RU2636608C1 - Method for construction of additional well bore of multi-lateral well and device for its implementation - Google Patents

Abstract

FIELD: oil and gas industry.SUBSTANCE: method for construction of additional well bore of the multi-lateral well includes preliminary expansion of inner diameter of the casing string of primary well bore in window location zone and above, lowering and installing a removable wedge-deflecting tool, opening the window and drilling a new additional well bore to the designed depth, removal of the wedge-deflecting tool and lowering a shank equipped with longitudinally corrugated suspension or made of longitudinally profiled tube with an enlarged perimeter in expansion zone of the primary casing string inner diameter. The shank is directed and placed in additional well bore by means of a guide shoe attached below, straightening the corrugated sections of the shank is performed by excessive pressure with fixation by flaring in additional well bore. The upper part of the shank is processed in two stages, at the first stage the guide window is cut out in the shank to create communication with the primary well bore, at the second stage- the upper part of the shank is expanded before pressing thereof flush to the expansion of the primary well bore walls. The device for processing of the upper part of shank includes a cutting tool lowered on a pipe string and configured for rotation, and placed below for cutting the window for communication with the well bore. Above the cutting tool, there is a rolling tool with rolling rotary extensible rollers. The distance between the cutting and rolling tools is not less than length of the window in longitudinal direction of primary well bore.EFFECT: simplified construction of multi-lateral well from previously drilled and cased wells, reduction of time, labour and material costs.2 cl, 10 dwg

Description

The invention relates to the oil and gas industry and can be used for drilling and fastening additional shafts from previously drilled cased wells.

A device for holding and attaching multilateral wells (copyright certificate SU No. 663825, IPC 2 Е21В 43/10, ЕВВ 7/08, published in Bull. No. 19 of 05/25/1979), which carry out the method of construction of multilateral wells, including the construction of the main trunk with a cut-out window in the casing, drilling an additional barrel through the window, lowering the casing of the additional barrel with a connecting pipe made in the form of a pipe with a corrugated sleeve, which is processed by turning to obtain a tight joint eniya.

The corrugated sleeve is processed by a device including a mandrel, pressing the sleeve against the inner wall of the casing of the main wellbore.

The disadvantages of this method are:

- the impossibility of using the method in previously constructed wells with a diameter of less than 750 mm, since the implementation of the method and the use of the device are possible only in newly constructed wells of large diameter - more than 750 mm, where the diameter of the additional wellbore is very small, otherwise the overall dimensions of the device will not allow it to be lowered into installation interval;

- a high probability of emergency situations, since the descent of the corrugated sleeve into the well with a pipe welded to it at a certain angle is associated with great difficulties, as it is jammed, and attempts to release it lead to deformation and breakage of the sleeve;

- great difficulty in fixing the casing of the main bore with cement, since casing with finished windows is used for cutting and drilling the additional bore as part of the casing used to fasten the main bore of the well, which creates great difficulties with orienting the windows in a given position.

The disadvantages of this device:

- additional tripping operations are required to remove the releasing tool and lowering the mandrel;

- in one pass of the mandrel, it is possible to increase the bore diameter of the sleeve by a small amount, therefore, several descents and ascents of the drilling tool with mandrels of various diameters are required;

- when pressing the sleeve against the wall of the casing of the main trunk to obtain a tight connection, equal backpressure is needed around the entire circumference of the barrel;

- a high requirement for the preparation of the inner surface of the casing of the main shaft, since the slightest contamination or damage to the string will lead to an increase in the axial load on the mandrel, its jamming, impossibility to release and create an emergency in the well;

- the lack of centering devices of the mandrel leads to its uneven movement and uneven compression of the corrugated sleeve along its length due to the ellipse and the difference in the pipe from which the corrugated sleeve is made, and hence the impossibility of obtaining a tight connection of the casing strings of a multilateral well;

- the impossibility of creating a tight connection in the window zone, since the mandrel will not experience backpressure in this zone and will tend to shift towards the window and even go into the window, thereby the sleeve in this zone will not be pressed against the wall of the casing of the main shaft and will not tight connection of the sleeve with the casing;

- the impossibility of creating a tight connection of casing strings of multilateral wells with a corrugated sleeve, which is straightened and pressed by the mandrel, due to residual internal stress in the body of the corrugated sleeve, which, with a small pressure drop, will tend to return to the previous state of internal equilibrium and seal the connection.

A device for attaching multilateral wells (copyright certificate SU No. 829882, IPC 3 Е21В 43/10, ЕВВ 7/08, published in Bull. No. 18 of 05/15/1981), which carry out the method of construction of multilateral wells, including the construction of the main barrel with a cut-out window in the casing, drilling an additional barrel through the window, lowering the casing of the additional barrel with a corrugated sleeve connected to the last pipe with a connecting pipe, while the corrugated sleeve has a smooth section and longitudinal slots, allowing -governing bend the tube inside the sleeve during the descent of the column and to return it to its original position in the window area, and the corrugated sleeve fixed in the main wellbore mandrel bore.

The corrugated sleeve is machined by a device including a mandrel that presses the sleeve against the walls of the well.

The disadvantages of this method are:

- the implementation of the method and the use of the device are not possible in existing wells, since there is no stop for the corrugated sleeve in the window area, and therefore, the cut-off plate will not bend to its original position, it will jam at the mouth of the additional trunk and create emergency situations;

- the impossibility of creating a tight connection of the casing strings of multilateral wells when processing the corrugated sleeve with a mandrel, since it has longitudinal slots and its structural integrity is compromised, under the action of internal elastic forces it will tend to return to its original position and overlap the bore of the main shaft;

- reducing the diameter of the main wellbore by an amount equal to the double wall thickness of the corrugated sleeve, and the likelihood of the tubing couplings landing on the protruding walls of the corrugated sleeve during tripping;

- a high likelihood of jamming of the drain tool (tap) after bending the cut-off smooth plate with the welded pipe to its original position and insertion into the additional barrel, since the axes of the pipe and drain tool will skew and jam together.

The disadvantages of the device for processing a corrugated sleeve, including a mandrel, which is designed to fix the sleeve in the main wellbore, are the disadvantages described in the previous device.

A known method of cutting holes in the pipe structure located in the wellbore (US Pat. US No. 5803176, IPC 7 ЕВВ 10/46, ЕВВ 10/50, issued September 8, 1998), including installing an axially elongated tubular milling guide, which connected to the liner suspension for azimuthal and axial orientation of the cut hole, to create a message with the main wellbore.

The pipe structure (shank) and the deflector wedge are machined with a device that includes a cutting tool (drill, chisel, milling cutter, etc.) for cutting a window in the bottom wall of the shank and a hole in the wedge body.

The disadvantages of this method are:

- a significant reduction in the diameter of the additional wellbore and the main section of the main bore, creating great difficulties for using standard equipment even in the main wellbore;

- high costs for diverse and sophisticated equipment used to implement the method, as well as a large number of operations involving highly skilled specialists of various kinds, which leads to additional costs;

- it is impossible to create a tight connection of the casing strings of multilateral wells with cement, since it is a porous substance;

- non-removable wedge-deflector, in which it is necessary to cut a large hole and drill a support packer to create a message with the main wellbore.

The disadvantage of this device is the small diameter of the cutting tool (drill), which is the initial processing of the pipe structure (shank) and the wedge-deflector, as it moves along the inner surface of the axially elongated tubular guide, which goes inside the shank and connects to its suspension for azimuthal and axial orientation of the cut hole. To increase the diameter of the hole, it is necessary to perform additional tripping operations to replace the tool and expand the hole to a predetermined size.

A device is known for holding and attaching multilateral wells (copyright certificate SU No. 192114, IPC 3 Е21В 43/10, ЕВВ 7/08, published in Bull. No. 5 of 04/06/1967), which carry out the method of construction of multilateral wells, including the construction of the main trunk and its mounting with a casing string, into which a pipe section with finished windows located at different heights and at equal angles is integrated, through which additional shafts are drilled and casing pipes are fed into them, and for guiding these pipes and the drilling tool into uzhnoe window is the dispensing head, is fixed in the length of pipe in the special grooves and clamp height so that its guide is located opposite the windows.

The disadvantages of this method are:

- the impossibility of applying the method in existing wells, as for fixing the main wellbore, a casing with an integrated pipe section with prefabricated windows is used, below which a smaller diameter casing is installed, which creates great difficulties with orienting windows in a given direction and cementing the string;

- great difficulties in creating a tight connection of the casing strings of the main and additional shafts, since there are no guides for the figured flange mounted on the upper end of the casing of the shank to accurately get into the socket made in the window of the casing of the distribution head, and there is no device that signals combining a figured flange with a casing socket;

- reducing the diameter of the main wellbore below the casing (pipe section with finished windows) for installing the distribution head in focus, which will complicate the repair and operation of the main wellbore;

- the difficulty of assembling equipment in the well to create a tight connection of the casing pipes of the main and additional shafts.

There is a method of providing communication of lateral branch trunks with a cased main wellbore and a device for its implementation (US Pat. RU No. 2239041, IPC 7 ЕВВ 7/08, 47/12, published in Bull. No. 30 dated October 27, 2004). The method includes installing a retrievable template for the side branch in the main trunk opposite the window, the template being equipped with means for guiding the connector into the side trunk and connecting them to each other with ridge-groove engagement elements, and a connector with a shank - cone-cone, if necessary connections can be equipped with seals to create a tight connection of casing strings.

A device for communicating lateral branch trunks having installed liners with a cased main wellbore in an underground formation having at least one window through which a lateral branch trunk passes, the device comprising a lateral branch pattern adapted for positioning and orientation inside the casing of the main wellbore in order to align it with the window and the lateral branch bore, the template having a guiding means and a first mutual blocking means fenders and a lateral branch connector adapted to engage with the guide means and move longitudinally relative to the template to a joint position in which a part of the lateral branch connector is located inside the side branch barrel, the connector including second interlocking means for interfacing with the first interlocking means for the formation of a node that provides communication with the side branch, creating a path of product flow, while first means for interlocking pattern and second means for interlocking the connector constructed and arranged substantially longitudinally along respectively a template body for lateral branch and longitudinally along the body of the connector for the lateral branch.

The disadvantages of this method and device are:

- the high complexity of the equipment design, requiring preliminary assembly and disassembly at the wellhead to check the collection and, as a result, the high qualification of the service personnel and a high production culture, which leads to a costlier work

- a significant reduction in the internal diameters of the main and additional shafts after the installation of the template and connector, which limits the application of the method and device in small diameter wells;

- the impossibility of use in existing wells, since in production cores there are no slots for installing and positioning the template.

The closest is the method of construction of multilateral wells (US Pat. RU No. 2279522, IPC 7 ЕВВ 7/08, published in Bul. No. 19 of 07/10/2006), including cutting a window in the casing of the primary wellbore and drilling a new additional wellbore to the design depth using a deflector wedge equipped with slots in the lower part and a landing platform that rests on a removable landing assembly with slots resting on the slots of the casing of the primary wellbore. After drilling an additional trunk, the deflector wedge is removed from the well and the liner with casing and assembly for lowering the mouth with an auxiliary wedge is lowered. The shank is cemented, and the auxiliary pipe with cuffs in the upper part is drilled with a chisel. At the end of the development of a new additional trunk, the landing unit is removed with an auxiliary wedge.

The upper part of the shank is processed by a device including a cutting tool (chisel), lowered on a pipe string and made with the possibility of rotation.

The disadvantages of this method are:

- the impossibility of applying this method in previously constructed wells, since they do not have equipment for the bottom of the casing of the main shaft with slots for landing on them an extractable landing unit with a landing casing, on the upper end of the sleeve of which an auxiliary wedge is installed;

- an increase in the number of additional operations for installing and removing removable equipment, injecting visco-plastic fluid, drilling an auxiliary nozzle with cuffs with a chisel, flushing the main barrel from visco-plastic fluid;

- a significant reduction in the diameter of the shank in the window zone, since a wedge placed on its surface for fixing unstable rocks in the window zone increases the diameter of the structure and its rigidity, which will lead to problems when the shank passes through the window and problems when pumping the grouting mixture into the annular space between the rock and the wall of the shank, since the gap between the shank and the walls of the window can be reduced to a technologically unacceptable value;

- the impossibility of creating a tight connection of the casing strings of the main and side shafts due to the large difference in the diameter of the window and the diameter of the shank and the construction of the shank in the window area, consisting of several pipe parts placed one into the other (auxiliary pipe with cuffs and wedge for uncoupling of unstable rocks) , and the use of cement to seal the gap between the casing strings in the window area;

- an increase in the percentage of accidents during work when lowering and securing the liner and drilling its upper part, since the slightest inaccuracy in installing the liner relative to the window will lead to the entry of a wedge designed to fix unstable rocks in the window zone, into the main wellbore and, accordingly, to drill additional metal, bit breakage and additional tripping operations, an increase in time and material costs in the construction of multilateral wells;

- a decrease in the production capabilities of the well and its profitability due to the fact that the casing of the additional well is secured by cement, and this leads to a decrease in the diameter of the additional well in the reservoir and pollution (clogging) of its cement.

The disadvantages of this device are:

- incomplete restoration of the bore of the main trunk, since the upper part of the auxiliary pipe with cuffs is drilled with a bit of a smaller diameter than the inner diameter of the casing of the main barrel, which means that part of the liner will protrude into the main barrel, and during any work the upper thin part will bend and block the passage to the main and secondary boreholes;

- destruction of the connection of the casing strings of a multilateral well, since the bit during the processing of the upper part of the liner (drilling) is not centered along the axis of the main shaft, which means that it will move along the path of least resistance along a helical path, drilling both the wall of the liner and the wall of the casing the main trunk, and in the window zone it will tend to shift towards the additional trunk, leaving a portion of the shank uncut, since there is no support plane from the side of the window, which will lead to many multiple treatments (drilling) in the shank region of the window and the destruction of the mechanical connection of casing and cement in the window area.

The technical objectives of the present invention are:

- the creation of a reliable tight connection between the casing strings of multilateral wells;

- maintaining the bore of the main wellbore after creating a connection between the casing strings of the multilateral wells;

- increase in the bore diameter of the additional wellbore;

- improving the reliability of the connection of the trunks by expanding the suspension of the liner or the column of shaped pipes and thereby preventing annular flow of formation fluid along the liner;

- the exception of cement technology when attaching an additional barrel with a shank;

- increasing the production capabilities of the well by maintaining the reservoir properties of the reservoir and the increased diameter of the additional wellbore;

- reduction of accident rate and construction time of multilateral wells and their cost.

Technical problems are solved by the method of constructing an additional multilateral wellbore, including opening a window in the casing of the primary wellbore and drilling a new additional wellbore to the design depth using an extractable deflector wedge, lowering the liner with casing pipes at the mouth of a new additional wellbore, followed by sealing the additional wellbore wells, processing the upper part of the liner to gain access to the lower part of the primary shaft, removing the wedge -otklonitelya.

What is new is that the inner diameter of the casing of the primary trunk is extended before the deflector wedge is lowered in the window location zone and higher, the deflector wedge with anchor is removed before the liner descends, which is equipped with a longitudinally-corrugated suspension in the window area or is made in the form of a longitudinal-profile pipes with an enlarged perimeter in the zone of expansion of the inner diameter of the primary casing string, the liner is placed in an additional barrel using a guide shoe attached at the bottom, the straightening is corrugated of sections of the shank is carried out by overpressure with fixing by flaring in the additional shaft, the upper part of the shank is processed in two stages, the first of which cuts the guide window in the shank to create a message with the primary shaft, and the second - expand the upper part of the shank before pressing it to expansion flush to the walls of the primary trunk.

Technical problems are also solved by a device for processing the upper part of the shank, including a cutting tool, lowered on a pipe string and made with the possibility of rotation.

What is new is that the cutting tool is placed below for cutting a window for communication with the primary barrel, a rolling tool with rolling rotating sliding rollers is installed above the cutting tool, and the distance between the cutting and rolling tools is not less than the length of the window in the longitudinal direction of the primary barrel.

In FIG. 1 shows a window cut in a casing wall and a cutout of an additional multilateral wellbore from an expanded casing section of a primary wellbore.

In FIG. 2 shows a liner suspension located in the expansion zone of the inner diameter of the casing of the primary wellbore.

In FIG. Figure 3 shows the processing of the upper part of the shank by flaring and cutting the guide window in the shank to create a message with the primary shaft.

In FIG. 4 shows a hermetic connection of casing of a multilateral well after expansion of the liner suspension.

In FIG. 5 shows a longitudinal section through a suspension of a shank made of a longitudinally profiled pipe with an enlarged perimeter.

In FIG. 6 shows a cross section AA of FIG. 5 longitudinally-profile pipes in the area with an increased perimeter.

In FIG. 7 shows a cross section BB of FIG. 5 longitudinally-profile pipe in the area with a smaller perimeter.

In FIG. Figure 8 shows a longitudinal section through a suspension of a liner straightened by fluid pressure and expanded by rolling tools with different working diameters.

In FIG. 9 shows a cross section BB of FIG. 8 parts of the liner suspension, which is located in the zone of expansion of the inner diameter of the casing of the primary wellbore.

In FIG. 10 shows a cross-section GG of FIG. 8 parts of the liner suspension, which is located in the additional wellbore.

A method of constructing an additional wellbore 1 (Fig. 1) of a multilateral well 2 includes opening a window 3 by arranging cutters 4 in the casing 5 of the primary wellbore 6 and drilling a new additional wellbore 1 to the design depth using an extractable deflector 7 (see RF patent No. 2414580, etc. - Fig. 1 is shown conditionally), the descent of the liner 8 (Fig. 2) with casing pipes (not shown in Fig. 2) at the mouth of a new additional wellbore 1 with subsequent sealing of the additional wellbore 1, processing top of hv Stovik 8 (Fig. 3) to gain access to the lower part of the primary barrel 6, removing the deflecting wedge 7 (Fig. 1), for example, using a device (see RF patent No. 2415250, etc., in Fig. 1 not shown) to remove the deflecting wedge 7. Before starting work on cutting the window 3, the inner diameter of the casing 5 of the primary wellbore 6 in the zone 9 of the window 3 and above is expanded, for example, with a sliding expander (see RF patent No. 2117747, etc. P. - in FIG. 1 is not shown) with a diameter exceeding the inner diameter of the casing 5 by an amount equal to the double thickness of the longitudinally-corrugated suspension 10 (Fig. 2) made of a longitudinally-shaped pipe 11 (Fig. 5) with an enlarged perimeter in a section 12 located in zone 9 (Fig. 2) of the extension of the casing 5. On the suspension 10, a shank 8 made of ordinary casing pipes, a slotted filter, or longitudinally shaped pipes is suspended (see RF patent No. 2463433, etc., in Fig. 2 -4 not shown). The shank 8 is guided and placed in an additional barrel 1 using a guide shoe attached from below (see RF patent No. 2483187, etc., not shown in FIG. 2), the corrugated portions of the shank 8 are straightened by overpressure with fixing by flaring (for example, roller flare, mandrel, etc.) in the additional wellbore 1, which allows to seal the additional wellbore 1 and prevent formation fluid flow along the liner. In order to freely bring the liner 8 with the suspension 10 to the bottom of the additional barrel 1 (not shown in Fig. 2), reduce accidents and increase the bore diameter of the additional barrel 1 of the well, the liner 8 is made of longitudinally-shaped pipes with an equal perimeter along the entire length (on Fig. 2 is not shown). In this case, the suspension 10 (Fig. 2) is made of a longitudinally profiled pipe 11 (Fig. 5) with an enlarged perimeter in section 12 (Figs. 5 and 6) and a smaller perimeter in section 13 (Figs. 5 and 7) equal to the perimeter longitudinally-profile pipes of which the shank is made 8. For connection with a drain tool (not shown in FIG. 2) and shank 8 (FIG. 2), the longitudinally-shaped pipe 11 (FIG. 5) has cylindrical sections 14 at the ends (FIG. 5 and 2) and can be connected with them by thread, welding, etc. compounds (in Fig. 2, 3, 4, 5, and 8 not shown). When folded, the longitudinal-profile pipe 11 has a dimension (outer) in diameter (Fig. 5-7) not exceeding the diameter of the couplings (not shown in Fig. 2-4) of ordinary casing pipes lowered into the additional barrel 1 (Fig. 2). When placing the shank 8 in the additional barrel 1 (Fig. 2), the section 12 with the increased perimeter of the longitudinal-profile pipe 11 (Fig. 5), from which the suspension 10 is made (Fig. 2), is located in the expansion zone 9 (Fig. 1) the casing 5 of the primary shaft 6, and the section 13 (Fig. 5) with a smaller perimeter in the additional barrel 1 (Fig. 2). Thus, when straightening the corrugated sections of the shank 8 and suspension 10 with excess liquid pressure, they are completely straightened and fixed in the sections of the primary 6 and additional 1 trunks with different perimeters. In the process of expanding the shank 8 and the section 13 of the longitudinal-profile pipe 11 (Figs. 5 and 7), from which the suspension 10 (Fig. 2) is made (for example, by roller flare, mandrel, etc.), the inner diameters of the longitudinal-profile the pipes from which the shank 8 and the lower section 13 (Figs. 8 and 10) of the longitudinally profiled pipe 11 from which the suspension 10 is made (Fig. 2) are made become perfectly round (Figs. 8 and 10), the walls of the shank 8 ( Fig. 2) and pendants 10 are hardened and hardened. In order to exclude cement technologies when attaching the liner and preserving the reservoir properties of the formation, increasing the production capabilities of the well in difficult geological conditions, when along the length of the additional wellbore 1 (not shown in Fig. 2), formations with abnormally high and low pressure or formations prone to shedding are located on the surface of the profile pipes, seal packers are installed (see RF patent No. 2365728, etc. - not shown in Fig. 2-4), which are pressed tightly against the walls during expansion of the shank 8 body trunk 1 and additionally seal its annular space without the use of cement technology.

Processing the upper part of the shank 8 (Fig. 3), i.e. the suspension 10 is carried out in two stages, the first of which cuts the guide window 15 in the suspension 10 of the shank 8, made of a longitudinal-profile pipe 11 (Fig. 5) with an enlarged perimeter to create a message with the primary barrel 6, cutting tool 16 ( Fig. 3), run on a pipe string (not shown in Fig. 3) and rotatable, for example, by arranging cutters for cutting a window in the casing wall, a cutter for drilling broken pipes in a well, and the like. At the second stage, the suspension 10 of the shank 8 is flared until it is pressed against the extension 9 flush with the walls of the casing 5 of the primary shaft 6 with a rolling tool 17 with rolling rotating sliding rollers 18, for example, an expanding flare (see RF patent No. 2392415, etc. ), giving the upper part 12 (Fig. 8) of the profile pipe 11 the final form (Figs. 8 and 9) with a diameter equal to the inner diameter of the casing 5 of the primary wellbore 6, tightly and hermetically pressing it to the extension 9 (Fig. 4) of the primary barrel 6 casing onny 5.

The diameter of the additional barrel 1 (Fig. 2) is always much smaller than the inner diameter of the primary barrel 6, therefore, the use of a suspension 10 made of a longitudinally-shaped pipe 11 (Fig. 5) with an enlarged perimeter in section 12 allows the suspension 10 to be expanded and finally densely rolled (Fig. 2) to the extension 9 of the casing 5 of the primary shaft 6 without destruction. In this case, the expansion of the profile pipe 11 occurs within the strength characteristics laid down by the manufacturer.

To reduce tripping operations to one and centering the cutting tool 16 (Fig. 3) when cutting the guide window 15 in the suspension 10 of the shank 8 and when expanding the upper part of the suspension 10 with a rolling tool 17, a device has been developed that combines these two operations. The device includes a cutting tool 16 located below, above which a rolling tool 17 with rolling rotating sliding rollers 18 is installed, the distance between the cutting 16 and the rolling tools 17 is not less than the length of the window 3 in the longitudinal direction of the primary barrel 6. The tools 16 and 17 are interconnected rigid sub 19 with a diameter close to the diameter of the cutting tool 16, and a length not less than the length of the window 3 in the longitudinal direction of the primary barrel 6.

The connection of two tools 16 and 17 into one by means of a rigid sub 19 with a diameter close to the diameter of the cutting tool 16 and a length not less than the length of the window 3 in the longitudinal direction of the primary barrel 6, will lead to the fact that in the process they will mutually center each other and to contribute to the performance of their functions when working in the window zone 3. At the moment when the expanding flare 17 begins to expand the suspension 10 of the shank 8, the entire tool will be rigidly centered on the axis of the primary barrel 6. Cutting tool NT 16 under the action of a rigid sub 19 will begin to cut out the window 15 in the wall of the suspension 10 with practically no deviation from the axis of the primary barrel 6. After cutting the guide window 15 (Fig. 3) in the suspension 10, the sub 19 of the cutting tool 16 begins to work as the lower centering support of the flare 17 , which flares the suspension 10 in the area of the window 3. This causes a smooth distribution of the perimeter of the suspension 10 along the perimeter of the connection of the trunks, its partial stretching and tight pressing against the extension 9 flush with the walls of the casing 5 6 ervichnogo wellbore (FIG. four). Then, in the zone of the guide window 15 (Fig. 3) in the suspension 10, the flare 17 smoothly flares (rolls out) the window 15, increasing its size to the size of the inner diameter of the casing 5 of the primary bore 6 (Fig. 4) of the well with virtually no runout relative to the axis of the primary bore 6. In the process of flaring, the inner diameter of the suspension 10 made of a longitudinally profiled pipe 11 (Fig. 5) with an enlarged perimeter in section 12 (Figs. 5 and 6) becomes perfectly round of the required diameter, section 12 (Figs. 8 and 9 ) snaps tightly to 9 flush extension to the walls of the casing 5 of the primary borehole 6 (FIG. 4). The walls of the suspension 10 (Fig. 4) during processing with a rolling tool 17 with rolling rotating sliding rollers 18 are hardened and hardened. The result is a reliable tight connection between the casing 5 of the primary shaft 6 and the shank 8 of the additional barrel 1 of a multilateral well 2.

The proposed method and device for its implementation simplify the construction of a multilateral well from previously drilled and cased wells and, as a result, reduce time, labor and material costs by reducing tripping operations for installing and removing extracted equipment and combining operations to process the upper part of the liner, exceptions of cement technologies, reduction of the volume of drilled metal of the upper part of the liner and multiple treatments of the liner in the window zone, ix accident and thus reducing the time and cost of construction of multilateral wells. In addition, an increase in the diameter of the additional wellbore and the exclusion of cement technology when attaching the liner can save reservoir properties of the formation and increase production capabilities of the well.

Claims (2)

1. A method of constructing an additional multilateral wellbore, including opening a window in the casing of the primary wellbore and drilling a new additional wellbore to the design depth using a retractable deflector, lowering the liner with casing at the mouth of the new additional wellbore, followed by sealing the additional wellbore , processing the upper part of the shank to gain access to the lower part of the primary trunk, removing the deflector wedge, characterized by m, that the inner diameter of the casing of the primary shaft is extended before the deflector wedge is lowered in the window location zone and higher, the deflector wedge with anchor is removed until the liner descends, which is equipped with a longitudinally-corrugated suspension in the window area or is made in the form of a longitudinal-profile pipe with enlarged perimeter in the zone of expansion of the inner diameter of the primary casing string, the liner is placed in an additional barrel using a shoe attached at the bottom, straightening corrugated sections the joint is carried out by overpressure with fixing by flaring in the additional barrel, the upper part of the shank is processed in two stages, the first of which cuts the guide window in the shank to create a message with the primary shaft, the second - flares the upper part of the shank until it is pressed flush to expand to the walls of the primary trunk. 2. A device for processing the upper part of the shank, including a cutting tool, lowered on a pipe string and made for rotation, characterized in that the cutting tool is placed below for cutting a window for communication with the primary shaft, a rolling tool with rolling rotating sliding tools is installed above the cutting tool rollers, and the distance between the cutting and rolling tools is not less than the length of the window in the longitudinal direction of the primary barrel.

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