Teleco Oilfield Services Inc.

Robert J Maron

Frederick A Stone

Apparatus is presented for measuring weight, torque and side force (bending) on a drill bit for oil and gas well drilling. This apparatus includes radial holes which do not pass completely through the wall of the drill collar sub, but instead, pass only partially through the wall of the drill collar sub. Strain gages are located in the partial radial openings. These strain gages measure each of the three parameters of weight, torque and bending. Each partially formed hole is sealed by a plug and retained in place by a retaining ring. For torque and bending measurements, the strain gages are arranged with symmetry of position between diametrically opposed holes. The strain gages are positioned in an array which departs from symmetry of position to minimize errors in the weight measurement caused by pressure changes in the drilling fluid.

Apparatus for measuring weight, torque and side force on a drill bit

Apparatus is presented for measuring weight, torque and side force (bending) on a drill bit for oil and gas well drilling. Strain gages are located in radial holes in the wall of a drill collar sub for measuring each of the three parameters of weight, torque and bending. The holes are sealed by inner and outer plugs and a ring and bolt structure retains the plugs in place. For torque and bending measurements, the strain gages are arranged with symmetry of position beteween diametrically opposed holes. The strain gages are positioned in a novel array which departs from symmetry of position to minimized errors in the weight measurement caused by pressure changes in the drilling fluid.

An insulating coupling for drill collars and a method of manufacture thereof are presented wherein the coupling consists of an electrically insulating ceramic coating applied in thickness from 0.002 to 0.006 inch to the threads of the coupling by a detonation gun process and sealed with an epoxy sealer to reduce porosity.

Growing community of inventors

Cromwell, CT, United States of America

Robert J Maron