System analysis of alternative procedures for deep drilling technique for depth between 6,000 and 10,000 meters

Worldwide research activities were carried out in the field of rock destruction. Approximately 30 different techniques are concerned. These techniques were tested for applicability to the deep drilling technique as an alternative drilling method within the range of 6000 to 10,000 m. Approximately 3 to 5 of the drilling techniques can be rated functionally practicable but inferior to the rotary drilling systems. The potential of the drilling speed cannot be utilized due to the limitation of the secondary systems. The rotary drilling system is superior to other systems in economy, efficiency, and reliability. Improvement in the present rotary drilling system can be obtained by intensive research and development.