Abstract:
A measurement device is provided that determines fluid properties from vibration frequencies of a sample cavity and a reference cavity. In one embodiment, the measurement device includes a sample flow tube, a reference flow tube, vibration sources and detectors mounted on the tubes, and a measurement module. The sample flow tube receives a flow of sample fluid for characterization. The reference flow tube is filled with a reference fluid having well-characterized properties. The measurement module employs the vibration sources to generate vibrations in both tubes. The measurement module combines the signals from the vibration detectors on the tubes to determine properties of the sample fluid, such as density, viscosity, compressibility, water fraction, and bubble size. The measurement module may further detect certain flow patterns such as slug flow, for example. To measure the sample fluid density, the measurement module determines the difference between resonance frequencies of the sample flow tube and the reference flow tube. The density can then be calculated according to a formula. Other fluid properties may be determined from the sample tube's resonance peak amplitude, peak width and/or peak shape. Variation of the density measurements may be used to detect and characterize multiple phase fluid flow. The use of a reference tube in the disclosed measurement device is expected to greatly enhance the accuracy and reliability of the measurement device over a range of temperatures, pressures, and shock accelerations such as those that may be found downhole in a well.
Abstract:
A method for determining the composition of a fluid by using measured properties of the fluid. One embodiment of the method of the current invention generally comprises: selecting a fluid property that has a response to fluid composition that is linear, or can be approximated as linear; measuring the selected fluid property at a series of specific time intervals; and plotting the measured property as a function of the selected property. In effect, plotting the measured property as a function of fluid composition in an arbitrary set of units. This allows for a in-situ qualitative evaluation of fluid composition by measuring a fluid property that has a known linear relationship to fluid composition. Another embodiment of the present invention further comprises, establishing the endpoints of contamination and plotting the measured properties through these endpoints. Once the endpoints have been established a quantitative evaluation of the fluid composition can be performed. One preferred fluid property that can be used is density.
Abstract:
A method and apparatus for analyzing a deposited layer on the inner surface of a fluid container wall having inner and outer surfaces are disclosed. One embodiment of the method comprises (a) transmitting an acoustic signal from a transmitter at a first distance from the outer surface of the wall; (b) receiving a first received signal A, comprising a reflection from the wall outer surface; (c) receiving a second received signal B, comprising a reflection from the wall inner surface; (d) receiving a third received signal C from the wall inner surface; (e) calculating a coefficient Rwp from A, B and C, and (f) calculating a coefficient Rpd from A, B and Rwp, and calculating the acoustic impedance of the deposited layer Zd from Rwp, Rpd, and Zw, where Zw is the acoustic impedance of the material between the transmitter and the wall outer surface. A preferred embodiment of the apparatus comprises a piezoelectric or ferroelectric transducer having front and back faces; a backing member acoustically coupled to said transducer back face and impedance-matched to said transducer element, said backing member having proximal and remote faces; and a delay material disposed between said transducer front face and the wall outer surface.
Abstract:
A method for determining the composition of a fluid by using measured properties of the fluid. One embodiment of the method of the current invention generally comprises: selecting a fluid property that has a response to fluid composition that is linear, or can be approximated as linear; measuring the selected fluid property at a series of specific time intervals; and plotting the measured property as a function of the selected property. In effect, plotting the measured property as a function of fluid composition in an arbitrary set of units. This allows for a in-situ qualitative evaluation of fluid composition by measuring a fluid property that has a known linear relationship to fluid composition. Another embodiment of the present invention further comprises, establishing the endpoints of contamination and plotting the measured properties through these endpoints. Once the endpoints have been established a quantitative evaluation of the fluid composition can be performed. One preferred fluid property that can be used is density.