RU2504645C1 - Method of construction of multi-bottom wells and bearing plate to this end - Google Patents

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: after drilling parent hole and its anchoring to design depth, bore is expanded with cutting of casing interval of parent hole to make top and bottom parts of said parent hole. Expansion interval is cemented to drill the cement in expansion interval thereafter. Extra holes are drilled to run bearing plate which is to be oriented, fitted in place and tightly fixed by expansion so that plate side branches are located in appropriate extra holes. Bearing plate comprises two tightly connected hollow elements, one a bit longer than another one, that can expand. Note here that shorter element is composed of the first branch tor extra hole. Note also that longer element has at least one extra branch, similar to the first one. Said branches are located at different levers of longer element and are bidirectional elements.

EFFECT: possibility to construct multi-bottom wells from cased wells.

2 cl, 6 dwg

Description

The invention relates to the field of drilling and overhaul of oil and gas wells, namely, it is used for drilling sidetracks (BS) from previously drilled cased wells and their fastening with the creation of a tight connection of additional shafts with the main.

A device is known as a three-barrel well with separate guide blocks for the drilling assembly and casing (patent US 4415205, IPC 7 Е21В 43/28, 29/06, publ. 15.11.83), including the construction of the main trunk and its mounting with a casing having at least two easily accessible sections, which are windows located at different vertical heights, and an internal combining gripping device, sequential drilling of each of the side shafts, while at least two of the side shafts mentioned above are drilled I through the two windows mentioned above, respectively, first through the bottom window, during which the guide block for the drilling assembly is coupled with a matching gripping device for orienting the layout of the bottom of the drill string, in addition, the multi-tube guide block is lowered into the main shaft with one casing for each side barrel, while the above-mentioned guide block engages with a matching gripping device, directing the casing strings into the corresponding side shafts and their cement tating.

The disadvantages of the three-barrel well with separate guide blocks for the drilling assembly and casing are:

- the complexity of the design of devices for implementing the method of construction of multilateral wells (MZS) and their operation;

- it is not possible to build BS of the required diameter, which allows efficient exploitation of the discovered oil or gas reservoir, several BSs with a multiple of a reduced diameter may be drilled from the main trunk (3 inch diameter BSs are drilled from the casing with a diameter of 9 5/8 inches);

- the inability to create a tight connection of the liner BS with the casing of the main wellbore;

- methods and equipment for their implementation are applicable only in the construction of new MZS and do not allow drilling BS from existing wells;

- the difficulty of cleaning installation sites for a removable wedge and devices for targeted entry into the BS after cementing the casing of the main wellbore.

The closest device to the present invention in technical essence and achieved by using the technical result is a base plate for drilling and arrangement of wells and the method of its use (patent RU No. 2186190 C2, IPC 7 ЕВВ 7/08, publ. Bull. No. 21 from 27.07. 02 g.). The base plate comprises a cylindrical body connected to the first casing, having one common entrance communicating with each of at least two hollow elements made diverging, and also means for attaching the body to said first casing, at least each of the two hollow the elements are either symmetrically deformed and have axial symmetry, or asymmetrically and do not have axial symmetry in the expanded state, one of the hollow elements mentioned can be made longer another, and as a means for attaching the housing to said first casing pipe, a weld or packer assembly located on the periphery of said housing is used, in addition, said first casing pipe connected to the base plate is either a clogging pipe or a guide casing pipe, or a surface casing pipe or an intermediate casing or production liner or intermediate liner, said at least two hollow elements are welded together th, and said first casing is rejected, and also comprises an elongated frame located between said at least two hollow elements and attached to them.

The method carried out using this base plate includes drilling the first wellbore and expanding its lower part in diameter, fastening it with a first casing equipped in the lower part of the base plate with two hollow elements that are placed in the expanded part of the first wellbore, expanding the hollow elements , installing a whipstock or orienting cam in the first hollow element of the base plate, drilling the first side trunk (BS) through the second hollow element of the base plate and fastening it with a liner, then installation of the whipstock or orienting cam into the next hollow element, drilling through the first hollow element of the second BS and its fastening with a liner-string.

The disadvantages of the known base plate for drilling and arrangement of wells and the method of its use are:

- a significant reduction in the diameter of the side shafts relative to the main one;

- the need to multiply expand the installation site of the base plate, which is associated with great difficulties;

- the inability to use in the construction of BS from existing wells;

- the need to drill cement from the hollow elements of the base plate after cementing.

The technical objectives of the invention are the creation of a method and a simple, reliable design of the base plate, allowing the construction of multilateral wells from cased-hole production wells without significantly reducing the diameter of the main and additional shafts, reducing the cost of constructing multilateral wells.

Technical problems are solved by the method of constructing multilateral wells, including drilling the main trunk and securing it with casing, expanding the trunk in the construction area of additional trunks, lowering, expanding the pressure and attaching the base plate with branches for additional trunks, cementing the expansion of the trunk, drilling additional trunks and securing them .

What is new is that the main trunk is drilled and fixed to the design depth, the barrel is expanded by cutting the interval of the casing of the main shaft to obtain the upper and lower parts of the main shaft, cementing the casing expansion section, drilling cement in the expansion zone with the creation of a message of the upper and lower parts with a diameter exceeding the inner diameter of the casing string by the wall thickness of the main barrel of the base plate, drilling and drilling of multidirectional and multilevel additional boreholes s with the installation of a removable deflector wedge, and the removal of the deflector wedge is carried out before the descent of the base plate, which is equipped with additional multilevel and multidirectional branches corresponding to the additional trunks of the main trunk, is oriented along the geophysical instruments during descent into the well, installed and hermetically fixed by expansion so so that the side branches of the slab are placed in the respective additional trunks.

The technical problems for the implementation of the method are also solved by a base plate comprising two hermetically connected hollow elements made with the possibility of deformation and the ability to expand, one of these elements being made longer than the other.

What is new is that the long element is made to expand to an internal diameter equal to or greater than 3% of the inner diameter of the casing of the well, and the short element is made in the form of a first branch under an additional barrel, while the long element is equipped with at least one additional branch , similar to the first, under another additional trunk, and the branches are placed at different levels of the long element and are made multidirectional.

Figure 1 shows the base plate for the construction of additional shafts of a multilateral well (section).

Figure 2 shows a section aa in figure 1.

Figure 3 shows a section bB in figure 1.

Figure 4 shows the drilling of cement in the expansion zone with the creation of the message of the upper and lower parts of the main trunk with a diameter exceeding the inner diameter of the casing string by the wall thickness of the long element of the base plate (section).

Figure 5 shows the drilling of additional shafts from a removable deflector wedge (section).

Figure 6 shows the installation and tight fixation by expansion of the base plate with the placement of the side branches of the plate in the respective additional trunks (section).

The base plate 1 (Figs. 1-3, 6) contains two hermetically connected hollow elements 2 (Figs. 1-3, 6) and 3 (Figs. 1-3), made with the possibility of deformation and the ability to expand, while the long element 2 (Figs. 1-3, 6) is configured to expand to an internal diameter equal to or greater than 3% of the inner diameter of the casing 4 (Figs. 4-6) of the well, and a short element 3 (Figs. 1-3) made in the form of a first branch 5 (Fig.6) under the additional barrel 6 (Fig.5, 6). In addition, the long element 2 (Figs. 1-3, 6) is equipped with at least one additional branch 7 (Fig. 6), similar to the first 5, under another additional barrel 8 (Figs. 5, 6). Moreover, the branches 5 (Fig.6) and 7 (Fig.1, 6) are placed at different levels and are made multidirectional.

The method is implemented in the following sequence.

Drill the main shaft 9 (Figs. 4-6) to the design depth and fasten it with the casing 4. Extend the main shaft 9 by cutting the interval 10 of the casing 4 of the main shaft 9 with a device for cutting a section of the pipe string in the well (see, for example, patent RF №2110665 - not shown in Fig. 4) to obtain the upper 11 and lower 12 parts of the main trunk 9. After this, the expansion interval 10 of the main trunk 9 is cemented. After waiting for the cement 13 to solidify, it is drilled with a bit 14 (fig. 4 shown conventionally) in interval 10 (Fig.4-6) expansion with the communication of the upper 11 and lower 12 parts of the main shaft 9 with the simultaneous expansion of the expander 15 (see, for example, RF patent No. 2117747 - shown in Fig. 4 conditionally) with a diameter exceeding the inner diameter of the casing 4 (Figs. 4-6) by the wall thickness of the long element 2 (Figs. 1-3, 6) of the base plate 1. At the same time, sections 16, 17 (Figs. 4-6) of 0.5-1 m length of the casing 4 of the upper 11 and lower 12 parts of the main trunk are milled 9.

Then, in the expansion interval 10, the descent and oriented installation of the removable deflector wedge 18 is carried out (see, for example, RF patent No. 2414580 - shown in FIG. 5 conventionally), from which the additional trunk 8 is drilled. The deflector wedge 18 is removed (FIG. 5) using the device for extracting the deflecting wedge (see, for example, RF patent No. 2415250 — not shown in FIG. 5) and similarly drill the next additional barrel 6 (FIGS. 5, 6) from the removable deflecting wedge 19 ( figure 5).

After that, in the expansion interval 10 on the drain tool, for example, on the landing head, on the flare calibrator (see, for example, RF patent No. 1782079 - not shown in Fig. 6), etc. produce the descent of the base plate 1 (Fig.1-3, 6), not reaching 1.5-2 m to the first additional barrel 6 (Fig.5, 6). Orient using geophysical instruments, the base plate 1 (Fig.1-3, 6) so that the branches 5, 7 (Fig.6) are located in the direction of the additional trunks 6, 8 (Fig.5, 6). The creation of internal overpressure begins to straighten the base plate 1 (Figs. 1-3, 6), while simultaneously releasing it at a speed of 0.5 m / s, while branches 5, 7 (Fig. 6) are included in additional trunks 6, 8 and the base plate 1 is fully straightened, fixed in the expansion interval 10, and its upper part is located in section 16, and the lower - in section 17 of the casing 4 of the upper 11 and lower 12 parts of the main trunk 9. After that, the drain tool is disconnected and rolling long element 2 (figures 1-3, 6) to the main trunk 9 ( 4-6), capture the shoe 20 (Fig. 1 shows conditionally - see, for example, RF patent No. 2172387 or RF patent No. 59695) and remove it to the surface, or it disassembles and falls into the face. Take the tool to the surface. Then, a recoverable wedge-deflector with a roller flare is launched into the well (not shown in Fig. 6). install it in the main trunk 9 (Figs. 4-6) so that the wedge gutter is opposite the entrance to the additional barrel 6 (Figs. 5, 6), disconnect the flare and roll off branch 5 (Fig. 5) in the additional trunk 6 ( 5, 6). Capture shoe 21 (shown in FIG. 1 conditionally) and remove it to the surface, or it disassembles and falls into the face. The additional barrel 6 is fastened (FIGS. 5, 6) by a slotted filter (not shown in FIG. 6) with its suspension to the lower end of branch 5 (FIG. 6), or by a column of shaped tubes (see, for example, patent RU No. 2079633 - not shown in Fig. 6). Then remove the wedge-deflector to the surface and similarly roll out the branch 7 (Fig.6) and mount the additional barrel 8 (Fig.5, 6).

If it is necessary to attach additional shafts 6, 8 with a cemented liner (not shown in FIG. 6), branch 5 (FIG. 6) is rolled (as described above) and the deflecting wedge is removed from the well. The descent and input of the shank into the additional barrel 6 is carried out using a self-orienting device for a multilateral well (see, for example, patent RU No. 76675 - not shown in Fig. 6), after which the additional barrel 6 is secured by cementing the shank according to standard technology. Similarly produce the mounting of the additional barrel 8.

This invention allows the construction of multilateral wells from cased-hole production wells without significantly reducing the diameter of the main and additional shafts, as well as reducing the cost of constructing multilateral wells.

Claims (2)

1. A method of constructing multilateral wells, including drilling the main trunk and securing it with casing, expanding the trunk in the construction area of additional trunks, launching, expanding the pressure and securing the base plate with branches for additional trunks, cementing the expansion of the trunk, drilling additional trunks and securing them, characterized in that the main trunk is drilled and fixed to the design depth, the barrel is expanded by cutting the interval of the casing of the main trunk to obtain the upper and the lower part of the main shaft, cementing the casing expansion interval, drilling cement in the expansion interval, creating a message of the upper and lower parts of the main shaft with simultaneous expansion with a diameter exceeding the inner diameter of the casing by the wall thickness of the long element of the base plate, drilling and drilling of multidirectional and multilevel additional shafts with the installation of removable deflecting wedges, and the extraction of deflecting wedges is carried out before the descent of the base plate, which boruduyut additional multidirectional branches and levels corresponding additional trunks main trunk orient during descent into the wellbore on geophysical instruments is set and hermetically fixed extension so that the side branches plates were placed in the respective additional trunks. 2. A base plate for implementing the method, including two hermetically connected hollow elements made with the possibility of deformation and the ability to expand, moreover, one of these elements is made longer than the other, characterized in that the long element is made with the possibility of expansion to obtain an internal diameter equal to or greater up to 3% of the inner diameter of the casing of the well, and the short element is made in the form of the first branch for an additional barrel, while the long element is equipped with at least one them an additional branch, similar to the first, for another additional trunk, and the branches are placed at different levels of the long element and are made multidirectional.

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