SU1726729A1 - Pipe-cutting mill - Google Patents

Abstract

FIELD OF THE INVENTION The invention relates to the mining industry, namely, devices for eliminating breakdowns in wells. The purpose of the invention is to increase the cutting efficiency of thick-walled pipes. The pipe cutter includes a housing 1 with an axial hole and longitudinal windows of tool holders (RD) 7 installed in longitudinal windows with cutting tools of the milling type and located on the housing 1 in the lower part of its windows and limiters 10 extending out of the cutters 8 in the washing hole b under the taxiway 7 there is a ball valve. 4.

Description

the rear surfaces of the taxiway 7 are made of longitudinal grooves m, which in the initial position of the taxiway 7 form an axial pressure channel. Installed RD 7 in the longitudinal windows tightly and with the ability to interact with each other, the rear surfaces. To simplify the construction, the body is made of composite and has an upper cylindrical part and a lower conical guide 3 with a saddle under

non-return valve 4 and limiter 5 for cutters 8; Extension of cutters 8 to the working position is achieved by creating a pressure drop in the axial channel of housing 1. Thanks to these design features, the pipe cutter works efficiently even with low flow rate of flushing fluid 7 significant torque. 3 il.

The invention relates to the mining industry, more specifically to the construction and repair of mine workings, referred to as wells, in particular to the elimination of accidents that occur during the construction, operation and repair of wells by cutting and then removing emergency drilling, pump-compressor and casing from wells.

A wellbore cutter-cutter is known that includes a housing with flushing channels and grooves for accommodating hinged tool holders and a piston with a chopper mounted movably in the housing cavity for interacting with the tool holder, a rod with a conical tip at the bottom of the housing for improved fixation of the tools at the end of cutting . The drawback of the downhole pipe cutter-milling cutter is the unreliability of the attachment of the tool holders, since the piston and choke to which the tool holders are attached have the possibility of rotational deviations around the longitudinal axis, and the contact area of the tool holders with the groove walls is insufficient for reliable fixation of the tool holders in tangential directions. .

The disadvantages include the complexity of the design and the complexity of its manufacture,

A device for cutting a section of a pipe string in a borehole is known, comprising a split housing, cutters hinged in the grooves of the lower part of the body and a spring-loaded piston with a pusher rod installed in the housing cavity and for flushing without opening the cutters for sticking. the upper and lower parts of the housing are telescopically connected with the possibility of axial movement and the formation of passages for the circulation of fluid.

A disadvantage of the known device is the unreliability of the attachment of the tool holders, since the piston and the rod, to which

the incisors have the possibility of rotational deviations around the longitudinal axis, and the contact area of the tool holders with the walls of the housing grooves is insufficient for

reliable fixation of tool holders at the end of cutting. The disadvantages also include the complexity of the design and the complexity of its manufacture.

Closest to the present invention is a device for cutting pipes in a well, comprising a housing with a cutting part protruding above the body of each of them, equal to a predetermined depth of cut, and internal bevels that act as a signal

node, notifying the end of the cutting increase in fluid flow, in the body there are two rows of radial channels, the lower of which is blocked in the off position by levers. and the top

has a message through the holes in the levers-reaber, and the end of the body is plugged.

A disadvantage of the known device for cutting pipes in the well is a high flow rate of flushing fluid, unreliable fastening of the reamer levers, since as the reamer levers open during cutting, their contact with the walls of the longitudinal grooves decreases and the axial load cannot be cut.

pipes due to the low height of the cutting part of the reamer levers, since in the transport position the reamer levers should not protrude beyond the dimensions of the device body. The purpose of the invention is to increase the cutting efficiency of thick-walled pipes and expand the range of use of a pipe cutter-mill.

The goal is achieved by the fact that in a pipe cutter mill, comprising a housing with

axial bore and longitudinal windows hinged in the longitudinal windows of the tool holders with milling cutters located on the body in the lower part of its windows

cutters, according to the invention, it is provided located in the axial bore hardened

Under the tool holders, ball valve, longitudinal grooves are made on the back surfaces of the tool holders, and the tool holders are sealed in the housing with the ability to interact with each other in the initial position with their rear surfaces and to align their longitudinal grooves to form an axial pressure channel.

FIG. 1 shows a pipe cutter, cutter, section, general view; in fig. 2 shows section A-A in FIG. one; in fig. 3 shows a section BB in FIG. one.

A pipe cutter milling cutter comprising a housing 1 with an axial bore and longitudinal windows a, tool holders 7 with cutters 8 of a milling type hinged in the longitudinal windows, positioning holders 10 cutters on the housing in the lower part of its windows. A ball valve 4 is installed under the tool holders in the axial bore of the housing, longitudinal grooves are made on the rear surfaces of the tool holders 7, and the tool holders are installed in the housing on the axes 11 tightly with the ability to interact with each other in the initial position with their rear surfaces due to spring 12 torsions mounted on axles 11. In this case, the longitudinal grooves of the tool holders are aligned to form a pressure channel.

Truborez-frezer works as follows.

On a pipe hanger, consisting of drill pipes or tubing pipes of a larger diameter, connected by a sub from smaller diameter tubing (shank) to which the pipe cutter is attached, it is lowered into the well and, together with the shank, is in emergency (stuck) pipes to be cut. In doing so, the torsion springs 12 fix the tool holders 7 in the closed position, preventing them from opening. During the pipe cutter-milling cutter runoff, the fluid in the well (drilling mud), through the flushing holes b, the reverse ball valve 4, the flushing channel formed by the semi-cylindrical channels 2 of the tool holders 7, through the slots between the walls of the radial flushing channels in and the tool holders 7 and the flushing channel of the pipe cutter-milling cutter enters the tube space. This prevents the extrusion of fluid from the well, which guarantees against possible oil and gas production.

After creating a circulation flushing unit with a certain flow rate in the pipe cutter-mill,

The closing of the check ball valve 4 also creates a pressure differential, under the effect of which a force is created on the tool holders 7, which push the tool holders 7 with the cutters 8 to the inside surface of the pipe being cut.

The presence of tool holders 7, which overlap the radial channels in all positions, makes it possible to perform cutting with a small amount of washing liquid. This allows the use of low-capacity flushing units, and units with significant wear.

5 When the tube is rotated, the emergency pipes are cut by the rotor of the lifting (drilling) unit. In this case, the tool holders 7 are held by the axle 11 and the walls of the longitudinal grooves 6. which together

0 makes it reliable to fix the tool holders, and the large height of the cutting overlay ensures the cutting of thick-walled pipes. Significant pressure drops will not only be generated when passing

5 fluids through flushing radial channels in, but in the annular space between the body of the pipe cutter-router with the shank and the pipe being cut.

The end of the cutting will be seen by the pressure drop on the pressure gauge of the flushing unit, since the outlet of the flushing channels into the liquid will be able to circulate not only through the annular space, but also through the cut holes at the cutting site and annular space.

The end of the cutting will also be seen by the pressure drop in the hydraulic system of the rotor of the lifting (drilling) unit, indicating a decrease in torque (cutting torque).

The pipe cutter-milling cutter can be used both independently and in assembling (complete set) with bark of known constructions.

5Thus, the use of the proposed invention makes it possible to cut the emergency pipes with a low flow rate of flushing fluid, ensures reliable attachment of the cutters to

0 throughout the cutting, provides cutting of thick-walled pipes, which generally improves the efficiency of repair work. . .

When using the proposed well cutter pipe cutter, the labor intensity during the recovery of the emergency pipes is reduced, emergency operations are made cheaper by reducing the time the well is under repair and, therefore, receive additional gas production.

Claims (1)

Formula of an Invention Truborez-mill, comprising a housing with an axial bore and longitudinal windows, tool holders with milling cutters mounted in longitudinal windows, located on the housing in the lower part of its windows cutters extension, characterized in that, in order to improve cutting efficiency thick-walled pipes, it is equipped with located 0 in the axial bore of the housing under the tool holders by a ball valve, longitudinal grooves are made on the rear surfaces of the tool holders, and the tool holders are tightly installed in the body with the ability to interact with each other in the initial position with their rear surfaces and to form an axial pressure channel.