CORE BARREL Russian patent published in 1995 - IPC

FIELD: drilling equipment. SUBSTANCE: core barrel has body whose upper part is provided with sub and then lower part, with crown bit. Tightly connected to case lower end is sleeve with conical bore in which film diaphragm tightly sealing case from below is clamped with ring. Tight covering of case from atop is accomplished by means of cover to which core receiver is connected via suspension rotary support. Core receiver lower part has core catcher. Core entering is recorded by special devices located along the entire length of core receiver. Spaces of case and core receiver are filled prior to lowering into well with antifriction isolating substance through channel tightly closed with plug. Case is locked in assembly with core receiver in body by means of regulating unit to effect interaction of cover with case upper part and sleeve with conical bore. Regulating unit is made in form of screw engageable with nut made in sub which has holes for drilling mud circulation. EFFECT: higher yield and quality of core, reduced maintenance costs, higher operate reliability and maintainability. 4 dwg