RU2550614C1 - Hole opener - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: hole opener contains a centralizer, a housing with a central feedthrough channel and grooves, the blades fitted with rock cutting elements and ledges designed as a teeth, fixed in housing grooves with a possibility of extension and a mechanism of blade extension into the working position, a hollow shaft with the top thread for joining with the borehole equipment, a lateral hole and a lower bushing placed in the feedthrough channel of the housing with fixing due to twisting with reference to the housing, and the blades are fitted with the roots interacting with the hollow shaft bushing during extension of blades into the working position, and the device for fixing of blades in inoperative position containing radially spring-loaded circular segments. The roots are designed as radial pistons inserted into the housing with a possibility of limited radial movement under the action of internal excessive pressure due to the ring segments which are installed inside and blades installed which are installed outside. The roots are designed with a possibility of interaction with the hollow bushing of the shaft through ring segments, and the ring segments are designed as longitudinal plates.

EFFECT: reliability and durability of the hole opener.

4 dwg

Description

The invention relates to the field of drilling equipment, and in particular to devices for increasing the diameter of wells in a given interval.

A well-known extender wells (RF patent No. 2445431, IPC ЕВВ 7/28, published in Bull. No. 8 of 03/20/2012), containing a housing with inclined surfaces and a rod placed in it with the formation of a chamber, an annular piston with a pusher, placed in the chamber, paws made with the possibility of interaction with the corresponding inclined surfaces of the body and piston pusher and limited radial movement outward, while the piston pusher is made in the form of a multifaceted prism placed on top of the piston, and the paw is provided with a chamfer on the bottom for the corresponding the prism face of the piston, wherein the housing is equipped with top and bottom stops, capable of interacting respectively with the upper and lower ends of the tines to limitations in their radial movement outwards.

The disadvantage of this extender is the high probability of an emergency when lowering into the well due to insufficient fixation of the paws in the transport position.

The closest in technical essence and the achieved result is a sliding extender calibrator (RF patent No. 2425944, IPC Е21В 7/28, published in Bul. No. 22 of 08/10/2011), containing a centralizer, a housing with a central passage channel and grooves , blades equipped with rock cutting elements and tooth-shaped protrusions, fixed in the grooves of the housing with the possibility of extension, and a mechanism for extending the blades to the working position, containing a hollow shaft with a piston located in the passage channel of the housing, a pusher mounted in the cavity, the inner wall of the body and the outer wall of the hollow shaft, and a sleeve is inserted into the inner cavity of the hollow shaft, while the top of the hollow shaft is threaded for connection with downhole equipment, a side hole and is mounted against rotation from the body, the blades are equipped with shanks interacting with the sleeve the hollow shaft when the blades are extended to the working position, and a device for locking the blades in the idle position, containing radially spring-loaded annular segments interacting with and located in the groove of the shaft, and the groove corresponding to these segments in the inner wall of the housing, the centralizer dies are sliding and installed in additional grooves of the housing, and the shanks of the dies are equipped with dovetail protrusions interacting with mating grooves made on the inclined surfaces of the retainer mounted rigidly on the shaft below the piston and above the sleeve, and the working surface of the dies is made in the form of protruding screw protrusions, which are placed in rows with overlapping each other They are calibrated teeth mounted flush with the helical surface of the corresponding protrusions; moreover, the diameter of the described circle of the dies in the working position is 1-2% smaller than the diameter of the described circle of the blades, in addition, the dies are the same as the blades, and they are located with an offset of the value of half the angle relative to the blades.

The disadvantages of this design of the expander calibrator are:

- the simultaneous insertion of the dies and the lifting of the casing due to hydraulics, since the dies, crashing into the wall of the well, make it difficult to lift the casing, prevent the expander from fully opening into the working position and, as a result, the borehole expands by an amount less than the design one;

- low reliability, since the swivel joints of the dies and the housing have low strength, in addition, in the manufacture of a small diameter extender, this element has a small size and low resistance to stress.

The technical task of the proposed well expander is to create a reliable and durable design by simplifying the design and guaranteed reliable cutting of the dies into the rock to the desired expansion diameter.

The technical problem is solved by a borehole extender containing a centralizer, a housing with a central passage channel and grooves, blades equipped with rock cutting elements and tooth-shaped protrusions, fixed in the grooves of the housing with the possibility of extension, and a mechanism for extending the blades into position, a hollow shaft with upper thread for connection with downhole equipment, a side hole and a lower sleeve, located in the passage channel of the housing with fixation from rotation relative to the housing, the blades being provided with tail HOVIK interacting with the hollow shaft sleeve when extended blades in the operative position, and a device for locking the blades in the inoperative position, comprising a radially spring-loaded ring segments.

What is new is that the shanks are made in the form of radial pistons inserted into the housing with the possibility of limited radial movement under the action of internal overpressure due to the inside of the annular segments and the outside mounted blades, and the shanks are designed to interact with the hollow shaft sleeve through the annular segments, and annular segments are made in the form of longitudinal plates.

In FIG. 1 shows a well reamer in transport position, FIG. 2 is a section AA in FIG. 1, in FIG. 3 is a section BB in FIG. 1, in FIG. 4 is a section BB in FIG. 1 in working position.

The borehole extender (Fig. 1) contains a centralizer 1, a housing 2 with a central passage channel 3 and grooves 4. The central passage channel 3 has a constriction 5, which is necessary to create a differential pressure, the blades 6, equipped with rock cutting elements 7 and protrusions in the form of teeth 8 fixed in the grooves 4 of the housing 2 with the possibility of extension, and the mechanism for extending the blades 6 in the working position, the hollow shaft 9 with the upper thread 10 for connection with the downhole equipment, the side hole 11 and the lower sleeve 12, located in the passage channel 3 to housing 2 with rotation lock relative to the centralizer 1 (Fig. 2) and housing 2, and the blades are equipped with shanks 13 (Figs. 3 and 4), made in the form of radial pistons, interacting with the sleeve 12 (Fig. 1) of the hollow shaft 9 when the extension of the blades 6 in the working position, and a device for locking the blades in the idle position, containing radially spring-loaded annular segments 14, made in the form of longitudinal plates. Fixation from the rotation of the shaft 9 (Fig. 2) relative to the centralizer 1 occurs due to polyhedra (see Fig. 2) inserted into each other with the possibility of longitudinal movement, or longitudinal sampling on the shaft 9 or in the centralizer 1, interacting with the key (on Fig. 2 is not shown) of the centralizer 1 or shaft 9, respectively, or any other technological solution (not shown in Fig. 2).

Technological connections and device elements that do not affect operability are not shown in the drawings.

The expander works as follows.

The expander using a thread 10 is connected to a downhole screw motor (not shown in FIG. 1) and lowered into a well (not shown), while the hollow shaft 9 rests against the ring segments 14 with the lower bushing, thereby fixing the hollow shaft 9 from longitudinal movement relative to the centralizer 1 and the housing 2. The annular segments 14 are spring-loaded, thereby fixing the blades 6 from longitudinal movements in the grooves 4.

Flushing fluid (drilling mud) is supplied at a given depth, as a result of which a downhole screw motor (not shown) starts to rotate the expander. Flushing fluid (drilling fluid) through the central passage channel 3 enters the flushing holes of the bit (not shown). Under the action of the differential pressure of the liquid over the narrowing 5, the annular segments 14 through the shanks 13 bring the blades 6 to the working position. The destructive elements 7 begin to crash into the walls.

Further, by feeding the tool down, the well is expanded in a predetermined interval. In this case, the hollow shaft 9 (Fig. 4) is lowered downward, and the lower sleeve 12 fixes the spring-loaded annular segments 14 from longitudinal movement, thereby keeping the working diameter of the expander constant regardless of changes in fluid pressure.

After completion of the expansion of the well, the injection of flushing fluid is stopped and the expander is raised. In this case, under the influence of its own weight, the centralizer 1 with the housing 2 moves down to the stop, the remaining flushing fluid leaves through the side hole 11, and the lower sleeve 12 releases the spring-loaded ring segments 14. Due to this, the ring segments 14 with shanks 8 and blades 6 are returned to their original position inside the housing 2.

The advantage of the proposed well expander is that due to the reliable fixation of the dies in the transport position, the teeth are protected from chipping during descent into the expansion interval. Fixing the dies in the working position allows you to evenly expand the wellbore regardless of pressure drops and changes in axial loads on the expander. In addition, the absence of vibration protects the teeth from chipping, extending the life of the blades. The proposed design of the expander is reliable and durable due to the simplification of the design of the nodes of the output of the blades in the working position and their fixation in this position.

Claims (1)

A wellbore extender comprising a centralizer, a housing with a central passage channel and grooves, blades provided with rock cutting elements and tooth-shaped protrusions, fixed in grooves of the housing with the possibility of extension, and a mechanism for extending the blades to the working position, a hollow shaft with upper thread for connection with downhole equipment, a side hole and a lower sleeve, located in the passage channel of the housing with fixation from rotation relative to the housing, and the blades are equipped with shanks that interact a hollow shaft sleeve when extending the blades to the working position, and a device for locking the blades in the idle position, containing radially spring-loaded annular segments, characterized in that the shanks are made in the form of radial pistons inserted into the housing with the possibility of limited radial movement under the action of internal overpressure due to mounted on the inside of the annular segments and mounted on the outside of the blades, and the shanks are configured to interact with the hollow sleeve in Ala through the annular segments, and the annular segments are made in the form of longitudinal plates.

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