Hydraulic fracturing device and process

Abstract

The present invention relates especially to a hydraulic fracturing device which comprises:—a tubular conduit ( 1 );—and, against its external face, a cylindrical sleeve ( 2 ) whereof the opposite ends ( 20 ) are connected together and hermetically to this external face;—the wall of said tubular conduit ( 1 ) comprising at least one opening ( 10 ) to have it communicate with the interior of the sleeve ( 2 ). This device is remarkable in that said sleeve ( 2 ) comprises at least one mechanical weakening zone ( 21 ) which is peripheral, sinuous and with closed contour, that is, its opposite ends rejoin, this mechanical weakening zone being capable of breaking under the effect of predetermined pressure ( 10 ) known as “burst pressure” applied to the interior of the latter to form in its wall a sinuous opening ( 3 ).

1 . A hydraulic fracturing device which comprises:
 a tubular conduit;   and, against its external face, a cylindrical sleeve whereof the opposite ends are connected fixedly and hermetically to this external face;   the wall of said tubular conduit comprising at least one opening to have it communicate with the interior of the sleeve,   wherein said sleeve comprises at least one mechanical weakening zone which is peripheral, sinuous and with a closed contour, that is, its opposite ends rejoin, this mechanical weakening zone being capable of breaking under the effect of predetermined pressure known as “burst pressure” applied inside the latter to form in its wall a sinuous opening.   
     
     
         2 . The device as claimed in  claim 1 , wherein said mechanical weakening zone comprises a region of the wall of reduced thickness. 
     
     
         3 . The device as claimed in any one of  claims 1  or  2 , wherein said weakening zone comprises at least one groove formed in the external wall of said sleeve. 
     
     
         4 . The device as claimed in  claim 1 , wherein said winding comprises first portions of lines which extend generally parallel to the generatrices of the sleeve which alternate with second portions generally perpendicular to the first portions, the extent of the first portions being greater than that of the second portions. 
     
     
         5 . A process for hydraulic fracturing of the rock of a well, wherein it comprises the following steps:
 placing in said well a device as claimed in any one of the preceding claims;   creating an annular seal between said conduit and the wall of said well, on either side of said metallic sleeve;   injection inside said sleeve, via said conduit, of fracturing fluid under fracturing pressure such that it is capable of breaking the wall of the sleeve before the latter comes into contact with the wall of the well.