time, the clamping pin 8C is clamped in the inner core groove located on the lower side. When the sliding sleeve inner core 2C reaches the maximum distance of downward movement, the overflow hole is in a closed state. At this time, the clamping pin 8C is clamped in the inner core groove located on the upper side, so as to maintain the opening state of the overflow hole. The clamping pin 8C contacts the sliding sleeve inner core 2C through the arc end structure on the clamping pin 8C. When the sliding sleeve inner core 2C moves longitudinally, the arc end structure contacts the edge of the inner core groove. The arc end structure is extruded by the edge of the inner core groove, so as to provide a component force moving into the press cover groove, so that the spring 6C is further compressed, and the clamping pin 8C retreats into the press cover groove.

[0051] The first opening of the intelligent fracturing sliding sleeve uses the intelligent key tag A6, referring to FIGS. 5 and 6, including an electric control cavity E3 with an upper opening, an actuator E9 is fixedly connected in the electric control cavity E3, the actuator E9 can adopt an electric motor or a linear push rod, when the actuator E9 is an electric motor, an actuator fixing part E4 is connected in the electric control cavity E3 through screw fit, a flange of the actuator E9 is arranged in an inner hole of the actuator fixing part E4, an end of the actuator fixing part E4 is fixedly connected with the flange of the actuator E9 through a jackscrew, the jackscrew E8 is arranged on the actuator fixing part E4, and the jackscrew E8 is used for axial and radial fixation of the actuator E9, a connecting shaft E6 is fixedly connected on an output shaft of the actuator fixing part E4, a transmission rod E2 is fixedly connected on the connecting shaft E6, a first gland E1 is inserted into a lower part of the electric control cavity E3, the first gland E1 can slide up and down on the electric control cavity E3, an inner thread is arranged in the first gland E1, an outer thread is arranged on the transmission rod E2, and the first gland E1 and the transmission rod E2 are screw transmission; when the actuator E9 is a linear push rod, the actuator fixing part E4 is connected in the electric control cavity E3 through screw fit, the flange of the actuator E9 is arranged in an inner hole of the actuator fixing part E4 and fixedly connected, the first gland E1 is inserted into a lower part of the electric control cavity E3, the first gland E1 can slide up and down on the electric control cavity E3, and a telescopic end of the actuator E9 is fixedly connected on the first gland E1, the first gland E1 is driven to move relative to the electric control cavity E3 by telescopic driving of the actuator E9;

[0052] The first gland E1 and the electric control cavity E3 are provided with a sealing element E5, the lower end of the sealing element E5 is provided with an inner hole wedge surface I, the upper end of the first gland E1 is provided with a protrusion I matched with the inner hole wedge surface I, the sealing element E5 can move radially relative to the first gland E1, the inner periphery of the sealing element E5 is provided with an inner hole wedge surface II, the outer periphery of the electric control cavity E3 is provided with a first wedge surface, the distance from the first wedge surface to the axis of the electric control cavity E3 increases from bottom to top, so that when the sealing element E5 moves upward along the first wedge surface, the sealing element E5 is pushed by the first wedge surface, the diameter of the sealing element E5 expands continuously, and the opening of the sealing element E5 is realized. Conversely, when the sealing element E5 moves downward along the first wedge surface, the diameter of the sealing element E5 continuously decreases. However, in actual operation, because the intelligent key tag A6 of the fracturing sliding sleeve is a disposable tool, the initial position of the sealing element E5 is when the diameter of the sealing element E5 is the smallest, so when in use, only the first gland E1 needs to be moved upward under the rotation of the lead screw, and the lead screw does not need to drive the first gland E1 to move to the side during the whole working process. When the actuator E9 drives the connecting shaft E6, the connecting shaft E6 drives the transmission rod E2 to rotate, the transmission rod E2 drives the first gland E1 to move upward on the electric control cavity E3, the purpose is to drive the sealing element E5 to move upward along the first wedge surface by the first gland E1. The electric control cavity E3 is provided with a mounting hole I, and the inductive device E7 is mounted in the mounting hole I. The first gland E1 is provided with a gland channel, the electric control cavity E3 is fixedly connected with a liquid passing pipe E10, the electric control cavity E3 is provided with an electric control cavity channel, the upper end of the electric control cavity E3 is connected with a second end cover E12 through thread cooperation, the second end cover E12 is located in the opening of the electric control cavity E3, the second end cover E12 is provided with an end cover channel, and the electric control cavity E3 and the second end cover E12 are fixedly connected with a central pipe E11. The gland channel, the liquid passing pipe E10, the electric control cavity channel, the central pipe E11 and the end cover channel distributed from bottom to top are communicated to form a reverse discharge channel. The fracturing ball E13 for plugging the reverse discharge channel is arranged in the end cover channel, the pumping pressure of the ground can make the fracturing ball E13 plug in the end of the liquid passing hole of the end cover E12 to keep the effect of closing the reverse discharge channel, the upper part of the second end cover E12 is connected with a second gland E14 through thread cooperation, and the fracturing ball E13 and the second gland E14 form a sealing cavity in the end cover channel.

[0053] Preferably, the outer periphery of the liquid passing pipe E10 is provided with two sealing rings closely arranged on the inner wall of the first gland E1 and the electric control cavity E3, and the two sealing rings are respectively located on the upper and lower sides of the liquid passing pipe E10. In addition, the outer periphery of the central pipe E11 is provided with two sealing rings closely arranged on the inner wall of the gland second end cover E12 and the electric control cavity E3, and the two sealing rings are respectively located on the upper and lower sides of the central pipe E11.

[0054] After the sealing element E5 is expanded, it is clamped and blocked in the inner core 2C of the sliding sleeve, and the first opening of the sliding sleeve and the fracturing operation are completed with the pressurization of the pump truck.

[0055] The battery-powered self-identification switch control system is used for switching the single target intelligent fracturing sliding sleeve A4, and the principle block diagram is shown in FIG. 14:

[0056] The battery-powered self-identification switch control system includes an intelligent key tag circuit and a ground controller 1-1, and the intelligent key tag circuit includes a serial communication circuit 3-1, an induction module 3-2, a first microcontroller 3-3, a first state display circuit 3-4, a power supply circuit 3-5, a first driver circuit 3-6 and a first actuator 3-7.

[0057] The ground controller 1-1 communicates with the intelligent key tag through the serial communication 3-1 to query the tag state and set the target address information. The serial communication circuit 3-1 is an information exchange path of the ground controller 1-1 and the first microcontroller 3-3. The induction module 3-2 can use a Hall sensor to sense the magnetic field signal. The first microcontroller 3-3 is used for communication, signal acquisition and processing, and logical operation. The first state display circuit 3-4 is used to indicate the state of the intelligent key tag A6 for first opening of the intelligent fracturing sliding sleeve. The power supply circuit 3-5 provides power supply for the induction module 3-2, the first microcontroller 3-3, the first state display circuit 3-4 and the first driver circuit 3-6.

[0058] The intelligent key tag A6 for first opening of the intelligent fracturing sliding sleeve senses the magnetic signal of the first identification ring 2b or the second identification ring 3C through the induction module 3-2 to count, and drives the circuit 3-6 to drive the first actuator to act after reaching the target sliding sleeve, such as driving the actuator E9 to start.

[0059] The first opening implementation of the intelligent fracturing sliding sleeve A4 at each level is as follows:

[0060] The first opening intelligent fracturing sliding sleeve is transported downhole by the intelligent key tag A6 pumped by the ground, combined with Figure 1, when the target intelligent fracturing sliding sleeve A4 of fracturing is the Nth intelligent fracturing sliding sleeve A4, the target address is set as "N" through the electric control system 17, then the first opening intelligent fracturing sliding sleeve is transported downhole by the intelligent key tag A6, when the inductive device E7 in the first opening intelligent fracturing sliding sleeve intelligent key tag A6 detects the magnetic signal emitted by the identification ring 2B in the identification short circuit A2 and detects the magnetic signal emitted by the identification ring 2B in the identification short circuit A2, the count is "1", and the first opening intelligent fracturing sliding sleeve intelligent key tag A6 is transported downhole by the intelligent key tag A6, when the inductive device E7 in the first opening intelligent fracturing sliding sleeve intelligent key tag A6 detects the magnetic signal emitted by the identification ring 3C, the count is "2", and the first opening intelligent fracturing sliding sleeve intelligent key tag A6 is transported downhole by the intelligent key tag A6, when the inductive device E7 in the first opening intelligent fracturing sliding sleeve intelligent key tag A6 detects the magnetic signal emitted by the identification ring 3C, the count is "N", the electric control unit of the first opening intelligent fracturing sliding sleeve intelligent key tag A6 receives the signal, and the actuator E9 drives the transmission rod E2 to rotate through the rigid connecting shaft E6, so that the diameter of the sealing element E5 expands continuously, when the first pressure cover E1 moves according to the fixed stroke, the outer diameter of the sealing element E5 also expands to the specified size, so that the sealing element E5 is clamped and sealed in the inner core 2C, and the inner core 2C is driven to move downward through the pressure, at this time, the clamping pin 8C is clamped in the inner core groove on the upper side, the overflow hole is opened, and the opening of the intelligent fracturing sliding sleeve A4 is completed.

[0061] Wherein, combined with Figure 11, the intelligent switch tool A3 comprises: a tubing connection piece 1, the lower end of the tubing connection piece 1 is provided with external threads, the upper end of the electric control cavity 2 is provided with internal threads, the lower end of the tubing connection piece 1 and the upper end of the electric control cavity 2 are connected through thread cooperation, the lower end of the electric control cavity 2 is provided with internal threads, the upper end of the connecting piece 4 is provided with external threads, the lower end of the electric control cavity 2 and the upper end of the connecting piece 4 are connected through thread cooperation, the lower end of the connecting piece 4 is provided with internal threads, the upper end of the clamping jaw protector 9 is provided with external threads, the connecting piece 4 and the clamping jaw protector 9 are connected through thread cooperation, the lower end of the clamping jaw protector 9 is provided with internal threads, the upper end of the guide piece 15 is provided with external threads, the clamping jaw protector 9 and the guide piece 15 are connected through thread cooperation, and the guide piece 15 at the end of the intelligent switch tool A3 plays a guiding role during the downhole process;

[0062] Further illustrate, the oil pipe connecting piece 1, electric control cavity 2 and connecting piece 4 form a cavity, the electric control cavity 2 is fixed with signal detection system 3, motor 16 and electric control system 17 in the cavity, the electric control system 17 is electrically connected with the motor 16, the output shaft of the motor 16 is fixed with the screw rod 8, the shaft body part of the screw rod 8 is rotatably connected in the connecting piece 4, the first sealing sleeve 5 for supporting the screw rod 8 is installed on the connecting piece 4, the lower end of the connecting piece 4 is provided with a connecting piece groove, the upper end of the claw guard 9 is fixed with the lead screw gland 6 in the connecting piece groove, the lower part of the shaft body part of the screw rod 8 is provided with two diameter expansion sections, the lower side diameter expansion degree is greater than the upper side diameter expansion degree, to form two screw rod shaft body shoulders, the lower end of the lead screw gland 6 abuts on the upper end of the two screw rod shaft body shoulders, the screw rod shaft body is rotatably connected in the lead screw gland 6, the lower end of the lead screw gland 6 is fixed with the pressure sleeve 7, the screw rod 8 is screw driven with the transmission rod 10, the inner wall of the pressure sleeve 7 is provided with a key groove along the axis direction, the transmission rod 10 is fixed with a key, the key is matched in the key groove, so that the transmission rod 10 can move along the axis of the output shaft of the motor 16 when the screw rod 8 rotates, the sealing sleeve mounting groove is formed between the claw guard 9 and the pressure sleeve 7, the second sealing sleeve 11 is installed in the sealing sleeve mounting groove, the sealing sleeve 11 is used for the support and sealing effect of the transmission rod 10, the lower end of the transmission rod 10 is provided with external threads, the inner wall of the first end cover 14 is provided with internal threads, the first end cover 14 is connected at the lower end of the transmission rod 10 through thread cooperation, the upper end of the first end cover 14 is fixed with the claw mounting body 13, the upper side of the claw mounting body 13 is provided with the claw 12;

[0063] Wherein, the claw 12 includes a claw body, the claw body is provided with two mirror image symmetrical and radially extending guide grooves, the lower end of the claw guard 9 is fixed with a guide block matched with the first guide groove, so that the claw body can slide radially along the claw guard 9, the inner end of the claw body forms a second wedge surface with an increasing inner diameter from top to bottom, the inner end of the claw body is fixed with a convex strip extending along the second wedge surface, the outer surface of the claw mounting body 13 is a third wedge surface with an increasing diameter from top to bottom, the claw mounting body 13 is provided with a second guide groove extending along the third wedge surface, the convex strip is matched in the second guide groove, so that when the claw mounting body 13 moves upward, it can push the claw 12 to move away from the axis of the supporting screw rod 8 to open; When the claw mounting body 13 moves downward, because the convex strip is in the second guide groove, the same as the principle of the key and the key groove cooperation, the claw mounting body 13 gives the convex strip a force towards the axis of the supporting screw rod 8, which can push the claw 12 to move towards the axis of the supporting screw rod 8 to shrink.

[0064] In the later stage of production, any one level of intelligent fracturing sliding sleeve A4 implementation is closed separately:

[0065] When the single-layer intelligent fracturing sliding sleeve A4 needs to be opened or closed during production, the intelligent switching tool A3 carried by the coiled tubing is conveyed downhole through the casing. When the signal detection system 3 in the intelligent switching tool A3 passes through the identification short circuit A2 and detects the magnetic signal emitted by the identification ring 2B in the identification short circuit A2, the count is "1". When the coiled tubing carrying the intelligent switching tool A3 continues to pass through the magnetic signal emitted by the identification ring 2B in the first-stage sliding sleeve, the count is "2", and when it passes through the N-1 stage sliding sleeve, the count is "N".

[0066] In combination with FIG. 9, when the target sliding sleeve to be opened or closed is the first-stage sliding sleeve, the target address is set to "1" by the electric control system 17, and the coiled tubing carrying the intelligent switching tool A3 is conveyed downhole through the casing. When the signal detection system 3 in the intelligent switching tool A3 passes through the identification short circuit A2 and detects the magnetic signal emitted by the identification ring 2B in the identification short circuit A2, the count is "1". At this time, after the electric control system 17 receives the signal, the motor 16 is started to make the pawl 12 radially move to complete the variable-diameter opening, so that the pawl 12 is clamped in the sliding sleeve inner core 2C. The sliding sleeve inner core 2C is moved downward along the axis by dragging the coiled tubing, and at this time, the clamping pin 8C is clamped in the inner core groove on the upper side, the overflow hole is opened, and the opening of the intelligent fracturing sliding sleeve A4 is completed.

[0067] In the later stage of production, the opening and closing control implementation mode of the one-time operation multi-stage intelligent fracturing sliding sleeve A4 is as follows:

[0068] When the multi-layer intelligent fracturing sliding sleeve A4 needs to be opened or closed during production, the coiled tubing carries the intelligent switching tool A3 connected by the cable A0 to perform the opening or closing work.

[0069] The coiled tubing built-in cable power supply and communication switching control system includes an intelligent switching tool circuit and a carrier wave ground controller 1-1. The ground controller 1-1 is used for managing and reading and writing the intelligent switching tool A3. Referring to FIG. 15, the intelligent switching tool circuit includes a carrier wave communication circuit 6-1 for amplifying, modulating and demodulating signals, an induction unit 6-2, a third microcontroller 6-3 for communication, signal acquisition and processing, logical operation, a second state display circuit 6-4, a carrier wave power supply circuit 6-5, a second driver circuit 6-6 and a second actuator 6-7. The ground controller 1-1 includes an industrial computer 5-1, a second microcontroller 5-2, a carrier wave communication circuit 5-3 for amplifying, modulating and demodulating signals, a carrier wave power supply circuit 5-4 for providing power supply to the intelligent switching tool A3 and a carrier wave communication cable 5-5 for amplifying, modulating and demodulating signals.

[0070] Wherein, the industrial computer 5-1 inquires the tag state and sets the target address information through the second microcontroller 5-2, the carrier wave communication circuit 5-3, the carrier wave communication cable 5-5, the intelligent switch tool A3, the carrier wave communication circuit 6-1. The industrial computer 5-1 is used for managing and reading and writing the intelligent switch tool A3. The second microcontroller 5-2 receives the instruction of the industrial computer 5-1 and sends it to the intelligent switch tool A3. The second microcontroller 5-2 receives the data returned by the intelligent switch tool A3 and sends it to the industrial computer 5-1. The carrier wave power supply circuit 6-5 provides power supply for the induction unit 6-2, the third microcontroller 6-3, the second state display circuit 6-4 and the second driver circuit 6-6. The induction unit 6-2 also adopts the Hall sensor for sensing the magnetic field signal. The intelligent switch tool A3 senses the magnetic signal of the first identification ring 2b or the second identification ring 3C through the induction unit 3-2. When there is the magnetic signal, the information is transmitted to the industrial computer 5-1. After reaching the target intelligent fracturing sliding sleeve A4, the industrial computer 5-1 sends the command to the tag driving circuit 3-6 to drive the second actuating mechanism 6-7 to act, such as starting the motor 16.

[0071] Wherein, the intelligent switch tool A3 connected by the coiled tubing carries the cable to be conveyed to the downhole. When the signal detection system 3 in the intelligent switch tool A3 detects the magnetic signal of the identification ring 2B in the identification short circuit A2, the count is “1”. When the coiled tubing carrying the intelligent switch tool A3 continues to pass through the magnetic signal of the identification ring 2B in the first stage sliding sleeve, the count is “2”. When passing through the N-1 stage sliding sleeve, the count is “N”.

[0072] When the target sliding sleeve to be opened or closed is the first stage intelligent fracturing sliding sleeve A4, the target address is set as “1” through the electric control system 17. The coiled tubing carrying the intelligent switch tool A3 is conveyed to the downhole through the casing. When the signal detection system 3 in the intelligent switch tool A3 detects the magnetic signal of the identification ring 2B in the identification short circuit A2, the count is “1”. At this time, the electric control system 17 receives the signal and feeds back the signal to the ground controller 1-1 through the cable A0. After receiving the signal, the ground controller 1-1 sends the signal to the electric control system 17 to make the motor 16 make the jaw 12 move radially to complete the variable-diameter opening, so that the intelligent switch tool A3 is clamped in the sliding sleeve inner core 2C. The coiled tubing is dragged to drive the sliding sleeve inner core 2C to move downward along the axis. At this time, the clamping pin 8C is clamped in the inner core groove on the upper side to open the overflow hole and complete the opening of the intelligent fracturing sliding sleeve A4.

[0073] It is further illustrated that according to different geological characteristics and engineering designs of different well sites, the overflow holes of the intelligent fracturing sliding sleeve can be designed and processed to have different phases, different numbers and different diameters.

Claims

1. An intelligent switching tool (A3) characterized in that, The utility model relates to a kind of oil pipe connector (1), electrically controlled cavity (2) detachably connected in the lower end of oil pipe connector (1), connector (4) detachably connected in the lower end of electrically controlled cavity (2), claw guard (9) detachably connected in the lower end of connector (4), the lower end of claw guard (9) is detachably connected with guide (15); Oil pipe connector (1), electrically controlled cavity (2) and connector (4) form cavity, electrically controlled cavity (2) is fixed with motor (16) and control motor (16) electric control system (17) in the cavity, the output shaft of motor (16) is fixed with lead screw (8), lead screw (8) is rotatably connected in connector (4), the lower end of screw rod gland (6) is fixed with pressure sleeve (7), lead screw (8) is screw driven with transmission rod (10), the inner wall of pressure sleeve (7) is provided with key groove along the axis direction, key is fixed on transmission rod (10), key is fitted in key groove, first end cover (14) is connected in the lower end of transmission rod (10) by thread cooperation, the upper end of first end cover (14) is fixed with claw mounting body (13), the upper side of claw mounting body (13) is provided with claw (12);When claw mounting body (13) moves upwards, claw (12) can be pushed to move away from the axis direction of supporting lead screw (8) and open. Claw (12) includes claw body, two mirror image symmetrical and radially extending guide grooves are provided on claw body, the lower end of claw guard (9) is fixed with guide block matched with first guide groove, so that claw body can slide along claw guard (9) radially;Second wedge surface is formed in the inner end of claw body, the interval of second wedge surface from the axis of lead screw (8) increases from top to bottom, the inner end of claw body is fixed with convex strip extending along second wedge surface, the outer circumferential surface of claw mounting body (13) is provided with third wedge surface, the interval of third wedge surface from the axis of lead screw (8) increases from top to bottom, claw mounting body (13) is provided with second guide groove extending along third wedge surface, convex strip is fitted in second guide groove.

2. The intelligent switching tool (A3) according to claim 1, characterized in that Electrically controlled cavity (2) is fixed with signal detection system (3) in the cavity.

3. The intelligent switching tool (A3) according to claim 1, characterized in that ​ 4. A smart key tag (A6) for a first opening smart frac slide, characterized by, The electric control cavity (E3) includes an upper opening, an executor (E9) is fixedly connected in the electric control cavity (E3), a first gland (E1) is slidably connected to the lower part of the electric control cavity (E3), the executor (E9) is used for adjusting the distance between the first gland (E1) and the electric control cavity (E3), a sealing element (E5) is arranged between the first gland (E1) and the electric control cavity (E3), the lower end of the sealing element (E5) is provided with an inner hole wedge surface I, the upper end of the first gland (E1) is provided with a protrusion I matched with the inner hole wedge surface I, the sealing element (E5) can move radially relative to the first gland (E1), the inner periphery of the sealing element (E5) is provided with an inner hole wedge surface II, the outer periphery of the electric control cavity (E3) is provided with a first wedge surface, the distance from the first wedge surface to the axis of the electric control cavity (E3) increases from bottom to top, so that when the sealing element (E5) moves upward along the first wedge surface, the sealing element (E5) is pushed and extruded by the first wedge surface, the diameter of the sealing element (E5) continuously expands, and when the sealing element (E5) moves downward along the first wedge surface, the diameter of the sealing element (E5) continuously decreases; the first gland (E1) is provided with a gland channel, a liquid passing pipe (E10) is fixedly connected in the electric control cavity (E3), the electric control cavity (E3) is provided with an electric control cavity channel, the upper end of the electric control cavity (E3) is detachably connected with a second end cover (E12), the second end cover (E12) is provided with an end cover channel, the electric control cavity (E3) and the second end cover (E12) are fixedly connected with a central pipe (E11), the gland channel, the liquid passing pipe (E10), the electric control cavity channel, the central pipe (E11) and the end cover channel are communicated to form a back flushing channel, a fracturing ball (E13) for plugging the back flushing channel is arranged in the end cover channel, the upper part of the second end cover (E12) is threadedly connected with a second gland (E14), the fracturing ball (E13) and the second gland (E14) form a sealing cavity in the end cover channel.

5. The smart key tag (A6) for a first-time opening smart frac sleeve according to claim 4, wherein the electrical control is The cavity (E3) is provided with a mounting hole I inside, and an induction device (E7) is mounted in the mounting hole I.

6. An intelligent fracturing sliding sleeve (A4) characterized by, The sleeve upper connector (1C) is provided with a flow hole, the sleeve inner core (2C) is inserted into the sleeve upper connector (1C), the outer wall of the sleeve inner core (2C) has a reduced diameter section, two inner core grooves are arranged on the outer wall of the sleeve inner core (2C), and the two inner core grooves are located on the upper and lower sides of the reduced diameter section. The sleeve inner core (2C) can slide in the sleeve upper connector (1C), the upper side of the inner wall of the sleeve upper connector (1C) has a necking to form a sleeve upper connector shoulder, the sleeve upper connector shoulder can block the sleeve inner core (2C) from moving upward further, the lower end of the sleeve upper connector (1C) is detachably connected with a sleeve lower connector (4C), the outer wall of the sleeve lower connector (4C) is provided with a second identification ring mounting groove, and the second identification ring (3C) is fixedly connected in the second identification ring mounting groove. The inner wall of the lower end of the sleeve upper connector (1C) is threadedly connected with the sleeve lower connector (4C), and the second identification ring (3C) is located between the sleeve upper connector (1C) and the sleeve lower connector (4C).

7. A downhole string, characterized by The identification short circuit (A2) comprises a short circuit upper joint (1b), and a short circuit lower joint (3b) is detachably connected to the lower end of the short circuit upper joint (1b); a first identification ring mounting groove is arranged on the outer periphery of the upper portion of the short circuit lower joint (3b), and a first identification ring (2b) is fixedly connected in the first identification ring mounting groove; and the identification short circuit (A2) is connected with the intelligent fracturing sliding sleeve (A4) through a casing.

8. A switchable smart frac sleeve system based on smart tags and coiled tubing control, characterized in that, The intelligent switch tool (A3) and the downhole pipe string, or the intelligent key tag (A6) for first opening of the intelligent fracturing sliding sleeve and the downhole pipe string, or the intelligent switch tool (A3), the intelligent key tag (A6) for first opening of the intelligent fracturing sliding sleeve and the downhole pipe string.

9. The switchable smart frac sleeve system based on smart tags and coiled tubing control of claim 8, wherein, When the single target intelligent fracturing sliding sleeve (A4) is switched, a battery-powered self-identification switch control system is used, and the battery-powered self-identification switch control system comprises a serial communication circuit (3-1), an induction module (3-2), a first microcontroller (3-3), a first state display circuit (3-4), a power supply circuit (3-5), a first driver circuit (3-6) and a first actuator (3-7). When the multi-layer intelligent fracturing sliding sleeve (A4) needs to be opened or closed, a coiled tubing built-in cable power supply and communication switch control system is used, and the coiled tubing built-in cable power supply and communication switch control system comprises a carrier wave ground controller and an intelligent switch tool circuit; the carrier wave ground controller comprises an industrial computer (5-1), a second microcontroller (5-2), a carrier wave communication circuit (5-3), a carrier wave power supply circuit (5-4) and a carrier wave communication cable (5-5); and the intelligent switch tool circuit comprises a carrier wave communication circuit (6-1), an induction unit (6-2), a third microcontroller (6-3), a second state display circuit (6-4), a carrier wave power supply circuit (6-5), a second driver circuit (6-6) and a second actuator (6-7).

10. A fracturing method characterized by, The switchable intelligent fracturing sliding sleeve system based on the intelligent tag and the coiled tubing control according to claim 8 or 9 comprises the following steps: the intelligent key tag (A6) for first opening of the intelligent fracturing sliding sleeve (A4) is used when the intelligent fracturing sliding sleeve (A4) is first opened, and the intelligent switch tool (A3) is used when the intelligent fracturing sliding sleeve (A4) is opened and closed during water plugging in the production process.

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