One Trip Metal Seal Tieback Connection to Wellhead with Telescoping Joint

Abstract

A tieback string assembly features a metal to metal nose seal weighted down with casing extending between a lower end of a telescoping joint optionally having metal to metal seals for spacing out to a wellhead casing hanger. The telescoping joint is located so that the hanging weight off the telescoping joint lower end is sufficient to energize the metal to metal nose seal engaged to a sleeve or a liner top packer. The tieback string is smaller in outside diameter than the parent casing through which it is run. The assembly retains high pressure by avoiding lower pressure rated elastomers in the nose seal or the telescoping joint.

1 . A method of connecting a tieback string to a wellhead hanger, comprising:
 providing a metal to metal nose seal on a lower end of a tieback string;   connecting said nose seal to an existing string in the borehole;   locating a telescoping joint in the tieback string in a position where a lower portion of the tieback string connected to a lower portion of the telescoping joint provides weight needed to keep said nose seal activated.   
     
     
         2 . The method of  claim 1 , comprising:
 providing a metal to metal seal in said telescoping joint.   
     
     
         3 . The method of  claim 1 , comprising:
 cementing around said nose seal when said nose seal is connected to the existing string.   
     
     
         4 . The method of  claim 1 , comprising:
 using the telescoping joint to adjust the length of the tieback string for connection to the wellhead.