to expand the same and by axially drawing the resilient sleeves 16 and 17 under tension to contract them and insure that they positively disengage the well bore 11 even though there might be deformities in the well bore in which the resilient packer sleeves might otherwise become stuck the upper and lower packing sleeves 16 and 17 are thus expandable radially outward for sealing engagement with well bore 11 to seal off section 22 thereof intermediate the packing sleeves for subsequent supply of fluid under pressure to this sealed off section through ports 19 for fracturing referring additionally to fig1 and 2 flexible fluid conduit 14 is connected at its lower end fig3 and 3a to communicate with the upper end of longitudinally extending bore 13 and the other end of flexible high pressure conduit 14 is connectable at 23 fig1 and 2 to a fluid source under pressure not shown high pressure flexible fluid conduit 14 is coiled on reel 24 for pay off into the well bore 11 through well casing 25 reel 24 is in turn mounted on the bed of truck 26 for mobility flexible conduit 14 is paid off of reel 24 into well bore 11 by passing over pulley 27 to lower packer assembly 10 down the well bore packer assembly 10 is additionally supported by two flexible wire cables 28 which are coiled onto reels 30.