the inside of the casing 22 the packer 26 also functions to center the tubing 24 in the casing 22 and thereby defines a casing annulus 28 between the tubing and the casing because the foregoing are well known in the art they will not be described in further detail herein in accordance with the present invention the casing 22 is perforated with an explosive device not shown in a conventional manner in the lower zone 16 below the packer 26 so that a plurality of perforations 40 are formed therein for facilitating fluid communication between the lower zone 16 and the interior of the casing 22 below the packer 26 and the tubing 24 in a similar manner the casing 22 is perforated with an explosive device not shown proximal to the upper zone 12 above the packer 26 so that at least one perforation 42 is formed to permit fluid pressure communication between the upper zone 12 and the casing annulus 28 a conventional wellhead 43 is positioned at the top of the wellbore 20 in a manner well known in the art fracturing fluid injection equipment as known to the art such as a reciprocating pump 50 is located on the ground surface and high pressure hoses.