Abstract: A tool for use in wellbore drilling that is suitable for use with a drill string for drilling a wellbore having an inner wall. The tool comprises a cylindrical abrasion surface for contacting the inner-wall and generating particles of solid material, and a smearing device coupled with the drill string for applying radial and circumferential force to smear the generated particles onto the inner wall of the wellbore.

Abstract: The invention describes a method of lining a well using expandable tubing including the steps of lowering a expandable tubing in a well bore; injecting a sealant composition into said well; letting the sealant composition solidify into a deformable matrix embedding at least a bottom section of said tubing within said well; and expanding the tubing. The invention allows the creation of a high quality seal at the shoe of the expandable casing because the deformable material is highly stressed by the expansion, and it also allows for the rest of the casing to be properly supported and protected by conventional cement, without incurring excessive wait-on-cement times.

Abstract: Methods and systems are disclosed for downhole processing of measurements made in a wellbore during the construction of the wellbore. The system includes sensors located downhole adapted to measure downhole parameters. The system uses a downhole processor to calculate a statistical relationship, preferably covariance, between the two downhole parameters. A transmitter located downhole and in communication with the downhole processor is used to transmit the calculated statistical relationship to the surface. At the surface the statistical relationship is compared with surface acquired data and surface drilling operating parameters are altered based on the statistical relationship.

Abstract: The present invention provides method for detecting the possible presence of surfaces layers of diagenetic origin by establishing divergence between well signatures such as logs, particularly for use in predominantly carbonate reservoirs.

Abstract: This invention relates in general to measuring depth of well-tools, such as logging tools or the like, in a borehole. Embodiments of the present invention may provide for disposing transponders along a wireline that may be used to suspend and move the well-tool in the borehole, where the transponders may be disposed along the wireline at predetermined locations. A reader may be located at a reference location and may read when a transponder passes through the reference location and this information may be used to determine the depth of the well-tool in the borehole. Additionally, this invention provides for combining depth measurements from the transponders with measurements from odometer wheels in frictional contact with the wireline and/or time of flight measurements of optical pulses passed along a fiber optic cable coupled with the wireline to accurately and robustly measure the depth of the wireline in the borehole.

Abstract: Data processing means are described for calculating an estimated time of arrival of a seismic or microseismic P or S wave at a sensor station, based on a P to S wave velocity ratio, a calculated estimated time of origin of the event and, where the estimated arrival time of a P wave is to be calculated, a picked arrival time of the S wave at the sensor station or, where the estimated arrival time of a S wave is to be calculated, a picked arrival time of the P wave at the sensor station.

Abstract: A system for communicating information, particular for use in a hydrocarbon well, is described including one or more releasable vessels having radio frequency (RF) circuitry responsive, when in use, to an RF reader system, the vessel including counteracting means to reduce the effect of destabilizing flow forces thereby extending the coupling time with the reader system.

Abstract: Embodiments of the present invention provide systems and methods for deriving a source signature for an array of seismic sources for marine seismic analysis, wherein the systems and methods include factors for determining the source signature taking into consideration both sea-surface and sea-floor reflections of signals produced by the seismic sources. In certain aspects, reflection coefficients of the sea-surface and the sea-floor and relative lengths of paths between a seismic source image and a detector are applied to a series of simultaneous equations that are solved using measurements of the pressure field produced by the array at a plurality of known locations to determine individual source signatures for each seismic source in the array and these individual source signatures may then be superposed to provide a source signature for the array that accounts for sea-floor reflections of outputs from the seismic sources.

Abstract: A system for inferring geological classes from oilfield well input data is described using a neural network for inferring class probabilities and class sequencing knowledge and optimising the class probabilities according to the sequencing knowledge.

Abstract: A downhole apparatus and method for maintaining or reducing the level of liquids at the bottom of a gas producing well is described including a constriction or throat section, such as a Venturi, in which a production gas flow from the well is used to generate a low pressure zone having a pressure less that the ambient formation gas pressure and at least one conduit providing a flow path from an liquids at the bottom of said well to said low pressure zone. The conduit may be adaptable in length to provide for maintaining the flow path as the level of the liquids changes.

Abstract: The invention concerns an aqueous viscoelastic fracturing fluid for use in the recovery of hydrocarbons. According to the invention, the fluid comprises a viscoelastic surfactant and a hydrophobically-modified polymer wherein the concentration of the hydrophobically-modified polymer is comprised between its overlap concentration c* and its entanglement concentration ce.

Abstract: A treatment apparatus and method for wellbore instability is described including a caliper with one or more radially extending arms which are capable of extending and retracting movement in a radial direction and a fluid supply facility to deliver treatment fluid from the ends of the arms to the wellbore wall, with a sensing and valve mechanism such that in use fluid is being delivered from the end of any extended arm to a breakout region of the wellbore where there is instability.

Abstract: Methods and tools are described to reduce sanding including the steps of fracturing the cement sheath in a localized zone around the casing and having the fractured zone act as sand filter between the formation and openings in the casing, with the openings being best pre-formed but temporarily blocked so as to allow a conventional primary cementing of the casing. The fracturing step can also be used for remedial operation to reopen blocked formation or screens.

Abstract: The invention concerns an aqueous viscoelastic fluid for use in the recovery of hydrocarbons. According to the invention, the aqueous viscoelastic fluid comprises a monomer, a dimer or an oligomer of a viscoelastic surfactant able to form a viscoelastic gel under downhole conditions, said surfactant comprising a hydrophobic tail and a hydrophilic head, and being of the following formulae: R—X—Y-Z where R is the hydrophobic tail of the surfactant, Z is the hydrophilic head of the surfactant, said hydrophilic head being charged, X is a stabilising group and Y chain is a linear, saturated or unsaturated, hydrocarbon chain of 1, 2 or 3 carbon atoms or a branched, saturated or unsaturated hydrocarbon chain wherein the main chain is of 1, 2 or 3 carbon atoms, possibly incorporating an aromatic ring.

Abstract: A method and system is disclosed for monitoring one or more characteristics associated with a fluid. An insulating layer comprising non-conducting diamond is positioned within a housing and has a surface exposed directly or indirectly to the fluid. A plurality of microelectrodes made of electrically conducting diamond each have a surface exposed directly or indirectly to the fluid. An electrical circuit in electrical communication with each of the microelectrodes is adapted to convert electrical signals from the microelectrodes into at least one signal associated with a characteristic being monitored. The sensing system is well suited to hydrocarbon wellbore related applications, but can also be used in other applications.

Abstract: A method of and apparatus for processing seismic data. A method of processing seismic data comprising the steps acquiring seismic data in at least two shots that have different source-receiver azimuths from one another, and selecting events arising from interface seismic waves in each shot. The interface wave events are processed to provide information about azimuthal dependence of the velocity of seismic energy in the near-surface of the earth's interior. The invention may be used to process events arising from Scholte waves in marine seismic data, or to processing events arising from Love waves or Rayleigh waves in land seismic data. The method may be applied to seismic data acquired specifically to provide information about the near-surface or to seismic data acquired to provide information about the underlying geological structure.

Abstract: The invention concerns a method of monitoring flow in a flow pipe. According to the invention, the method comprising the following steps: providing a flow pipeline having a unique photon detector at a first position on the periphery of said pipe, a first photon source at a second position on the periphery of of said pipe, said detector and first source defining a first chord across said pipe, and one or more additional photon sources at positions on the periphery of said pipe defining one or more additional chords across said pipe; determining the density across said first chord from the count rate detected from the first source by the detector; and determining the densities across said one or more additional chords from the count rate detected from the one or more additional sources by the detector in order to determine the deposition of solid in the pipe.

Abstract: The disclosure concerns a method and a system for monitoring the composition of a cement slurry or wellbore service fluid, the method and system including one or more feeder units for solid particulate material; one or more mixing or blending units adapted to receive material from the feeder units; one or more outlet tubes to direct the cement slurry or wellbore service fluid to a storage facility or into a wellbore; and a control unit connected to at least one densitometer to monitor the density of the cement slurry or wellbore service fluid; wherein the densitometer comprises a generator free of radioactive material and capable of generating high-energy photons based on accelerating or decelerating electrons.

Abstract: Methods and systems are disclosed for downhole processing of measurements made in a wellbore during the construction of the wellbore. The system includes a sensors located downhole adapted to measure a two downhole parameters. The system uses a downhole processor to calculate a statistical relationship, preferably covariance, between the two downhole parameters. A transmitter located downhole and in communication with the downhole processor is used to transmit the calculated statistical relationship to the surface. At the surface the statistical relationship is compared with surface acquired data and surface drilling operating parameters are altered based on the statistical relationship.

Abstract: A surface mud pipeline system is described with a mechanical acoustic filter (1245) tuned to a predetermined frequency band so as to attenuate pump noise (132) within this band. The filter can be combined with a Venturi constriction to provide enhanced attenuation and is used to improve signal transmission of a mud pulse telemetry system (113-2).