Device for cutting a vertical slot-like unloading opening

Abstract

A device is provided for creating vertical slot-like unloading openings approximate to a well, comprising: a casing pipe enclosed into the well, a generator of abrasive hydro-jets, a column for delivering the hydro-jets, a hydraulic brake, a perforator descended into the casing pipe including a pair of nozzles for creating the hydro-jets, a pair of centralisers mounted on the perforator, and a pair of cutting rotating discs, mounted under the pair of nozzles on racks, partially springly retractable and projectable depending on hydro-jet pressure. Additional embodiments include: designing turnable racks, mounting the centralisers on similar projectable and retractable racks, installing an additional pair of centralisers, selecting their installation places, setting predetermined ranges of the racks projection and retraction in static and perforation modes. The innovations allow for accelerated cutting of the casing pipe, improving accuracy of the openings, and increasing durability and reliability of the device.

1 . A device for creating a vertical slot-like unloading opening in a zone approximate to a well, said device comprising:
 a casing pipe enclosed into the well;   a generator of abrasive hydro-jet mounted in proximity to the well on the ground surface, said generator capable to develop a predetermined pressure of the hydro-jet;   a column of pump-compressor pipes for conducting the hydro-jet, said column enclosed into the casing pipe, the upper end of said column connected to the generator;   a hydraulic brake having a first end and a second end, with the first end substantially connected to the lower end of said column;   a perforator capable to be descended into the casing pipe while being controlled by the hydraulic brake, said perforator connected to the second end of said hydraulic brake, said perforator having at least a body and an interior cavity therein, said perforator including
 at least one pair of nozzles for creation of abrasive hydro-jets, said nozzles diametrically mounted on said perforator body, the nozzles oriented at directions towards the well wall, 
 at least one pair of centralisers mounted on said perforator body, and 
 at least one pair of cutting rotating discs, partially springly retracted into the perforator body and capable of being automatically projected into the casing pipe depending on said pressure of the hydro-jet, said pair of cutting discs being mounted under the pair of nozzles, 
 wherein the planes of said cutting discs oriented vertically and perpendicularly to the well wall corresponding to the directions of said nozzles. 
   
   
   
       2 . The device according to  1 , wherein
 said device capable of operation   in a static mode particularly characterized in that the cutting edge of said discs being moved out of the perforator body for a distance not exceeding the difference between the inner radius of the casing pipe and the outer radius of the perforator, and   in a casing pipe perforation mode particularly characterized in that the cutting edge of said discs being moved out of the perforator body for a distance equal to at least the difference between the inner radius of the casing pipe and the outer radius of the perforator plus an additional distance within the range of from 3 mm to 5 mm.   
   
   
       3 . The device according to  claim 1 , further including:
 at least one pair of expulsive hydraulic channels connected to said interior cavity and capable to conduct the hydro-jet creating a predetermined expulsive force therein;   at least one pair of pull-in springs, each said spring having a first spring end connected to the perforator body, and a second spring end;   at least one pair of movable racks, said racks each connected to the second spring end of each said spring and being attracted with a predetermined traction force tending to retract the racks,   said racks connected to said hydraulic channels and being repelled with the expulsive force tending to eject the racks;   the cutting discs being fixedly mounted on said racks; and   the expulsive force being greater than the traction force during operation of the perforator.   
   
   
       4 . The device according to  3 , wherein
 said device capable of operation   in a static mode characterized in that the cutting edge of said discs being moved out of the perforator body for a distance not exceeding the difference between the inner radius of the casing pipe and the outer radius of the perforator, and   in a casing pipe perforation mode characterized in that the cutting edge of said discs being moved out of the perforator body for a distance equal to at least the difference between the inner radius of the casing pipe and the outer radius of the perforator plus an additional distance within the range of from 3 mm to 5 mm.   
   
   
       5 . The device according to  claim 3 , wherein said racks being turnable. 
   
   
       6 . The device according to  claim 5 , wherein
 said device capable of operation   in a static mode characterized in that the cutting edge of said discs being moved out of the perforator body for a distance not exceeding the difference between the inner radius of the casing pipe and the outer radius of the perforator, and   in a casing pipe perforation mode characterized in that the cutting edge of said discs being moved out of the perforator body for a distance equal to at least the difference between the inner radius of the casing pipe and the outer radius of the perforator plus an additional distance within the range of from 3 mm to 5 mm.   
   
   
       7 . The device according to  claim 1 , wherein
 the pair of said centralisers disposed substantially at the level of location of the pair of said nozzles and the axis connecting the centralisers being perpendicular to the axis connecting the nozzles.   
   
   
       8 . The device according to  claim 1 , wherein
 the pair of said centralisers disposed at the level within the range of from 3 cm to 5 cm above the level of location of the pair of said nozzles, and the axis connecting these centralisers being perpendicular to the axis connecting the nozzles.   
   
   
       9 . The device according to  claim 1 , wherein
 at least one additional pair of centralisers disposed beneath said nozzles in parallel to said pair of centralisers.   
   
   
       10 . The device according to  claim 9 , wherein
 the centralisers of said pair of centralisers and of said additional pair of centralisers being mounted on additional racks;   said additional racks connected by means of additional pull-in springs to the perforator body;   said additional pull-in springs capable to develop a predetermined additional traction force applied to the additional racks;   said additional racks connected to additional expulsive hydraulic channels communicating with said interior space;   said additional expulsive hydraulic channels capable to develop a predetermined additional expulsive force; and   the additional expulsive force being greater than the additional traction force.   
   
   
       11 . The device according to  claim 3 , wherein
 at least one additional pair of centralisers disposed beneath said nozzles in parallel to said pair of centralisers.   
   
   
       12 . The device according to  claim 11  wherein
 the centralisers of said pair of centralisers and of said additional pair of centralisers being mounted on additional racks;   said additional racks connected by means of additional pull-in springs to the perforator body;   said additional pull-in springs capable to develop a predetermined additional traction force applied to the additional racks;   said additional racks connected to additional expulsive hydraulic channels communicating with said interior space;   said additional expulsive hydraulic channels capable to develop a predetermined additional expulsive force; and   the additional expulsive force being greater than the additional traction force.   
   
   
       13 . The device according to  claim 1 , further comprising
 at least one pair of expulsive hydraulic channels connected to said interior cavity and capable to conduct the hydro-jet creating a predetermined expulsive force therein;   at least one pair of pull-in springs, each said spring having a first spring end connected to the perforator body, and a second spring end;   at least one pair of movable racks, said racks each connected to the second spring end of each said spring and being attracted with a predetermined traction force tending to retract the racks,   said racks connected to said hydraulic channels and being repelled with the expulsive force tending to eject the racks;   said centralisers being fixedly mounted on said racks; and   the expulsive force being greater than the traction force during operation of the perforator.   
   
   
       14 . The device according to  claim 10 , wherein
 said additional racks being turnable.   
   
   
       15 . The device according to  claim 12 , wherein
 said additional racks being turnable.   
   
   
       16 . The device according to  claim 13 , wherein
 said racks being turnable.   
   
   
       17 . The device according to  claim 1 , wherein the strength of the material of the cutting edges of said cutting discs being greater than that of the material of said casing pipe.