RU2774996C1 - Pipe collet catcher - Google Patents

Abstract

FIELD: mining industry.

SUBSTANCE: invention relates to external pipe traps and is intended for grippping and retaining various equipment from wells during the liquidation of accidents. The device includes an adapter, a housing, a washer, a set of replaceable elements: collet grips. The body is made in the form of a pipe made of structural, alloy steel, the inner surface of the lower part of the housing is made in the form of a conical constriction, inside there is a collet with one conical surface with five symmetrical slots forming springy petals that compress, providing a reliable grip and fixation of the pipe body. The inner diameter of the collet is smaller than the outer diameter of the captured tubular elements. A conical surface is made on the inner side of the housing, interacting with the conical surface of the collet, this makes it possible for the collet to freely enter the housing with the possibility of limited upward movement at the adapter’s stop, and from below, a conical constriction of the inner part of the housing. The locking washer is used to prevent unscrewing the thread of the housing-adapter connection by wedging into the slots of the housing and the adapter.

EFFECT: metal consumption is reduced, the reliability of guaranteed grip is increased, the range of extracted pipes is expanded while simplifying the design.

2 cl, 4 dwg

Description

The pipe collet catcher belongs to the emergency tools used in the construction of wells, during the extraction of body products of telesystems, hydraulic downhole motors, drill collars during the elimination of accidents with scrapping during well construction.

An overshot with a short grip is known (United States patent US 2743130 A, dated April 24, 1956), contains a sub for connecting to the fishing string, carrying a housing with an internal spiral conical surface inside which a collet is installed with the possibility of axial movement. A collet is a part that has a helical surface on the outside, corresponding to the helical surface in the body. To transfer torque from the body to the collet during emergency work, a collet insert is used.

The disadvantages of this device are:

- manufacturing complexity due to a large number of technically complex surfaces (spiral conical surface with very large thread pitches) on parts and assemblies, which leads to an increase in the cost of the device;

- small range of collet grip relative to the nominal size;

- Difficulty in maintenance and operation.

Known pipe catcher (patent of the Russian Federation No. 469802, dated 08/05/1975), consists of a body with an internal conical stepped surface, which houses a shaped collet, while the ridges of the interacting steps of the gripping sleeve and the body are made with decreasing diameters from top to bottom. The shaped sleeve is rigidly attached to the body by means of pins rigidly attached to the collet and interacting with the shaped collet.

The disadvantages of this device are:

- the high cost of the device associated with the complexity of manufacturing a shaped collet, with a large number of parts and components of the mechanism;

- small size range of pipes to be extracted during well construction; - complexity in service and high cost;

- the spear is designed to extract only one diameter.

The closest analogue of the claimed invention is a mechanical pipe spear (patent of the Russian Federation No. 2182217, dated May 10, 2002), the device has a telescopic body, consisting of an inner and outer part, which are spring-loaded and have a spline connection, a collet is installed inside the body

pressed by a spring, the groove and the thrust end are made on the inner surface of the outer part of the housing, two expanding rings are installed on the collet and the outer surface of the inner part of the housing with the possibility of stopping in the unclenched position of the first in the thrust end, and the second in the groove, respectively, the collet is mounted with the possibility of a stop into the inside of the case.

The disadvantages of this device are:

- the manufacture of the splined mechanism and expansion rings is due to the high cost of the device, with a large number of technically complex parts, which leads to an increase in the cost of the design with a small gap between the body and the borehole wall; LBT;

- small range of collet grip relative to the nominal size; - complexity in maintenance and operation, a large number of contacting parts, the stepwise inclusion of which depends on each other, which reduces the reliability of the device and leads to high metal consumption.

At the same time, the prototype pipe spear has an extremely complex design, which in many cases can be prone to frequent breakdowns and jamming of the collet during operation, there are also several dangerous sections on the body, the large dimensions of the body do not provide the ability to extract the pipe string with a small gap between the body and well wall.

The technical objective of the invention is to simplify the design and expand the range of retrievable pipes from the well, the advantage of the developed pipe collet catcher due to the presence of one conical surface in the collet and a body with a conical narrowing to the bottom on the inside, in addition, this design allows the use of a pipe collet catcher to extract several pipe diameters when replacing only the collet. At the same time, the proposed design of the collet allows solving the problem of capturing pipes of at least 5-6 different diameters without changing other elements of the assembly. The collet is replaceable, has diameters: D=160 mm, 163 mm, 169 mm, 172 mm, 175 mm.

The essence of the invention is illustrated by drawings, which show:

Figure 1 - shows a General view of the catcher pipe collet in longitudinal section;

Figure 2 shows the collet in longitudinal section;

Figure 3 - node A in figure 2;

Figure 4 shows the collet in a perspective view. The collet pipe catcher contains a body 1 (figure 1), having in its lower part a conical narrowing 2 with a sub 5 and a collet 3 (figure 2), as well as a lock washer 4. The sub 5 is connected to the body 1 using a lock washer 4 by wedging the washer into the grooves of the body and the sub 5. In the cavity of the body 1 is the collet 3 (figure 2). The collet 3 (figure 2) has one conical surface 6 (figure 3) with five symmetrical slots 8 (figure 4) forming spring petals, in addition, teeth 7 (figure 3) are located on the inside, which provide grip and containment of the emergency object.

The principle of operation of the pipe collet catcher is as follows. To install the collet 3 (figure 2) of the required diameter, the body 1 is unscrewed from the sub 5; 5.

Then connect the pipe collet catcher to the drill string and lower it into the well, 1-5 m short of the top end of the emergency object, stop the descent, turn on the supply of flushing fluid and flush during one cycle. Turn off the supply of flushing fluid and start descent, by rotating to grab the end of the emergency object. When it gets inside the end of the emergency pipe, the petals of the collet 3 (figure 2) are opened due to the slots 8 (figure 4), its diameter increases, and at a certain load, passing the emergency object inside the collet 3 (figure 2), and also automatically compressed providing a secure grip, since the inner diameter of the collet is 2.5-3 mm (determined by practical means) less than the outer diameter of the equipment to be retrieved. After that, by pulling the column, capture the emergency object - on the conical surface of the body 1 in the lower part of the conical narrowing 2, the collet 3 will jam (Fig. 2) and the teeth will cut 1.5 mm (Fig. 3) into the emergency object. Raising the fishing string , control the load on the hook on the weight indicator. If the load on the hook exceeds the initial one, then the emergency object is captured. Retrieve the emergency object to the surface in whole or in parts.

Release of the pipe collet catcher from the emergency object on the surface, for this it is necessary to install the emergency object on the rotor or elevator. Lower the fishing string, unloading it 20-50 kn below its own weight. Install the chain spider housing 1 (figure 1) and withdraw from contact the collet 3 (figure 2) catcher pipe collet, while wedging and releasing the collet 3 (figure 2) from the emergency object. Remove the body of the pipe collet catcher from the emergency facility.

The use of the specified pipe collet catcher solves the issue of expanding its scope, that is, increasing the range of sizes of pipes to be retrieved, by using only a few sets of interchangeable parts for the corresponding pipe size. For example, if there are interchangeable 5 sets of collets, it is possible to grab and retrieve drill pipes, drill collars, and drill pipes of 5 diameters from 163 to 178 mm, while the cost of the set is reduced by at least 10-15 times.

At the same time, the quality of manufactured parts and the reliability of the pipe collet catcher as a whole are improved. All this ultimately leads to a reduction in the cost of fishing and a reduction in the number of manufactured catchers.

The presence of interchangeable collets for the corresponding pipe diameters will allow you to refuse to use other parts in the pipe collet catcher without changing the design and dimensions to extract 5-6 diameters. At the same time, the reliability of the pipe collet catcher increases due to the simplification of the design. The catcher can be manufactured industrially, which is confirmed by tests of an experimental batch and meets the criterion of "industrial applicability".

Claims (2)

1. Pipe collet catcher, consisting of a body, a collet located inside the body, a lock washer, a sub, characterized in that the inner surface of the lower part of the body is made in the form of a conical narrowing, a replaceable collet with one conical surface with five symmetrical slots is installed inside, forming springy petals, the collet is made with an inner diameter 2.5-3 mm less than the outer diameter of the emergency equipment retrieved from the well, teeth 1.5 mm deep are cut on the inner surface of the collet, the lock washer serves to lock the thread of the body-sub connection by wedging the washer into grooves case and translator. 2. Pipe collet catcher according to claim 1, characterized in that the replaceable collet has diameters: 160mm, or 163mm, or 169mm, or 172mm, or 175mm.

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