RU2719880C1 - Expander for simultaneous drilling and expansion on casing string - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to drilling equipment of oil and gas industry, in particular to devices for increasing diameter of well in given interval. Expander for simultaneous drilling and expansion on a casing string consists of a body with through slots, in which on axes there are blades reinforced with hard alloy, spring-loaded piston with central rod and expanding cone at end interacting with blades made with ledge and installed with possibility of its contact with expander cone surface. Housing is made integral with coupling lower thread and is equipped with flushing holes, in which nozzles are installed, aimed at hard-alloy blade cutters in working position. Piston is made integral with expanding cone and is installed so that it under pressure drops moves downwards relative to housing. On external surface of piston there is a locking ring interacting with internal groove of housing in working position. Blades have cutting profile allowing uniform distribution of load on cutters, and in upper inner part are equipped with shanks, which interact with upper end surface of expanding cone and retaining blades in transport position.

EFFECT: ensuring reliability and durability of the structure.

1 cl, 3 dwg

Description

The invention relates to drilling equipment in the oil and gas industry, in particular to devices for increasing the diameter of a well in a given interval.

A well-known extender wells (patent RU No. 64255, IPC ЕВВ 7/20, publ. 06/27/2007, bull. No. 23), comprising a hollow body with an internal protrusion and radial holes in which retractable cutting elements with carbide teeth are mounted on the cutting surface and with shanks, an annular piston placed in the cavity of the housing with rotation-free locking with a latch that interacts in the working position with the shanks, side hole, upper and lower stops on the outer surface and means for connecting to the drill string, cylinder, soy internal with the housing and forming with the annular piston a hydraulic chamber communicated by its side hole with the cavity of the housing, and a device for locking the cutting elements in the idle position, containing an additional annular piston located below the side openings of the piston in the hydraulic chamber of the expander, radially spring-loaded annular segments located in the outer grooves of the annular piston and the recesses corresponding to these segments - in the cylinder, and between the additional piston and the annular segments of the device with axes of cutting elements, a pusher is installed to withdraw said segments from engagement with the expander body. Moreover, the cutting elements are spring-loaded inwardly and connected to the housing articulated, with the possibility of their rotation in a plane passing through the longitudinal geometric axes of the housing and cutting elements, and the latch is made hollow with a conical surface below, configured to interact with the shanks, and rigidly connected to the annular piston while the inner cavity of the annular piston or retainer below the side hole is made tapering.

The disadvantages of this extender are:

- the inability to work with the bit while drilling and expanding the well, since there is no supply of flushing fluid to the bit;

- insufficient output of the cutting elements to expand under the casing, due to the design of the expander;

- the fragility of the tool associated with an unreliable and multi-element design of the stopper assembly, which is difficult to manufacture, assemble and leads to its sludge;

- the absence of directed washing on the working part of the blades leads to overheating of the cutting elements and their catastrophic wear.

The closest in technical essence and the achieved result is an expander (patent RU No. 2612166, IPC ЕВВ 7/28, published 02.03.2017, bull. No. 8), consisting of a housing with through grooves in which the blades are located on the axes, reinforced with a hard alloy of a spring-loaded piston with a central rod and an expanding cone at the end that interacts with the blades, characterized in that it is additionally equipped with a casing with longitudinal windows made symmetrically through the grooves of the housing, and connected with a thread, the conical surface is provided with and an annular protrusion facing the annular groove in the body of the housing, and longitudinal grooves on the conical surface made symmetrically to the longitudinal windows of the casing, the position of the conical surface being fixed by a stopper associated with the central rod, and the blades are made with a protrusion and are installed with the possibility of face contact with conical surface in the longitudinal grooves and the casing in the extreme position of the blades.

The disadvantages of this design of the expander are:

- the impossibility of simultaneously drilling with expansion, since the casing is not designed to transmit torque when drilling with a chisel;

- the absence of the blade lock in the transport position can lead to premature opening and jamming of the blades during tripping during the building process, which will lead to jamming of the device and create an emergency;

- the absence of the blade retainer in the working position may lead to the inability to obtain an expanded barrel of the required diameter due to pulsations of the pump, as a result, the blades may oscillate;

- the fragility of the rock-cutting elements associated with their overheating due to the lack of supply of flushing fluid directly to the zone of the rock-breaking elements during rock destruction;

- non-optimal form of the working part of the blades, as a result, high torque during expansion, wear of rock-cutting elements.

The technical task of the proposed device is to create a reliable and durable design of the reamer for simultaneous drilling and expansion on the casing by using a design that allows you to transmit torque from the bit, fixing the blades in the transport and working positions, as well as ensuring the supply of flushing fluid directly to the area of rock cutting elements during the destruction of the rock, allowing to ensure the wellbore of strictly necessary diameter while drilling and expanded and the casing.

The technical problem is solved by an expander for simultaneous drilling and expansion on the casing string, consisting of a body with through grooves in which the blades reinforced with hard alloy are placed on the axes, a spring-loaded piston with a central rod and an expanding cone at the end, which interacts with the blades made with protrusion and installed with the possibility of its contact with the surface of the expanding cone.

What is new is that the housing is made integral with the sleeve lower thread and is equipped with flushing holes in which nozzles are mounted directed to the carbide blades of the blades in the working position, the piston is integral with the expanding cone and mounted so that under the action of the differential pressure it moves down relative to the housing , on the outer surface of the piston a snap ring is installed, interacting with the internal groove of the housing in the working position, the blades have a cutting profile that evenly distributes the load on cutters, and in the upper inner part are equipped with shanks interacting with the upper end surface of the expanding cone and holding the blades in the transport position.

In FIG. 1 shows an expander in a transport position, a longitudinal section;

in FIG. 2 - in working position, longitudinal section;

in FIG. 3 is an example of the use of an expander.

The extender for simultaneous drilling and expansion on the casing string comprises a housing 1 (Fig. 1) with through grooves 2 in which the blades 4 are located on the axles 3. The outer surfaces of the blades 4 are reinforced with carbide cutters 5. A piston 7 spring-loaded with a spring 6 is located inside the housing 1 with a central rod 8 and an expanding cone 9, which interacts with the protrusion 10 (Fig. 2) of the blades 4.

The housing 1 is made integral with the sleeve lower thread 11 and is equipped with flushing holes 12, in which nozzles 13 are mounted, directed to carbide cutters 5 of the blades 4 in the working position. The piston 7 is made integral with the expanding cone 9 and is mounted so that under the influence of a differential pressure it moves downward relative to the housing 1. On the outer surface of the piston 1 a snap ring 14 is installed, which interacts with the internal groove 15 of the housing 1 in the working position. The blades 4 have a cutting profile 16 that allows you to evenly distribute the load on the cutters 5. The blades 4 (Fig. 1) in the upper inner part are equipped with shanks 17, interacting with the upper end surface 18 of the expanding cone 9 and holding the blades 4 in the transport position.

Expander for simultaneous drilling and expansion on the casing operates as follows.

The assembly is assembled - a chisel 19 (Fig. 3), an expander, a downhole screw motor 20, then a connecting tool assembly 21 of a drilling tool (for example, Pat. RU No. 2663856, IPC ЕВВ 7/20, Е21В 7/28, publ. 10.08.2018 ., Bull. No. 22), which in turn is already connected to the casing 22. In this sequence, the layout is lowered into the well for simultaneous drilling and expansion.

Due to the fact that the blades 4 in the upper inner part are equipped with shanks 17 interacting with the upper end surface 18 of the expanding cone 9 of the piston 7, which is spring loaded 6 upward relative to the housing 1, the blades 4 are held in transport position during the descent of the assembly. Thus, the blades 4 during the descent are in a recessed position in the grooves of the housing 1 and do not interfere with the descent of the layout.

Then the pump is turned on (not shown in FIG.), Flushing fluid is pumped through the casing 22 (FIG. 3). The layout at this time is on weight. In the process of pumping the flushing fluid through the nozzles of the bit 23, a differential pressure is created. At this time, the downhole motor 20 begins to rotate, the piston 7 compresses the spring 6 and the expanding cone 9 of the piston 7, bumping over the protrusions 10 of the blades 4 brings them to the working position. In this case, carbide cutters 5 cut into the walls of the well 24. After the blades 4 have fully reached their working position, they begin to create an axial load on the bit 19, while the drilling process begins (diameter D), and the expander increases the diameter of the well (diameter D1) . Flushing fluid, passing through the holes 12 (Fig. 2) and nozzles 13, falls on the working surface of carbide cutters 5, cooling and cleaning them. The circlip 14, located on the piston 7 in the working position, is fixed in the groove 15 located on the inner surface of the housing 1 and fixes the piston 7 in this position, preventing the piston 7 from moving from the pulsation of the pump (not shown in Fig.). In this case, the blades 4 are rigidly fixed in the working position, which makes it possible to obtain the optimum well diameter after expansion, which allows the casing 22 to be freely let loose.

After completing simultaneous drilling and expanding the specified interval, the mud pump is turned off, under the action of the spring 6, the piston 7 returns to its original transport position, and the upper end surface of the expanding cone 9 of the piston 7 engages in the shanks 17 of the blades 4 and returns the blades 4 to the grooves 2 of the housing 1.

Then the tool is lowered on the drill pipe string, the equipment is disconnected and removed at the wellhead, and the casing is cemented by any known method.

Due to the fact that the blades have a cutting profile that allows you to evenly distribute the load on the cutters, vibrations are significantly reduced at complex intervals and shock loads are reduced, which increases their durability. In addition, a wellbore is provided after expansion without ledges and curvatures.

The proposed design of the expander for simultaneous drilling and expansion on the casing is a reliable and durable design due to the use of a design that allows you to transmit torque to the bit, fixing the blades in the transport and working positions, as well as ensuring the supply of flushing fluid directly to the area of rock cutting elements during rock destruction , allowing to provide a wellbore of strictly necessary diameter while drilling and expanding on the casing.

Claims (1)

Expander for simultaneous drilling and expansion on the casing string, consisting of a body with through grooves, in which the blades reinforced with hard alloy are placed on the axes, a spring-loaded piston with a central rod and an expanding cone at the end, which interacts with the blades made with a protrusion and installed with the possibility of its contact with the surface of the expanding cone, characterized in that the housing is made integral with the sleeve lower thread and is equipped with flushing holes in which the nozzles are installed, for example aligned with the carbide blades of the blades in the working position, the piston is integral with the expanding cone and installed so that under the influence of the pressure differential it moves downward relative to the housing, a snap ring is installed on the outer surface of the piston interacting with the internal groove of the housing in the working position, the blades have a cutting profile , evenly distributing the load on the cutters, and in the upper inner part are equipped with shanks that interact with the upper end surface of the expanding cone and hold their blades in the transport position.

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