73258784
Apr 21, 1980
Mar 9, 1982
Measuring Instruments Used in Drilling Operations-Namely, Consoles which Measure Drilling Rate Response, Pump Pressure, Strokes Per Minute, Gallons Per Minute, Total Pump Strokes, Pit Level and Flow Data, Flow-Rate Returns, Rotary Revolutions Per Minute and Mud Weight
Electrical and Scientific Apparatus