Mechanics-electronics-hydraulics integrated directional tool for continuous tubing drilling

Abstract

A directional tool for coiled tubing drilling has an electronic control module; a hydraulic driving module having a motor in signal connection with the electronic control module, an oil bladder unit arranged between the electronic control module and the motor, a bidirectional hydraulic pump connected to the motor, and a piston a first liquid cavity and a second liquid cavity in communication with the bidirectional hydraulic pump being formed at both ends of the piston, respectively; and a mechanical transmission module, with both ends thereof connected to the piston and a downhole drilling tool, respectively. The electronic control module is configured to transmit the ground control command to the hydraulic driving module, so that the motor drives the bidirectional hydraulic pump to generate high-pressure oil and low-pressure oil in the first liquid cavity and the second liquid cavity alternately, thus driving the piston to perform axial movement reciprocally.

1 . A directional tool for coiled tubing drilling, comprising:
 an electronic control module ( 200 ), for receiving a ground control command;   a hydraulic driving module ( 300 ), which comprises a motor ( 14 ) in signal connection with the electronic control module ( 200 ), a bidirectional hydraulic pump ( 18 ) connected to the motor ( 14 ), and a piston unit comprising a piston housing ( 28 ) and a piston ( 27 ) arranged within the piston housing, a first liquid cavity ( 201 ) and a second liquid cavity ( 202 ) in communication with the bidirectional hydraulic pump ( 18 ) being formed at both ends of the piston, respectively; and   a mechanical transmission module ( 400 ), with both ends thereof connected to the piston and a downhole drilling tool, respectively,   wherein the electronic control module is configured to transmit the ground control command to the hydraulic driving module, so that the motor drives the bidirectional hydraulic pump to generate high-pressure oil and low-pressure oil in the first liquid cavity and the second liquid cavity alternately, thus driving the piston to perform axial movement reciprocally under differential pressure, and   the mechanical transmission module is configured to convert the axial movement of the piston into a rotational movement, in order to drive the downhole drilling tool to rotate and thus adjust downhole tool face.   
     
     
         2 . The directional tool for coiled tubing drilling according to  claim 1 , characterized in that the electronic control module ( 200 ) includes a circuit pressure-bearing cylinder ( 6 ), and a control circuit ( 9 ) arranged inside the circuit pressure-bearing cylinder and in signal connection therewith. 
     
     
         3 . The directional tool for coiled tubing drilling according to  claim 2 , characterized in that the directional tool further comprises an upper joint ( 1 ), a pressure-bearing shell ( 4 ) and a mechanical transmission shell ( 36 ) connected in sequence,
 wherein the electronic control module ( 200 ) and the hydraulic driving module ( 300 ) are arranged within the pressure-bearing shell ( 4 ), and the mechanical transmission module ( 400 ) is arranged inside the mechanical transmission shell ( 36 ), an annular flow passage ( 5 ) for circulation of drilling fluid being formed between the electronic control module ( 200 ), the hydraulic driving module ( 300 ) and the pressure-bearing shell ( 4 ).   
     
     
         4 . The directional tool for coiled tubing drilling according to  claim 2 , characterized in that the control circuit is installed inside the circuit pressure-bearing cylinder through a circuit framework ( 8 ), and configured to receive the ground control command through a cable connector ( 2 ). 
     
     
         5 . The directional tool for coiled tubing drilling according to  claim 4 , characterized in that the hydraulic driving module ( 300 ) further includes a motor housing ( 16 ) fixedly connected to an upper end of the piston housing, and the motor ( 14 ) and the bidirectional hydraulic pump ( 18 ) are arranged within the motor housing. 
     
     
         6 . The directional tool for coiled tubing drilling according to  claim 5 , characterized in that the hydraulic driving module ( 300 ) further includes an oil bladder unit ( 10 ) arranged between the electronic control module ( 200 ) and the motor ( 14 ), for storing compensating hydraulic oil for balancing a difference between an internal pressure and an external pressure of the hydraulic driving module. 
     
     
         7 . The directional tool for coiled tubing drilling according to  claim 6 , characterized in that the oil bladder unit ( 10 ) is arranged between the circuit pressure-bearing cylinder ( 6 ) and the motor housing ( 16 ), and comprises an oil bladder framework ( 11 ) and a bladder ( 15 ) arranged thereon, wherein an annular space for storing the compensating hydraulic oil is formed between the oil bladder framework ( 11 ) and the bladder ( 15 ). 
     
     
         8 . The directional tool for coiled tubing drilling according to  claim 7 , characterized in that a wire connector ( 12 ) is installed inside the oil bladder framework, for connecting the control circuit to the motor. 
     
     
         9 . The directional tool for coiled tubing drilling according to  claim 7 , characterized in that the upper joint ( 1 ) and the circuit pressure-bearing cylinder ( 6 ) are respectively provided with a first flow hole ( 3 ) and a second flow hole ( 13 ) extending through side walls thereof, the second flow hole ( 13 ) corresponding to the oil bladder unit ( 10 ) in position,
 wherein the drilling fluid from an uphole drilling tool flows to the oil bladder unit through the first flow hole, the annular flow passage and the second flow hole in sequence, in order to balance the difference between the internal and external pressures of the hydraulic driving module.   
     
     
         10 . The directional tool for coiled tubing drilling according to  claim 1 , characterized in that the bidirectional hydraulic pump ( 18 ) comprises a first oil port ( 19 ) and a second oil port ( 21 ) in communication with the first liquid cavity ( 201 ) and the second liquid cavity ( 202 ) respectively, and the hydraulic driving module further comprises a two-way hydraulic valve ( 20 ) connected between the bidirectional hydraulic pump ( 18 ) and the piston housing ( 28 ), wherein a first oil path and a second oil path respectively in communication with the first oil port ( 19 ) and the second oil port ( 21 ) are arranged within the two-way hydraulic valve ( 20 ). 
     
     
         11 . The directional tool for coiled tubing drilling according to  claim 10 , characterized in that a first flow passage ( 24 ) and a second flow passage ( 26 ) in communication with the first liquid cavity and the second liquid cavity respectively are provided within a side wall of the piston housing, wherein the first flow passage is in communication with the first oil path to form a first hydraulic passage, and the second flow passage is in communication with the second oil path to form a second hydraulic passage,
 wherein the bidirectional hydraulic pump is configured to:   when the motor rotates in a forward direction, suck the low-pressure oil from the second hydraulic passage, which is compressed to form the high-pressure oil and then transported to the first liquid cavity through the first hydraulic passage, so that the piston extends axially downward, and   when the motor rotates in a reverse direction, suck the low-pressure oil from the first hydraulic passage, which is compressed to form the high-pressure oil and then transported to the second liquid cavity through the second hydraulic passage, so that the piston retracts axially upward.   
     
     
         12 . The directional tool for coiled tubing drilling according to  claim 10 , characterized in that a first safety valve ( 22 ) and a second safety valve ( 23 ) are respectively provided in the first oil path and the second oil path of the two-way hydraulic valve. 
     
     
         13 . The directional tool for coiled tubing drilling according to  claim 1 , characterized in that a pressure balance hole ( 25 ) is arranged in the side wall of the piston housing, for communicating the annular flow passage with an upper area of the piston, in order to balance the pressure on both ends of the piston. 
     
     
         14 . The directional tool for coiled tubing drilling according to  claim 1 , characterized in that a hydraulic joint ( 29 ) is fixed to a lower end of the piston housing, wherein a lower end of the piston extends through the hydraulic joint to form a dynamic seal. 
     
     
         15 . (canceled) 
     
     
         16 . The directional tool for coiled tubing drilling according to  claim 1 , characterized in that the mechanical transmission module ( 400 ) comprises a transmission shaft ( 41 ) connected to the piston and a rotating cylinder ( 42 ) adaptively connected to the transmission shaft, and is configured to drive the rotating cylinder to rotate through an axial movement of the transmission shaft. 
     
     
         17 . The directional tool for coiled tubing drilling according to  claim 16 , characterized in that the transmission shaft is fixedly connected to the piston through a drive shaft ( 34 ), which has a central flow passage ( 35 ), and a third flow hole ( 33 ) passing through a side wall thereof for communicating the central flow passage ( 35 ) with the annular flow passage ( 5 ). 
     
     
         18 . The directional tool for coiled tubing drilling according to  claim 16 , characterized in that a plurality of first key ways ( 50 ) and a plurality of second key ways ( 60 ) both evenly distributed along a circumferential direction are formed on an outer surface of the transmission shaft, wherein the first key ways and the second key ways are spaced apart along an axial direction and offset from each other at a certain angle circumferentially, so as to be in communication with but offset from each other along the circumferential direction, and
 at least one engaging protrusion ( 70 ) is arranged on an inner surface of the rotating cylinder, and configured to alternately engage with one of the first key ways and one of the second key ways when the transmission shaft ( 41 ) moves along the axial direction, thus driving the rotating cylinder to rotate.   
     
     
         19 . The directional tool for coiled tubing drilling according to  claim 18 , characterized in that a first side wall at a lower end of each first key way is formed as a first guiding inclined surface ( 51 ), which is opposite to a corresponding second key way to receive the engaging protrusion from said second key way,
 a first side wall at an upper end of each second key way is formed as a second guiding inclined surface ( 61 ), which is opposite to a corresponding first key way to receive the engaging protrusion from said first key way, and   a first engaging inclined surface ( 71 ) that engages with the first guiding inclined surface is formed on a second side opposite to a first side, and at an upper end of the engaging protrusion, while a second engaging inclined surface ( 72 ) that engages with the second guiding inclined surface is formed on the second side and at a lower end of the engaging protrusion.   
     
     
         20 . The directional tool for coiled tubing drilling according to  claim 16 , characterized in that the mechanical transmission module further comprises:
 a ratchet cylinder ( 40 ), with an upper end thereof sleeved on the drive shaft ( 34 ), and a lower end thereof extending downward to engage with an upper end of the rotating cylinder, ratchets formed at the lower end of the ratchet cylinder and the upper end of the rotating cylinder being configured to engage with each other; and   a spring ( 38 ), wherein a step with an end surface facing downward is provided on an inner wall of the mechanical transmission shell, and the spring is arranged between the step and an upper end surface of the ratchet cylinder, the lower end of the ratchet cylinder pressing tightly against the upper end of the rotating cylinder, in order to allow the rotating cylinder to rotate in only one direction.   
     
     
         21 . The directional tool for coiled tubing drilling according to  claim 16 , characterized in that an output joint ( 47 ) is fixedly connected to a lower end of the rotating cylinder ( 42 ) for connecting to the downhole drilling tool, a sealing joint ( 44 ) being arranged between the output joint and the mechanical transmission shell, and
 the sealing joint is fixed connected to the mechanical transmission shell, and engages with both the rotating cylinder and the output joint through a thrust bearing ( 43 ), wherein a rotary sealing ring ( 46 ) is arranged between the output joint and the sealing joint, in order to ensure a rotary seal therebetween.   
     
     
         22 . (canceled)