RU2513956C1 - Method for construction of downhole splitter and whipstock for its implementation - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: method lies in installation of fixing unit with a whipstock for one deflective surface in the main hole constructed up to the design depth. The fixing unit is made in the form of hydromechanical anchor with mounting seat, at that the anchor is fixed below the sidetracking space. Before sidetracking the casing pipe is penetrated by window cutting and after offshoot construction the whipstock is retrieved from the well disconnecting it from the fixing unit; auxiliary longer whipstock is run in till it interacts with the mounting seat of the anchor fixing it from rotation; before sidetracking of additional offshoot the casing pipe is penetrated by additional window with subsequent retrieval of auxiliary whipstock after construction of the second offshoot. The device for method implementation includes a whipstock run in at the pipe string and equipped with one deflective surface and connected from below by breakable elements through the crossover shoe with the fixing unit made in the form of hydromechanical anchor equipped with longwise corrugated pipe blinded from below with the shoe and a hydraulic centring skid located below the crossover shoe. At that centring skid is manufactured as a body with a gallery communicating with longwise corrugated pipe, pipe string and pushers located evenly along the perimeter and height of the body limits radial movement outside until interaction with the casing walls at excess pressure in the gallery; at the top the body is equipped with a groove for matching intrusions of the crossover shoes of the whipstock and auxiliary whipstock in order to exclude rotation and ensure their setting in preset direction.

EFFECT: group of inventions allows drilling of two opposing additional boreholes from the same level of the existing well, engaging of the main borehole into operation and reducing material costs for construction of the downhole splitter.

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Description

The invention relates to the oil and gas industry, namely to drilling equipment, and can be used for the construction of multilateral wells, including from wells of the old stock.

A device is known for multilateral drilling of one formation by a single well (patent RU No. 2064041, IPC ⁶ ЕВВ 7/08, published in Bulletin No. 20 of 07/20/1996), containing a nozzle connected to the housing and made with a landing sleeve for an extractable wedge , side longitudinal windows and an outer cuff packer above the side longitudinal windows. The recoverable wedge is made with a bottom perpendicular to its axis and an orienting retainer rigidly connected to the bottom and configured to adjust the radial angle between the orienting retainer and the deflecting plane of the recoverable wedge. The orienting latch is made in the form of a guide sleeve with an annular landing pad and veneer, and the landing sleeve is with a reciprocal internal support protrusion. In addition, the drill string in the lower part is made with a nozzle-body, in the lower part of which there is a check valve, and above it is a circulation valve, while the nozzle-body is made with an annular landing belt and veneer for the landing sleeve and radial openings covered by a sleeve with a shear pin, as well as a casing at the mouth, are made with lateral bends equipped with gate valves communicating its annular and intra-annular space with external space at the mouth.

The method carried out using this device includes drilling the main wellbore and securing it with a casing string with a production pipe equipped with pre-cut windows and a special coupling in the lower part, assembling and lowering a self-orienting deflecting wedge into the well, introducing the wedge veneer into the keyway by slowly turning the drill string the groove of the special coupling, after removing the drain device, drilling an additional barrel, then removing the deflecting wedge, turning the orientation retainer 180 °, releasing the wedge, installation in a special coupling, drilling of the second additional wellbore and development of a multilateral well.

The disadvantages of the method and device are:

- the difficulty of attaching the casing of the main trunk;

- the difficulty of getting the veneer of the whipstock into the keyway of the special coupling;

- the complexity of the design of the device, which leads to an increase in material costs for well construction;

- the impossibility of building additional shafts from existing wells.

The closest in technical essence is a deflecting device for drilling (patent RU No. 21114440, IPC ⁶ ЕВВ 7/08, published in Bulletin No. 24 dated 08/27/1998), containing a pipe with open ends, equipped with a connecting end means for connecting the pipes with open ends to the casing string, and a guide element located in the pipe with open ends at its lower end, and this guide element includes two hollow inclined guides located on opposite sides, the pipe wall being open At these ends it has elongated holes facing the inclined guides, and also includes a device for re-entry, which is used in conjunction with a deflecting device and is a sleeve having a deflecting surface that is joined to one of the two inclined guides of the deflecting device.

The method carried out using this device includes drilling the main wellbore and securing it with a casing string with a pipe with a guiding element, lowering the drill string with an engine, a chisel and oriented drilling of the first branch, the guiding element deflecting the tool. If necessary, to facilitate entry into one of the curved branches into the deflecting device, a device for re-entry can be omitted, after which the second branch is drilled in the same way.

The disadvantages of the known deflecting device and method are:

- the difficulty of attaching the casing of the main trunk;

- the complexity of the design of the device, which leads to an increase in material costs for well construction;

- the impossibility of involving the main barrel in operation, because the guide element is not removed from the well;

- the impossibility of building additional shafts from existing wells.

The technical objectives of the invention are the creation of a method and a simple, reliable design of the deflecting device, allowing to drill two additional directional shafts from the same level from existing wells, as well as reducing material costs for the construction of a multilateral well.

Technical problems are solved by the method of constructing a multilateral well, including the construction of the main wellbore, the installation of a fixing unit with a deflecting wedge, and the sequential drilling of a pair of opposed sidetracks.

The new one is that the main trunk is built to the design depth, the deflector wedge is made in the form of a wedge with one deflecting surface, and the fixing unit is in the form of a hydromechanical anchor with a seat, and the anchor is fixed below the cutoff interval, before milling the side shaft, milling is performed by milling windows, and after the construction of the sidetrack, the deflector wedge is removed from the well, disconnected from the fixing unit, an additional longer deflector wedge is lowered to interact with the landing m a hydromechanical anchor, fixing it against rotation, and before drilling an additional side trunk, milling is performed by milling an additional window with the subsequent extraction of an additional deflecting wedge after the construction of the second side trunk.

The technical problems for the implementation of the method are also solved by a deflecting device, including a wedge-deflector lowered on the pipe string, which can be fixed in the casing of the main shaft.

What is new is that the deflector wedge is provided with one deflecting surface, connected at the bottom by shear elements through an adapter with a fixing unit made in the form of a hydromechanical anchor, equipped with a longitudinally corrugated pipe, plugged at the bottom with a shoe, and a hydraulic centralizer located at the bottom of the adapter, and the centralizer is made in a case with a longitudinal channel in communication with a longitudinally corrugated pipe, a pipe string and pushers located evenly around the perimeter and height of the body with the possibility of Strongly limited radial movement outwardly to interaction with the walls of the casing at a pressure within the longitudinal bore, the top sub is provided with a slot for the back protrusion whipstock and an additional whipstock to exclude cranking and install them in a predetermined direction.

Figure 1 shows a wedge-deflector with a fixing unit installed in the main wellbore (section).

Figure 2 shows a section aa in figure 1.

Figure 3 shows a section bB in figure 1.

Figure 4 shows an additional wedge-deflector for the construction of the second additional barrel installed in the seat of the housing after the construction of the first additional barrel (section).

The deflecting device (Figs. 1, 4) includes a wedge-deflector 1 (Fig. 1), equipped with one deflecting surface 2, connected from below by shear elements 3 through a sub 4 with a fixing unit 5 (Figs. 1, 4), made in the form of hydromechanical anchors equipped with a longitudinally-corrugated pipe 6, muffled from below either by a deaf or collapsible (see, for example, RF patent No. 59695) shoe (not shown in Fig.), and a hydraulic centralizer 7 located below the sub 4 (Fig. 1). The centralizer 7 is made in the form of a housing 8 (Figs. 1-3) with a longitudinal channel 9 (Figs. 1, 3), with common with the longitudinally corrugated pipe 6 (Fig. 1), a pipe string (not shown in Fig.) and pushers 10 (Fig. 1,3), arranged uniformly around the perimeter and height of the casing 8 (Figs. 1-3), the possibility of limited radial movement outward before interacting with the walls of the casing 11 (Fig.1-4) at overpressure in the longitudinal channel 9 (Fig.1, 3). At the same time, the housing 8 (Figs. 1-3) is provided with a groove 12 (Figs. 1, 2, 4) under the mating protrusions 13 (Figs. 1, 2), 14 (Fig. 4) of the sub 4 (Fig. 1) of the wedge deflector 1 and 15 (figure 4), an additional wedge of the deflector 16 with a deflecting surface 17 to prevent rotation and install them in a given direction.

At the factory, an adapter 4 (Fig. 1) is attached, for example, by thread, welding, etc. the pipe 18 (Fig.1, 3) with holes 19 made coaxially with the holes 20 of the housing 8 (Fig.1-3), in which the pushers 10 are installed (Fig.1, 3), and the holes 19 of the pipe 18 are made smaller in diameter than the holes 20 of the housing 8 (Fig.1-3). Moreover, in the holes 20 (Figs. 1, 3) of the housing 8 (Figs. 1-3), latches are installed (in Fig. Not shown, for example, such as dogs, spring clips, etc.), but due to the fact that the holes 19 (FIGS. 1, 3) are made smaller in diameter than the holes 20, the pushers 10 do not fall into the internal cavity of the pipe 18. Then, the housing 8 is pushed onto the pipe 18 (FIGS. 1-3) until the latter stops at the end of the sub 4 ( figure 1), in which the channel 21 is made, and fixed with shear elements 3, while the space between the housing 8 (figures 1-3) and the pipe 18 (figures 1, 3) is sealed with cuffs 22 (FIG. 1). To the lower end of the housing 8 (Figs. 1-3), for example, by means of threading, welding, etc., a longitudinally corrugated pipe 6 (Figs. 1, 4) is attached, which is muffled from below by a shoe. To the layout of the cutters 23 (figure 1), fixed to the wedge-deflector 1 using a shear pin 24, connect the upper end of the tube 25, and the lower end to the channel 21 of the sub 4.

The method is implemented in the following sequence.

In the interval of cutting additional side shafts 26 (Fig. 4) and 27 (Fig. 4 - shown in fig. Conventionally), the deflecting device is lowered (Fig. 1). Orient it in such a way that the wedge-deflector 1 with its deflecting surface 2 is directed towards the first side barrel 26 (figure 4). They create fluid pressure, while passing through a column of pipes (not shown in Fig.), The layout of the milling cutters 23 (Fig. 1), tube 25 (Figs. 1, 2), channel 21 (Fig. 1) of the sub 4 in the fixing unit 5 (Figs. 1, 4), made in the form of a hydromechanical anchor equipped with a longitudinally corrugated pipe 6, and a hydraulic centralizer 7 (Fig. 1), straightens the longitudinally corrugated pipe 6 (Figs. 1, 4), t .to. the space between the housing 8 (Fig.1-3) and the pipe 18 (Fig.1, 3) is sealed with cuffs 22 (Fig.1), and fixes the deflecting device to the walls of the casing 11 (Fig.1-4). Moreover, the anchor is fixed below the cutoff interval of the side shafts 26, 27 (Fig. 4). When passing through the Central channel 9 (Fig. 1, 2), the liquid through the holes 19 (Fig. 1, 3) of the pipe 18 and the hole 20 in the housing 8 (Figs. 1-4) acts on the pushers 10 (Figs. 1, 3) which are made with the possibility of limited radial movement outward and with sealing by means of rubber rings 28 (Fig. 3) are advanced until they interact with the walls of the casing 11 (Figs. 1-4) and are fixed in this position by means of latches installed in the holes 20 (figures 1, 3) of the housing 8 (figures 1-3). By tensioning the tool, a pin 24 is cut (Fig. 1), securing the arrangement of the milling cutters 23 to the diverter wedge 1, the casing 11 is opened by milling the “window” 29 (Fig. 4 is a fig. Shown conditionally) and after removing the milling cutter 23 ( figure 1) drill the first additional lateral barrel 26 (figure 4). After removing the tool from the well and attaching the first additional side trunk 26 to the installation interval of the deflector 1 (Fig. 1), the device for releasing the wedge from the well is lowered (see, for example, RF patent No. 2415250 - not shown in Fig.) And capture of the diverter wedge 1. By tensioning the drill pipe string, shear elements 3 are cut and the diagonal wedge 1 is removed with a sub 4 and pipe 18 (Figs. 1, 3) to the surface. After that, an additional deflector wedge 16 (FIG. 4) of a larger length is lowered into the well, to prevent it from falling into the “window” 29, the platform 30 in the upper part of the deflector 16 is increased, in addition to this, the hydraulic centralizer 7 (FIG. 1) also holds an additional wedge deflector 16 (figure 4). Orient it with a deflecting surface 17 in the opposite direction from the first additional side trunk 26. In this case, the protrusion 14 of the sub 15 enters the groove 12 of the housing 8 (Figs. 1-3), which prevents the rotation of the additional deflector 16 (Fig. 4) during cutting and drilling the second additional side shaft 27. By tensioning the tool, a pin 31 is cut securing the arrangement of the milling cutters 32 to the additional deflecting wedge 16. The casing 11 is opened by milling the “window” 33 (Fig. 4 is shown conventionally) and after extraction the assembly of milling cutters 32 drills a second additional sidetrack 27. After removing the tool from the well and attaching the second additional sidetrack 27 to the installation interval of the additional deflector 16, the device for extracting the wedge from the well is lowered and the additional deflector wedge 16 is pulled. 16. Tension of the drill pipe string extracting an additional deflector wedge 16 with a sub 15 to the surface.

If it is necessary to engage the main well 34 in the operation, the pipe string is lowered into the inner part of the fixing unit 5 (Figs. 1, 4) and the shoe is knocked to the bottom.

The advantage of the proposed method for constructing a multilateral well and a diverting device for its implementation is that they allow drilling of two additional directional additional shafts from the same level from existing wells, involving the main well in operation, and also reduce material costs for constructing a multilateral well.

Claims (2)

1. A method of constructing a multilateral well, including the construction of a main wellbore, the installation of a fixing unit with a deflecting wedge, sequential drilling of a pair of opposed sidetracks, characterized in that the main well is built to the design depth, the deflecting wedge is made in the form of a wedge with one deflecting surface and the fixing unit is in the form of a hydromechanical anchor with a seat, and the anchor is fixed below the cutoff interval, an opening is performed before drilling the side trunk the casing string by milling the window, and after constructing the sidetrack, the deflector wedge is removed from the well, disconnected from the fixing unit, the extra deflector wedge is lowered to interact with the seat of the hydromechanical anchor, which secures it from twisting, and an autopsy is performed before drilling the additional sidetrack casing string by milling an additional window followed by extraction of an additional deflecting wedge after the construction of the second sidetrack. 2. A deflecting device for implementing the method, including a wedge-deflector lowered on the pipe string, which is capable of being fixed in the casing of the main shaft, characterized in that the wedge-deflector is provided with one deflecting surface, connected from below by shear elements through an adapter with a fixing unit made in the form of a hydromechanical anchor, equipped with a longitudinally corrugated pipe, muffled from below by a shoe, and a hydraulic centralizer located at the bottom of the sub, the centralizer being made in the form of a housing with a longitudinal channel in communication with a longitudinally corrugated pipe, a string of pipes and pushers located uniformly around the perimeter and height of the housing with the possibility of limited radial movement outward before interacting with the walls of the casing with excess pressure in the longitudinal channel, with the housing on top equipped with a groove for the reciprocal protrusions of the deflector wedge and the additional deflector wedge to prevent turning and installing them in a given direction.

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