| 摘要 |
<p>WELL LOGGING METHOD AND APPARATUS USING FRICTION-REDUCING AGENTS. A well logging instrument has a fluid chamber at its lower end and a plurality of controlled flow orifices leading from the chamber to the exterior of the instrument. A piston within the chamber, having a spring at its upper end, forces a friction-reduction agent from the chamber through the flow-controlled orifices into the earth borehole to facilitate the movement of the well logging instrument through the borehole. The upper portion of the fluid chamber, above the piston, is also ported to the fluid within the borehole to equalize the pressure across the piston. In an alternative embodiment of the invention, the acceleration of the borehole instrument creates a velocity signal which is compared with the velocity of the logging cable at the earth's surface and upon a sufficient difference in velocity, the friction-reduction agent is caused to be ported into the earth borehole.</p> |
