RU2719875C1 - Assembly of drill string bottom for drilling of offshoots from horizontal part of uncased well - Google Patents

Abstract

FIELD: soil or rock drilling; mining.

SUBSTANCE: invention relates to technical means for drilling side holes from the horizontal part of an open-hole, in particular to drilling devices using long-length flexible pipes - coiled tubing. Assembly of the bottom of the drill string (ABDS) for drilling of offshoots from the horizontal part of the open-hole includes serially arranged from the bottom-up up the bit, screw downhole motor (SDM), long flexible pipes (LFP). Additionally, after the bit there is an oscillator-turbulence promoter, after the SDM there arranged is a curve adapter, a telesystem and a connecting unit. Curved adapter is made in the form of a branch pipe of a weighted drill pipe with possibility of threaded connection with an SDM and a telesystem by means of threads with intercepting axes at angle of 2°. Telesystem consists of a housing made from an alloyed drill pipe, in a bottom-up housing there are modules of inclination, gamma-ray logging and pressure gauge of internal pressure, axial load and annular pressure. Between the modules in the body of the telesystem there installed are flexible centralizers made in the form of a ring on the external surface of which there are three spring-loaded lamps from sheet steel. Telesystem housing on the outside at both ends is equipped with centralisers made in the form of rings, on external surface of which corresponding overflow channels are made in the form of longitudinal cylindrical grooves with possibility of working fluid overflow. Outer diameter of centralizers is equal to diameter of bit, telesystem is connected by geophysical cable, which is stored inside LFP column through geophysical tip, with ground equipment. Above the geophysical tip on the inner surface of the body of the telesystem there are notches with the possibility of catching the body of the telesystem. Connecting assembly is made in form of mechanical disconnector, which is a shear pin, destructing at design load.

EFFECT: technical result consists in providing drilling accuracy, monitoring downhole parameters, determining ABDS position in real time, enlarging functional capabilities, increasing drilling speed of offshoot, reducing probability of emergencies in well.

4 cl, 3 dwg, 3 ex

Description

The invention relates to technical means for drilling sidetracks from the horizontal part of an open hole, in particular to devices for drilling using long flexible pipes (coiled tubing).

Also known is the layout of the bottom of the drill string (BHA) for drilling directional and horizontal wells with a downhole motor (patent RU No. 2280748, IPC ЕВВ 7/04, published on July 27, 2006, in bull. No. 21), consisting of a drilling columns, chisels, downhole motor and a telescopic system installed between the bottom pipe of the drill string and the downhole motor of the telescopic system, including a cylinder made in the lower part with openings and connected to the drill string, and a hollow piston located inside it connected to the housing motor, wherein the arrangement is provided with fixed slide valve formed as a sleeve with an elastic liner and in-cylinder above its openings, the elastic shank to enter it, the piston is formed with a conical surface and with annular grooves in which are arranged sealing rings of elastomeric material.

The disadvantages of the layout are:

- firstly, the inability to control the sidetracking path from the horizontal part of the open hole due to the lack of a geophysical navigation device with real-time control of the sidetrack drilling trajectory;

- secondly, the monitoring of downhole parameters and determination of the BHA position in real time is not provided, which leads to a deviation of the sidetrack from a given trajectory and a high probability of opening the aquifer and flooding of the main horizontal trunk;

- thirdly, the limited functionality of the device, since it is impossible to perform sidetracking relative to an uncased horizontal wellbore with an angle of inclination from 2 ° to 5 ° in the direction from the bottom to the mouth, and also during the drilling process to change the trajectory of the sidetracks relative to the uncased horizontal wellbore;

- fourthly, the low speed of drilling a sidetrack due to an increase in the load on the bit with increasing depth of the well, as well as rock hardness;

fifth, the low reliability of the BHA due to the high probability of the BHA sticking due to the formation of slurry cushions during drilling from the sidetrack from the horizontal part of the uncased borehole, which is facilitated by rigid centralizers without overflow channels and a weighted drill pipe;

- sixth, the impossibility of disconnecting the BHA from the string of long flexible pipes (DHT) during the formation of a BHA sticking and, as a consequence, the occurrence of an emergency.

The closest in technical essence and the achieved result is the layout of the bottom of the drill string (patent RU No. 2236538, IPC ЕВВ 7/06, 17/00, publ. September 20, 2004, in bull. No. 26), including sequentially placed from the bottom up chisel, downhole screw motor - VZD, DGT. In addition, the BHA is equipped with centralizers located after the drill bit weighted after the downhole motor. At the same time, the BHA is equipped with a motor eccentric working pair consisting of a housing in which a screw element is mounted, which is rigidly connected to a DHT, with adapters with stuffing box seals installed on both ends of the housing, and ribs mounted at an angle to the axis on the outer surface of the housing and adapters layouts.

The disadvantages of the layout are:

- firstly, the inability to control the sidetracking path from the horizontal part of the open hole due to the lack of a geophysical navigation device with real-time control of the sidetrack drilling trajectory;

- secondly, the monitoring of downhole parameters and determination of the BHA position in real time is not provided, which leads to a deviation of the sidetrack from a given trajectory and a high probability of opening the aquifer and flooding of the main horizontal trunk;

- thirdly, the limited functionality of the device, since it is impossible to perform sidetracking relative to an uncased horizontal wellbore with an angle of inclination from 2 ° to 5 ° in the direction from the bottom to the mouth, and also during the drilling process to change the trajectory of the sidetracks relative to the uncased horizontal wellbore;

- fourthly, the low reliability of the BHA due to the high probability of the BHA sticking due to the formation of slurry pads during drilling from the sidetrack from the horizontal part of the uncased borehole, which is facilitated by rigid centralizers without overflow channels and a weighted drill pipe;

fifth, the low reliability of the BHA due to the high probability of the BHA sticking due to the formation of slurry cushions during drilling from the sidetrack from the horizontal part of the uncased borehole, which is facilitated by rigid centralizers without overflow channels and a weighted drill pipe;

- sixth, the impossibility of disconnecting the BHA from the column of DHT during the formation of a stick of the BHA and, as a consequence, the occurrence of an emergency.

The technical objectives of the invention are to develop a BHA design that ensures the accuracy of sidetracking from the horizontal part of an open hole along a pre-planned trajectory, and allows you to control downhole parameters and determine the position of the BHA in real time, expand the functionality of the device, as well as increase the speed of drilling (wiring) sidetrack, reducing the likelihood of emergencies in the well.

Technical problems are solved by arranging the bottom of the drill string for drilling lateral shafts from the horizontal part of the uncased borehole, including the bit sequentially placed from the bottom up, the downhole screw motor - VZD, long flexible pipes - DHT.

What is new is that, in addition to the bit, an oscillator-turbulator is placed, after the VZD the telesystem sub-curve and the connecting unit are placed, while the sub-curve is made in the form of a drill pipe fitting with the possibility of threaded connection with the VZD and the telesystem using threads with intersecting axes at an angle 2 °, the telesystem consists of a body made of an alloy drill pipe, modules: inclinometry, gamma-ray logging and internal pressure gauge pressure, axial load and annular pressure, while between the modules in the housing of the television system flexible centralizers are installed, made in the form of a ring, on the outer surface of which three spring-loaded lamps made of sheet steel are welded, the housing of the television system is equipped on the outside from both ends with centralizers made in the form of rings, on the outer surface of which the corresponding transfer channels are made in the form of longitudinal cylindrical grooves with the possibility of overflow of the working fluid, and the outer diameter of the centralizers is equal to the diameter the drill bit, the telesystem is connected by a geophysical cable, stored inside the DGT column through a geophysical tip, to ground equipment, and notches are made above the geophysical tip on the inner surface of the telesystem body, which allows the telesystem body to be gripped, the connecting unit is made in the form of a mechanical disconnector, which is a shear pin breaking at design load.

Also new is that when sidetracking with an angle of inclination from 2 ° to 3 °, the device is equipped with the usual VZD.

Also new is that when sidetracking with a tilt angle of 3 ° to 4 °, the device is equipped with a shortened IDP.

Also new is that when sidetracking with an angle of inclination of 4 ° to 5 °, the device is equipped with a short IDR.

In FIG. 1 schematically shows the proposed BHA for the implementation of the side trunk.

In FIG. 2, an enlarged view schematically shows annular notches made internally in the upper part of the body of the television system of the opposite direction to notches of a fishing tool with an internal grip.

In FIG. 3 schematically depicts an uncased lateral wellbore after performing sidetracks.

BHA for drilling the sidetrack 1 (Fig. 1-3) from the horizontal part of the open hole consists of a column of DHT 2, for example, with a diameter of 44.55 mm. At the lower end of the column of DHT 2, a bit 3, for example, 68 mm in diameter, an oscillator-turbulator 4, a VZD 5 with a curved sub 6, with a deviation angle of 2 °, and a television system 7 are sequentially placed from bottom to top.

The oscillator-turbulator 4 is connected to the bit 4 and the VZD 5 using a threaded connection. Oscillator-turbulator 4 of any known design, for example, manufactured by RosPromBur.

Depending on the angle of inclination during sidetracking, the BHA includes the VZD 5:

- at an angle of inclination from 2 to 3 ° - VZD 5 'usual (3.0-3.5 m long), for example, VZD brand D1-54M manufactured by "VNIIBT Drilling tool", having a length of 3200 mm;

- at an angle of inclination from 3 ° to 4 ° - a 5-inch VZD shortened (2.5-3.0 m long), for example, a D-54.5 / 6.12 brand VZD manufactured by Permneftemashremont, having a length of 2803 mm;

- at an angle of inclination from 4 ° to 5 ° - the 5 '' 'VZD is short (2.0-2.5 m long), for example, the D-54.5 / 6.07 brand VZD manufactured by Permneftemashremont, having a length of 2066 mm.

One of the VZD 5 ', 5' ', 5' '' of one diameter of 54 mm is used.

Curved sub 6 is a branch pipe of a weighted drill pipe with intersecting axes of connecting threads at an angle of 2 °, for example, an outer diameter of 60 mm and a length of 0.4 m. Curved sub 6 is connected to the VZD 5 and the tele-system 7 using a threaded connection.

The telesystem 7 consists of a housing 8 made of an alloy drill pipe (LBT) according to GOST 23786-79 from an aluminum alloy DT 16 with a chemical composition according to GOST 4748-74. Modules: inclinometry 9, gamma-ray logging and manometer of internal pressure 10, axial load and annular pressure 11, power and communication 12 are sequentially placed in the housing 8 of the television system 7, all modules are interconnected using threaded ends at the ends assembly (disassembly). All modules of the telesystem 7 are cylindrical.

The inclinometry module 9 provides the measurement of inclinometric parameters: azimuthal and zenith angles of the BHA position. Use the inclinometry module 9 of any well-known manufacturer, for example, the brand "ORBI-3-LSK 2M" manufactured by JSC NPF "Geofizika" (Russian Federation (RF), Republic of Bashkortostan, Ufa).

The gamma-ray logging module and internal pressure gauge 10 provides measurements of the natural gamma activity of the rocks and the pressure of the flushing fluid in front of the VZD 5 in order to match the operating mode of the VZD 5 with its passport data. Use the gamma-ray logging module and internal pressure gauge 10 of any well-known manufacturer, for example, the brand "GKM-36" produced by JSC NPF "Geofizika" (RF, Republic of Bashkortostan, Ufa).

The axial load and annular pressure module 11 provides measurements of the axial load on the bit 3 and the pressure in the annulus, for example, the axial load in the range from 0 to 100 kN and the pressure in the range from 0 to 40 MPa. The axial load and annular pressure module 11 of any well-known manufacturer is used, for example, the "MON" brand manufactured by OAO NPF "Geofizika" (RF, Republic of Bashkortostan, Ufa).

The power and communication module 12 provides electrical power for the modules: inclinometry 9, gamma-ray logging and internal pressure gauge 10, axial load and annular pressure 11, and also provides communication between the tele-system 7 and ground equipment through geophysical cable 13, for example, a 3-wire 3-wire KG brand , 5-70-150, manufactured by Katel CJSC (RF, Tver).

In the housing 8 between the above modules of the television system 7 flexible centralizers 14 are installed (Fig. 1 is shown conditionally), made in the form of a ring, on the outer surface of which three spring-loaded lamps made of sheet steel are welded. Flexible centralizers 14 are rigidly fixed, for example, by means of a welded joint on the outer surface of the nozzles (shown in Fig. 1 conventionally). Pipes, by means of a thread made at their ends, connect the modules to each other inside the housing 8 of the telesystem 7. Flexible centralizers 14 provide alignment between the above modules of the telesystem 7 and at the same time are absorbers of radial and axial loads arising in the telesystem 7 during drilling of the sidetrack 1.

The layout is equipped with a connecting node (Fig. 1), made in the form of a mechanical disconnector 15, which is a shear pin, breaking at the rated load, for example 50 kN.

The telesystem 7 is connected to the geophysical cable 13, stocked into the column of the DGT 2 through the geophysical tip 16, connected by a threaded connection to the housing 8 of the telesystem 7. The telesystem 7 is controlled from ground equipment (not shown in Fig. 1-3) through the geophysical cable 13 ( Fig. 1). The housing 8 of the television system 7 is equipped on both sides from the outside with centralizers 17 'and 17' 'with corresponding transfer channels 18' and 18 ''. The centralizers 17 'and 17' 'are made in the form of rings, on the outer surface of which the corresponding transfer channels 18' and 18 '' are made in the form of longitudinal cylindrical grooves with the possibility of overflow of the working fluid during operation of the device. The centralizers 17 'and 17' 'are rigidly fixed to the housing 8 of the television system 7, for example, by means of a welded joint.

The outer diameters of the centralizers 17 'and 17''- d _c (Fig. 1) are equal to the diameter of the bit 3 - D _d , i.e. (d _c = D _d ). As indicated above, use a bit 3 with a diameter of D _d = 68 mm Then the diameter centralizers 17 'and 17''d _u = D _d = 68 mm.

Above the geophysical tip 16, notches 19 are made on the inner surface of the housing 8 of the television system 7, designed to capture the housing 8 with a special fishing tool 20 in the event of a BHA sticking during sidetrack drilling.

On the outer surface of the fishing tool 20, annular notches 21 are made in the opposite direction to the notches 19 of the housing 8 of the tele-system 7. The outer surface of the fishing tool 20 can be made in the form of radially spring-loaded dies (not shown in Fig. 1-2), compressing when the notches 21 enter fishing tool 20 inside the housing 8 of the telesystem 7 and open when fixing notches 21 fishing tool 20 in the notches 19 of the housing 8 of the telescope 7.

O-ring 22 provides tightness during operation of the device.

BHA for drilling a sidetrack from a horizontal part of an open hole works as follows.

Consider the work of the BHA.

Prior to launching the proposed BHA into the horizontal part of the open hole, the wedge diverter (not shown in Fig. 1-3) of any known design is lowered into the required interval, allowing to orient (in the direction of sidetracking 1 ', or 1' ', or 1' '' in azimuth from 0 to 360 °) and reject the proposed BHA for drilling sidetrack 1 from the horizontal part of the open hole at an angle of 2 to 5 °.

Example 1

From the main horizontal open-hole wellbore, it is necessary to make a sidetrack 1 '. A wedge-diverter with a deviation angle of 2.5 ° with respect to the main horizontal open-hole wellbore is installed in an open hole at a depth of 1020 m, while the lateral hole must be made in the azimuth direction of 150 °.

To do this, BHA is assembled at the wellhead using 5 'VZD (Fig. 1).

After the BHA is lowered into the interval of drilling of the sidetrack 1 '(to a depth of 1020 m) from the horizontal part of the open hole.

Using a pumping unit (not shown in Fig. 1-3), a working fluid, for example waste water with a density of 1000 kg / m ^{3, is} injected into the column of DHT 2 (Fig. 1). Under the action of the working fluid, the BHA 5 'starts to operate. VZD 5 'through the oscillator-turbulator 4 transmits the rotation to the bit 3. The bit 3 is drilled into the rock and the sidetrack 1' is drilled from the horizontal part of the uncased borehole with the following technological parameters: the load on the bit 3 is 0.8 t, the working fluid pressure 12 MPa, the flow rate of the working fluid is 3.5 l / s, the speed of penetration of the bit 3 during drilling is 2.3 m ³ / h, the annular pressure is 7 MPa.

In this case, the BHA passes through the deflector wedge (not shown in Figs. 1–3) and deviates from the horizontal part of the open hole by an angle of 2.5 ° in the direction relative to the main horizontal open hole in the azimuth direction of 150 °.

Thus, a BHA with a VZD 5 'and a curved sub 6 (Figs. 1, 3) drills a lateral shaft 1' '' in the interval 1020-1200 m. After that, the BHA is removed from the well.

First, during the kick-offs and during the drilling of the sidetrack 1 'using the telesystem 7 via geophysical cable 15, data such as anti-aircraft and azimuthal BHA angles, annular pressure are transmitted to ground equipment with a software package (not shown in Figs. 1-3) axial load on bit 3, the natural gamma activity of the rocks and the pressure of the flushing fluid in front of the VZD 5 'in real time. Ground equipment consists of blocks: transmit-receive, power, depth measurement, computer (not shown in Fig. 1-3). Using ground-based equipment, data are collected, stored and visualized, the design and actual paths are built during the drilling of the sidetrack 1 '(Figs. 1, 3), and the sidetracking path of the sidetrack 1' is also controlled.

Example 2

From the main horizontal open-hole wellbore, a 1 '' lateral wellbore is required. A whipstock is installed in an open hole at a depth of 950 m with a deviation angle of 3.5 ° with respect to the main horizontal open hole, while the lateral hole must be made in the azimuth direction of 210 °.

To do this, BHA is assembled at the wellhead using 5 '' VZD (Fig. 1). Then, the BHA is lowered into the 1 '' sidetracking interval (to a depth of 950 m) from the horizontal part of the open hole.

Using a pumping unit (not shown in Fig. 1-3), a working fluid, for example waste water with a density of 1010 kg / m ³ , is pumped into the column of DHT 2 (Fig. 1). Under the action of the working fluid in the BHA, the VZD 5 begins to work. The VZD 5 '' through the oscillator-turbulator 4 transmits rotation to the bit 3. The bit 3 is drilled into the rock and the sidetrack 1 '' is drilled from the horizontal part of the uncased borehole with the following technological parameters: the load on the bit 3 is 1.0 t, pressure the working fluid is 14 MPa, the flow rate of the fluid is 3.7 l / s, the penetration rate of bit 3 during drilling is 2.5 m ³ / h, the annular pressure is 8 MPa.

In this case, the BHA passes through the deflector wedge (not shown in Figs. 1–3) and deviates from the horizontal part of the open-hole well by an angle of 3.5 ° in the direction relative to the main horizontal open-hole well in the azimuth direction of 210 °.

Thus, a BHA with a 5 '' VZD and a curved sub 6 (Fig. 1, 3) drills a 1 '' sidetrack in the interval 720-890 m. After that, the BHA is removed from the well.

First, during the kick-offs and during the drilling of the sidetrack 1 '' using the telesystem 7 via geophysical cable 15, data such as anti-aircraft and azimuthal BHA angles, annular pressure are transmitted to ground equipment with a software package (not shown in Fig. 1-3) , axial load on the bit, the natural gamma activity of the rocks and the pressure of the flushing fluid in front of the VZD in real time. Ground equipment consists of blocks: transmit-receive, power, depth measurement, computer (not shown in Fig. 1-3). Using ground-based equipment, data are collected, stored and visualized, the design and actual trajectories are constructed during the drilling of the sidetrack 1 '' (Fig. 3), and the path of the sidetrack 1 '' is also controlled.

Example 3

From the main horizontal open-hole wellbore, it is necessary to make a sidetrack 1 '' '. A wedge-diverter with a deviation angle of 4.5 ° relative to the main horizontal open-hole borehole is installed in an open hole at a depth of 720 m, while the 1 '' 'lateral hole must be made in the azimuth direction of 270 °.

To do this, BHA is assembled at the wellhead using 5 '' VZD (Fig. 1). After that, the BHA is lowered into the drilling interval of the sidetrack 1 '' '(to a depth of 720 m) to make the sidetrack 1 from the horizontal part of the open hole.

Using a pumping unit (not shown in Fig. 1-3), a working fluid, for example, waste water with a density of 1020 kg / m ³ , is pumped into the column of DHT 2 (Fig. 1). Under the action of the working fluid in the BHA, the VZD 5 '' begins to work. The VZD 5 '''through the oscillator-turbulator 4 transmits the rotation to the bit 3. The bit 3 is drilled into the rock and the sidetrack 1''' is drilled from the horizontal part of the open hole with the following technological parameters: the load on the bit 3 is 1.2 t , the pressure of the working fluid is 16 MPa, the flow rate of the working fluid is 3.9 l / s, the penetration rate of bit 3 during drilling is 2.7 m ³ / h, the annular pressure is 9 MPa.

At the same time, the BHA passes through the deflector wedge (Fig. 1, 3) and deviates from the horizontal part of the open hole by an angle of 4.5 ° in the direction relative to the main horizontal open hole in the azimuth direction of 270 °.

Thus, a BHA with a 5 '' VZD and a curved sub 6 (Figs. 1, 3) drills a 1 '' 'sidetrack in the range of 720-890 m. Then, the BHA is removed from the well.

First, during the kick-off and during the drilling of the lateral well G "using the telesystem 7 via geophysical cable 15, data such as anti-aircraft and azimuth angles of BHA, annular pressure are transmitted to ground equipment with a software package (not shown in Fig. 1-3) axial load on the bit, the natural gamma activity of the rocks and the pressure of the flushing fluid in front of the VZD in real time. Ground equipment consists of blocks: transmit-receive, power, depth measurement, computer (not shown in Fig. 1-3). With the help of ground equipment, data are collected, stored and visualized, the design and actual paths are constructed during the drilling of the sidetrack 1 '' '(Fig. 1), and the path of the sidetrack 1' '' is also controlled.

The use of oscillator-turbulator 4 in the design of the BHA leads to oscillation of low-frequency oscillations of the working fluid pumped along the column of DHT 2 and creates low-amplitude longitudinal vibrations that contribute to the creation of a dynamic load on bit 3, leading to more efficient destruction of rock and reduce wear of the bit 3. Experienced it was found that the use of an oscillator-turbulator increases the mechanical drilling speed (wiring) of the sidetrack by 40-50% in hard rocks, regardless of the load on Lotto 3, associated with an increase in well depth.

The expansion of the device’s functionality is achieved through the use of a curve sub 6 with VZD 5 of various lengths in the BHA design, which allows sidetracking relative to the uncased horizontal wellbore with an angle of inclination from 2 ° to 5 ° in the direction from the bottom to the mouth, and also to change the trajectory during the drilling of the sidetracks relative to the uncased horizontal wellbore.

Also, the use of a curve sub 6 with an angle of deviation of 2 ° (angle of displacement of the axes of the threads) helps to reduce the consumption of bits 3, the time of mechanical drilling, tripping (when using a wedge diverter), preparatory-final and auxiliary work, which reduces the duration of work, and therefore saves costs.

Owing to the presence of the telesystem 7 in the BHA design, the accuracy of sidetracking from the horizontal part of the uncased borehole is observed along a predetermined path, the downhole parameters are monitored and the BHA position is determined in real time.

Control of downhole parameters is achieved by using load module 11 in the BHA design. The annular pressure is measured in space 23 of the drilled lateral shaft G, or 1 ", or G" and the axial load on the bit 3 during drilling of the lateral shaft G, or 1 ", or G "

To do this, lift the BHA using DHT 2 for 10-20 m and flush the drilled sidetrack 1 ', or 1' ', or 1' '', after which the sidetrack is drilled 1 ', or 1' ', or 1' ' 'continue in compliance with the design and actual trajectory, which is visually controlled using ground equipment.

At the end of the drilling of the sidetrack 1 ', or 1' ', or 1' '', the BHA is removed from the sidetrack 1 ', or 1' ', or 1' '', the deflecting wedge and the horizontal part of the open hole. To drill the sidetrack in a different interval, the diverter wedge is moved in the horizontal part of the uncased borehole and the next sidetrack is drilled using the BHA described above.

Measurement of the azimuthal and zenith angle angles of the BHA position in the continuous mode is achieved by using the inclinometry module 9 in the BHA design, and they also orient the curve of the sub 6 while stopping sidetracking 1 ', or 1' ', or 1' ''.

BHA implements continuous remote monitoring and changing the direction of the trajectory over the entire interval of drilling the sidetrack 1 ', or 1' ', or 1' '' from the horizontal part of the open hole.

Control of downhole parameters is achieved by using load module 11 in the design of BHA.

Due to the presence of overflow channels 18 'and 18' 'in the BHA design at the centralizers 17' and 17 '' on the outer surface of the housing 8 of the telesystem 7, the probability of a BHA sticking in the side trunk 1 ', or 1' 'is reduced by 1.5-2 times, or 1 '' 'due to the absence of formation of slurry cushions in the sidetrack during its drilling.

The connecting unit 14 in the design of the BHA eliminates damage (breakage, stretching) of the DGT column 2 and the breakage of the geophysical cable 15 when the BHA is tacked and, as a result, the probability of emergency situations in the well is reduced. BHA grabbing is possible, for example, as a result of shedding of weakly cemented drilled rocks. By pulling upwards, a load is created in the column of DHT 2 sufficient to destroy the connecting unit 14. For example, pulling the column of DHT 2 upward with a force of 5.5 kN, at which the connecting node 14 is destroyed and the geophysical cable 15 is broken in the seal of the telescopic tip 16. Then the column DHT 2 with a geophysical cable 15 is removed from the well, after which, on a pipe string (not shown in Fig. 1, 2), a special fishing tool 21 with an internal grip having notches 20 (conventionally shown in Fig. 1) is lowered into the well the direction of the annular notches 19 (Fig. 1 and 2) of the housing 8 of the telesystem 7. Carry out the BHA capture tool 21 for the annular notches 19 (Fig. 1 and 2) of the housing 8 of the telescope 7, then remove the tied BHA side trunk 1 ', or 1 '', or 1 '' ', deflector wedge and horizontal part of the open hole.

The proposed layout of the BHA allows you to:

- comply with the accuracy of sidetracking from the horizontal part of the open hole along a pre-planned path;

- provide control of downhole parameters and determine the position of BHA in real time;

- expand the functionality of the device;

- increase the speed of penetration of the bit when drilling a sidetrack, which reduces the time of work and reduce costs;

- reduce the likelihood of emergency situations in the well.

Claims (4)

1. The layout of the bottom of the drill string - BHA for drilling sidetracks from the horizontal part of an uncased borehole, including a bit sequentially placed from bottom to top, a downhole screw motor - VZD, long flexible pipes - DGT, characterized in that an oscillator-turbulator is additionally placed after the bit, after the VZD there is a curve sub, a tele-system and a connecting unit, with This curve sub is made in the form of a pipe of a weighted drill pipe with the possibility of a threaded connection with a PDW and a telesystem using threads with intersecting axes at an angle of 2 °, the telesystem is um from a housing made of an alloy drill pipe, the modules: inclinometry, gamma-ray logging and internal pressure gauge, axial load and annular pressure are sequentially placed from the bottom to the top of the housing, while flexible centralizers made in the form of a ring are installed between the modules in the television system housing , on the outer surface of which three spring-loaded lanterns made of sheet steel are welded, the body of the television system is equipped on both sides with centralizers made in the form of rings, on the outer surface of which corresponding flow channels in the form of longitudinal cylindrical grooves with the possibility of overflow of working fluid, the external diameter of the centralizers being equal to the diameter of the bit, the telesystem is connected by a geophysical cable stored inside the DHT column through a geophysical tip to ground equipment, while above the geophysical tip on the inner surface of the telesystem housing notches are made that provide the ability to capture the body of the tele-system, the connecting node is made in the form of a mechanical The unit, which is a shear pin, collapsing at rated load. 2. BHA for drilling sidetracks from the horizontal part of an uncased borehole according to claim 1, characterized in that when cutting a sidetrack with an angle of inclination of 2 ° to 3 °, the device is equipped with a conventional VZD. 3. BHA for drilling sidetracks from the horizontal part of an open hole according to claim 1, characterized in that when sidetracking with an angle of inclination from 3 ° to 4 °, the device is equipped with a shortened VZD. 4. BHA for drilling sidetracks from the horizontal part of an uncased borehole according to claim 1, characterized in that when cutting a sidetrack with an angle of inclination of 4 ° to 5 °, the device is equipped with a short VZD.

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