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(11) | EP 2 025 861 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Remote actuation of downhole tools using fluid pressure from surface |
| (57) An apparatus for and a method of transmitting signals from the surface of a well
to a location downhole in the well utilize a downhole fluid pressure sensor (52),
a signal processing means (54; 56; 58) located downhole in electrical connection with
the pressure sensor (52) and a downhole programmable logic unit (60) capable of counting
at least two signals received by the downhole pressure sensor (52). Typically, signals
transmitted from the surface comprise a peak in pressure of downhole fluid located
in production tubing run into a well bore and these signals are sensed by the downhole
fluid pressure sensor (52). The logic unit (60) outputs a signal to a tool to be actuated
if it receives a number of signals within a particular time period, wherein the logic
unit (60) actuates the tool by the frequency of signals received rather than the amplitude
of the signals received.
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