RU2504636C1 - Construction method of additional shaft in well - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: at implementation of the method, the main shaft is drilled and fixed till design depth; after that, the shaft is enlarged by cutting-out a casing string interval of the main shaft so that upper and lower parts of the main shaft are obtained. Enlargement interval is cemented; cement is drilled at enlargement interval with creation of interaction of the upper and lower parts of the main shaft with simultaneous enlargement of the diameter exceeding inner diameter of the casing string by wall thickness of long element of the support plate. An additional shaft is drilled and a removable diverting wedge is installed. The diverting wedge is removed prior to lowering of the support plate that is oriented during lowering to the well as per geophysical instruments, installed and rigidly fixed by enlargement so that a side branch of the support plate can be arranged in the additional shaft.

EFFECT: possibility of performing construction of additional shafts out of wells cased with a production string so that flow passage of the main shaft is maintained without considerable reduction of diameter of the additional shaft.

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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 go 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 an additional wellbore in the well and its operation;

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

- the inability to create a tight connection of the shank of the additional wellbore with the casing of the main wellbore;

- the methods and equipment for their implementation are applicable only during the construction of new MZS and do not allow drilling of an additional wellbore from existing wells.

- the difficulty of cleaning installation sites for a removable wedge and devices for targeted entry into the additional shaft 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, IPC 7 Е21В 7/08, publ. Bull. No. 21 from 07.27.02 d), including drilling the first wellbore and expanding its lower part in diameter, fixing it with a first casing, equipped in the lower part with a base plate with two hollow elements that are placed in the expanded part of the first wellbore, expanding the hollow the 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 installing the whipstock or orienting cam in the next hollow element, drilling through the first hollow an 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 additional shafts from existing wells;

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

The technical objectives of the alleged invention are to provide a method that allows the construction of additional shafts from cased-hole production wells while maintaining the main section of the main bore without significantly reducing the diameter of the additional well, as well as reducing the cost of constructing multilateral wells.

Technical problems are solved by the method of constructing an additional wellbore in the well, including drilling the main wellbore and securing it with a casing string, expanding the wellbore in the construction area of the additional wellbore, lowering, expanding the pressure and fastening the base plate with a branch for the additional wellbore, cementing the expansion of the wellbore, drilling the additional wellbore its mount.

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 trunk, cementing the interval of expansion of the casing, drilling cement in the expansion interval with creating a message of the upper and lower parts the main trunk with simultaneous expansion with a diameter exceeding the inner diameter of the casing string by the wall thickness of the long element of the base plate, drilling and drilling for barrel additionally installing a removable whipstock and whipstock extraction to produce a shutter base plate, which is oriented during the descent into the wellbore on geophysical instruments is set and hermetically fixed extension so that the lateral branch of the base plate was taken in a further bore.

Figure 1 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 2 shows the drilling of an additional barrel with a removable deflector wedge (section).

Figure 3 shows the base plate for the construction of an additional wellbore in the well (section).

Figure 4 shows a section aa in figure 1.

Figure 5 shows a section bB in figure 1.

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

The method is implemented in the following sequence.

Drill the main shaft 1 (Figs. 1, 2, 6) to the design depth and attach it to the casing 2. Extend the main shaft 1 by cutting out the interval 3 of the casing 2 of the main shaft 1 by a device for cutting a section of the pipe string in the well (see, for example , RF patent No. 2110665 - not shown in Fig. 1) to obtain the upper 4 (Figs. 1, 2, 6) and the lower 5 parts of the main trunk 1. After this, the expansion interval 3 of the main trunk 1 is cemented. After waiting for the cement to solidify 6 drill a bit 7 (figure 1 is shown conditionally) in the interval 3 (figures 1, 2, 6) irrigation with the creation of the message of the upper 4 and lower 5 parts of the main barrel 1 with the simultaneous expansion of the expander 8 (see, for example, RF patent No. 211 17747 - shown in figure 1 conditionally) with a diameter exceeding the inner diameter of the casing 2 (figure 1, 2 , 6) the wall thickness of the long element 9 (Fig.3-5) of the base plate 10 (Fig.3-6). At the same time, sections 11, 12 (FIGS. 1, 2, 6) with a length of 0.5-1 m of the casing 2 of the upper 4 and lower 5 parts of the main trunk 1 are milled.

Then, in the expansion interval 3, the descent and oriented installation of the removable wedge-deflector 13 is carried out (see, for example, RF patent No. 2414580 - FIG. 2), from which the additional barrel 14 is drilled. The wedge-deflector 13 is removed using a wedge extraction device a deflector (see, for example, RF patent No. 2415250 — not shown in FIG. 2).

After that, in the expansion interval 3 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 10 (Fig.3-6), not reaching 1.5-2 m to the additional barrel 14 (Fig.2, 6). Orient using geophysical instruments, the base plate 10 (Fig.3-6) so that the branch 15 (Fig.6) was located in the direction of the additional shaft 14 (Fig.2. 6). The creation of internal overpressure begins to straighten the base plate 10 (FIGS. 3-6), while simultaneously releasing it at a speed of 0.5 m / s, with branch 15 (FIG. 6) entering the additional barrel 14 and the base plate 10 completely, straightening, it is fixed in the expansion interval 3, and its upper part is located in section 11, and the lower part is in section 12 of the casing 2 of the upper 4 and lower 5 parts of the main barrel 1. After that, the drain tool is disconnected and the long element 9 is rolled (Fig. 3-6) to the main trunk 1 (6), s grab shoe 16 (figure 3 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 retractable wedge-deflector with a roller flare is lowered into the well (not shown in Fig. 6), it is installed in the main shaft 1 (Fig. 6) so that the wedge gutter is opposite the entrance to the additional barrel 14, the flare is disconnected and rolled branch 15 in the additional barrel 14. Capture shoe 17 (shown in Fig. 3 conventionally) and remove it to the surface, or it disassembles and falls into the face. The additional barrel 14 (FIG. 6) is fastened with a slit filter (not shown in FIG. 6) with its suspension to the lower end of the branch 15 (FIG. 6), or with a column of shaped tubes (see, for example, patent RU No. 2079633 - 6 is not shown). Then remove the wedge deflector to the surface.

If it is necessary to fasten the additional shaft 14 with a cemented liner (not shown in FIG. 6), branch 15 (FIG. 6) (as described above) is rolled out and the deflecting wedge is removed from the well. The descent and input of the shank into the additional barrel 14 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 14 is secured by cementing the shank according to standard technology.

This invention allows the construction of additional shafts from cased-hole wells while maintaining the main section of the main bore without significantly reducing the diameter of the additional shafts, as well as reducing the cost of constructing additional shafts.

Claims (1)

A method of constructing an additional wellbore in a well, including drilling the main wellbore and securing it with a casing string, expanding the wellbore in the construction area of the additional wellbore, lowering, expanding the pressure and attaching the base plate with a branch for the additional wellbore, cementing the expansion of the wellbore, drilling the additional wellbore and securing it, characterized in that the main trunk is drilled and fixed to the design depth, the extension of the trunk is made by cutting the interval of the casing of the main trunk to obtain the upper and lower parts of the main trunk, cementing the casing expansion interval, drilling cement in the expansion interval with creating a message of the upper and lower parts of the main bore while expanding 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 an additional bore with the installation of a removable deflector wedge, and the extraction of the deflector wedge is carried out before the descent of the base plate, which is oriented during the descent into the well a geophysical instrument, is installed and hermetically fixed by the extension so that the lateral branch of the base plate is placed in an additional trunk.

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