Method and apparatus for measuring fluid process variable in a well

摘要

A sensor system for sensing a process variable of fluid at a first location including a variable resonator disposed at the first location having a resonant frequency which varies in response to the process variable of the fluid and responsively provides a resonant acoustic signal at the resonant frequency indicative of the process variable. An acoustic sensor disposed at a second location which is spaced apart from the variable resonator is configured to receive the resonant acoustic signal transmitted from the variable resonator. Measurement circuitry coupled to the acoustic sensor configured to provide a process variable output related to the process variable of the fluid in response to the received resonant acoustic signal.

主权项

1. A sensor system for sensing a process variable of a process fluid at a first location in a well, comprising:
a variable resonator disposed in contact with the process fluid at the first location in the well having a resonant frequency which varies in response to the process variable of the fluid and responsively provides a reflected acoustic signal at the resonant frequency indicative of the process variable, wherein the first location comprises a down hole location in the well; an acoustic sensor disposed at a second location spaced apart from the variable resonator and configured to receive the resonant acoustic signal transmitted from the variable resonator, wherein the second location comprises a location proximate earth surface; and measurement circuitry coupled to the acoustic sensor configured to provide a process variable output related to the process variable of the fluid in response to the frequency of the acoustic signal received from the variable resonator, wherein the process variable of the fluid comprises at least one of pressure and flow; wherein the reflected acoustic signal is carried along a pipe of the well; wherein the variable resonator includes an elongate element having an interior cavity and the interior cavity is coupled to a pressure of the fluid.