摘要 |
<p>A system for verifying the effectiveness of electromagnetic signal control of a subsurface safety valve installed in a well. Signals are transmitted from a surface station to actuate the subsurface installed valve. Signals received at the valve are decoded and information relating to them is stored. A sensor detects actual valve actuation and provides signals indicative thereof which are also stored. After the valve is removed from its downhole installation, the stored signals are read, and the data indicated thereby is compared with data recorded at the time of signal transmission from the surface.</p> |