摘要 |
<p>An apparatus operable on a wireline logging cable for drilling a hole in the sidewall of a drill hole which comprises a hydraulically operated backup shoe for wedging the apparatus at a selected location in the drill hole, a hydraulic motor with a drilling bit connected thereto for rotation by the hydraulic motor and hydraulic means connected to the hydraulic motor for moving the bit into drilling engagement with the sidewall of the drill hole. In the improvement of this invention, the hydraulic means for moving the bit into drilling engagement comprises a new flow restrictor valve. This flow restrictor valve has an orifice and a slender pointed rod for restricting the flow of fluid through the orifice. Opposing spring means and control fluid means engage the rod for controlling its movement toward and away from the orifice. 79166ART0152</p> |