Abstract:
An apparatus for performing a measurement of a downhole property includes an optical fiber having a first section that has a first set of fiber Bragg gratings with a first resonant wavelength inscribed therein and a second section that has a second set of fiber Bragg gratings with a second resonant wavelength different from the first resonant wavelength inscribed therein. The second section is in series with the first section. An optical interrogator emits a swept-wavelength frequency domain light signal having varying wavelength amplitude modulation into the optical fiber, receives a frequency domain return light signal, and transforms the frequency domain return signal into a time domain to determine a resonant wavelength shift of each fiber Bragg grating and the corresponding location of each interrogated fiber Bragg grating. A processor converts the resonant wavelength shift of each interrogated fiber Bragg grating into the downhole property measurement.
Abstract:
Die Erfindung betrifft einen Lichtvorhang für die optische Detektion von abschattenden Objekten in einer zu überwachenden Fläche, wobei die zu überwachende Fläche von einer Lichtquelle aus durch einen kollimierten, in seiner Richtung veränderbaren Lichtstrahl wiederholt überstrichen wird, wobei die Leistung des die Fläche durchquerenden Lichtes gemessen wird, wobei durch eine auswertende Steuerung aus dem zeitlichen Verlauf der gemessenen Leistung unter Kenntnis des zeitlichen Verlaufes der Richtung des Lichtstrahls auf die Schattengrenzen und damit auf Position und Größe eines abschattenden Objektes geschlossen wird. Entlang des Randes der zu überwachenden Fläche ist eine als flächiger Lichtwellenleiter ausgebildete optische Detektorfläche (3) angeordnet, in welche photolumineszente Partikel integriert sind und an welcher ein oder mehrere photoelektrische Sensoren (3.4) angebracht sind. Damit ist ein Lichtvorhang realisierbar, durch welchen abschattende Objekte mit sehr guter Auflösung detektierbar sind, wobei der Lichtvorhang eine sehr gute Robustheit hat und mit geringen Herstellungskosten bereitstellbar ist.
Abstract:
An apparatus for estimating at least one parameter includes: a deformable member configured to deform in response to the at least one parameter; a housing surrounding at least a portion of an external surface of the deformable member to define an isolated region around the portion and an isolated surface of the deformable member; and at least one optical fiber sensor disposed on the isolated surface and held in an operable relationship with the isolated surface, the at least one optical fiber sensor configured to generate a signal in response to a deformation of the deformable member.
Abstract:
The invention provides a safety arrangement for a laminating machine, the safety arrangement including a plurality of fiber optic sensors (40, 42, 44) and a dynamic braking arrangement. The fiber optic sensors are arranged to cover an entry safety zone (36) disposed prior to the nip (26) such that a standard test finger (46) of 12 mm entering the safety zone will obstruct at least one of the lights from the fiber optic sensor to cut power to the motor driving the rollers (22, 24). When power is so cut, a dynamic braking arrangement provides for rapid arrest of the motor by short-circuiting the motor coil via a relay connected across the voltage applied to the motor.
Abstract:
Eine Vorrichtung und ein Verfahren sind zum Erkennen eines Objekts O in einer verschliessbaren Öffnung vorgesehen, die mittels eines beweglichen Teils (12) verschließbar ist. Mittels einer Lichtquelle (1, 2) wird Licht in wenigstens einen Lichtleiter (33, 34) eingespeist und mittels wenigstens eines Empfängers (Ea, Eb) werden Veränderungen im empfangenen Licht detektiert, wobei der Lichtleiter zumindest teilweise entlang des Rands der Öffnung (11) angeordnet ist. Ein erster Lichtleiter sendet Licht quer zu seiner Längserstreckung aus, das von einem zweiten Lichtleiter quer zu seiner Längserstreckung empfangen wird. Der zweite Lichtleiter (34) steht mit dem Empfänger (Eb) in Verbindung. Die Lichtleiter sind am Rand der Öffnung (11) so angeordnet, dass sich ein zumindest teilweise die Öffnung überbrückendes Lichtfeld (F) ergibt. Jedem Lichtleiter (33, 34) ist jeweils wenigstens eine Lichtquelle (1, 2) und wenigstens ein Empfänger (Ea, Eb) zugeordnet und es ist eine Taktschaltung vorgesehen, die Licht wechselweise in die Lichtleiter einspeist, das vom jeweiligen Empfänger empfangen wird. Vergleichsmittel sind vorgesehen, die die an den Empfängern vorliegenden Signale zum Erkennen des Objekts vergleichen.
Abstract:
A wellbore system includes a logging unit having a retrievable logging cable coupled to a downhole tool within a wellbore and a depth correlation unit in the downhole tool that provides current depth data for the wellbore through the retrievable logging cable for recording of a current depth by the logging unit. The wellbore system also includes a distributed acoustic sensing unit that includes a seismic processing unit and a seismic profiling unit connected to a separate optical cable of the retrievable logging cable having distributed acoustic sensing channels, wherein an assignment of the distributed acoustic sensing channels along the separate optical cable is determined by an offset distance between the current depth of a formation reference region within the wellbore and a previous reference depth of the formation reference region within the wellbore. A distributed acoustic sensing method is also included.
Abstract:
Systems capable of seismically investigating the earth can include seismic sources and a disposable seismic sensor such as a fiber optic seismic sensor included within a drill string. The fiber optic seismic sensor can include a plurality of fiber Bragg gratings. Related methods can include using the seismic sources and the fiber optic seismic sensor to conduct seismic investigations.
Abstract:
A method for determining flow distribution in a formation having a wellbore formed therein includes the steps of positioning a sensor within the wellbore, wherein the sensor generates a feedback signal representing at least one of a temperature and a pressure measured by the sensor, injecting a fluid into the wellbore and into at least a portion of the formation adjacent the sensor, shutting-in the wellbore for a pre-determined shut-in period, generating a simulated model representing at least one of simulated temperature characteristics and simulated pressure characteristics of the formation during the shut-in period, generating a data model representing at least one of actual temperature characteristics and actual pressure characteristics of the formation during the shut-in period, wherein the data model is derived from the feedback signal, comparing the data model to the simulated model, and adjusting parameters of the simulated model to substantially match the data model.
Abstract:
An optical detection system. The optical detection system includes a host node having (a) an optical source for generating optical signals, and (b) an optical receiver. The optical detection system also includes a plurality of fiber optic sensors for converting at least one of vibrational and acoustical energy to optical intensity information, each of the fiber optic sensors having: (1) at least one length of optical fiber configured to sense at least one of vibrational and acoustical energy; (2) a reflector at an end of the at least one length of optical fiber; and (3) a field node for receiving optical signals from the host node, the field node transmitting optical signals along the at least one length of optical fiber, receiving optical signals back from the at least one length of optical fiber, and transmitting optical signals to the optical receiver of the host node.
Abstract:
An apparatus for estimating at least one parameter includes: a deformable member configured to deform in response to the at least one parameter; a housing surrounding at least a portion of an external surface of the deformable member to define an isolated region around the portion and an isolated surface of the deformable member; and at least one optical fiber sensor disposed on the isolated surface and held in an operable relationship with the isolated surface, the at least one optical fiber sensor configured to generate a signal in response to a deformation of the deformable member.