Abstract: A method for constructing a three-dimensional representation of an internal surface of a conduit comprises obtaining a plurality of images of the internal surface of the conduit, for example from a camera mounted on an inspection tool, constructing, from the plurality of images, a composite image of the internal surface, providing a shape model of the internal surface, constructing, using the shape model, a three-dimensional mesh of the internal surface, and constructing a three-dimensional representation of the internal surface by assigning a pixel value from the composite image to a corresponding node of the mesh. The three-dimensional representation may be derived from two or more sets of images obtained under different image acquisition conditions, such as different camera angles, lighting conditions or spectral sensitivities.

Abstract: Methods for correcting for non-centred tool geometry in image data obtained by a conduit inspection tool are disclosed. Embodiments of the invention apply to inspection tools with one or multiple sideview cameras and to inspection tools with downview cameras. The methods include obtaining at least two overlapping images of the internal surface of the conduit using the tool, identifying one or more features common to at least a pair of the overlapping images, determining, based on the positions of the or each common feature, the position of the tool with respect to a longitudinal axis of the conduit, determining a correction function based on the position of the tool and applying the correction function to the image data. Methods for determining the dimension of a feature of interest on the internal surface of the conduit are also disclosed.

Abstract: A method for determining a corrected axial displacement parameter of a conduit inspection tool, in particular a downhole inspection tool, during transit of the tool axially along a conduit is disclosed. The tool used in the method has an imaging device and may be attached to a control module with a connecting line. The method comprises obtaining successive axially overlapping images of an internal wall of the conduit, determining, from the images, an observed axial displacement parameter of the tool as a function of transit time, identifying, in the images, a plurality of reference points, determining an estimated axial displacement parameter of the tool over an of transit time between successive reference points, and computing the corrected axial displacement parameter of the tool by applying a correction factor to the observed axial velocity of the tool.

Abstract: Inspection assemblies that include one or more sideview cameras for capturing images of an interior surface of a pipe or conduit include an elongate housing, a sideview camera within the housing and arranged to capture an image of a region within a field of view external to the housing, and a viewport element mounted in the housing and located such that light is transmitted through the viewport element and into said sideview camera, wherein the viewport element has a concave internal surface, closer to the camera, and a convex external surface, further from the camera, and wherein the centre of the radius of curvature of the internal surface is closer to the viewport element than the centre of the radius of curvature of the external surface.

Abstract: The field of inspection assemblies and in particular to inspection assemblies that include light sources for illuminating a field of view of a camera including an elongate housing having a longitudinal axis, a camera mounted in the housing and arranged to capture an image of a region within a field of view external to the housing, a light source mounted in the housing and arranged to illuminate the field of view, and a window element mounted in the housing, the window element comprising a light transmitting material and being located such that light emitted by the light source passes through the window element before illuminating the field of view. The window element has an internal surface, closer to the light source, and an external surface, further from the light source, and the external surface comprises a concave region.

Abstract: A method of constructing a three-dimensional model of an internal surface of a tubular structure comprises obtaining image data from an area of the internal surface of the structure, obtaining measured height profile data from the internal surface in a plurality of sub-regions of the area, for example using a multi-finger caliper tool, determining image properties from the image data, correlating the measured height profile data with the image properties in the sub-regions, and constructing expected height profile data for at least part of the area outside the sub-regions using the correlated measured height profile data and image properties.

Abstract: Inspection assemblies that include one or more sideview cameras for capturing images of an interior surface of a pipe or conduit include an elongate housing, a sideview camera within the housing and arranged to capture an image of a region within a field of view external to the housing, and a viewport element mounted in the housing and located such that light is transmitted through the viewport element and into said sideview camera, wherein the viewport element is diffusion bonded to a metal support.

Abstract: An optical cap that protects a camera lens of the inspection assembly is disclosed herein. The disclosed optical cap for an inspection assembly may include an optically clear dome-shaped window element and a metal collar attached to the window element, the collar including means for securing the optical cap to said inspection assembly, wherein the collar is bonded to the window element by means of brazing or welding.

Abstract: This invention relates to an inspection assembly comprising a light source and a lens. In particular this invention relates to the provision of a reflection surface for improving the illumination of a field of view of a wide angle camera. An inspection assembly comprises a main body having a longitudinal axis and a distal end; a lens located at the distal end; a light source positioned to illuminate an area beyond the distal end of the main body; and a reflection surface, an angle between the reflection surface and the longitudinal axis of the main body being between 10° and 70°, wherein the reflection surface is positioned such that, in use, a first fraction of the light emitted by the light source is reflected by the reflection surface and a second fraction of the light emitted by the light source travels to an area beyond the distal end of the main body without being reflected by said surface.

Abstract: This invention is designed for use in transmission of data between downhole module in a wellbore and a controlling module at the surface. The invention provides an apparatus for receiving data signals from a telemetry module comprising first and second adaptive equalisers, and in which in a first modulation mode the coefficients of the first adaptive equaliser are updated until an error signal falls below a predetermined threshold and in a second modulation mode the coefficients of the first adaptive equaliser are locked and coefficients of the second adaptive equaliser are updated to continually minimise an error signal in which the number of bits encoded by the symbols of the first signal in an initial modulation mode is fewer than the number of bits encoded by the symbols of the second signal in a subsequent modulation mode.

Abstract: The present invention relates to an optical element for use in a camera system for the inspection of passageways, a camera system for the inspection of passageways and a method of illuminating a passageway during inspection with a camera. An optical element for use in a camera system for the inspection of passageways comprises a first optical portion arranged to transmit light into a camera, a second optical portion arranged to transmit light emitted from a light source, the second optical portion located adjacent the first optical portion, and barrier means arranged to prevent light being transmitted from the second optical portion into the first optical portion.

Abstract: An inspection apparatus for use in wellbores in the oil and gas industries relates in general to the field of transmission of data between downhole module in a wellbore and a controlling module at the surface. The invention provides a method and apparatus for determining analog filter parameters for an analog front end comprising a plurality of filter stages receiving signals from a telemetry module, by repeating the steps of; receiving a signal of a known frequency and processing said signal by determining the magnitude of the frequency of the received signal until a plurality of signals have been received and processed; calculating an optimum set of filter parameters in dependence upon the measured frequency magnitudes and a predefined set of filter stage frequency responses.

Abstract: A pipeline inspection apparatus includes a main body. A sealing structure attached to the main body seals against an internal surface of the pipeline. An imaging module includes a camera and a light source. The light source is arranged to emit light in a direction towards the internal surface of the pipeline. The camera is arranged such that, in use, the camera captures image data of the internal surface of the pipeline. Control circuitry includes a power supply and memory for storing data captured by said camera, wherein the sealing structure forms a seal against the internal surface of the pipeline such that, in use, a fluid flowing along the pipeline applies a driving force to the pipeline inspection apparatus to propel the apparatus along the pipeline.

Abstract: A camera assembly (10) for the inspection of passageways, particularly wellbores, and designed to operate in high temperature environments. A camera assembly for the inspection of wellbores comprises an elongate housing (12) having a first end (30) and a second end (42) and, extending between the ends, a side wall comprising an inner wall (22) and an outer wall (24), with a vacuum formed between the inner and outer walls; an elongate relay lens (52) having a first end (56) and a second end (62), the relay lens being located within the housing; an optically transparent window (46) located at the first end of the relay lens; an image sensor (48) located at the second end of the relay lens for capturing an image of an object viewable through the relay lens and window; and a light source (16) arranged to emit light from the housing, for illuminating the viewable object.

Abstract: The present invention relates to inspection apparatus for use in wellbores in the oil and gas industries. In particular the invention relates in general to the field of transmission of data between downhole module in a wellbore and a controlling module at the surface. The invention provides a method and apparatus for determining analog filter parameters for an analog front end comprising a plurality of filter stages receiving signals from a telemetry module, by repeating the steps of; receiving a signal of a known frequency and processing said signal by determining the magnitude of the frequency of the received signal until a plurality of signals have been received and processed; calculating an optimum set of filter parameters in dependence upon the measured frequency magnitudes and a predefined set of filter stage frequency responses.

Abstract: A method and associated system for determining geometry of a deformed pipe or conduit or wellbore, the method comprising: collecting, determining and/or receiving measurement data indicative of a plurality of radii of the pipe or conduit using equipment centred in the pipe at two or more points a known distance from the measurement point but not at the measurement point itself; selecting a deformation type and/or deformation model; processing the measurement data to determine one or more geometrical properties of the pipe or conduit, the geometrical properties being indicative of, or associated with, one or more deformations, shapes or profiles of at least part of the pipe or conduit; and guiding and/or constraining at least a part of the processing of the measurement data using the selected deformation type or model and/or fitting the selected deformation model to the measurement data.

Abstract: The present invention relates to inspection apparatus for use in wellbores in the oil and gas industries. In particular the invention relates in general to the field of transmission of data between downhole module in a wellbore and a controlling module at the surface. The invention provides a method an apparatus for receiving data from a telemetry module, the data being modulated according to a quadrature amplitude modulation coding scheme, in which a receiver has a carrier recovery circuit comprising a phase detector, a loop filter and a signal synthesizer generating an inphase and a quadrature demodulation signal. The method comprises receiving a preamble sinusoidal signal representing a symbol; determining the cross product of the received inphase and quadrature components and ideal inphase and quadrature components; indexing a look up table with said cross product to determine a phase adjustment and adjusting the phase of the demodulation signals in accordance with said determined phase adjustment.

Abstract: The present invention relates to inspection apparatus for use in wellbores in the oil and gas industries. In particular the invention relates in general to the field of transmission of data between downhole module in a wellbore and a controlling module at the surface. The invention provides a method and apparatus for determining analogue filter parameters for an analogue front end comprising a plurality of filter stages receiving signals from a telemetry module, by repeating the steps of; receiving a signal of a known frequency and processing said signal by determining the magnitude of the frequency of the received signal until a plurality of signals have been received and processed; calculating an optimum set of filter parameters in dependence upon the measured frequency magnitudes and a predefined set of filter stage frequency responses.

Abstract: This invention relates to a pipeline inspection apparatus and to a method of inspecting the internal surfaces of a pipeline using a pipeline inspection apparatus.

Abstract: The present invention relates to an optical element for use in a camera system for the inspection of passageways, a camera system for the inspection of passageways and a method of illuminating a passageway during inspection with a camera. An optical element for use in a camera system for the inspection of passageways comprises a first optical portion arranged to transmit light into a camera, a second optical portion arranged to transmit light emitted from a light source, the second optical portion located adjacent the first optical portion, and barrier means arranged to prevent light being transmitted from the second optical portion into the first optical portion.