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A well has a downhole flow meter that is installed in a sub in
a string of tubing. The flow meter has a body having an external
profile that lands on a landing profile in the sub. The body has
a passage with a throat area of reduced diameter. Upstream and downstream
body ports in a side wall of the body are in fluid communication
with the throat area and a downstream portion of the passage downstream
of the throat area. Seals are located between the body and the sub,
defining an upstream annular chamber and a downstream annular chamber
surrounding the body, the chambers being in communication with the
upstream and downstream body ports. Upstream and downstream sub
ports in a side wall of the sub are in fluid communication with
the upstream and downstream chambers. A sensor circuit is in operative
engagement with the sub ports for determining a flow rate based
on a pressure difference sensed between the throat area and the
downstream portion of the passage in the body.
A method of improving the accuracy of a variable orifice flow meter
that includes characterizing the discharge coefficient of the flow
meter orifice for different orifice openings and for different differential
pressures. The method may be particularly useful with a flow metering
and controlling device that includes a fluid flow conduit having
at least one planar inner wall and an element having a linear edge
configured to mate with the at least one planar inner wall of the
fluid flow conduit. The element is movable relative to the conduit
to define a flow orifice and vary a cross-sectional area of the
orifice. The device also includes a processor configured to calculate
the fluid flow based on the cross-sectional area of the orifice,
the differential pressure, and the discharge coefficient.
A wedge unit according to the present invention is used for an
ultrasonic Doppler flow meter, being mounted on the outer wall of
a pipe in which a fluid flows, supplying an ultrasonic wave to the
fluid, receives the reflected wave and supplies the reflected wave
to a flow rate calculation unit, comprises a wedge with one surface
thereof being mounted on a part of the outer circumference of the
pipe and on another surface thereof being equipped with an ultrasonic
oscillator that generates the ultrasonic wave in response to an
electric signal and receives the reflected wave; and an ultrasonic
wave attenuation unit being mounted on the outer circumference of
the pipe so as to include a position where an ultrasonic wave injected
from the ultrasonic oscillator into the pipe by way of the wedge
first reaches the outer wall of the pipe after being reflected by
the inner wall thereof.
An insertion vortex flow meter for measuring a flow rate of a process
fluid in a pipe has a mounting assembly, a shedding bar and a sensor
assembly. The mounting assembly is attached to a surface of the
pipe adjacent an opening in a side wall of the pipe. The shedding
bar is inserted through the opening and extends an entire diameter
of the pipe. The shedding bar is held in place by a compression
force exerted by the sensor assembly on a proximal end of the shedding
bar, such that the shedding bar is held by the compressive force
between the sensor assembly and an opposing side wall of the pipe.
The sensor assembly is adapted to measure motion of a pivoting element
corresponding to vortices in the process fluid caused by the shedding
bar. The sensor assembly adapted to produce an output indicative
of the volumetric flow rate based on the frequency of the measured
motion.
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