RU2225501C1 - Device for finishing wells - Google Patents

Abstract

FIELD: oil and gas extracting industry. SUBSTANCE: device has double cylindrical body with apertures and a sliding valve with ring-shaped spring fixing means. Device also includes a lock with pyrocartridges and spring-loaded differential piston. Piston interacts with spring-loaded sliding-valve and signal receiver for activating pyrocartridges. Body apertures are overlapped with sliding valve. Sliding valve is moveable by means of tubing spring for opening said apertures and fixing sliding valve in upper position with differential piston. Sliding valve can be moved for closing apertures by activating a pyrocartridge. EFFECT: decreased time needed for starting device operation. 2 dwg

Description

The invention relates to the oil and gas industry, namely to completion of oil and gas wells.

The main way to separate the strata in oil wells is to create in the annular space of the wellbore instead of the natural artificial insulating bridge, destroyed by drilling, usually representing a shell of hardened cement stone [1]. However, cement during cementing of the casing penetrates into the reservoir, polluting it. This in turn leads to reduced productivity of the drilled well.

This drawback is deprived of the tool for completion used in the casing and preventing pollution of the oil reservoir with cement mortar [2].

The tool consists of a double cylindrical body with holes, a spool with an annular spring clip and packers installed above and below the device. Opening and closing the holes in the housing is performed when moving the spool by moving the tubing string with a special key that engages with the spool.

The spool is fixed in two opposite directions by annular springs located in the annular grooves of the spool and engaged with the annular grooves in the device body.

The main disadvantage of the known device is the considerable time spent on the operation of moving the spool, since it requires the descent of the tubing string during the opening and closing of the holes in the device.

The objective of the invention is to reduce the time required to bring the device into action.

This problem is solved in that the device, consisting of a double cylindrical body with holes and a spool with an annular spring lock, is additionally equipped with a shutter with squibs and a spring-loaded differential piston interacting with a spring-loaded spool, and a signal receiver for triggering the squibs, while the openings of the housing are closed spool with the ability to move it to open holes in the tubing string, fixing this spool in the upper position of the differential a differential piston and move the spool to close openings at operation of the cutter.

This design of the device allows you to perform the operation of closing the holes in the housing of the device using a signal from the surface, without spending time and money for lowering the string of tubing. This leads to a significant reduction in the cost of putting the device into operation.

In FIG. 1 shows the device in its original position. In FIG. 2 - the same device after triggering the spool.

The device consists of a double cylindrical body 1 with holes 2, a spool 3 with an annular spring clip 4. The spool is spring-loaded with a spring 5. In the case 1 there is a shutter 6 with squibs 7 and a differential piston 8. The piston 8 is spring-loaded with a spring 9. There is also a receiver in case 1 10 signals for triggering the squibs 7. Above and below the device, as well as in the prototype, packer devices (not shown) are installed.

The device operates as follows. The device along with the packers is installed as part of the casing, lowered into the well. In this case, the holes 2 are blocked by a spring-loaded spool 3. After completion of the descent of the casing, it is cemented. Due to the design of the device and the presence of packing devices above and below it, the cement in the zone of the reservoir does not contact the reservoir rock, passing along the annular gap B of the double cylindrical body 1. After the cementing process is completed, the tubing is lowered to open the hole 2 into the casing 11 with a special key fixed to them 12. A special key 12 is mechanically connected to the spool 3 and by moving the tubing up, the spool is moved to the upper position. When the spool is moved to the upper position, the spring 5 is compressed and the differential piston 8 moves under the action of the spring 9 until it stops at the end B. Thus, the spool will be fixed in the upper position by the radially located differential piston 8, pressed by the spring 9. The spring 5 is in a compressed state (figure 2).

This opens the holes 2, communicating the inner cavity of the casing string with the reservoir. After raising the tubing string with the special key disconnected, it is possible to study the reservoir.

To close the holes 2 from the mouth of the command. By a remote command from the wellhead, the signal is received by the receiver 10, amplified and fed to the actuator - squib 7. When the squib is triggered, an excess pressure is created in chamber A, under which the differential piston moves until it stops at end D, and the piston stop is recessed into the wall device (figure 1). The spool 3 under the action of the spring 5 is moved all the way to the end E and is fixed in this position by an annular spring retainer 4. The compressed gas from the chamber A is vented through the hole D into the existing free zone of the bypass cavity (not shown).

The total number of device operations is determined by the number of installed squibs.

In this case, the signal for the next operation will be supplied to the next igniter 7 prepared for operation.

Using the proposed tool for well completion can reduce the time and cost of its installation.

Sources of information

1. Gaivoronsky A.A., Tsybin A.A. Well fixing and formation separation. M .: Nedra, 1981, p. 76.

2. US patent No. 5203412, MKI E 21 23/04, 06/06/1991 (prototype).

Claims (1)

A tool for completing wells, including a double cylindrical body with holes and a spool with an annular spring retainer, characterized in that the tool is additionally equipped with a shutter with pyrocartridges and a spring-loaded differential piston interacting with a spring-loaded spool, and a signal receiver for actuating the pyrocartridges, while blocked by a slide valve with the possibility of its movement, for opening holes, a tubing string, fixing this slide valve to the top position with a differential piston and displacement of the spool, to close the holes, when the igniter is triggered.

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