RU2415250C1 - Device for extracting wedge-deflector from well - Google Patents

Abstract

FIELD: gas-and-oil producing industry.

SUBSTANCE: device consists of hollow stem with fishing hook made in form of doubled beard in lower part of stem and of upper thread for connection with drill string. A sub is installed on upper thread for connection with the drill string; the sub deflects the fishing hook with its back side away from axis of well. Additionally, in the stem there are made differently directed radial channels communicated with its internal cavity. The lower channel is made on the back side of the fishing hook, while the upper one is overlapped from inside with a bushing equipped with a seat for a ball. Also, the bushing is secured with shear elements relative to the stem; the bushing performs limited travels downward opening the upper radial channel.

EFFECT: simplified operation for wedge orientation, trouble-free extraction of wedge, and essential reduction of material and time expenditures.

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Description

The invention relates to the oil and gas industry and can be used in the construction of multilateral wells and drilling sidetracks from cased wells.

A device for extracting a whipstock is known (see page 13, “Using a removable whipstock for drilling a well with two horizontal shafts,” Oil and Gas Technologies, 1994, No. 1-2), including a fishing bell.

The disadvantages of this device are:

- the difficulty of connecting the bell with the whipstock, because the gap between the wipstock wedge and the production casing is small and the bell is difficult to get into this gap;

- the difficulty of disconnecting the bell from the whipstock in case it cannot be removed from the well.

The closest technical solution is a fishing hook (see page 13, “Using a removable whipstock for drilling a well with two horizontal shafts”, Oil and Gas Technologies, 1994, No. 1-2), including a beard located in the lower part, which comes with the front side of a wipstock wedge into a through slot in his body.

The disadvantages of this fishing hook are:

- the need to orient the fishing hook relative to the slot in the body of the wipstock;

- the possibility of non-extraction of whipstock from the well, because the fishing hook has only one fulcrum and the whipstock can skew during extraction, which will lead to its jamming;

- the difficulty of disconnecting the fishing hook from the whipstock if it is not removed from the well.

The technical task of the invention is the creation of a reliable design of a device for extracting a deflecting wedge from a well, which eliminates the call of a geophysical lot for its orientation, which leads to a significant reduction in material and time costs, as much as possible to exclude cases of non-extraction of the deflecting wedge at large angles of inclination of the well and also to eliminate the need for emergency work to unhook the device when it is impossible to remove the deflector wedge from the well.

The technical problem is solved by a device for extracting a whipstock from the well, including a barrel with a fishing hook at the bottom and an upper thread for connecting with a drill pipe string.

What is new is that the trunk is hollow, muffled from below, with a double-bearded fishing hook, while the width of the fishing hook exceeds the gap between the wedge groove and the casing wall, and an adapter with a skew angle is installed on the upper thread for connection with the drill pipe string, allowing you to deflect the fishing hook with the back side from the axis of the well, in addition, in the barrel there are multidirectional radial channels communicated with its internal cavity, the lower of which is made with a reverse double beard ny, and the upper one is covered from the inside by a sleeve with a saddle under the ball, fixed with shear elements relative to the barrel and made with the possibility of limited downward movement with the opening of the upper radial channel.

Figure 1 shows a device for extracting a wedge-deflector, lowered into the well in the interval of installation of the deflector (longitudinal section).

Figure 2 shows a device for extracting a deflecting wedge during engagement with a deflecting wedge.

Figure 3 shows a device for extracting a deflecting wedge with emphasis on the "head" of the wedge.

A device for extracting the deflecting wedge from the well (Fig. 1) includes a hollow shaft 1, muffled from the bottom, with a fishing hook 2 with a double beard 3. Moreover, the width H (Fig. 3) of the fishing hook 2 exceeds the gap L between the groove 4 of the wedge 5 and the wall of the casing 6. On the upper thread 7 (Fig. 1) of the barrel 1 for connecting to the drill pipe string (not shown) an adapter 8 is installed with a skew angle α, which allows the fishing hook 2 to be deflected with the back side of the well axis (not shown). In the barrel 1 there are made multidirectional radial channels 9, 10 communicated with the internal cavity 11 of the barrel 1. The lower radial channel 9 is made with a reverse double beard 3 of the side, and a nozzle 12 can be installed in it, for example, a bit nozzle, fitting, etc. The upper radial channel 10 is blocked by a sleeve 13 installed in the internal cavity 11 of the barrel 1 with a seat 14 under the ball 15 (shown conditionally). The sleeve 13 is fixed to the barrel 1 by shear elements 16, for example by shear pins, and is configured to move downwardly relative to the barrel 1 with the opening of the upper radial channel 10.

A device for extracting a wedge deflector operates as follows.

The device on the drill pipe string is lowered into the interval 1.5-2 m above the “head” of the wedge 5. Then, its descent is continued at a minimum speed. In this case, due to the skew angle α of the sub 8 mounted on the upper thread 7 of the barrel 1, the device freely enters the gap between the groove 4 of the wedge 5 and the wall of the casing 6. When the hook 2 with the double beard 3 approaches the design interval for finding the cutouts 17 (Fig. .2) on the chute 4 of the wedge 5, the descent of the device is stopped. The pump is turned on (not shown) and flushing fluid is supplied through the drill pipe string into the internal cavity 11 (Fig. 1) of the barrel 1. In this case, due to the pressure difference on the nozzle 12 of the hole 9 in communication with the internal cavity 11 of the barrel 1, the device is pressed against the opposite side of nozzle 12, i.e. to the wedge 5. Then, the tool is tensioned, and if the weight of the pipe string increases on the weight indicator (not shown), then the wedge 5 (Fig. 2) is engaged. By further tensioning the drill string, the anchor (not shown — for example, see patent for utility model RU No. 66399 U1) is used to unfasten the deflector and remove it from the casing string 6 of the well.

If during the stretching of the tool in the interval of finding the cuts 17 on the trough 4 of the wedge 5, no increase in weight is observed and the device is removed freely, then hook 2 (Fig. 1) with its double beard 3 entered the gap between the trough 4 of the wedge 5 and the wall of the casing 6 in the opposite direction from the wedge 5. Stop the pump, raise the device 1.5-2.0 m above the “head” of the wedge 5 and turn it 180 ° and repeat the operations described above.

If the device has not reached the interval of finding the cutouts 17 on the groove 4 of the wedge 5, and the instrument is fixed on the weight indicator, then the device rested on the “head” of the wedge 5 (Fig. 3), the width H of the fishing hook 2 exceeds the gap L between the trough 4 of the wedge 5 and the wall of the casing 6. Lift the device 1.5-2.0 m above the “head” of the wedge 5, rotate it 45 ° and repeat the operations described above.

If it is impossible to remove the deflecting wedge from the well (emergency situation), the ball 15 is thrown into the internal cavity 11 (Fig. 1) of the barrel 1. Ball 15 sits in the saddle 14 of the sleeve 13, after which the pump is turned on and the flushing fluid is supplied. Under the action of pressure, the shear element 16 is cut off, for example, the shear pin, and the sleeve 13 slides down, opening the upper radial channel 10 in communication with the internal cavity 11 of the barrel 1. Due to the pressure difference on the radial channel 11, the device is squeezed from the wedge 5. At the same time this load the drill pipe string, and the double beard 3 leaves the cutouts 17 (figure 2) on the groove 4 of the wedge 5, after which the device is lifted to the surface.

The advantage of the proposed device for extracting the deflecting wedge from the well is that its design eliminates the challenge of the geophysical lot for its orientation, which leads to a significant reduction in material and time costs, as much as possible to exclude cases of non-extraction of the deflecting wedge at large angles of inclination of the wellbore, and also to eliminate the need for emergency work to unhook the device when it is impossible to remove the deflector wedge from the well.

Claims (1)

A device for extracting a deflecting wedge from a well, including a barrel with a fishing hook at the bottom and an upper thread for connecting to a drill pipe string, characterized in that the barrel is hollow, plugged from below, and the fishing hook is made with a double beard, while the width of the fishing hook exceeds the gap between the wedge trough and the casing wall, and a sub with a skew angle is installed on the upper thread for connection with the drill pipe string, which allows the fishing hook to be deflected with the back from the borehole axis moreover, in the barrel there are multidirectional radial channels communicated with its internal cavity, the lower of which is made with a reverse double beard of the side, and the upper one is covered from the inside by a sleeve with a saddle under the ball, fixed with shear elements relative to the barrel and made with the possibility of limited downward movement with opening upper radial channel.

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