RU2477782C2 - Cement dump-bailer - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: dump-bailer contains casing with holes, head for input of armoured cable, plugging agent, plug and explosive assembly additionally contains nose piece. Nose piece is connected to casing via thread, it has central through-hole that is closed by glass disc destroyed due to explosion. There is an explosive cartridge installed at specified distance from the disc. The cartridge is fixed relatively longitudinal axis of dump-bailer via fixing element in a form of a crosspiece that is at the same time a current-conducting part of electric-explosive circuit. Fabrication hole for the plug is located at the bottom side part of the casing. Dump-bailer at bottom end part is equipped with protective shield. Invention provides improvement of performed works efficiency on creating cement disconnecting bridge that allows performing different well operations.

EFFECT: device is simple in handling, use of this device ensures high quality, safety and economy of performed works.

1 cl, 1 dwg

Description

The invention relates to the oil and gas industry and may find application in the construction and repair work in the well, in particular, for installing dividing bridges to isolate productive horizons and sections of the wellbore from each other.

In US fisheries, the Grant cementing bore is used; it consists of a container body, in the upper part of which there are loading windows. The bottom case is closed by a plastic disk, which is held by a locking device (Kharkov V.A. Overhaul of oil and gas wells. M: Nedra, 1969, p. 34-35).

The disadvantage is the inability to cement the well in a given interval at a considerable distance from the bottom.

As an analogue, a device for repairing oil and gas wells was selected (patent RU No. 2134769, IPC ⁷ ЕВВ 29/10 dated 10/07/1997), which contains a container for delivering cement mortar to a predetermined depth. The top of the container is closed with a lid for connection to the cable, and the bottom is a plug. The container is equipped with centralizers installed in the lower and upper parts of the container, which ensure the location of the container along the axis of the production string. In the upper part there is a pump for filling with cement mortar through the loading window in its wall, as well as for supplying flushing fluid through the same windows into the container and creating the necessary pressure on the cement mortar. A perforator is placed in the lower part of the container, and the container walls opposite the perforator have unloading windows closed by an elastic sheath. The device operates as follows. The container is lowered into the well, as the specified depth is reached, the pumping of the washing liquid into the container and the forcing of the cement mortar begin.

In this case, the elastic shell is stretched to close contact with the wall of the production string. At this moment, the punch is turned on and punches a hole through the elastic shell and the wall of the production string into the cement ring. The cement mortar is continued to be pressed into the formed cylinder from the elastic membrane and then through the perforations in the cement ring. Further, if it is necessary to expand the boundaries of the cementing interval, raise the container at the mouth, replace the elastic membrane and repeat all the above operations.

The disadvantage of this design is the unreliability of the separation system.

As a prototype, a bailer for temporary isolation of the formation (patent RU No. 2209930, IPC ЕВВ 27/02 of 06/05/2001. A method of temporary isolation of the formation, material and bailer for its implementation) is selected, which contains a hollow cylindrical body with windows in the upper part, a cover fixed to the housing on shear elements, a head for cable entry, a diffuser that divides the body cavity into two chambers, the upper one to accommodate the charge with an electric igniter and the lower one to accommodate the plugging material and a plug made in the form of elas segmental membrane, with a spherical surface facing the housing cover of the same material as the combustible clogging material serving as the bottom of the housing. The plug is equipped with a durable polymer thread that binds it to the plugging material. Windows are designed for the exit of gases in excess of the permissible pressure in the upper chamber of the baffle.

The disadvantage of this design is the small volume of the chamber of the flap, which significantly reduces the performance. The presence of a combustible clogging material, which consists of fuel and an oxidizing agent, an electric igniter, significantly increases the complexity and environmental hazard of work.

The technical task of the present invention is to increase the efficiency, safety and reliability of this device.

The solution to the technical problem is achieved by the fact that the bailer, comprising a housing with windows, a head for inputting an armored cable, a plugging material, a plug and an explosive device, further comprises a tip connected to the housing by means of a thread, the tip has a central through hole covered by a glass that is destroyed by the explosion a disk, at a certain distance from which an explosive cartridge is mounted, fixed relative to the longitudinal axis of the baffle by means of a mounting device in the form of cr stoviny that is both conductive part electroexplosive circuit, wherein the process opening under the plug located at the bottom side of the housing, moreover, bailer the bottom end portion has a protective casing.

Figure 1 shows the cementing choke, which contains 1 - cable lug (head for entering armored cable, device for lowering and lifting the chute); 2 - current lead; 3 - the body of the flap; 4 - filling window; 5 - wire from the current lead to the explosive cartridge; 6 - explosive cartridge; 7 - mounting device for mounting an explosive cartridge in the form of a cross, 8 - glass disk; 9 - tip; 10 - through central hole, 11 - technological hole for the plug; 12 - a protective casing, 13 - armored cable braid.

The cementing choke is intended for installation in a cased well of a cement uncoupling bridge, which allows various downhole operations to be carried out with the tool resting on artificial slaughter, including acid treatment of the formation. The efficiency and quality of the cement uncoupling bridge installation largely depends on the manufacturability, safety and reliability of the baffle.

Device operation

A glass disk (8) is installed in the tip (9) on the sealant, an explosive cartridge (6) with a wire (5) is fixed in the mounting socket of the mounting device in the form of a cross (7). A cement mortar is poured through the pouring window (4), the current lead (2) is connected with a wire (5) with an explosive cartridge (6). The cable head is connected to the perforator head at the last moment before the flap is lowered into the well, and the armored cable sheath (13) and the flap body (3) are massively connected to the crosspiece (7). The lowering of the baffle is carried out at a speed of 2 m / s, at the speed of a charged punch.

The flap works as follows. Explosive cartridge (6) is initiated from a special explosive high-frequency device PVV-1. An explosive cartridge (6) is installed perpendicular to the glass disk (8) at a small distance, which ensures the complete destruction of the glass disk (8) and ensures the complete exit of the high-density cement mortar from the choke. When the cartridge explodes, a shock wave is formed and gases expand, which act on the plug (wooden cork) inserted into the technological hole (11), pushing it out, and at the same time loosen the cement in the lower part of the choke, which has been compacted during the chute descent into the well. The absence of mechanical locking devices - valves, gates and gate valves - greatly simplifies the operation of the device and ensures high reliability of its operation. When the explosive cartridge (6) is triggered, the energy of the expanding gases, knocking out a wooden cork, simultaneously ejects a portion of the cement mortar through the technological side (11) and the central through hole (10). Cement mortar due to higher density (well fluid 1.17-1.20 g / cm ³ ) flows through the central through channel of the tip and the side hole. A protective casing (12) located in the lower part of the bailer protects the glass disk (8) from unauthorized destruction during installation of the bailer at the mouth and during its descent into the well.

The glass disk is made of thick glass, resistant to shock, falling and mechanical damage, as well as the load generated when the bailer is lowered into the well. Provides reliable retention of cement in the chamber. At the same time, it is guaranteed to collapse from an explosive cartridge located at a certain distance, without leaving large fragments.

The crosspiece is a special metal device for placing an explosive cartridge with adjustable mounting legs, which provide reliable positioning in the housing of the bobbin with any internal diameter and electrical connection of the cartridge body with the bobbin case.

Since the cavity of the flap is not divided, it has a large capacity of at least 25 liters compared to the prototype, which can significantly increase the amount of cement slurry delivered, thereby significantly reducing the number of flaps into the well, saving material and financial resources.

The quality of the explosive cartridge uses PGN-150, which guarantees the safety of work with this device. This cartridge works only from the high-frequency device PVV-1 and a current pulse with a frequency of 15 kHz.

This device is used repeatedly. With each use of the bailer, a new glass disk is installed in the tip, a cement mortar with a density (p = 1.4 ... 1.6 g / cm ³ ) is poured into the filling window.

The technical and economic advantage of the proposed technical solution is as follows.

The invention provides an increase in the efficiency of ongoing work to create a cement uncoupling bridge, which allows for various downhole operations. This device is easy to use, the use of this device provides high quality, safety and economy of the work.

Claims (1)

A cementing shutter comprising a case with windows, an armored cable entry head, a plugging material, a plug and an explosive device, characterized in that it further comprises a tip connected to the housing by a thread, the tip has a central through hole covered by a glass disk that is destroyed by explosion, at a certain distance from which an explosive cartridge is mounted, fixed relative to the longitudinal axis of the bobbin, by means of a mounting device in the form of a cross, which at the same time is a conductive part of the electric explosion circuit, and the technological hole for the plug is located in the lower side of the housing, in addition, the bailer has a protective casing.

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