CORE SAMPLER Russian patent published in 2002 - IPC

FIELD: mining, particularly, devices for well coring. SUBSTANCE: core sampler has body with coupling, rock cutting tool, sub consisting of external sleeve secured to body and internal sleeve connected by means of nipple with drill string. External and internal sleeves are engageable with each other with the help of splines made on them and reciprocating relative to each other along their axes. Centralizer is secured to internal sleeve. Installed on centralizer is radial bearing, thrust bearing and plug-like radial valve. Inner barrel is installed by means of core catchers on support provided with thrust ball bearing and seal. Inner barrel upper end is installed on radial ball bearing and engageable with thrust ball beating, and plug-like radial valve which closes or opens radial windows made on inner barrel which is provided with ejectors whose channels are communicated with radial windows. Inner barrel accommodates chamber with pushing plunger. Made on pushing plunger is axial channel, and head is secured which is engageable with seal and core. Invention ensures production of isolated core coated with core-insulating composition to provide for more accurate determination of hydrocarbon reserves. EFFECT: higher degree of recovery of representative core protected from its washing with drilling mud. 5 cl, 1 dwg core-insulating composition