Abstract: The present invention provides a roller sub for use downhole in oil or gas wells as part of a toolstring or drill string to reduce friction between the string and wellbore. The roller sub is a modular assembly of parts which assemble together to trap the roller wheels in place between them, avoiding need for grub screws to fasten the individual wheels and rendering the roller sub very compact.

Abstract: An apparatus and method for use in severing casing as it is pulled from a wellbore. An apparatus is first provided, comprising a clamping assembly, a drilling assembly and a cutting assembly. In one aspect, the apparatus is disposed at the end of a telescopic arm, with the components being remotely operated by personnel using a control panel. The apparatus can be positioned adjacent casing and clamped thereto. Thereafter, the apparatus can drill a hole completely through the casing for the insertion of a retention pin. The apparatus can then severe the casing into manageable lengths to facilitate disposal, such as during a plugging and abandonment procedure.

Abstract: A wavelength-tunable laser consists of a resonant semiconductor cavity coupled to a sampled Bragg reflector grating having reflectivity peaks for N optical frequencies. The resonant cavity is formed of two opposite reflector members that are not wavelength selective and delimit an amplifier section coupled to a phase tuning section. The optical length of the cavity is adjustable electro-optically as a function of a control voltage applied to it. The laser can be tuned quickly over a wide band.

Abstract: A fiber grating pressure sensor includes an optical sensing element which includes an optical fiber having a Bragg grating impressed therein which is encased within and fused to at least a portion of a glass capillary tube and/or a large diameter waveguide grating having a core and a wide cladding. Light is incident on the grating and light is reflected from the grating at a reflection wavelength &lgr;1. The sensing element may be used by itself as a sensor or located within a housing. When external pressure P increases, the grating is compressed and the reflection wavelength &lgr;1 changes. The shape of the sensing element may have other geometries, e.g., a “dogbone” shape, so as to enhance the sensitivity of shift in &lgr;1 due to applied external pressure and may be fused to an outer shell.

Abstract: The present invention provides an apparatus and method expanding a portion of a tubular. The expansion apparatus is run into a wellbore on a working string. The expansion apparatus first comprises a rotary expander for expanding an expandable tubular. The expansion apparatus further comprises a spline assembly for coupling the rotary expander to a motor disposed on the work string. The rotary expander and spline assembly have hollow bodies that allow them to encircle the work string and rotate relative thereto. The spline assembly comprises an inner sleeve and outer sleeve. The inner sleeve is attached to the motor and the outer sleeve is attached to the rotary expander. The inner and outer sleeves are coupled to each other using a spline and groove connection. The connection allows the rotary expander to be rotated by the motor, while at the same time, allow the rotary expander to move axially relative to the motor. The rotary expander comprises two rows of rollers for expansion against the tubular.

Abstract: A method and apparatus for etching a magnetic memory cell stack are described. More particularly, HCl is used as a main etchant gas for etching a magnetic memory cell stack. HCl is used in part to reduce corrosion and improve selectivity. Additionally, use of an amorphous carbon or hydrocarbon based polymer resin for a hard mask is described, as well as a post-etch passivation with a water rinse, a water vapor plasma treatment or an ammonia plasma treatment. Moreover, in an embodiment, a diffusion barrier layer dispose most of the magnetic memory cell stack is etched with hydrogen and fluorine containing gas in a separate process chambers.

Abstract: A positive displacement pump for pumping fluids from a downhole formation to the earth's surface is provided. The pump first comprises a plunger. The plunger is reciprocated axially within the wellbore by a linear actuator, such as a submersible electrical pump, in order to form an upstroke and a downstroke. A pump inlet is disposed near the bottom end of the plunger, while a pump outlet is disposed near the top end of the plunger. The pump is configured such that it is able to pump a first volume of fluid upward within the wellbore during the pump's upstroke, and a second volume of fluid upward within the wellbore during the pump's downstroke. Thus, the pump is “double-acting.

Abstract: A method and apparatus for operating a matching network within a plasma enhanced semiconductor wafer processing system that uses pulsed power to facilitate plasma processing.

Abstract: 1. Multi-mode Interferometric coupler comprising: a first amplifying part (2), a second transparent part (4) to guide radiation previously amplified in the first part.

Abstract: The present invention seeks to provide a GFF with a technique amenable to manufacturing in large volume and having a filter with a more precise control of the spectral response.

Abstract: A flame detection apparatus has a focused array based sensor which is responsive to radiation having a predefined wavelength for generating an image of the infrared radiation emitted within a monitored region, and means for measuring the spectral ratio of the intensity of radiation having a first wavelength emitted within the monitored region to the intensity of radiation having a second wavelength emitted within the monitored region. Processing means analyzes the output of the focused array based sensor and the spectral ratio measuring means for responses indicative of the presence of a flame within the monitored region.

Abstract: An apparatus and a method for positioning a tubular relative to a tong is provided. In one aspect, a positioning tool may be mounted on a lower portion of the tong. The positioning tool includes a positioning member for determining a position of the tubular and a centering member for engaging the tubular. The positioning tool further includes an actuation device for actuating the centering member. The position of the tubular may be actively adjusted by actuating the centering member.

Abstract: A multiphase flow meter distributed system is disclosed that is capable of measuring phase flow rates of a multiphase fluid. The distributed system includes at least one flow meter disposed along the pipe, an additional sensor disposed along the pipe spatially removed from the flow meter, and a multiphase flow model that receives flow related parameters from the flow meter and the additional sensor to calculate the phase flow rates. The flow meter provides parameters such as pressure, temperature, fluid sound speed and/or velocity of the fluid, and the additional sensor provides a parameter indicative of pressure and or temperature of the fluid. Depending on production needs and the reservoir dimensions, the distributed system may utilize a plurality of flow meters disposed at several locations along the pipe and may further include a plurality of additional sensors as well. The distributed system preferably uses fiber optic sensors with bragg gratings.

Abstract: The present invention provides an optical waveguide phase shifter that comprises a planar silicon-dioxide-containing optical glass waveguide whose core contains glass, and also a planar optical polymer waveguide whose core contains a polymer and/or a mixture of polymers, furthermore means that effect the change in the temperature of the planar optical polymer waveguide and wherein the refractive index of the planar optical polymer waveguide is greater than the refractive index of the planar silicon-dioxide-containing optical waveguide. The refractive indices of the planar optical polymer waveguide and of the silicon-dioxide-containing optical glass waveguide can consequently be matched even by a small increase in the temperature of the planar optical polymer waveguide. In addition, only the propagation constant of the optical field in a silicon-dioxide-containing optical waveguide according to the invention is influenced by the coupling mode between silicon-dioxide waveguide and polymer waveguide.

Abstract: An optical waveguide Bragg grating fabrication apparatus (1) comprises a light source (2) providing ultra-violet (UV) light and optical means (4,5A-B,6A-B,7A-B,9) for adapting the light beam to form an interference pattern in a photosensitive optical waveguide (8). The interference pattern has a spatial intensity modulation along the length of the optical waveguide and thus providing an optical grating in the waveguide in the form of a refractive index modulation. The optical means comprises a movable non-uniform diffractive mask (4) for dividing the optical beam in at least two beams (12A-B) and optical elements for collecting two or more of the light beams to interfere on the optical waveguide. The optical means comprises position control means for controlling the position of at least one mirror or lens. Corresponding methods and the use of a super-periodic diffractive mask in such fabrication are described.

Abstract: A pressure-isolated Bragg grating temperature sensor includes an optical element, which includes an optical fiber having at least one Bragg grating disposed therein. The Bragg grating is encased within and fused to at least a portion of an inner glass capillary tube, or comprises a large diameter waveguide grating having a core and a wide cladding and having the grating disposed therein, encased within an outer tube to form a chamber. An extended portion of the sensing element that has the grating therein extends inwardly into the chamber, which allows the grating to sense temperature changes but isolates the grating from external pressure. More than one grating or pair of gratings may be used and more than one fiber or optical core may be used. At least a portion of the sensing element may be doped between a pair of gratings to form a temperature tuned laser, or the grating or gratings may be configured as a tunable DFB laser disposed in the sensing element.

Abstract: A circuit configuration for a current switch of a bit line or a word line of a magnetoresistive random access memory (MRAM) device, comprising a directional switch and a voltage driver that, in operation, reduces the ON resistance of the directional switch. In one embodiment, each terminal of the line is provided with such a switch.

Abstract: The present invention generally relates to a method for recovering productivity of an existing well. First, an assembly is inserted into a wellbore, the assembly includes a tubular member for transporting drilling fluid downhole and an under-reamer disposed at the end of the tubular member. Upon insertion of the assembly, an annulus is created between the assembly and the wellbore. Next, the assembly is positioned near a zone of interest and drilling fluid is pumped down the tubular member. The drilling fluid is used to create an underbalanced condition where a hydrostatic pressure in the annulus is below a zone of interest pressure. The under-reamer is activated to enlarge the wellbore diameter and remove a layer of skin for a predetermined length. During the under-reaming operation, the hydrostatic pressure is maintained below the zone of interest pressure, thereby allowing wellbore fluid to migrate up the annulus and out of the wellbore.

Abstract: An optical fiber amplifier system includes an optical fiber adapted for use as an optical wave guide amplifier, and at least one optical pump optically coupled into the optical amplifier, wherein the pump receives both a DC electrical input and an AC electrical input, and wherein the pump provides an optical pump power to the optical fiber having both a DC optical power component and an AC optical power component. The optical fiber amplifier system also includes an optical pump power detector optically coupled to the pump, and at least one controller operatively connected to the pump power detector to determine the DC optical power component of the optical pump power, and wherein the controller adjusts the DC electrical input to the pump based on the DC optical power component.

Abstract: A method and apparatus for reducing the sensitivity of semiconductor processing to chamber conditions is provided. Process repeatability of common processes are affected by changing surface conditions which alter the recombination rates of processing chemicals to the chamber surfaces. In one aspect of the invention, a composition of one or more etchants is selected to optimize the etch performance and reduce deposition on chamber surfaces. The one or more etchants are selected to minimize buildup on the chamber surfaces, thereby controlling the chamber surface condition to minimize changes in etch rates due to differing recombination rates of free radicals with different surface conditions and achieve etch repeatability. In another embodiment, the etchant chemistry is adjusted to reduce the change to internal surface conditions after a cleaning cycle. In another embodiment, a process recipe is selected to reduce the sensitivity of the etch process to the chamber conditions.