Abstract:
An embodiment of an apparatus for estimating a parameter includes a light source configured to emit an optical signal, and an interferometer including a first reflector assembly having at least one reflective surface and a second reflector assembly having a plurality of individual reflective surfaces facing the at least one reflective surface. At least one of the first reflective assembly and the second reflector assembly is moveable in response to a stimulus, the plurality of individual reflective surfaces disposed at a fixed location relative to each other, each individual reflective surface defining a different optical cavity length relative to the first reflector assembly.
Abstract:
A downhole positioning apparatus includes: a carrier configured to be disposed in a borehole in an earth formation, the carrier including at least one measurement tool and an extendable member configured to be actuated between a first position in which the extendable member is disposed at the carrier and a second position in which the member is extended from an outer surface of the carrier; and a receiving element fixedly disposed at a borehole casing, the receiving element configured to receive the elongated member when the member is in the second position and guide the carrier to a selected orientation as the carrier is moved axially through the borehole.
Abstract:
An apparatus and method for estimating a parameter of a fluid flowing in a tubular is disclosed. A source of a primary magnetic field is coupled to the tubular and is configured to induce the primary magnetic field in the fluid to align nuclei of the fluid in the tubular along the primary magnetic field. A transmitter transmits an excitation signal into the fluid. A receiver detects a signal from the aligned nuclei responsive to the excitation signal. A processor estimates the parameter of the fluid from the detected signal. The source of the primary magnetic field is removable from the tubular. A coil may induce a secondary magnetic field to either enhance the strength of the primary magnetic field in the tubular or substantially cancel the primary magnetic field in the tubular, for example, to reduce particle build-up in the tubular.
Abstract:
An apparatus and method for estimating a parameter of interest using values of a beam property from two or more electromagnetic beams that both pass through at least part of an optical displacement device. The apparatus may include a Fabry-Perot interferometer, a collimated light source, and a detection array. At least one mirror of the interferometer may be operably coupled to an element receiving an external stimulus, such as pressure, force, and/or acceleration. The method includes using the apparatus.
Abstract:
A method and apparatus for estimating a flow rate of a phase of a multiphase fluid is disclosed. A first velocity distribution is obtained for a first set of nuclei in the fluid from a Nuclear Magnetic Resonance (NMR) signal received for the fluid in response to a first NMR excitation signal. A second velocity distribution is obtained for a second set of nuclei in the fluid from an NMR signal received for the fluid in response to a second NMR excitation signal. A velocity of the phase is estimated from the first velocity distribution and the second velocity distribution. The flow rate of the phase is estimated using the estimated velocity of the phase and an estimated volume fraction of the phase.
Abstract:
A method and apparatus for estimating a flow rate of a phase of a multiphase fluid is disclosed. In the first method, nuclei in the fluid are polarized over two distances and a measured magnetization gives the relative fraction of two components of the fluid for a selected velocity. In the second method, nuclei in the fluid are polarized over a specified distance and measurements of the decay of spin echo signals is used to give the relative fraction of two components of the fluid for the selected velocity.
Abstract:
An apparatus and method for estimating a parameter of interest using values of a beam property from two or more electromagnetic beams that both pass through at least part of an optical displacement device. The apparatus may include a Fabry-Perot interferometer, a collimated light source, and a detection array. At least one mirror of the interferometer may be operably coupled to an element receiving an external stimulus, such as pressure, force, and/or acceleration. The method includes using the apparatus.
Abstract:
A method for inversion of multiple echo trains with different wait times uses a cutoff times for each of the echo trains for full polarization. Simultaneous inversion is carried out for T2 bins where full polarization exists. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
Abstract:
A method to correct for a systematic error of a sensor having a plurality of accelerometers configured to measure gravitational acceleration, the method including: rotating the plurality of accelerometers about a first axis; obtaining a first set of calibration measurements from the plurality of accelerometers from the rotation about the first axis; determining a first systematic error for each accelerometer in the plurality using the first set of calibration measurements; and removing the first systematic error from sensor measurements to correct for the systematic error.
Abstract:
A method for acquiring nuclear magnetic resonance measurements of a material uses a modified CPMG sequence with a refocusing pulse having a tipping angle less than 180 °. The results of using the shortened refocusing pulse with reduced power requirements are comparable to those obtained with a conventional CPMG sequence.