SHUT-OFF DEVICE FOR TESTING FORMATIONS Russian patent published in 1995 - IPC

FIELD: mining industry. SUBSTANCE: shut-off device for testing formations includes hollow rod 4 and body 1 with upper adapter 2 and lower adapter 3 for axial motion relative to each other. They form annular chamber 5. Rigidly connected to rod 4 is sleeve 8 with controlling cones: right cone 9 and reversed cones 10 and 11. Sleeve 8 is located in annular gap between body 1 and upper adapter 3. Installed in recesses 12 of upper adapter on axles 13 are bell-cranks 14 with protrusions 15 serving as locking members. Bell-crank 14 may interact, from outer side, with controlling conical surfaces 9 of sleeve 8, and, from inner side, with recess of removable valve. The latter is made of sealing bushing freely installed on logging cable. Device without removable valve is lowered into well. Rod 4 is supported with spring 7 and bell-cranks 14 are placed in recesses 12 of adapter 3 under the action of sleeve 8. Axial valve in this case is open to provide free access to under-packer space for performance of various technological operations, such as well flushing, perforation, treatment of formation. EFFECT: higher operate reliability of device and safety in formation testing due to exclusion of motion of pipe string on wellhead. 2 cl, 4 dwg