Abstract: The present invention provides an apparatus and method for sensing subsurface data. One embodiment of the invention comprises a shuttle attached to a conveyance where the conveyance and shuttle are adapted to be spooled downhole into a borehole for sensing seismic data. The shuttle contains a sensor package that is preferably acoustically isolated in the shuttle. The sensor package includes a sensor array and a magnet clamp. A sensor section can contain several shuttles, each shuttle containing at least one sensor. In one embodiment, the sensor can be a fiber optic sensor. The magnet clamp is operable to controllably clamp and acoustically couple together the sensor package, the shuttle, and the adjacent structure which is typically the borehole casing. The magnet clamp is likewise operable to unclamp and uncouple the shuttle from the adjacent structure so as to be retracted uphole for subsequent use.

Abstract: A method and apparatus for determining formation parameters including a seismic array for receiving seismic waves at plurality of depth simultaneously, thereby enabling a determination of a formation velocity by using a difference in the seismic waves received by the various portions of the array.

Abstract: Remote sensing systems are provided including a recorder, a cable network and a plurality of downhole sensor nodes. The cable network comprises a first cable and a second cable. The first and second cables form a loop. The recorder and the plurality of downhole sensor nodes are connected to the cable network in series. The first cable delivers power to the nodes and the second cable comprises a power return and closes the loop to the recorder.

Abstract: To attenuate a surface seismic wave, seismic sensors having a predetermined orientation with respect to a surface are provided, where the seismic sensors receive seismic waves including a seismic wave reflected from a subterranean structure and the surface seismic wave propagating in at least a first direction that is generally parallel to the surface. A signal that represents a partial derivative of a wavefield containing the surface seismic wave is provided, and the signal is integrated to obtain a response in which the surface seismic wave is attenuated.

Abstract: Methods and apparatus for creating a velocity profile of a formation surrounding a borehole by checkshot measurements while moving the tool along the borehole. A conveyance and a sensor section are configured to move the sensor section in the borehole. At least one receiver is configured to detect signals generated at or near the surface while the sensor section is moving in the borehole.

Abstract: Various techniques are described which may be used to facilitate and improve seismic exploration activities. For example, one aspect of the present invention is directed to a technique for enabling in-situ measurement of geophone response parameters. Another aspect of the present invention is directed to a technique for improving geophone calibration and for improving the accuracy of measurement of geophone response parameters. Yet another aspect of the present invention is directed to a technique for compensating geophone response output data in order to improve the accuracy of such data.

Abstract: The present disclosure provides, among other things, apparatuses and methods for sensing subsurface data. One embodiment comprises borehole conveyance system tool, the borehole conveyance system tool comprising a conveyance, a sensor array disposed on the conveyance, and an acquisition electronics section disposed on the conveyance distal of the sensor array. One embodiment includes at least one downhole tension sensor to help indicate when a tool is stuck and what part of the tool is stuck.

Abstract: The present invention provides an apparatus and method for sensing subsurface data. One embodiment of the invention comprises a shuttle attached to a conveyance where the conveyance and shuttle are adapted to be spooled downhole into a borehole for sensing seismic data. The shuttle contains a sensor package that is preferably acoustically isolated in the shuttle. The sensor package includes a sensor array and a magnet clamp. A sensor section can contain several shuttles, each shuttle containing at least one sensor. In one embodiment, the sensor can be a fiber optic sensor. The magnet clamp is operable to controllably clamp and acoustically couple together the sensor package, the shuttle, and the adjacent structure which is typically the borehole casing. The magnet clamp is likewise operable to unclamp and uncouple the shuttle from the adjacent structure so as to be retracted uphole for subsequent use.

Abstract: Various techniques are described which may be used to facilitate and improve seismic exploration activities. For example, one aspect of the present invention is directed to a technique for enabling in-situ measurement of geophone response parameters. Another aspect of the present invention is directed to a technique for improving geophone calibration and for improving the accuracy of measurement of geophone response parameters. Yet another aspect of the present invention is directed to a technique for compensating geophone response output data in order to improve the accuracy of such data.

Abstract: Subterranean oilfield sensor systems and methods are provided. The subterranean oilfield sensor systems and methods facilitate downhole monitoring and high data transmission rates with power provided to at least one downhole device by a light source at the surface. In one embodiment, a system includes uphole light source, a downhole sensor, a photonic power converter at the downhole sensor, an optical fiber extending between the uphole light source and the photonic power converter, and downhole sensor electronics powered by the photonic power converter. The photonic power converter is contained in a high temperature resistant package. For example, the high temperature resistant package and photonic power converter may operate at temperatures of greater than approximately 100° C.

Abstract: The present invention provides an apparatus and method for sensing subsurface data. One embodiment of the invention comprises a shuttle attached to a conveyance where the conveyance and shuttle are adapted to be spooled downhole into a borehole for sensing seismic data. The shuttle contains a sensor package that is preferably acoustically isolated in the shuttle. The sensor package includes a sensor array and a magnet clamp. A sensor section can contain several shuttles, each shuttle containing at least one sensor. In one embodiment, the sensor can be a fiber optic sensor. The magnet clamp is operable to controllably clamp and acoustically couple together the sensor package, the shuttle, and the adjacent structure which is typically the borehole casing. The magnet clamp is likewise operable to unclamp and uncouple the shuttle from the adjacent structure so as to be retracted uphole for subsequent use.

Abstract: The present invention provides methods and apparatus for measuring subterranean strain. The methods and apparatus use fluid expansion principles to compensate for temperature variations and increase the accuracy of the strain measurements. The methods and apparatus contemplate the use of multiple fluid chambers according to some embodiments in order to remove temperature dependence from stress or strain measurements.

Abstract: A vibration transducer such as a geophone, comprising a central pole piece (110) with a magnet (112) and coil (118) concentrically arranged around it. The position of the magnet (112) is fixed relative to the pole piece (110) and the coil (118) is movable relative to the magnet (112). A method of manufacturing a vibration transducer is characterised in that a bobbin carrying the coils is formed from a substantially tubular body which is positioned on a mandrel and at least one coil is wound around its outer surface, the mandrel being removed from the bobbin when the coil is complete. Another method is characterised in that the coil is formed separately and the bobbin is formed from a substantially tubular body which is positioned inside the coil and expanded to contact the coil when in position.

Abstract: The present invention provides methods and apparatus for measuring subterranean strain. The methods and apparatus use fluid expansion principles to compensate for temperature variations and increase the accuracy of the strain measurements. The methods and apparatus contemplate the use of multiple fluid chambers according to some embodiments in order to remove temperature dependence from stress or strain measurements.

Abstract: Various techniques are described which may be used to facilitate and improve seismic exploration activities. For example, one aspect of the present invention is directed to a technique for enabling in-situ measurement of geophone response parameters. Another aspect of the present invention is directed to a technique for improving geophone calibration and for improving the accuracy of measurement of geophone response parameters. Yet another aspect of the present invention is directed to a technique for compensating geophone response output data in order to improve the accuracy of such data.

Abstract: A method of monitoring the path of a borehole comprises acquiring drill bit seismic data while a borehole is being drilled. The acquired drill bit seismic data is used to determine whether the drilling path of the borehole is correct, for example by using the acquiring drill bit seismic data to update the geological model used to determine the drilling path. The drilling path of the borehole is updated using seismic data acquired as the borehole is being drilled, so that it is not necessary to interrupt the drilling process in order to update the drilling path. The invention thus makes possible a real-time, or near real-time, method of progressively updating the drilling path. The invention also provides a method of determining the properties of a surface or near-surface layer (7). The source of seismic energy for this method is acoustic energy, generated by the impact of the drill bit (9), that is transmitted up the drill string (10) and re-radiated into the earth at the top of the borehole (6).

Abstract: The present invention provides an apparatus and method for sensing subsurface data. One embodiment of the invention comprises a shuttle attached to a conveyance where the conveyance and shuttle are adapted to be spooled downhole into a borehole for sensing seismic data. The shuttle contains a sensor package that is preferably acoustically isolated in the shuttle. The sensor package includes a sensor array and a magnet clamp. A sensor section can contain several shuttles, each shuttle containing at least one sensor. In one embodiment, the sensor can be a fiber optic sensor. The magnet clamp is operable to controllably clamp and acoustically couple together the sensor package, the shuttle, and the adjacent structure which is typically the borehole casing. The magnet clamp is likewise operable to unclamp and uncouple the shuttle from the adjacent structure so as to be retracted uphole for subsequent use.

Abstract: A vibration transducer such as a geophone, comprising a central pole piece (110) with a magnet (112) and coil (118) concentrically arranged around it. The position of the magnet (112) is fixed relative to the pole piece (110) and the coil (118) is movable relative to the magnet (112). A method of manufacturing a vibration transducer is characterised in that a bobbin carrying the coils is formed from a substantially tubular body which is positioned on a mandrel and at least one coil is wound around its outer surface, the mandrel being removed from the bobbin when the coil is complete. Another method is characterised in that the coil is formed separately and the bobbin is formed from a substantially tubular body which is positioned inside the coil and expanded to contact the coil when in position.

Abstract: A downhole seismic exploration device comprises a seismic detector such as a geophone and a magnetic clamp, supported by O-rings in an open cradle carrier which can be secured to a cable linking several such devices into an array. The array is lowered into a cased borehole and the magnetic clamps are operated to clamp the devices temporarily to the casing. Seismic signals detected by the geophones are transmitted to the surface via the cable, the O-ring supports acting to reduce or eliminate transmission of vibrations from the borehole fluid and the cable via the carrier to the geophone. The array is then unclamped and moved to another location in the borehole and the operation repeated. The magnetic clamp comprises a rotatable permanent magnet with radial poles disposed between a pair of parallel pole piece plates protruding on each side of the device and separated by non-magnetic blocks on eahc side of the magnet.

Abstract: A downhole seismic exploration device comprises a seismic detector such as a geophone and a magnetic clamp, supported by Q-rings in an open cradle carrier which can be secured to a cable linking several such devices into an array. The array is lowered into a cased borehole and the magnetic clamps are operated to clamp the devices temporarily to the casing. Seismic signals detected by the geophones are transmitted to the surface via the cable, the O-ring supports acting to reduce or eliminate transmission of vibrations from the borehole fluid and the cable via the carrier to the geophone. The array is then unclamped and moved to another location in the borehole and the operation repeated. The magnetic clamp comprises a rotatable permanent magnet with radial poles disposed between a pair of parallel pole piece plates protruding on each side of the device and separated by non-magnetic blocks on each side of the magnet.