Abstract: A method for monitoring for seismic events by interrogating an optic fiber which forms part of an existing communications infrastructure to provide distributed acoustic sensing (DAS). The signals provided by the distributed sensing provide measurements at each of a plurality of discrete portions along the fiber, which may be many tens of kilometers in length. Warning or measurement and consequently prediction of seismic activity can be provided by collecting data over a wide area, without the need to deploy a correspondingly large fiber network.

Abstract: This application relates to methods and apparatus for monitoring hydraulic fracturing in well formation and fracture characterization using distributed acoustic sensing (DAS). The method involves interrogating a optic fiber (102) arranged down the path of a bore hole (106) to provide a distributed acoustic sensor and also monitoring flow properties of fracturing fluid pumped (114) into the well. The acoustic data from the distributed acoustic sensor is processed together with the flow properties data to provide an indication of at least one fracture characteristic.

Abstract: A value stream process or method for forming vehicle rails from extruded aluminum tubes includes the steps of extruding an aluminum tube and hydroforming the extruded aluminum tube into a vehicle rail. More specifically, the method includes extruding the aluminum tube, bending the aluminum tube, preforming the aluminum tube, hydroforming the aluminum tube into a vehicle rail, trimming the vehicle rail to length and then artificially aging the rail followed by batch chemical pretreatment. In an alternative embodiment the artificial aging and batch chemical pretreatment processes are performed in reverse order. In either of the embodiments, localized induction annealing to recover formability may be performed between bending and preforming, between preforming and hydroforming or both.

Abstract: Methods and apparatus for downhole monitoring are provided by interrogating an unmodified optic fibre (102) arranged along the path of a well bore (106) to provide a distributed acoustic sensor and sampling data gathered from a plurality of contiguous sensing portions of the fibre. The sampled data is processed to determine one or more well bore parameters. The well bore parameters may comprise a well condition profile, and may be obtained in response to an acoustic stimulus.

Abstract: A rack for simultaneously processing a plurality of parts includes a frame, a plurality of defined locations on the frame for receiving and holding individual parts for processing and a latching assembly for locking the parts to the frame in the defined locations. The rack further includes a security feature for indicating if the latching assembly is opened after the parts have been loaded and locked into the defined locations on the frame.

Abstract: Methods and apparatus for tracking objects in conduits, especially for tracking the movement of a pig in a pipeline, are disclosed. Distributed acoustic sensing is used to obtain signal returns from a plurality of discrete longitudinal sensing portions of a fibre optic cable which is laid along the length of the conduit. The method involves detecting an acoustic signature corresponding to the object moving in the conduit. The acoustic signature may comprise a series of pressure pulses caused by the object traversing joints etc. in the conduit. Preferably the method involves detecting pressure waves caused by the object as it moves through the conduit. Detecting the characteristic pressure wave signal provides discrimination of the object from other acoustic disturbances. In pipeline applications a pig can be tracked in real time, if the pig stops moving an alert can be generated and the location of the pig will be known.

Abstract: A method for attaching a roof panel to a roof rail of a vehicle bodyside frame, wherein the roof rail prohibiting access to an underside of an area at which the roof panel attaches to the roof panel, can include applying a single-component adhesive to a roof rail or to a portion of a roof panel that rests on the roof rail, placing the roof panel onto the roof rail, attaching the roof panel to the roof rail using single-sided spot welds, and heating the roof panel and vehicle bodyside frame to a temperature that cures the single-component adhesive.

Abstract: This application relates to methods and apparatus for monitoring hydraulic fracturing during oil/gas well formation. A fiber optic cable (102) deployed down a well bore (106), which may be the well bore in which fracturing is performed, is interrogated to provide a distributed acoustic sensor. Data is sampled from at least one longitudinal sensing portion of the fiber and processed to provide at least fracturing characteristic. The fracturing characteristic may comprise the characteristics of high frequency transients indicative of fracturing events (606). The intensity, frequency, duration and signal evolution of the transients may be monitored to provide the fracturing characteristic. Additionally or alternatively the fracturing characteristic may comprise the longer term acoustic noise generated by fracture fluid flow to the fracture sites. The intensity and frequency of the noise may be analyzed to determine the fracturing characteristic. The method allows real-time control of the fracturing process.

Abstract: The invention relates to a distributed fiber optic sensor (104, 106) having a first spatial resolution (301, 303) and a second, different, spatial resolution (302, 304). The sensor, which may be a distributed acoustic sensor, has an optical source (112) configured to interrogate an optical fiber (104) with optical radiation and a detector (116) configured to detected optical radiation back-scattered from within the fiber. A processor (108) is configured to process the detected back-scatter radiation to provide a plurality of longitudinal sensing portions of fiber. The optical source and processor are adapted to provide the first and second spatial resolutions, for instance by changing the duration and/or separation of the optical pulses and analysis bins. The first and second spatial resolutions may be provided sequentially or simultaneously and the spatial resolution used may be varied as part of a default pattern or in response to a detection event.

Abstract: A fiber-optic sensor package (10) comprises a serial array of fiber-optic sensing coils (14, 16, 18, 20, 22) each of which is comprised in a respective fiber-optic sensor. Four (14, 16, 18, 22) of the coils are housed in a protective casing (24). One of the coils (22) is comprised in a fiber-optic electromagnetic field sensor. The other coils are comprised in respective fiber-optic geophones and/or hydrophones. A single package of the invention allows detection of both seismic and electromagnetic signals. An array of packages of the invention provides detection of both seismic and electromagnetic signal at a series of positions over a long distance or wide area, thus avoiding the need for two conventional arrays. A packages of the invention, and an array of such packages, require little or no electrical power input.

Abstract: A method for attaching a roof panel to a roof rail of a vehicle bodyside frame, wherein the roof rail prohibiting access to an underside of an area at which the roof panel attaches to the roof panel, can include applying a single-component adhesive to a roof rail or to a portion of a roof panel that rests on the roof rail, placing the roof panel onto the roof rail, attaching the roof panel to the roof rail using single-sided spot welds, and heating the roof panel and vehicle bodyside frame to a temperature that cures the single-component adhesive.

Abstract: A plurality of sensors output information into a distributed acoustic sensing (DAS) system via acousto-mechanical signals. The sensors are coupled to the optic fibre at the centre of the DAS system indirectly, the acousto-mechanical signal being transmitted via an intermediary body, such as the ground or a conduit.

Abstract: A method for attaching a roof panel to a roof rail of a vehicle bodyside frame, wherein the roof rail prohibiting access to an underside of an area at which the roof panel attaches to the roof panel, can include applying a single-component adhesive to a roof rail or to a portion of a roof panel that rests on the roof rail, placing the roof panel onto the roof rail, attaching the roof panel to the roof rail using single-sided spot welds, and heating the roof panel and vehicle bodyside frame to a temperature that cures the single-component adhesive.

Abstract: This application describes methods and apparatus for distributed acoustic sensing providing enhanced sensitivity for certain acoustic signals. The method uses a fibre optic distributed acoustic sensing (DAS) apparatus (106) to detect acoustic signals wherein the fibre optic distributed acoustic sensor comprises at least one optical fibre (104) deployed in an area of interest (204) such that at least one section of said optical fibre is deployed to monitor the acoustic response of a cavity (206) to incident acoustic signals. The cavity is dimensioned such that the cavity resonates at a desired frequency and thus the relevant sensing portions of the DAS sensor show an enhanced response to acoustic signals which excite resonance in the cavity. The optical fibre (104) may be deployed to run through said cavity.

Abstract: This application relates to methods and apparatus for seismic surveying using optical fibre distributed acoustic sensing (DAS). The method involves using a fibre optic distributed acoustic sensor to detect seismic signals. The fibre optic distributed acoustic sensor comprises an interrogator (106) arranged to interrogate at least one optical fibre (104) buried in the ground (204) in the area of interest. The method involves stimulating the ground using a seismic source (201) and detecting the seismic signals, for example reflected from various rock strata (202, 203).

Abstract: A method of distributed acoustic sensing (DAS) whereby the derivative or rate of change of a signal backscatted from a fiber is measured. The change, or derivative of the phase measured in this way has a much smaller amplitude than the signal itself if the difference between the two times at which the signal is measured is much less than the period of the signal being measured, resulting in lower sensitivity. Frequency shifts can be applied to temporally displaced return signals to compare the rate of change, for example by employing an output interferometer arranged to modulate the signal in each arm by a different frequency shift.

Abstract: This application relates to methods and apparatus for monitoring hydraulic fracturing in well formation and fracture characterisation using distributed acoustic sensing (DAS). The method involves interrogating a optic fibre (102) arranged down the path of a bore hole (106) to provide a distributed acoustic sensor and also monitoring flow properties of fracturing fluid pumped (114) into the well. The acoustic data from the distributed acoustic sensor is processed together with the flow properties data to provide an indication of at least one fracture characteristic.

Abstract: A device for monitoring the extent of cure of an adhesive located between at least two components. The device includes a data logger operably connected to at least one of the components, and configured to record data related to time and temperature, obtaining a thermal history data of the component during a heating process. An algorithm, installed in the data logger, processes the thermal history data of the component. A kinetic cure model is included in the algorithm calculating and predicting an extent of adhesive cure according to the processed thermal history. The device further includes a visual display operably connected to the data logger and configured to indicate the extent of adhesive cure.

Abstract: There is provided a system (100) for magnetic field detection, comprising a fibre optic interrogator (104) adapted to interrogate a first length of optical fibre (102) with interrogating radiation, detect radiation backscattered from said optical fibre and analyse said detected radiation to provide distributed sensing indicative of mechanical disturbances of said optical, wherein the optic fibre is mechanically coupled to a material whose dimensions vary dependant on applied magnetic field. Changes in dimensions of the optic fibre as can be detected by virtue of changes in back-scattering of light from said fibre using the principles of fibre optic distributed acoustic sensing.

Abstract: A system for moving object (402) detection is provided, the system comprising a fibre optic interrogator (106) adapted to provide distributed acoustic sensing on a optic fibre (104), for example arranged along a border. The measurement signals from each of a plurality of sensing portions (404, 406, 408, 410, 412) of said fibre are analysed to determined a characteristic of a Doppler shift. The characteristic of a Doppler shift may be a generally continuous decrease in detected frequency. By detecting the time at which the rate of change of frequency is at a maximum for each of the sensing portions the time of closest approach (ti, t2, t3, t4, t5) of the object to those sensing portions can be determined with the sensing portion the object approaches closest to showing the greatest value of maximum rate of change of frequency. The distance of closest approach and velocity can be determined.