摘要:
A pressure transducer for high-pressure measurements comprising a housing and a piezoelectric resonator located in the housing, wherein the resonator comprises double rotation cut piezoelectric material configured or designed for vibrating in the fundamental tone of dual modes of the fast and slow thickness-shear vibrations.
摘要:
Described is method and system of determining horizontal stress from radial profiles of dipole shear together with the far-field estimate of the Stoneley shear modulus. The system and method include selecting an optimal number of regression points on measured radial profiles for obtaining reliable estimation of maximum and minimum horizontal stress magnitudes in the presence of noisy data, where measured radial profiles of dipole shear moduli might exhibit a small amount of random fluctuations.
摘要:
Described is method and system of determining horizontal stress from radial profiles of dipole shear together with the far-field estimate of the Stoneley shear modulus. The system and method include selecting an optimal number of regression points on measured radial profiles for obtaining reliable estimation of maximum and minimum horizontal stress magnitudes in the presence of noisy data, where measured radial profiles of dipole shear moduli might exhibit a small amount of random fluctuations.
摘要:
Methods and apparatus facilitating measurement of anisotropy are disclosed. According to some aspects, anisotropy can be determined while drilling. Monopole/quadrupole interactions, as well as monitoring dipole excitations and other methods, may be used to find the principal shear directions of a formation while drilling or during wireline or other operations.
摘要:
Methods and apparatus facilitating radial profiling of shear slowness or shear modulus c66 in the cross-sectional plane of a borehole in an anisotropic formation with the vertical X3-axis are disclosed. According to some aspects of the invention, sonic tool bias is accounted for and removed from radial profiles. According to some aspects, sonic tool bias is accounted for by modeling the sonic tool as a heavy-fluid.
摘要:
A tool generates signals indicative a shear wave slowness of the formation surrounding a borehole. The tool comprises a collar portion adapted for mounting in a drill string, a quadrupole sonic transmitter mounted to the collar portion, and a quadrupole sonic receiver array mounted to the collar spaced apart from the transmitter. A method determines shear wave slowness of the formation. The method includes propagating quadrupole wave energy into the formation and detecting quadrupole dispersive waveform received at a second location. Formation shear wave slowness is calculated using dispersive slowness time coherence processing.
摘要:
A method provides for locating and measuring mechanical damage in rock surrounding a borehole by detecting one or both of reductions in ultrasonic compressional wave velocity in the rock as a function of azimuth, and by detecting focused acoustic energy in the rock from local increases in ultrasonic compressional wave amplitude resulting from velocity gradients. A first preferred embodiment uses a combination of azimuthal ultrasonic compressional wave velocity data and azimuthal ultrasonic compressional wave energy data. A second embodiment uses azimuthal ultrasonic compressional wave velocity data and omni-directional sonic velocity data, with a comparison test or a curve fitting test. A third embodiment uses azimuthal ultrasonic compressional wave energy data.
摘要:
A method for obtaining high-quality well logging data acquired during a drilling operation includes acquiring well logging data during a pump-off period when a mud pump is turned off; and extracting a subset of data from the acquired well logging data, wherein the subset of data corresponds to a quiet period within the pump-off period, wherein the quiet period is substantially free of interference from turning the mud pump on or off.
摘要:
A method for monitoring a formation property includes determining at least two slowness values from at least two datasets each characterizing an acoustic wave having a different frequency traversing a formation; and deriving an indicator based on the at least two slowness values. A system for monitoring a formation property includes a process and a memory, wherein the memory stores a program having instructions for: determining at least two slowness values from at least two datasets each characterizing an acoustic wave having a different frequency traversing a formation; and deriving an indicator based on the at least two slowness values.
摘要:
Methods and apparatus facilitating radial profiling of shear slowness are disclosed. According to some aspects of the invention, acoustic tool bias is accounted for in the calculation of radial profiles. According so some aspects, acoustic tool bias is accounted for by replacing acoustic tool structure with a resonance-impedance model. The resonance-impedance modeling according to principles of the present invention is applicable to vertical, deviated, and horizontal boreholes.