DEVICE FOR WELL DRILLING WITH RETRIEVABLE CORE RECEIVER Russian patent published in 1994 - IPC

FIELD: coring. SUBSTANCE: retrievable core receiver has perforated tube whose holes accommodate isolated electrodes made of permanent magnets and connected with terminals on rod of catching head, core catcher and overshot with terminals on catchers, flexible collar and rope, and cable connected with surface high-voltage source. Core catcher has electromagnets interacting with nonworking ends of levers. Hollow of core receiver is filled with electrorheological suspension. Core is held in core receiver hollow and isolated from drilling mud with rheological suspension which secures it with well walls and whose viscosity sharply rises with d.c. applied to electrodes. In this case, levers with their working ends clamp core due to attraction of their nonworking ends by electromagnets. EFFECT: higher efficiency. 2 cl, 4 dwg