| 摘要 |
<p>In accordance with an illustrative embodiment of the present invention, a new and improved weight-on-bit and/or torque measuring apparatus for use in making measurements-while-drilling includes a tubular housing adapted to be attached in the drill string above the bit, the housing having diametrically opposed, radially directed holes that are enclosed to provide a sealed chamber isolated from ambient well fluids. The holes have peripheral wall surfaces to which are attached sensors that measure strain induced by axial and/or torsional loading of the housing. The strain sensors are attached to the walls at locations to be substantially insensitive to strains induced by temperature gradients, and an internal sleeve is utilized in combination with pressure equalization to eliminate spurious stresses in the region of the holes caused by pressure differences inside and outside the housing.</p> |
