SU1745858A1 - Hole reamer - Google Patents

Abstract

Use: for expanding wells in any interval. SUMMARY OF THE INVENTION: The reamer comprises blades kinematically connected to a piston rod mounted in a housing. When expanding, the drilling fluid passes between the throttle fastened to the drill string and the washer installed in the piston. The pressure drop across the expander depends on the position of the blades. This allows control of the expansion process, 5 Il.

Description

The invention relates to drilling equipment, and specifically to devices for expanding the wellbore in any interval, allowing to combine the expansion with drilling, to drill without expansion, to expand as in the top-down scheme, and in the bottom-up scheme, without lifting the extender to the surface.

A device for the formation of a broadening in a well is known, comprising a housing, an expander in the form of plates hinged to the housing on the axles and pressed against it. The hulls are made in the case, and the stop is made in the form of a washer that is freely seated on the body, while the reamer plates have protrusions located with the possibility of their stop in the working position in the shoulders, and the diameter of the hole in the plate through which the axis is passed is greater than the diameter of the axis .

The disadvantage of the device is that. that expansion can only be done in one downstream direction.

Closest to the invention according to the technical essence of the present invention is a hollow body expander connected through an upper sub to a drill string containing a power piston with a hollow rod, on the outer side of which there are gear racks that engage with the toothed sectors of the incisors, mounted on axles in housing slots.

The disadvantages of this reamer are the inability to drill with the reamer (when the cleaning agent is supplied, the reamer is permanently turned on; limited scope (the reamer works only from top to bottom); the accumulation of sludge at the bottom of the well in the process of extending the intervals placed above the bottom hole, since cleaning agent to the bottom does not reach: relatively complex control of the angle of the blades on the differential pressure in the injection lis With

2

SP 00

cl

00

him (requires recording equipment).

The closest in functionality is the expander comprising a hollow body, an elastic inflatable chamber with a valve, a spring and a retainer. The extender refers to the number of non-removable, reusable.

The most significant disadvantages of this expander are: the expander does not provide the wellbore expansion according to a rigid scheme, the diameter of the expansion depends on a number of parameters: pressure in the chamber, physical and mechanical properties of rocks, expansion rate, etc .; impossibility of drilling with expansion, since the central channel is closed during the work of the expander; the possibility of accumulation of solid fractions in the chamber between the piston and the elastic chamber and, as a consequence, jamming of the piston; complexity, taking into account the operating conditions of the valve control unit, blocking the central channel.

The purpose of the invention is to increase the versatility of the expander (expansion in any given interval from top to bottom or bottom to top, drilling without expansion or with simultaneous expansion) and reliability.

The goal is achieved by the fact that the expander comprises a hollow body with longitudinal grooves, in which the cutters are hinged with toothed sectors that engage with toothed racks located on the outer side of a hollow rod rigidly connected to a spring-loaded piston with a throttle washer placed in it with a bypass channel, connected to a drill string with a spline connection with a specified axial movement, with a drill string (splined shaft), a choke connected with a throttle washer, with This area of the normal cross-section of the flow channel between the washer and the throttle is maximum when open (expansion) and. closed blades x.

The dependence of the area of the bypass channel f on the given differential pressure AH and the flow rate of cleaning agent Q is given in the table.

The calculations are made by the formula

Q Y PM | 2d ln1;

where Y 0,8 - the coefficient of discharge; f is the area of the bypass channel;

g is the acceleration of the earth's t goteni; Y N - pressure drop in meters of water. Art.

f

Q

J V 2 7Ш

FIG. 1-2 depicts an expander at the bottom of a well during drilling without expansion; in fig. 3 shows section A-A in FIG.

one; in fig. 4B in FIG. one; in fig. 5-section BB in FIG. 2

The expander consists of a housing 1, in which working blades 2 and 3 are placed, connected to the housing 1 by means of

axes 4, part of the blade placed in the housing, is made in the form of a toothed sector that engages with a hollow rod 5, on the diametrical sides of which teeth are cut, which engage with the teeth

blades 2 and 3. The hollow rod 5 is connected to the upper extended part of the piston 6. Between the housing 1 and the piston 6 is placed a spring 7, the preliminary deformation of which excludes the opening of the blades from

centrifugal forces during well drilling. In the piston 6, a throttle sleeve 8 is placed with a side channel, the area of which is designed for a given pressure drop. Piston 6 moves

In the cylinder 9, placed in the cylinder body 10, a splined coupling 11 is connected to the upper part of the cylinder body 10, in which the splined shaft 12 is connected and connected to the throttle 13. The upper and lower parts of the splined shaft 12 move in the area of the seals and have an equal section . axial movements of the shaft do not change the volume between the seals. With slotted shaft 12,

the drillstring 16 is connected by means of subs 14, 15.

The extender works as follows. When drilling without expansion

(Fig. 1) the load on the bottom is transmitted from the drill string through the sub 14 to the splined coupling 11, the cylinder body 10. the housing 1 and further to the rock-breaking tool. Splined shaft 12 (throttle 13)

occupies the lowest position, the cleaning agent goes through the throttle sleeve 8, washes away the throttle 13, in the extended part of the rod 5 and further along the internal channel of the rod to the bottom of the well. Leak out exclude seals placed in the bottom of housing 1.

If necessary, the expansion (Fig. 2) raises the drill string 16, therefore the splined shaft 12 by the amount

free running h, with throttle 13

moves to the zone of the sleeve of the throttles 8 and the cleaning agent goes to the bottom by the bypass channel (Fig. 4). calculated for a given pressure drop. Under the action of overpressure, the piston 6 moves downward, compressing the spring 7. The magnitude of the displacement is determined by the height of the throttles 13 by the maximum diameter and the height of the hub of the throttles 8 by the minimum diameter. The magnitude of the axial movement of the piston 6 (Eshtok 5) corresponds to the complete opening of the blades 2 and 3. Next, the sleeve 8 moves into the zone of the lower conical part of the throttles 13, the opening for the passage of the cleaning agent increases, the pressure drops, which informs about the opening of the blades 2 and 3. The blade opening process is performed by rotating the column. Further drilling is conducted either downwards with simultaneous expansion, or expansion is conducted from bottom to top, while the pressure from the blades on the ground is perceived by the piston 6. If the expansion mode is bottom-up, for example, an accelerated feed causes partial folding of the blades 2 and 3 pressure will increase in the injection line, as the toothed sectors of the blade will raise the rod 5 (piston 6 and throttle bushing 8), the throttle 13 will move into the region of the narrowed part of the throttle bushing 8 and cause an increase in pressure.

To stop expansion, it is sufficient to temporarily turn off the flushing, under the action of the potential energy of the spring 7, the piston 6 with the rod 5 will move upwards, the blades will enter the longitudinal grooves of the housing 1 and will take up their original position. The device can be put on the face - to continue drilling or move to any given interval and, if necessary

bridges, to produce its expansion according to the described scheme.

The radial displacement of the expander excludes body 1 (when drilling from bottom to top) and the body and the roller bit when drilling with expansion.

The advantages of the proposed reamer are as follows: the reamer can be reused to expand any well interval in a bottom-up and top-down schemes; drill without expansion; drill while expanding

These factors increase the technological and economic performance in practical use.

Claims (1)

Invention Formula The expander, comprising a hollow body, a hollow spring-loaded piston with a rod housed in the body, blades pivotally connected to the body and kinematically connected to the rod can be rotated in a vertical plane with axial movement of the rod, a control mechanism for rotating the blades and a drill string adapter, characterized by that, in order to expand technological capabilities, the drill string adapter is connected to the body with the possibility of limited axial movement, and the control mechanism is made of throttles, fastened to the drill string adapter, and washers with a side channel on the inner surface located inside the piston, while the cross-sectional area between the washer and the throttle is maximum with the blades x open and closed. 4U ®uz1 eight / s / ss / 2 13