Drilling System with a Barrel Drilling Head Driven by a Downhole Tractor

Abstract

A drilling system for drilling out a sample of a formation, a well, or the like downhole. The drilling system has a drilling head having an at least partly hollow cylindrical body with a circumferential rim. The circumferential rim has at least one cutting edge. Furthermore, the drilling system has a driving unit for rotating the cylindrical body and the cutting edge for cutting a piece out of the formation, and a driving tool such as a downhole tractor for driving the drilling head forward in the well or formation.

1 . Drilling system for drilling out a sample of a formation, a well, or the like downhole, comprising:
 a barrel drilling head comprising:   an at least partly hollow cylindrical body with a circumferential rim, the circumferential rim having at least one cutting edge,   a driving unit for rotating the cylindrical body and the cutting edge for cutting a piece out of the formation, and   a driving tool such as a downhole tractor for driving the barrel drilling head forward in the well or formation.   
   
   
       2 . The drilling system according to  claim 1 , wherein the downhole tractor is connected to and powered through a wireline. 
   
   
       3 . The drilling system according to  claim 1 , further comprising at least one tightening means for providing a closing of the well above the drilling head for preventing a blowout. 
   
   
       4 . The drilling system according to  claim 3 , wherein the tightening means is expandable. 
   
   
       5 . The drilling system according to  claim 1 , wherein the cylindrical body has a closed end opposite the cutting edge. 
   
   
       6 . The drilling system according to  claim 1 , wherein the circumferential rim has a plurality of cutting edges. 
   
   
       7 . The drilling system according to  claim 1 , wherein the circumferential wall has at least one slot. 
   
   
       8 . The drilling system according to  claim 1 , wherein the hollow body has a length of up to 10 metres. 
   
   
       9 . The drilling system according to  claim 1 , further comprising a gas cartridge or a pump for inflation of the tightening means with gas or fluid from the well. 
   
   
       10 . Use of a downhole tractor for driving a barrel drilling head forward in the well or formation, wherein the barrel drilling head comprises:
 an at least partly hollow cylindrical body with a circumferential rim, the circumferential rim having at least one cutting edge, and wherein the barrel drilling head is rotated by a driving unit for cutting a piece out of the formation.   
   
   
       11 . The use according to  claim 10 , wherein the downhole tractor is connected to and powered through a wireline. 
   
   
       12 . The use according to  claim 11 , wherein at least one tightening means is providing above the drilling head around the wireline or the driving unit for a closing of the well and preventing a blowout. 
   
   
       13 . The use according to  claim 12 , wherein the tightening means is expandable.