摘要:
Improved receiver antennas are disclosed for long offset tensor induction army logging tools. The disclosed antennas include a bobbin which accommodates a ferromagnetic core. The outer surface of the bobbin is wrapped around a binding so that winding is thicker or includes more turns towards a center of the bobbin and is thinner or includes less turns towards the outer ends of the bobbin. The result is that the primary winding with a curved or parabolic profile that enhances the effective magnetic permeability and magnetic moment of the antenna. A secondary winding may also be utilized for flux feedback compensation. The elimination of winding turns towards the ends of the magnetic coil result in reduced DC resistance and the reduction in parasitic capacitance of the antennas. The disclosed antennas may be used in x-y-z receiver arrays.
摘要:
Improved receiver antennas are disclosed for long offset tensor induction army logging tools. The disclosed antennas include a bobbin which accommodates a ferromagnetic core. The outer surface of the bobbin is wrapped around a binding so that winding is thicker or includes more turns towards a center of the bobbin and is thinner or includes less turns towards the outer ends of the bobbin. The result is that the primary winding with a curved or parabolic profile that enhances the effective magnetic permeability and magnetic moment of the antenna. A secondary winding may also be utilized for flux feedback compensation. The elimination of winding turns towards the ends of the magnetic coil result in reduced DC resistance and the reduction in parasitic capacitance of the antennas. The disclosed antennas may be used in x-y-z receiver arrays.
摘要:
A well logging tool and method are disclosed comprising a conductive mandrel, an antenna array disposed around the conductive mandrel, wherein the antenna array comprises a plurality of antennas disposed on insulating supports and at least one contact spacer, the at least one contact spacer having at least one conductor channel having a contact assembly disposed therein, a sleeve disposed over the antenna array, wherein the sleeve includes at least one electrode assembly, the at least one electrode and the contact assembly adapted to provide a radially conductive path from an exterior of the well logging tool to the conductive mandrel and wherein the electrode assembly comprises a first conductor exposed to the exterior of the well logging tool and at least one second conductor conductively connected to the first conductor and exposed to an inner surface of the sleeve, wherein at least one of the first conductor or the second conductor being in sealed contact with the sleeve to prevent the passage of fluid through the sleeve.
摘要:
The invention refers to antenna configurations for electromagnetic logging tools. The antennas have one or more electrical conductors disposed on a dielectric substrate wrapped around a core or disposed directly on the core. The conductor or conductors are arranged such that the antenna has a first magnetic dipole moment substantially perpendicular to a longitudinal axis of the core. The invention also refers to antennas adapted for mutual balancing using interleaved conductive paths or disks to alter the magnetic dipole moments to mutually balance the antenna system.
摘要:
A well logging tool and method are disclosed comprising a conductive mandrel, an antenna array disposed around the conductive mandrel, wherein the antenna array comprises a plurality of antennas disposed on insulating supports and at least one contact spacer, the at least one contact spacer having at least one conductor channel having a contact assembly disposed therein, a sleeve disposed over the antenna array, wherein the sleeve includes at least one electrode assembly, the at least one electrode and the contact assembly adapted to provide a radially conductive path from an exterior of the well logging tool to the conductive mandrel and wherein the electrode assembly comprises a first conductor exposed to the exterior of the well logging tool and at least one second conductor conductively connected to the first conductor and exposed to an inner surface of the sleeve, wherein at least one of the first conductor or the second conductor being in sealed contact with the sleeve to prevent the passage of fluid through the sleeve.
摘要:
A well logging instrument housing includes an electrically non-conductive tube and at least one layer of fiber embedded in a matrix surrounding an exterior of the tube. The at least one fiber layer includes at least one carbon fiber. The at least one or carbon fiber is arranged to have substantially no closed loops.
摘要:
Systems, methods, and devices for two-way communication with a downhole tool string are provided. In one example, a method may include placing a downhole tool string into a pressure riser of a well while at least one component of the downhole tool string is not activated. Thereafter, a wireless control signal may be issued through the pressure riser to the downhole tool to cause the downhole tool string to activate the component. The wireless control signal may involve an acoustic signal, an optical signal, and/or an electromagnetic signal such as electrical dipole coupling or magnetic dipole coupling.
摘要:
A logging tool having a plurality of spatially separated antennas is provided and used to make propagation-style measurements in a formation. Tensors are formed using the propagation-style measurements and one or more quantities are computed using the tensors. A formation evaluation is performed using the computed quantities. The formation evaluation determines a formation property or parameter such as horizontal resistivity, vertical resistivity, relative dip, azimuthal dip, bed boundary location, or bed thickness. The computed quantities may include compensated phase shift resistivity, compensated attenuation resistivity, symmetrized phase shift resistivity, symmetrized attenuation resistivity, anti-symmetrized phase shift resistivity, and anti-symmetrized attenuation resistivity. The measurements may be corrected for antenna gain errors and an air calibration may be performed. A zero-dimension inversion may be performed, while drilling, and the determined horizontal resistivity, vertical resistivity, relative dip, and/or azimuthal dip information may be sent to an uphole processor in real-time.
摘要:
A well logging instrument housing includes an electrically non-conductive tube and at least one layer of fiber embedded in a matrix surrounding an exterior of the tube. The at least one fiber layer includes at least one carbon fiber. The at least one or carbon fiber is arranged to have substantially no closed loops.
摘要:
An induction or propagation apparatus for performing measuring the tensor resistivity of a sample of matter includes a non-conductive, generally cylindrical tubular member adapted to receive the matter therein, a triaxial transmitter, at least one triaxial receiver, and an electronic module. The electronic module is adapted to energize the triaxial transmitter, control acquisition of signals by the at least one triaxial receiver, and perform anisotropic measurements and analysis. The triaxial transmitter and the at least one triaxial receiver are disposed on the generally cylindrical tubular member in axial spaced relationship.