Weight-on-bit and torque measuring apparatus

Apparatus adapted for use in measuring forces applied to a drill bit during the drilling of a well, comprising:

• a tubular body adapted to be connected in a drill string above the bit and having a radially directed circular hole extending through the wall thereof;
• plug means for sealingly closing the external opening of said hole;
• support means sealingly closing the interior opening of said hole and engaging said plug means to prevent inward movement thereof due to well pressure;
• said plug means and support means providing an atmosphere chamber within said hole;
• and
• sensor means attached to peripheral wall surfaces of said hole within said chamber and adapted to detect strain due to application of forces to said body.

Apparatus adapted for use in measuring forces applied to a drill bit during the drilling of a well, comprising:

• a tubular body member having diametrically opposed, radially directed holes through the wall thereof;
• closure means sealingly closing the outer openings of said holes;
• a support member extending across the bore of said body member and abutting said closure means to prevent radial inward movement thereof due to well pressure, said support means being sealed with respect to said body member and providing together with said closure means an atmospheric chamber within said holes;
• and
• sensor means attached to the walls of said holes within said chamber and adapted to detect strain due to application of forces to said body member.

Apparatus adapted for use in measuring forces applied to a drill bit during the drilling of a well comprising:

• a tubular body adapted to be connected in a drill string above the bit and having a radially directed bore extending through the wall thereof, said bore having an outer portion and an inner portion;
• plug means sealing receiving in said outer portion of said bore for closing the same against entry of well fluids from externally of said body;
• support means extending through said inner bore portion and being sealed with respect thereto to prevent entry of fluid from the interior of said body, said support member having an end surface abutting said plug means to prevent inward movement thereof, said plug means, outer bore portion and support means defining an enclosed atmospheric chamber;
• and
• sensor means attached to peripheral wall surfaces of said outer bore portion in said chamber for detecting strain due to application of forces to said body.

Measuring apparatus comprising:

• a tubular member adapted to be connected to a drill bit and having a radially directed aperture in the wall thereof;
• means for isolating the peripheral side wall surfaces of said aperture from the effects of ambient well fluids;
• means for detecting ovalization of said aperture caused by force applied to said member and to the bit, and for providing an output indicating thereof;
• and
• means for transmitting to the surface of a borehole during drilling a signal having a predetermined relation to said output.