DEVICE FOR MEASURING DEFORMATIONS IN WELL WALLS Russian patent published in 2007 - IPC E21C39/00 

FIELD: geo-mechanics, possible use for determining stresses and deformations in rocks.

SUBSTANCE: device contains body, localizing rod, on which nut and claw nut are positioned, and cylindrical spring is pinned, limited on ends by washers, lid, packing collars, pressing segments having conic surface, made with possible extension towards well walls, rubber inserts and resistive-strain sensors positioned on pressing segments and contact mechanism. Lid is made in form of conic cap and is rigidly held on localizing rod with possible even, without force, removal from pressing segments due to movement of localizing rod during unscrewing of claw nut and extension of pressing segments towards well walls. Contact mechanism is mounted on localizing rod and conic cap, and consists of two polyvinyl chlorine inserts with spring held between them by means of press nut, inside the spring a wire is let through, which is held on contact rod, as base of which plastic lid on spring end is used, another wire is soldered to cylindrical rod. During compression of spring, contact rod with cylindrical rod are closed, and a lamp is lit on measuring device, pointing out the fact that packing collars are in right contact with cut well walls.

EFFECT: increased reliability of device operation.

2 dwg