An earthquake sensing module includes an acceleration sensor configured to detect accelerations on a plurality of detection axes, a module control unit configured to control the acceleration sensor, and a module storage unit configured to store state information of the acceleration sensor.

A down-hole apparatus comprises a unitary seamless section defining a chamber, a clamping section to engage a fiber optic cable, actuator electronics enclosed in the chamber, and an actuator to acoustically couple the actuator electronics to the fiber optic cable. The apparatus can include a temperature sensor, a microphone, or a geophone, enclosed by the chamber. The actuator can be an acoustic emitter or a piezoelectric device. The apparatus could be battery-operated by a battery enclosed in the chamber. A sensor enclosed within the chamber could be powered by signals propagated within the fiber optic cable. Additional apparatus, methods, and systems are disclosed.

An apparatus for acquiring seismic wave data includes a network of geophones and a seismic wave data receiving device coupled to the network and configured to receive the seismic wave data as an optical signal and process the seismic data in real time to provide locations and corresponding sizes of fractures in an earth formation. The network of geophones includes: a plurality of geophone channels, each channel having an array of geophones coupled to a field digitizer unit; an array of geophone patches having geophone channels connected in series by a metallic conductor; a plurality of geophone branches having a metallic conductor and a branch digitizer unit to connect geophone patches in series; a plurality of electrical to optical signal converters for converting signals received from branch digitizer units for transmission using an optical fiber; and a plurality of optical fiber segments for transmitting optical signals to the receiving device.

Methods, systems, and computer-readable medium to perform operations for suppressing seafloor geophone seismic data noise. A computing system applies a vertical geophone de-noise process to enhance a compressional wave signal that is free from (independent of) shear energy leakage. This enhances the signal to noise (S/N) ratio of the vertical geophone component and concurrently make the vertical geophone component consistent with a hydrophone component.

The application describes methods and apparatus for seismic monitoring using fiber optic distributed acoustic sensing (DAS). The method involves interrogating a first optical fiber (102) deployed in an area of interest to provide a distributed acoustic sensor comprising a plurality of longitudinal sensing portions of fiber and also monitoring at least one geophone (107) deployed in the area of interest. The signal from the at least one geophone is analyzed to detect an event of interest (105). If an event of interest is detected the data from the distributed acoustic sensor acquired during said event of interest is recorded. The geophone may be co-located with part of the sensing fiber and in some embodiments may be integrated (307) with the sensing fiber.

A switch responsive to a pressure differential, including a pressure response mechanism for providing a pressure response in response to the pressure differential and a device actuator arranged to interact with the pressure response mechanism and to utilize the pressure response of the pressure response mechanism to actuate a device. The device actuator actuates the device to an operative state when the pressure differential is below a lower pressure differential threshold, and may actuate the device to a non-operative state when the pressure differential is above an upper pressure differential threshold.

Disclosed is a geophysical or seismic exploration system. The system comprises a set of explosive device magazines configured for carrying a plurality of explosive device components, wherein the explosive device components are configurable to form individual explosive devices, and wherein each explosive device carries a set of explosive compositions and is configured for collimating an explosive shock wave produced thereby into a quasi-planar shock wave output from a distal end of the explosive device to produce a geophysical or seismic exploration wave. The system also includes a set of unmanned explosive device deployment support vehicles, wherein each unmanned explosive device deployment support vehicle comprises an aerial or land-based unmanned vehicle configured for carrying an explosive device magazine and delivering the explosive device magazine to a first in-field location at which each explosive device is deployable for carrying out a geophysical or seismic exploration operation.

Example sensor assemblies, seismic sensor incorporating the sensor assemblies, and methods relating thereto are disclosed. In an embodiment, the sensor assembly includes an electrically conductive outer housing, and an electrically insulating holder disposed within the outer housing. The holder comprises a recess. In addition, the sensor assembly includes a sensor element disposed within the recess of the holder. The sensor element is electrically insulated from outer housing by the holder.

A vibration sensor includes: a supporting structure provided with a cavity; a proof mass accommodated in the cavity; a plurality of elastic bodies, each connecting the proof mass to the supporting structure along a corresponding connection axis; an optical fibre portion arranged in contact with each elastic body and wound around the corresponding connection axis. The proof mass has an elongated shape according to a main reference direction (Z), and the plurality of elastic bodies comprises two or more first elastic bodies which are spaced along the main reference direction (Z) and are arranged so that they are all caused to be simultaneously compressed along their corresponding connection axes following a displacement of the proof mass in a first reference direction (X) perpendicular to the main reference direction (Z), and simultaneously stretched along their corresponding connection axes following a displacement of the proof mass in a direction opposite the first reference direction.

A system and method for seismic monitoring of large area subsurface reservoirs, for instance, the system comprising: multiple electro acoustic technology assemblies comprising seismic sensing elements, electronic circuits for converting the seismic sensing signals to frequencies, amplification circuitry to amplify the frequencies, an acoustic source that converts the amplified frequencies to an acoustic frequency signal; a fiber optic acoustic sensing system comprising a fiber optic cable deployed in a subsurface reservoir, where the multiple electro acoustic technology assemblies are proximate to and/or acoustic coupled with the fiber optic cable of the fiber optic acoustic sensing system, and a surface based distributed acoustic sensing interrogator connected to the fiber optic cable.