Method for Making Wellbore that Maintains a Minimum Drift

Abstract

A well having a minimum drift between or among strings is provided using strings that have a recessed segment and a hanging segment. The length of the recessed segment in the lower end of the upper string is substantially longer than the hanging segment of the lower string that is passed through it. The hanging segments define the drift dimension. In the event the lower string gets stuck in the open hole before it is fully advanced, the hanging segment of the lower string may still be in the recess of the upper string so that the drift dimension can be preserved. Preferably the recess segment is the substantial length of the tubular string apart from its hanging segment near its top end. One or more laterals can be extended through the recessed segments while retaining the drift dimension.

1 . A method of creating a well while maintaining a minimum drift between or among when connected successive tubular strings, comprising:
 providing at least one upper tubular string for support in a wellbore;   configuring said upper tubular string to have a hanging segment adjacent an upper end thereof whose internal dimension defines the drift dimension and an adjacent recess segment having a larger dimension than said internal dimension that defines said drift dimension;   positioning at least one lower tubular string through said internal dimension and overlapping said recess segment of said upper tubular string;   providing at least one of a sealing and a hanging device extending on said lower string down a predetermined distance from a top of said lower tubular string;   configuring the height of said recess dimension of said upper string to be substantially longer than said predetermined distance;   expanding said one of a sealing and hanging device of said lower tubular string into said recess segment so that the internal diameter of said predetermined distance is at least as large as said drift dimension.   
   
   
       2 . The method of  claim 1 , comprising:
 configuring the height of said recess dimension of said upper string to be long enough to accommodate at least one window that allows said lower tubular string to exit through said recess segment of said upper tubular string.   
   
   
       3 . The method of  claim 2 , comprising:
 creating a lateral by extending a portion of said lower tubular string through said window where the internal dimension of said window is at least as large as said drift dimension.   
   
   
       4 . The method of  claim 1 , comprising:
 making the recess segment of said upper tubular string extend the balance of the overall length of said upper tubular string beyond said hanging segment.   
   
   
       5 . The method of  claim 1 , comprising:
 extending the wellbore beyond said upper tubular string a sufficient depth to allow the top of said lower tubular string to reach a lower end within the recess segment of said upper tubular string;   being unable to fully advance said top of said lower tubular string to said lower end of said recess segment of said upper tubular string;   securing said at least one of a hanging and a sealing device on said lower tubular string to said recessed segment of said upper tubular string at whatever location said lower tubular string ceases to advance.   
   
   
       6 . The method of  claim 3 , comprising:
 creating at least one lateral drift dimension by adding at least one liner string to said lateral beyond said window.   
   
   
       7 . The method of  claim 1 , comprising:
 expanding another portion of said second tubular string to a larger dimension than said internal dimension that defines said drift to create a second tubular string recess segment.   
   
   
       8 . The method of  claim 7 , comprising:
 configuring said recess segment on said lower tubular string at least as long as said recess segment on said upper tubular string.   
   
   
       9 . The method of  claim 7 , comprising:
 creating a main bore with at least said upper and lower tubular strings that retains said drift dimension.   
   
   
       10 . The method of  claim 9 , comprising:
 providing at least one lateral from said main bore through at least one of said recess segments using another string.   
   
   
       11 . The method of  claim 1 , comprising:
 sealing an annular space around at least one of said upper and lower tubular strings with a sealing material.   
   
   
       12 . The method of  claim 1 , comprising:
 sealing an annular space around at least one of said upper and lower tubular strings with an open hole packer.   
   
   
       13 . The method of  claim 12 , comprising:
 using a swelling sealing element in said open hole packer.   
   
   
       14 . The method of  claim 11 , comprising:
 sealing an annular space around at least one of said upper and lower tubular strings with an open hole packer.