RU2469170C2 - Drill column bottom layout - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: layout includes in-series connection of drill pipe, centraliser and adapter. Centraliser is made in the form of a hollow cylinder with flattened surfaces. Adapter is connected to centraliser by means of thread of rectangular profile with a pitch of 6.35 mm. Connection of centraliser and drill pipe is performed by means of taper thread with conicity of 1:17, the cross-section profile of which represents non-equilateral trapezium with negative angle along the bearing face and positive angle along the embedded face. Height of centraliser thread profile is less than that of drill pipe thread profile. Centraliser has conical thrust face with conicity angle in the direction of taper thread on it, which interacts with conical thrust projection on the drill pipe. It is provided at the end of the whole thread profile with conical thrust projection interacting with conical thrust end of drill pipe.

EFFECT: increasing the tightness and resistivity to tensile, collapsing and bending loads of connections of rotatable drill pipe.

5 dwg

Description

Technical field

The invention relates to drilling equipment, and in particular to devices for centering a drilling tool, included in the layout of the bottom of the drill string. The layout of the bottom of the drill string - chisels, sub, assembled pipes, centralizers and drill pipes assembled together in the quantity and assortment necessary to ensure the well is wired with a certain orientation in space. Support-centering tools - drill string elements (calibrators, centralizers and stabilizers) are installed in its lower part to ensure the well construction process with specified parameters for effective diameter and spatial position.

State of the art

Known layout of the bottom of the drill string, containing a hollow centralizer in the form of a tubular body having working elements mounted on the body, made in the form of a disk with longitudinal slots, with tapered threads at the ends for attachment to the drill pipe and an adapter ("Choosing the layout of the bottom of the drill string for drilling wells. ”Survey information, Drilling series, issue 18, M .: VNIIOENG, 1986, p. 35-36, see also RU 2105860, E21B 17/00; 1998-02-27). This design has a low centering efficiency due to sticking to the body of the rock centralizer in the longitudinal slots and insufficient compaction of the joints.

Known threaded connection of drill pipes with tapered thread profile "dovetail", in which the necessary seal is provided by radial interference of adjacent surfaces in areas located near the free ends of the connected elements (WO 2004106797, F16L 15/06, 2004-12-09). This design requires excessive manufacturing precision and is not suitable for bottom hole assembly layouts including drill pipe, centralizer and sub.

Disclosure of invention

The objective of the invention is to simplify the design of the elements of the layout of the bottom of the drill string with the necessary tightness and strength of the joints of the drill pipe with the centralizer and the centralizer with the sub.

To solve this problem in a known design of the layout of the bottom of the drill string, including the serial connection of the drill pipe, centralizer and sub, the centralizer is made in the form of a hollow cylinder with flats, the sub is connected to the centralizer using a rectangular profile thread with a pitch of 6.35 mm. The centralizer and the drill pipe are connected using a tapered thread with a taper of 1:17, the cross-sectional profile of which is an isosceles trapezoid with a negative angle along the reference face and a positive angle along the embedded face, the height of the centralizer thread profile is less than the height of the drill pipe thread profile, and the centralizer has conical stop face with a taper angle in the direction of the conical thread on it, interacting with a conical stop ledge on the drill pipe, and at the end of the full thread profile There is a conical stop shoulder interacting with the conical stop face of the drill pipe.

The advantage of the claimed design in comparison with the known is the possibility of using as a centralizer a simple cylinder with flats with increased tightness of the joints and resistance to tensile, crushing and bending loads of the connections of the column set.

A brief description of the drawings.

Figure 1 shows the sequence of connection of the elements of the layout of the bottom of the drill string - drill pipe, centralizer and sub, figure 2 - threaded connection of the centralizer with the drill pipe, figure 3 - cross section of the threaded part of the centralizer adjacent to the drill pipe, in Fig. 5 is a thread profile of a centralizer in connection with a drill pipe (extension I), and FIG. 4 is a thread profile of a centralizer at an end connected to an adapter.

The best embodiment of the invention

The inventive layout of the bottom of the drill string includes a serial connection of the drill pipe 1, centralizer 2 with flats 3 and sub 4. In the connection of the drill pipe 1 and centralizer 2, a tapered thread is used in the form of an uneven trapezoid in cross section with a taper of 1:17, the thread profile has a negative the angle α along the reference face 5 and the enlarged angle β along the embedded face 6, while the height of the thread profile of the centralizer 2 is less than the height of the thread profile of the drill pipe 1 by b2. The thread is not tight. Tightness provides a metal-metal seal, which is structurally designed so that the centralizer 2 has a conical stop face 7 with a taper angle in the direction of the tapered thread on it, interacting with the tapered stop ledge 8 on the drill pipe 1, and has a tapered end thrust ledge 9, interacting with the conical thrust end 10 of the drill pipe 1. The centralizer 2 is connected to the sub 4 using a rectangular thread with a pitch P = 6.35 mm, while the thread may have Profile goal, determined by an angle of inclination of the profile γ.

Industrial applicability

The device is used as follows. The centralizer 2 is installed on the drill pipe 1 at the point of attachment to the core pipe (not shown) by means of a sub 4, using appropriate threaded connections. When lowering the drill pipe string, the centralizer 2 moves along with the drill string, centering the drill pipe string with flats 3 that facilitate rotation. In this case, the tightness of the connection of the drill pipe 1 and the centralizer 2 provides a seal formed as a result of the interaction of the thrust ledges 8, 9 with the thrust ends 7 and 10 during make-up. The threaded connection of the drill pipe and centralizer provides the perception of tensile load and bending, as well as partially compressive load.

Thus, the use of a simple cylinder with flats, a special profile tapered thread with a double-joint connection and a rectangular thread as a centralizer provides, with sufficient tightness of the joints, increased resistance to tensile, crushing and bending loads of the bottom of the drill string assembly joints.

Claims (1)

The layout of the bottom of the drill string, including the serial connection of the drill pipe, centralizer and sub, in which the centralizer is made in the form of a hollow cylinder with flats, the centralizer and the drill pipe are connected using a tapered thread with a taper of 1:17, the section profile of which is an isosceles trapezoid with a negative angle along the reference face and a positive angle along the embedded face, the centralizer thread profile height is less than the drill pipe thread profile height, and the centralizer has a conic a persistent end face with a taper angle in the direction of the tapered thread on it, interacting with a tapered stop ledge on the drill pipe, and at the end of the full profile of the thread has a tapered stop ledge interacting with the tapered stop end of the drill pipe, the sub is connected to the centralizer using a rectangular thread in increments of 6.35 mm.

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