

@6afrt&i 31 



TURBINE 

 DRILLING 



J. B. O'Connor 



Turbine drilling is a basic extension of the rotary drilling method, with 

 the motive power supplied directly to the bit. It uses a subterranean, fluid- 

 actuated turbine instead of drill pipe to rotate the bit. This new method of 

 drilling is destined to be an important adjunct to rotary, and in many instances 

 to take the place of other methods of drilling. 



The theory of drilling with the power source at the bit has held promise 

 for many years as the ultimately logical method of drilling. The power loss 

 inherent with conventional rotary drilling makes it an inefficient method, espec- 

 ially for deep drilling. Through its operating characteristics the turbodrill pro- 

 vides more power to the bit and eliminates many of the disadvantages of the 

 rotary method. 



DEVELOPMENT The development of the modern turbodrill 



has required many years of research. In 1873, 

 C. G. Cross obtained a patent entitled "Improvements in Drill for Boring Artesian 

 Wells." This design involved a single-stage hydraulic turbine used for drilling 

 with diamond-drill bits. In 1884, George Westinghouse, Jr., secured patents 

 that proposed a similar unit, but one that used a positive-displacement motor 

 instead of a turbine. These two designs were the first attempts toward the basic 

 concept of the turbodrill. 



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