A drilling auxiliary system

Abstract

The present invention provides a drilling auxiliary system, which is used for down hole EM data transmission and/or casing detection, wherein said drilling auxiliary system comprises an insulating device which is mounted on the drill pipe of a well and used for preventing entire electric current loss or suppressing partial electric current loss. When used for EM data transmission, the present invention can greatly reduce the unnecessary power consumption, thereby improving the efficiency of EM data transmission. When used for casing detection, the present invention can effectively increase the casing detection range.

1 .- 16 . (canceled) 
     
     
         17 . A drilling auxiliary system used for down hole EM data transmission and/or casing detection, wherein said drilling auxiliary system comprises an insulating device which is mounted on a drill pipe of a well and used for preventing entire current loss or suppressing partial current loss. 
     
     
         18 . A drilling auxiliary system according to  claim 17 , wherein said insulating device blocks or suppresses current flowing between the drill pipe and the medium surrounding the drill pipe, or blocks or suppresses current flowing between the drill pipe and the medium inside the drill pipe. 
     
     
         19 . A drilling auxiliary system according to  claim 18 , wherein said medium surrounding the drill pipe comprises formation adjacent to the drill pipe, said medium inside the drill pipe comprises mud inside the drill pipe. 
     
     
         20 . A drilling auxiliary system according to  claim 19 , wherein said insulating device surrounding said drill pipe is embedded into the wall of the drill pipe, or mounted on a position clinging to the drill pipe, or mounted on a position separated from the drill pipe. 
     
     
         21 . A drilling auxiliary system according to  claim 19 , wherein said drill pipe is tubular, and said insulating device comprises an outer insulating device and an inner insulating device, wherein said inner insulating device surrounds the inner wall of said drill pipe, and is embedded into the inner wall of said drill pipe, or mounted on a position clinging to or separated from the inner wall of said drill pipe; and wherein said outer insulating device surrounds the outer wall of said drill pipe, and is embedded into the outer wall of said drill pipe, or mounted on a position clinging to or separated from the outer wall of said drill pipe. 
     
     
         22 . A drilling auxiliary system according to  claim 19 , wherein said insulating device partially or completely covers the transmitting and receiving instruments mounted on the drill pipe. 
     
     
         23 . A drilling auxiliary system according to  claim 19 , wherein said insulating device completely surrounds the enwrapped drill pipe segment with 360 degrees, or partially surrounds the enwrapped drill pipe segment with less than 360 degrees. 
     
     
         24 . A drilling auxiliary system according to  claim 19 , wherein said insulating device is an insulating sheet with particular shape, for blocking the current in a particular position and/or azimuth. 
     
     
         25 . A drilling auxiliary system according to  claim 24 , wherein the shape of said insulating sheet is square, ellipse or any other shape. 
     
     
         26 . A drilling auxiliary system according to  claim 23 , wherein there are one or more gaps on said insulating device, and said one or more gaps allow the electric current to pass. 
     
     
         27 . A drilling auxiliary system according to  claim 24 , wherein there are one or more gaps on said insulating device, and said one or more gaps allow the electric current to pass. 
     
     
         28 . A drilling auxiliary system according to  claim 26 , wherein said gaps on said insulating device may be any shape. 
     
     
         29 . A drilling auxiliary system according to  claim 26 , wherein said gaps on said insulating device may locate at any position on said insulating device. 
     
     
         30 . A drilling auxiliary system according to  claim 26 , wherein said gaps on said insulating device is used for controlling the direction and/or the position of electric current flowing in or out. 
     
     
         31 . A drilling auxiliary system according to  claim 23 , wherein said insulating device enwraps or partially enwraps the insulating ring on the drill pipe and the partial or whole drill pipe segments which extend from the insulating ring in both directions. 
     
     
         32 . A drilling auxiliary system according to  claim 23 , wherein said insulating device enwraps or partially enwraps the insulating ring and the partial or whole drill pipe segment which extends from the insulating ring in one direction. 
     
     
         33 . A drilling auxiliary system according to  claim 23 , wherein said insulating device enwraps the partial or whole drill pipe segment which extends from the insulating ring in one direction.