this juncture without such feature the ultimate goal of a wider cross section for production fluids cannot be achieved because of the requirement for removal of fluids from the borehole annulus sufficient cement slurry is employed to fill the annulus 32 the invention now provides for expansion of section 12 to provide for a larger diameter cross section corresponding to that of section 13 as shown in fig6 sealing means 17 schematically shown at the bottom of liner section 13 is sealed to the ingress and egress of fluid in the normal case a wiper plug which is solid is sent downhole after sufficient cement slurry has been sent into annulus 32 to seal with the differential fillup collar the bottom of liner to egress of fluid as mentioned the technique of the aforementioned ser no 08 805 782 is preferred fluid pressure is then applied to the bore of the liner segment 13 by pumping a fluid through the pipe 25 into the bore of liner 13 any suitable wellbore fluid or liquid available may be used e g a displacement fluid a completion fluid water or sea water the fluid is pumped at sufficient pressure e g 3000 psig through pipe 25 to provide upward movement of die member 28 if the member is freed for movement to this end the position of the die assembly including die member 28 is adjusted or allowed to adjust upward by gradual upward movement of the running string 1 adjustment of the drillstring length is made at a rate sufficient to move the die member upward or allow upward movement thereof caused by the pressure on the die at a controlled rate in response to such continued sufficient application of fluid pressure.