SELF-CONTAINED BOTTOMHOLE DEVICE FOR MEASUREMENT OF FORCE PARAMETERS Russian patent published in 1999 - IPC

FIELD: well drilling equipment; applicable in measurement of force parameters in drill string, including those above drilling bit. SUBSTANCE: device has built-in drill string flexible member accommodating strain gages; protective sleeve installed tightly with respect to pipe pressure, and container with electronic unit, and pressure compensator consisting of two hollows separated by diaphragm. One of hollows is communicated with annular space, while another, is communicated with strain gage hollow located between internal surface of wall of flexible member and external surface of protective sleeve. Strain gages are located in internal walls of flexible member. Hollow of strain gages and pressure compensator hollow are interconnected by channel and filled with fluid inert relative to strain gages. The device is also provided with appliance for starting operation of electronic unit. The device allows measurement not only of axial load but also transverse forces and torque, and simplified starting of device on bottomhole by starting of mud pump. EFFECT: simplified design, higher measurement accuracy. 2 cl, 1 dwg