METHOD FOR DRILLING WITH SLIT DEPOSITION Russian patent published in 1996 - IPC

FIELD: well drilling. SUBSTANCE: device has lower end of drilling string provided with a bit, overbit reducer with hydromonitoring extensions and narrowing part of reducer passage in the form of diaphragm. Another option has transformer from lower internal diameter of the string to higher diameter. The diaphragm and reducer are installed downstream from hydromonitor extensions. A lock nut is there to adjust space to hydromonitor extensions. The third option has hydromonitor extension with step-wise internal passage. Additional flow drop is produce using the diaphragm. Mixture is fed using slit depositing extensions. EFFECT: high efficiency. 2 cl, 3 dwg