Patent ID: 6085838
Filing Date: 2000-07-11
Classification: E21B

Abstract:
A method of cementing a wellbore comprising providing a casing in a wellbore and drilling a further segment of enlarged wellbore;providing in the enlarged wellbore, through the casing, a liner of smaller external diameter comprising a minor section of further reduced external and internal diameter composed of a deformable liner material, and a remainder segment having an external diameter approximating the internal diameter of the casing, containing a movable fluid tight die member in the bore thereof at a location in the bore distant from the bottom end of said remainder segment, the liner further comprising means for transmitting a fluid to the bore of the remainder segment below the fluid tight die member, through the fluid tight die member, the section of reduced external and internal diameter being positioned in the lower portion of said casing in such manner, and the remainder segment of the liner below the lower portion of the casing in the enlarged wellbore, so that fluid may circulate without substantial impediment in the annuli formed by said liner and the enlarged wellbore and casing;pumping a cement slurry down the casing and through the liner, and into the wellbore annulus in an amount sufficient to cement said wellbore annulus;sealing the bottom of the remainder segment of the liner;transmitting a fluid to and applying sufficient fluid pressure to the bore of the remainder segment of the liner below the fluid tight die member to move the die member up the liner and expand said minor section, and allowing said fluid tight die member to move up the wellbore to provide an external diameter of the minor section equal to or approximating that of the remainder segment of the liner;and removing the fluid tight die member from the expanded minor section and allowing the cement to set.