RU158596U1 - FLEXIBLE PIPPER - Google Patents

Abstract

A fishing device for extracting a stuck string of flexible pipes from a well under pressure using a flexible pipe containing a check valve and a catch, characterized in that it is additionally equipped with a sub installed after the check valve and located downstream of the said sub with a hydraulic anchor, a deep hydraulic jack, while an overshot with a spiral grip was used as a catcher.

Description

The utility model relates to the oil and gas industry, and in particular to devices for extracting dangling stuck pipes in the process of overhaul of wells, in particular to fishing equipment for extracting a stuck string of flexible pipes using a string of flexible pipes lowered into an emergency well.

In domestic practice, various catchers are used to extract stuck pipes, for example, tubes, overshots, bells, taps, etc. [A reference book on the current and capital repair of oil and gas wells / Amirov A.D. and others. - M .: Nedra, 1979. - 309 s].

Known overshot containing the upper sub, housing, restrictive ring, guiding funnel, packer, spiral grip [Kempp G. Fishing gears in oil wells. Technique and technology: Per. from English - M .: Nedra, 1990 - S. 26-27, Fig. 10.6].

Known overshot for extracting dangling tubing and drill sleeve pipes, which contains a hollow body connected to a sub for threading with a pipe string, a through collet is installed inside the body with the possibility of axial movement, made in the form of a spring split sleeve with an outer cone interacting with an inner cone made from the side of the lower end of the housing, on the working surface of the collet teeth are made in contact with the outer surface of the body of the catch pipe, with the lower at the end of the housing, an additional cone is made for the pipe to enter, and the axial movement of the collet is limited by a retaining ring mounted on the outer surface of the collet and included in a wide annular groove made in the housing, and the upper end of the retaining ring and the abutting surface of the wide annular groove are conical, moreover, collet installation made a narrow annular groove for fixing the collet when released from the pipe [RU 149992 U1, E21B 31/18 (2006.01), publ. 01/27/2015].

However, the known overshot is not intended for catching flexible clutchless pipes, since the gripping mechanism is made in the form of a collet with slips on its inner surface, so it is possible for the teeth to slip along the collet of the collet along the column of the collarless flexible pipe and even break off this pipe when pulling a sand tube from the pipe that grabbed the pipe.

Known fishing device for extracting a tattered string of flexible pipes, consisting of a check valve, a downhole motor and a catcher [Bulatov A.I. Coiled tubing technology for drilling, completion and repair of oil and gas wells. Reference manual. - Krasnodar: Publishing House "Enlightenment-South", 2008. - S. 320, Fig. 15.1].

The main disadvantage of the known fishing device is the lack of reliability when removing the stuck string of flexible pipes due to the inability to create the necessary pulling force when removing the stuck string of flexible pipes and the lack of reliability of its capture and retention in the captured state due to fatigue failure of the stuck portion of the string of flexible pipes or the formation of longitudinal cracks in the upper end of the stuck tubing string.

The task of creating an overhead catcher on a flexible pipe is to design a fishing device that is lowered onto the flexible pipe string, which enables the extraction of the stuck portion of the flexible pipe string from its outer surface.

When implementing the claimed technical solution, the problem is solved by achieving a technical result, which consists in increasing the reliability of extraction without re-breaking by hooking an overhead catcher on a flexible pipe with a stuck portion of the string of flexible pipes over its outer surface and pulling it from the sticking point.

The task and technical result are achieved by the fact that in the known fishing device for extracting the stuck portion of the flexible pipe string using a flexible pipe string containing a check valve and a catcher, it is new that it is additionally equipped with a sub installed after the check valve and located after the specified sub from top to bottom with a hydraulic anchor, a deep hydraulic jack, while an overshot with a spiral grip was used as a catcher.

In FIG. 1 shows the inventive device, FIG. 2 - the same at the time of catching and removing the stuck part of the flexible pipe string.

The overhead catcher on a flexible pipe (Fig. 1) contains (from top to bottom) a check valve 1, a sub 2, a hydraulic anchor 3, a deep hydraulic jack 4, a catcher 5.

The elements of the overhead catcher are interconnected in a known manner, for example, by means of sub.

The check valve 1 is designed to prevent gas backflow into the string of flexible pipes, since the well is under pressure, preventing possible gas and oil manifestations, and is a cylindrical body with a saddle, overlapping using a spring-loaded shutter.

The sub 2 is designed to connect a check valve 1, placed on a column of flexible pipes 6 coiled tubing installation (not shown) with a hydraulic armature 3.

The hydraulic anchor 3 serves to fix the overhead catcher on the flexible pipe 6 in a stationary state at the time of operation of the deep hydraulic jack 4, while freeing the string of flexible pipes 6 with overshot 5 from axial load.

The deep hydraulic jack 4 is designed to transmit axial force to the stuck portion of the string of flexible pipes 7, allowing it to be pulled out of the sticking point.

An overshot was used as a catcher 5, which is a device consisting of a guiding funnel, an adapter, and a set of interchangeable elements, including a spiral grip, which makes it possible to reliably capture the emergency pipe in contrast to the collet grip, in which the collet can slide on the body of a flexible pipe, not having coupling connections. It is such a design that provides a reliable grip of the stuck column of flexible pipes by overshot and pulling it out of the sand cork that has taken hold of the column of flexible pipes due to the spiral grip loop formed and tightened on the pipe.

The process of capturing a stuck column of flexible pipes with an overshot is carried out due to the presence of spiral surfaces made on the outer surface of the casing and the inner surface of the spiral grip interacting with it.

Flexible pipe cutter is mounted as follows.

An upper sub (not shown) will be connected to the bottom of the string of flexible pipes 6 for connecting an overhead catcher with a flexible pipe 6 to which an overhead catcher is installed, the assembly of which includes a check valve 1, a sub 2, a hydraulic anchor 3, a hydraulic jack 4 and an overshot 5 with spiral grip.

Piping catcher on a flexible pipe works as follows.

The overhead catcher on flexible pipe 6 (Fig. 2) is lowered into a repaired well without killing, which is under pressure, equipped with production 8 and elevator 9 columns, in which the stuck portion of the flexible pipe string 7 is located, on the flexible pipe string 6 to the “head” 10 seized flexible pipe string parts 7.

To ensure the extension of the piston of the hydraulic depth jack 4, on which the stuck part of the flexible pipe 7 is fixed, the overhead catcher is fixed with a hydraulic anchor 3 in the annular space formed between the elevator column 9 and the deflected column of flexible pipes 6.

The descent of the overhead catcher on the flexible pipe 6 is controlled by the weight indicator. A deflated overhead catcher carefully covers the “head” 10 of the stuck portion of the string of flexible pipes 7, with a minimum speed of movement of the overshot 5.

Using a hydraulic deep jack 4, which allows to increase the pulling force, limited by the strength of the injector of the coiled tubing unit and the string of flexible pipes, the stuck portion of the string of flexible pipes 7 is pulled out of the sand plug 11 that has been seized during fracture of the reservoir 12. Pulling of the stuck portion of the string of flexible pipes 7 occurs due to the vertical movement of the output rod of the deep hydraulic jack 4, located in its inner cavity. In this case, the pulling force should not exceed more than 700 kN, the maximum allowable value for the strength of the string of flexible pipes 6, on which the stall and lift the stuck portion of the string of flexible pipes 7.

The inventive overhead catcher on a flexible pipe provides reliable extraction of the stuck portion of the string of flexible pipes under conditions of abnormally low reservoir conditions without killing the well, under pressure, applying quite large forces of up to 700 kN to it.

Thus, the claimed device, in addition to increasing the reliability and efficiency of fishing operations, significantly reduces the cost of repairing a well to extract the stuck portion of the flexible pipe string, their laboriousness and cost, ensures the safety of fishing operations and prevents breakage of the flexible pipe from overshot.

Claims (1)

A fishing device for extracting a stuck string of flexible pipes from a well under pressure using a flexible pipe containing a check valve and a catch, characterized in that it is additionally equipped with a sub installed after the check valve and located downstream of the said sub with a hydraulic anchor, a deep hydraulic jack, while an overshot with a spiral grip was used as a catcher.

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