Abstract: A directional tool and method of surveying a wellbore with the directional tool in a borehole string. A first sensor of the directional tool is disposed in a non-homogeneous ambient magnetic field. A first applied magnetic field is applied to the first sensor. A first measurement is obtained at the first sensor while the first sensor is disposed within the non-homogeneous ambient magnetic field and with the first applied magnetic field applied. A second applied magnetic field is applied to the first sensor. A second measurement is obtained at the first sensor while the first sensor is disposed within the non-homogeneous ambient magnetic field and with the second applied magnetic field applied. The directional tool is calibrated based on the first and second measurement. A downhole survey measurement is obtained with the calibrated directional tool in the wellbore.

Abstract: A drilling system includes a method of determining an orientation of a drill string in a borehole. Sensor readings of a magnetic field of a drill bit are obtained at a plurality of positions along a curve extending around the drill bit along a longitudinal bit axis from a first location to a second location. A drill string includes the drill bit and a downhole magnetic field sensor that obtains a measurement of a local earth magnetic field, wherein the measurement is affected by the magnetic field of the drill bit. A processor determines a magnetic dipole moment of the drill bit from the plurality of sensor readings, calculates a second measurement of the local earth magnetic field downhole using the magnetic dipole moment of the drill bit, and determines the orientation of the drill string from the calculated correction of the measurement of the local earth magnetic field.

Abstract: Method for obtaining a directional survey in a rotating downhole component include acquiring and generating, while rotating, sets of raw data having 3-axis magnetic field data and 3-axis gravity field data. A set of rotationally-invariant data is obtained for each of the sets of raw data to generate a first number of sets of rotationally-invariant data. An earth property value is calculated from each of the sets. An accuracy indicator is estimated for each of the sets using a respective earth property value, an earth property reference value, and an error model, to generate a plurality of accuracy indicators. A set of mean values is determined using the plurality of sets of rotationally-invariant data using a second number of sets of rotationally-invariant data of the plurality of sets of rotationally-invariant data. The directional survey is estimated and used to control the downhole component.

Abstract: A directional tool and method of surveying a wellbore with the directional tool in a borehole string. A first sensor of the directional tool is disposed in a non-homogeneous ambient magnetic field. A first applied magnetic field is applied to the first sensor. A first measurement is obtained at the first sensor while the first sensor is disposed within the non-homogeneous ambient magnetic field and with the first applied magnetic field applied. A second applied magnetic field is applied to the first sensor. A second measurement is obtained at the first sensor while the first sensor is disposed within the non-homogeneous ambient magnetic field and with the second applied magnetic field applied. The directional tool is calibrated based on the first and second measurement. A downhole survey measurement is obtained with the calibrated directional tool in the wellbore.

Abstract: A composition is provided which comprises a recombinant viral particle comprising a capsid, wherein the viral particle is encapsulated into an anionic liposome comprising lecithin and polyethylene glycol (PEG). A method for preparing and purifying the encapsulated viral particles is provided as well. Methods for treating patients by using the encapsulated viral particles are provided as well.

Abstract: A composition is provided which comprises a recombinant viral particle comprising a capsid, wherein the viral particle is encapsulated into an anionic liposome comprising lecithin and polyethylene glycol (PEG). A method for preparing and purifying the encapsulated viral particles is provided as well. Methods for treating patients by using the encapsulated viral particles are provided as well.