| Patent application number | Description | Published |
|---|
| 20100158435 | SIDE-HOLE CANE WAVEGUIDE SENSOR - A side-hole optical cane for measuring pressure and/or temperature is disclosed. The side-hole cane has a light guiding core containing a sensor and a cladding containing symmetrical side-holes extending substantially parallel to the core. The side-holes cause an asymmetric stress across the core of the sensor creating a birefringent sensor. The sensor, preferably a Bragg grating, reflects a first and second wavelength each associated with orthogonal polarization vectors, wherein the degree of separation between the two is proportional to the pressure exerted on the core. The side-hole cane structure self-compensates and is insensitive to temperature variations when used as a pressure sensor, because temperature induces an equal shift in both the first and second wavelengths. Furthermore, the magnitude of these shifts can be monitored to deduce temperature, hence providing the side-hole cane additional temperature sensing capability that is unaffected by pressure. Additionally, the side-hole cane can be used to measure a differential pressure between a first pressure ported to the side-holes and a second external pressure. | 06-24-2010 |
| 20110116099 | APPARATUS AND METHOD FOR DETECTING PRESSURE SIGNALS - An apparatus for detecting data in a fluid pressure signal in a conduit comprises an optical fiber loop comprises a measurement section and a delay section wherein the measurement section is disposed substantially circumferentially around at least a portion of the conduit, and wherein the measurement section changes length in response to the fluid pressure signal in the conduit. A light source injects a first optical signal in a first direction into the measurement section and a second optical signal in a second direction opposite the first direction into the delay section. An optical detector senses an interference phase shift between the first optical signal and the second optical signal and outputs a first signal related thereto. | 05-19-2011 |
| 20110308788 | CONTROLLING WELL OPERATIONS BASED ON MONITORED PARAMETERS OF CEMENT HEALTH - A method of controlling a well operation can include monitoring at least one parameter of cement lining a wellbore, the monitoring being performed via at least one optical waveguide, and modifying the well operation in response to the parameter being outside of a predetermined acceptable range. A well monitoring system can include at least one optical waveguide which is used to sense at least one parameter of cement lining a wellbore, an optical interrogation system optically connected to the at least one optical waveguide, and a control system which controls operation of at least one item of well equipment in response to information received from the optical interrogation system. | 12-22-2011 |
| 20120013893 | COMMUNICATION THROUGH AN ENCLOSURE OF A LINE - A communication system can include a transmitter which transmits a signal, and at least one sensing device which receives the signal, the sensing device including a line contained in an enclosure, and the signal being detected by the line through a material of the enclosure. A sensing system can include at least one sensor which senses a parameter, at least one sensing device which receives an indication of the parameter, the sensing device including a line contained in an enclosure, and a transmitter which transmits the indication of the parameter to the line through a material of the enclosure. Another sensing system can include an object which displaces in a subterranean well. At least one sensing device can receive a signal from the object. The sensing device can include a line contained in an enclosure, and the signal can be detected by the line through a material of the enclosure. | 01-19-2012 |
| 20120205103 | Cement Slurry Monitoring - Various disclosed cement slurry monitoring methods include monitoring one or more parameter of the cement slurry at various positions along the borehole during the curing process and responsively identifying a span over which the slurry extends and whether there are any gaps or voids in that span. At least some system embodiments include a distributed sensing arrangement to provide parameter measurements as a function of position and time during the curing process. A computer analyzes the measurements to determine the span of the cement slurry and whether any gaps exist. Contemplated measurement parameters include temperature, pressure, strain, acoustic spectrum, acoustic coupling, and chemical concentration. Individually or in combination, these measurements can reveal in real time the state of the cement slurry and can enable remedial actions to be taken during or after the curing process if needed to address deficiencies in the annular seal being provided by the cement. | 08-16-2012 |
| 20120257475 | Optical Fiber Based Downhole Seismic Sensor Systems and Methods - Various optical fiber-based seismic monitoring system embodiments include a light source that drives an optical fiber positioned within a borehole. At least one light sensor analyzes Rayleigh backscattered light to obtain an acoustic signal for each of multiple points along the borehole. One or more processors operate to determine microseismic event direction, distance, and/or intensity based at least in part on phase information of said acoustic signals. The acoustic signal cross-correlations, semblances, or phase-sensitive similarity measures can be determined as a function of scanning direction to accurately determine the relevant microseismic event information. The optical fiber may be positioned in the cemented annulus of a cased borehole having a shape that extends along more than one dimension (e.g., an L-shaped borehole). | 10-11-2012 |
| 20130056197 | OPTICAL CASING COLLAR LOCATOR SYSTEMS AND METHODS - Disclosed are fiber optic enabled casing collar locator systems including a wireline sonde or a coil tubing sonde apparatus configured to be conveyed through a casing string by a fiber optic cable. The sonde includes at least one permanent magnet producing a magnetic field that changes in response to passing a collar in the casing string. Such magnetic field changes induce voltages changes within associated pick-up electrical coil conductors. Some embodiments include a cylinder configured to change its diameter in response to the changes in the magnetic field and/or impressed voltage, and an optical fiber wound around the cylinder to convert the cylinder diameter change into an optical path length change for light being communicated along the fiber optic cable. The cylinder may include a magnetostrictive material or a piezoelectric material. | 03-07-2013 |
| 20130056202 | Optical Casing Collar Locator Systems and Methods - Fiber optic enabled casing collar locator systems and methods include a wireline sonde or a coil tubing sonde apparatus configured to be conveyed through a casing string by a fiber optic cable. The sonde includes at least one permanent magnet producing a magnetic field that changes in response to passing a collar in the casing string, a coil that receives at least a portion of the magnetic field and provides an electrical signal in response to the changes in the magnetic field, and a light source that responds to the electrical signal to communicate light along an optical fiber to indicate passing collars. | 03-07-2013 |
