SU1213168A1 - Double drill pipe - Google Patents

Description

one

The invention relates to a drilling technique and is intended to improve the efficiency of drilling with the transport of cuttings with a cleaning agent.

The aim of the invention is to reduce the thickness of the ring of a double drill pipe.

Figure 1 shows a double drill pipe, a slit; figure 2 - section aa in figure 1.

A double drill pipe and a pipe contains an inner pipe 1 with a fitting 2 and sleeves 3 at the ends, which form an airtight connection 4 during assembly of the column.

The inner pipe 1 is installed in the cavity of the outer pipe 5 concentric with it. The outer pipe 5 has a locking j connection including a grasped 6 and a threaded 7 7 and 1 around the grip. A bore 8 having a smooth cylindrical threaded part 9, a threaded section 10, as well as a tapered bore 11 is made in a revolving thread element 7 (coupling), and a conical bore 11 in the threaded part 9 of bore 8 of the engaging thread element 7 is fitted with a sleeve 12 of the centering element having ribs 13. I The locking threaded element 6 of the locking joint contains a conical surface 14 which is opposite to the conical bore 11, located in front of its threaded section.

The bore 8 of the sheathing threaded element 7 has a length H equal to the sum of the length H, the working part of the locking joint and the length H, of the holder 12 of the centering element. The end face 15 of the screwed threaded element 6 is in contact with the holder 12 during assembly. An annular gap 16 is formed between the inner 1 and outer 5 pipes.

Double drill pipe works as follows.

In the course of the assembly, the bolt-on element 6 is screwed into the gripping threaded element 7 up to the stop with the end 15 into the holder 12 of the centering element. In this case, the cone boring 11 is mated with a conic 21 3 1682.

This surface 14 is tensioned, which ensures the density and durability of the joint.

When the double drill pipe is operating, the torque and axial load are transmitted through the outer pipe 5, and the drilled material is transported to the surface by the upward flow of the cleaning agent through the inner pipe 1. The upward flow is formed when the straight flow passes through the bottom hole. annular gap 16.

Emphasis wrap element 6

15 by the end 15 in the yoke 12 prevents the enveloping threaded element 7 from expanding when perceived by the locking joint of a torque during the assembly and drilling process. it

20 is achieved by the equality ddgans H, the bore 8 the sum of the lengths H of the working part of the joint, and Hj of the holder 12 of the centering element.

25 The small taper of the surface 14 gives it the property of a stabilizing earthing element of the locking joint, which ensures the strength of the joint without increasing the outer

30 diameters, bypassing the threaded element 7, i.e. leads to a reduction in the thickness of the package connecting the outer tube.

The width of the annular gap 16 between the inner 1 and outer 5 pipes is selected from the conditions of tolerance of hydraulic resistances, and the thickness of the internal pipe 1 from the conditions of strength of its connection with

40 by fitting 3 and fitting 2, therefore, for each specific design of a double drill pipe, these values are constant.

Thus, reducing the thickness

The 45 pack of outer pipe connection causes a reduction in the thickness of the ring of the double drill pipe as a whole.

With decreasing package thickness

50, the joints of the outer pipe in its elements become comparable with the stresses in the internal pipes, which simplifies the design of the centering element.

1213168

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Editor I. Nikolaichuk

Compiled by V. Rodina

Tehred O. Vashchishin Proofreader A. Zimokosov

758/42

Circulation 548 Subscription VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch PPP Patent, Uzhgorod, st. Project, 4

Claims (1)

DOUBLE DRILL PIPE, including an inner pipe with a fitting and sleeves at the ends that form a tight joint during assembly of the string, an outer pipe with a locking joint containing a girth and girth threaded elements, a centering element with ribs and a ferrule located in the threaded part of the girth characterized in that, in order to reduce the thickness of the ring of the double drill pipe, the boring of the female thread of the threaded element has a length equal to the sum of the length of the working part of the connection and the length of the cage of the centering element, and in front of the threaded section of the wrapping element, a conical bore is made, and the wrapped threaded element has a surface mating to it. SUo., 1213168 ¹ 12