SELECTING THE SCHEME OF MUD CIRCULATION THROUGH ROLLER CUTTER BITS IN VARIOUS DRILLING CONDITIONS
Alexander M. Gusman - Dr.Tech.Dci., professor, head of department, OJSC NPO Burovaya Technika, email@example.com
Key words: bottomhole cleaning process, grindability of cuttings, scheme of mud circulation through drill bit, oriented jet nozzle, asymmetrical circulation schemes, packing, operating parameters, hydromechanical breaking of rocks, physical-mechanical properties of rocks.
The paper shows that successful bottomhole cleaning while drilling should be based on individual control of each of the three processes, namely, bottomhole face cleaning, bottom hole zone cleaning and bit cutting structure cleaning. Each process may have different or zero effect on drilling performance in different drilling conditions. Based on test findings and different drilling conditions, the author provides methods for the selection of a scheme of mud circulation through roller cutter bits and the bottomhole. It is also shown that the circulation scheme should suit the bit cutting structure.