An embodiment of a nuclear magnetic resonance (NMR) apparatus for estimating properties of an earth formation includes an NMR measurement device including a transmitting assembly configured to emit a pulse sequence and a receiving assembly configured to detect an echo train based on the pulse sequence, and a processor. The processor is configured to perform receiving input parameters including an axial speed of the NMR measurement device and a T.sub.1 value associated with a selected formation fluid, analyzing polarization data associated with the T.sub.1 value, the polarization data describing a dependency between polarization and axial speed, determining a wait time for the pulse sequence based on the polarization data, applying the pulse sequence with the determined wait time to the transmitting assembly, and estimating a property of the earth formation based on the echo train detected by the receiving assembly in response to the pulse sequence.

It is proposed a seismic data acquisition device (400) intended to be placed on an ocean bottom floor, comprising a polymeric casing (412) defining a chamber that houses at least art of a data acquisition system (440, 444, 445); and a metallic device (414) in which the polymeric casing (412) is trapped, the metallic device (414) comprising two metallic beams (4141, 4142) that extend on opposite sides of the polymeric casing (412).

It is also proposed a method for assembling such a device and a corresponding method for seabed seismic data acquisition.

A system and method for geophysical data collection, for use with resistivity and induced polarization. The system and method include the use of a single voltage reference wire to which all voltage recorders or nodes are connected by means of a piercing wire connector, the voltage recorders providing a measurement of the potential voltage between the reference wire and the ground and allowing for calculation of relative voltage potentials between adjacent recorders.

Methods or systems for identifying seismic or acoustic signals of interest originating with moving motorized vehicles or footstep movement or stationary or moving machinery. A related system for monitoring an area includes a plurality of sensing devices each comprising a frame and a piezo-electric sensor element. A monitoring device is coupled to receive information from each of the sensing devices. One method includes providing a processing chain coupled to receive signal data from a sensor device which receives the signals, including a detection stage, a Joint Time Frequency (JTF) domain stage, and a classification stage. The detection stage identifies presence of signals that emerge from the background. The JTF domain stage estimates the state of the signals of interest over time. The classification stage assesses the previously derived information to form a decision about source identity. In one embodiment, the detector stage performs detections on a single cycle basis.

Methods or systems for identifying seismic or acoustic signals of interest originating with moving motorized vehicles or footstep movement or stationary or moving machinery. A related system for monitoring an area includes a plurality of sensing devices each comprising a frame and a piezo-electric sensor element. A monitoring device is coupled to receive information from each of the sensing devices. One method includes providing a processing chain coupled to receive signal data from a sensor device which receives the signals, including a detection stage, a Joint Time Frequency (JTF) domain stage, and a classification stage. The detection stage identifies presence of signals that emerge from the background. The JTF domain stage estimates the state of the signals of interest over time. The classification stage assesses the previously derived information to form a decision about source identity. In one embodiment, the detector stage performs detections on a single cycle basis.

An embodiment of a nuclear magnetic resonance (NMR) apparatus for estimating properties of an earth formation includes an NMR measurement device including a transmitting assembly configured to emit a pulse sequence and a receiving assembly configured to detect an echo train based on the pulse sequence, and a processor. The processor is configured to perform receiving input parameters including an axial speed of the NMR measurement device and a T.sub.1 value associated with a selected formation fluid, analyzing polarization data associated with the T.sub.1 value, the polarization data describing a dependency between polarization and axial speed, determining a wait time for the pulse sequence based on the polarization data, applying the pulse sequence with the determined wait time to the transmitting assembly, and estimating a property of the earth formation based on the echo train detected by the receiving assembly in response to the pulse sequence.

In some embodiments, a magnetometer mounting apparatus and system may reduce noise and magnetic flux interference by mounting the magnetometer inside a cavity in a collar that fits around a tool insert. The cavity may be sealed with a hatch cover/outsert. Another embodiment mounts a plurality of magnetometers around the periphery of a mounting ring that is coupled to the insert. Yet another embodiment mounts the magnetometers in a gap sub in the BHA. Still another embodiment longitudinally mounts the magnetometers on the insert such that a diagonal distance between two magnetometers is the greatest possible on the insert.

A system and method for geophysical data collection, for use with resistivity and induced polarization. The system and method include the use of a single voltage reference wire to which all voltage recorders or nodes are connected by means of a piercing wire connector, the voltage recorders providing a measurement of the potential voltage between the reference wire and the ground and allowing for calculation of relative voltage potentials between adjacent recorders.

A sensor system responsive to acoustic or seismic signals. One system includes a frame and a piezo-electric sensor element. The sensor element, responsive to a wavefield of seismic or acoustic energy, is positioned about the frame. Coupling between the sensor element and the frame is so limited as to render direct coupling of the sensor element with the wavefield the predominant means for stimulating the sensor element with seismic energy. Another system includes a frame and a cable element, responsive to a seismic or acoustic wavefield, extending about the frame. Coupling between the cable element and frame is so limited as to render direct coupling of the sensor element with the wavefield the predominant means for stimulating the sensor element with acoustic or seismic energy. The element may be coaxial cable or have piezo-electric properties to generate a charge differential measurable as a voltage between conductors.

A tripod, a vertical coil and a total-field magnetometer are utilized to measure a geomagnetic field T.sub.0 without an additional magnetic field imposed, as well as two composite magnetic field values T.sub.1 and T.sub.2 when the geomagnetic field is added with a vertical upward magnetic field T.sub.f and a double vertical upward magnetic field 2T.sub.f, respectively. Calculate a vertical component Z, a horizontal component H and a geomagnetic inclination I of the geomagnetic field. Set up a horizontal coil such that a geometric center of the horizontal coil coincides with a geometric center of the vertical coil. Use the total-field magnetometer to measure two composite magnetic field values T.sub.+ and T.sub. after the geomagnetic field has been added with a horizontal forward magnetic field and a horizontal reverse magnetic field, respectively. Calculate a geomagnetic declination D.