Abstract:
A centralizer includes a body having a bore with an axis, the bore being configured to receive a tubular to be centralized, the body having at least one resilient device configured to extend radially from the axis of the bore, wherein the body has at least one collar member extending radially inwards from the centralizer body adjacent to an end of the body. The collars are fixed co-axially in the bore to be resistant to axial movement of the collar member, and can be retained in the body by radially extending a lip formed by forcing material radially inwards into the bore to retain the collar. The body is adapted to receive within the bore an anchoring device for connection to the tubular. The anchoring device is configured to engage the collar member within the bore so that relative movement of the centralizer and the tubular is restricted.
Abstract:
A centraliser is disclosed for an oil, gas or water well, the centraliser having a body, and the body having a bore with an axis, the bore being configured to receive a tubular to be centraliser, the body having at least one resilient device configured to extend radially from the axis of the bore, wherein the body has at least one collar member extending radially inwards from the centraliser body adjacent to an end of the body. The collar can be formed separately from the body and attached subsequently, so that the body and the resilient device can optionally be formed in a single stamping or forming step from a single sheet of resilient material. The collars (typically at each end) are typically fixed co-axially in the bore so as to be resistant to axial movement of the collar member within the bore relative to the body of the centraliser, and can be retained in the body by radially extending a lip formed by forcing material at the ends of the body radially inwards into the bore to retain the collar. The body is typically adapted to receive within the bore at least one anchoring device for connection to the tubular, and the anchoring device is configured to engage the collar member within the bore of the body so that relative movement of the centraliser and the tubular is restricted once the anchoring device is fixed to the tubular and the anchoring device engages the collar member. A method of centralising a tubular in a borehole for an oil, gas or water well, and a method of making a centraliser for centralising a tubular in an oil, gas or water well are also disclosed.
Abstract:
The present invention provides a wavelength multiplexer/demultiplexer comprising a plurality of regions of optically permissive material. The plurality of regions are disposed adjacent one another in a side by side relationship in order to define a stratified body. The materials in adjacent regions have differing indexes of refraction. The stratified body has a first surface and a second surface that are positioned in a non-parallel relationship with respect to one another. The first surface is a light-receiving surface, and the second surface is a light-exiting surface.
Abstract:
An integrated etched multilayer grating-based wavelength multiplexer/demultiplexer is disclosed wherein an etched multilayer grating structure is monolithically integrated within the optical waveguide stack of the multiplexer/demultiplexer to reflectively diffract an input optical beam. The multilayer grating structure is generally comprised of a series of etched diffractive elements and an etched multilayer reflector, the combined optical response of which providing the desired multiplexing/demultiplexing effect. The etched structures are generally comprised of shallow etch structures in a top surface of the multiplexer/demultiplexer waveguide stack. Monolithically integrated input and output ridge waveguides may also be provided, optionally fabricated in a same etching step as the etched multilayer grating.
Abstract:
The present invention provides a wavelength multiplexer/demultiplexer comprising a plurality of regions of optically permissive material. The plurality of regions are disposed adjacent one another in a side by side relationship in order to define a stratified body. The materials in adjacent regions have differing indexes of refraction. The stratified body has a first surface and a second surface that are positioned in a non-parallel relationship with respect to one another. The first surface is a light-receiving surface, and the second surface is a light-exiting surface.