SU1691505A1 - Outer self-releasing spear - Google Patents

Abstract

The invention relates to drilling, in particular to a fishing tool, and is intended to capture and remove a stuck pipe string from a well. The aim of the invention is to increase the reliability of the operation of the die and simplify its design. For this, the distance between the conical surface of the housing, where the gripping collet is located, and the internal annular abutment of the housing, limiting the movement of the gripping collet, is not less than two orders of length of the gripping collet. In operation, this allows for the buildup of tools and the drilling of emergency pipes to the required depth. On the inner surface of the gripping collet is made threading cutting. The angle of inclination to the longitudinal axis of the housing of the inner surface of the gripping sleeve on its upper portion is greater than on the lower one. This allows locks or thickenings to pass freely, prevents the gripping collet from being caught and allows it to disconnect securely from the emergency pipes. The threaded counter threads - on the conical surface of the housing and on the outer surface of the gripping sleeve are made with a thread of an incomplete profile, which allows for an accelerated disconnection from the emergency pipe. 1 hp f-ly, 2 ill.

Description

The invention relates to drilling, in particular to a fishing tool, and is intended to capture and remove a stuck pipe string from a well.

The aim of the invention is to improve the reliability of the operation of the die and simplify the design.

FIG. Figure 1 shows the outer release of the trumpet, a longitudinal section; in fig. 2 is a sectional view in FIG. one.

The nozzle includes a housing 1 with an inner conical surface 2 having a threaded cut, and an annular cutter 3 in the lower part of the housing. At the top

Part of the housing 1 has an internal thread 4 for connecting the die, either by means of a sub, or by means of an extension pipe to a string of fishing tools (not shown). Below the thread 4 there is an internal annular abutment 5. The distance between the conical surface of the housing and the annular abutment is at least two orders of length of the gripping collet. Above the conical surface 2, a gripping collet 6 with centering ribs 7 is installed with a possibility of movement by a considerable distance to the ring stop 5. On the inside of the conical

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the surface 2 and the mating part of the collet 6 are made of a left-handed threading 8 with an incomplete thread profile, which is sufficient for a reliable connection of the threads during screwing. The inner surface of the collet has a threaded thread 9, for example, in the form of a left thrust bearing 4-6 in order to ensure reliable adhesion to the emergency rough and speed up screwing along the pipe, if necessary, to get rid of the stuck projectile. In the upper part of the i-6, section 10 has a greater angle of inclination to the longitudinal axis of the body than the lower part of the collet to provide for unscrewing the collet along the thickenings or locks of the pipes.

Moreover, the angle of inclination is chosen on the basis of ensuring that the diameter in the upper part of the collet 6 is somewhat larger than, for example, the diameter of the pipe lock or the possible thickening on the pipe. The angle of inclination of the conical surface 2 is selected from the condition of ensuring the strength of the connection of the device with the pipe, which is close to the ultimate strength of the emergency pipes. To reduce the stiffness, the collet 6 has one through and several incomplete (for example, three to four) longitudinal grooves.

The tip works as follows.

At the required depth of the shoe of the emergency pipes, the body 1 is screwed out of casing or core pipes with a thread 4 to the drill pipe. An annular milling cutter 3 is screwed to the housing 1. At a distance of about 5 to 10 diameters of the housing 1 there is a tapered surface 2 with left-cut 8. An annular stop 5 is located at a distance slightly larger than one drill pipe. The collet 6 has an internal left-handed 9 and outer 8, having a tapered surface in the upper part and centering ribs 7, are screwed into the tapered surface 2. Not a return to the upper end of the emergency pipes limit the descent rate in order to control their entry into the annular mill 3 and the body t. Since the distance from the bottom end of the milling cutter 3 to the collet b with a conical surface 2 is known, in the case of an emergency pipe approaching, the head cover is judged to reduce the weight of the tool. Further, with an insignificant axial load, the right-hand rotation is performed, as a result of which the collet 6 is unscrewed from the conical surface 2, and is made when the tool is stuck. Significant axial movement of the collet 6, exceeding the length of one drill pipe, makes it possible to build the tool and equip the emergency pipes to the required depth. When drilling, for example, drill pipes with locks, the presence of a tapered surface on the inner thread 9 of the collet 6 allows locks or thickenings to pass freely through the emergency

pipes. At the same time, due to the friction rotation and the left internal cutting 9, the collet 6 will always be in the extreme upper position.

In the process of release from sticking

Emergency pipes by churning at any stage possible raskazhmvanie emergency pipes to lift them, Incomplete cutting profile 8 on the collet 6 and the conical surface 2 provides a strong grip

collet 6 with the outer surface of the emergency pipes. In case of premature release of the emergency pipes during the smoking process, they are kept from falling down due to collet 6, self-locking in the conical surface 2. The possibility to see collet 6 is eliminated due to tapering and centering ribs 7. But even when the collet 6 is seen, this secure pipe retention

in a conical surface 2.

Claims (2)

1. The outer release pipe, including the housing with the inner an annular stop and an inner conical surface with a threaded thread, mounted in the housing with the possibility of limited axial movement between the annular stop and a conical surface, a gripping collet with an external threaded thread, a counter-threaded cutting of the housing, and an internal threaded thread, which is reliability of the device and simplifying its design, the distance between the conical surface of the housing and its annular abutment is not less than two orders of length angi, and the angle of inclination to the longitudinal axis of the body the inner surface of the exciting sleeve on its upper portion is larger than the lower portion. 2. A ram pop, 1, characterized by the fact that the reciprocal threading body and gripping sleeves are threaded with an incomplete profile. Lll / lvw 1 2