| 摘要 |
<p>1511513 Pressure gauges SPERRY-SUN WELL SURVEYING CO 6 May 1975 [6 May 1974] 18956/75 Heading G1L Borehole pressure change rates are measured by pumping fluid down a small bore tube 29 to a much larger diameter chamber 27 having a volume greater than that of the tube and situated at the depth of the hole where pressure is to be measured, the base of the chamber communicating with the borehole environment. The chamber may be a simple tube with which the tube 29 communicates through a filter (42), Fig. 2 (not shown) at the top or an annular chamber 50 may surround the borehole pipe.</p> |
