CORE EQUIPMENT FOR ROTARY BORING WITH INTERNAL BOTTOMHOLE LIQUID CIRCULATION Russian patent published in 2009 - IPC E21B25/00 

FIELD: mechanics.

SUBSTANCE: invention refers to rotary boring of wells, and namely to devices creating reverse internal bottomhole circulation of flushing liquid in core barrel of case and well. Case includes core barrel with drill crown, adapter for drilling string and ball valve including metal body, seat with central through channel for liquid passage, ball made from stainless steel for channel closure, slurry feeding tube with holes in its side walls for discharging liquid and slurry of drilled rocks via them to the well. Ball is hollow, holes for discharging liquid and slurry to the well are made in side walls of valve body. Inner diametre of valve body is taken equal to inner diametre of core barrel, diametre of channel of valve seat and outer diametre of ball are chosen as maximum possible ones based on minimisation of resistances to liquid discharge from core barrel and diametre of channel of valve seat is determined based on equality of sectional area of seat channel and sectional area of annular gap between ball and internal walls of valve body.

EFFECT: improving core quality.

2 cl, 3 dwg, 1 tbl, 1 ex