Guidance method for multilateral directional drilling

Abstract

Guidance methods for guiding the drilling, of wells while reducing trajectory drift. Each drilled well incorporates signalling devices which are used together or in a selected sequence to guide additional well drilling. With the progressive addition of the signalling devices spacing, positioning and connection of wells, particularly multilateral wells, is focused and precise.

We claim: 
     
         1 . A method for drilling in a predetermined configuration within a geologic formation, comprising:
 drilling in said formation a well having an inlet well and an outlet well;   drilling with signalling for communication between said inlet well and said outlet well to form a continuous well having an interconnecting well segment between said inlet well and said outlet well, said interconnecting well segment having a predetermined geometric configuration relative to said inlet well and said outlet well within said formation; and   signalling for communication from at least one of said inlet well, said outlet well and said interconnecting well segment to drill a second interconnecting well segment operatively connected to said continuous well in a predetermined geometric configuration within said formation.   
     
     
         2 . The method as set forth in  claim 1 , wherein said inlet well and said outlet well are co-located. 
     
     
         3 . The method as set forth in  claim 1 , wherein said geologic formation has an irregular and inconsistent thermal gradient. 
     
     
         4 . The method as set forth in  claim 1 , further including the step of drilling a partial well proximate or distal from at least one of said inlet well and said outlet well for signalling for communication with at least one of said inlet well, said outlet well and said interconnecting well segment. 
     
     
         5 . The method as set forth in  claim 1 , further including the step of establishing further signaling for communication from said continuous well and said second interconnecting well segment for guiding the drilling of further interconnecting well segments and continuous wells in operative connection in a predetermined configuration within said formation. 
     
     
         6 . The method as set forth in  claim 1 , wherein signalling for communication comprises transceiving between said wells. 
     
     
         7 . The method as set forth in  claim 1 , wherein signaling for communication is conducted simultaneously between wells. 
     
     
         8 . The method as set forth in  claim 1 , wherein signaling for communication is conducted in a predetermined sequence between wells. 
     
     
         9 . The method as set forth in  claim 1 , wherein said drilling is conducted independently from discrete locations for said inlet well and said outlet well for intersection to form said continuous well with said interconnecting well segment. 
     
     
         10 . The method as set forth in  claim 2 , further including providing superterranean signalling devices, subterranean signalling devices and combinations thereof proximate said discrete locations for guiding drilling. 
     
     
         11 . The method as set forth in  claim 1 , wherein said formation is a thermally productive formation. 
     
     
         12 . The method as set forth in  claim 1 , wherein said formation is a geothermal formation. 
     
     
         13 . The method as set forth in  claim 1 , further in conditioning at least said interconnecting well segment to facilitate thermal recovery by working fluid flow through said continuous well without casing or liner material in said interconnecting well segment. 
     
     
         14 . The method as set forth in  claim 13 , wherein conditioning is effected by at least one of continuously, discontinuously, during, after and in sequenced combinations of drilling of at least one of said inlet wee, said outlet well and said and said interconnecting segment. 
     
     
         15 . The method as set forth in  claim 13 , further including the step of dynamically modifying said conditioning responsive to signalling data from at least one of the operations of said inlet well, said outlet well and said interconnecting well segment. 
     
     
         16 . A method for drilling in a predetermined configuration within a geologic formation, comprising:
 drilling in said formation a well having an inlet well and an outlet well;   drilling a partial well proximate or distal from at least one of said inlet well and said outlet well for signalling for communication with at least one of said inlet well and said outlet well; and   drilling an interconnecting well segment continuously connecting said inlet well and said outlet well with signaling for communication between at least one of said inlet well, said outlet well and said partial well.   
     
     
         17 . The method as set forth in  claim 16 , further including the step of forming a second well having an inlet well and an outlet well from said partial well. 
     
     
         18 . The method as set forth in  claim 16 , wherein said partial well comprises a plurality of individual spaced apart wells. 
     
     
         19 . The method as set forth in  claim 18 , further including signalling between said plurality of individual spaced apart wells to form connected continuous wells. 
     
     
         20 . The method as set forth in  claim 16 , wherein signalling comprises transceiving between wells.