Abstract: An accelerator-based neutron tool is provided. The tool includes a deuterium-tritium gas mixture such that the tool outputs a desired ratio of 2.45 MeV and 14 MeV neutrons.

Abstract: A method comprising using inelastic and capture gamma-ray count rates from two detectors in a borehole logging tool and determining formation water saturation. In this method the formation water saturation is determined without prior knowledge of the carbon density in the pore hydrocarbons.

Abstract: A method and apparatus for measuring a substance in formations surrounding an earth borehole being drilled with a drill bit at the end of a drill string, using drilling fluid that flows downward through the drill string, exits through the drill bit entrained with drilled earth formation cuttings, and returns toward the earth's surface in the annulus between the drill string and the borehole, the method including the following steps: waiting for any of the substance that is dissolved in the drilling fluid to be substantially in equilibrium with any of the substance in the earth formation cuttings; and then measuring, downhole, the substance dissolved in the drilling fluid.

Abstract: A method for determining a property of earth formations surrounding a borehole, including the following steps: isolating a region of the borehole, and obtaining a sample of borehole fluid from the isolated region; and implementing measurements, dowhole, of the Raman scattering of electromagnetic energy directed at the fluid sample; the property of the earth formations being determinable from the measurements. In a disclosed embodiment, the steps of isolating a region of the borehole and obtaining a sample of borehole fluid from the isolated region include: providing a logging device in the borehole in sealing engagement with the isolated region, causing formation fluid from the isolated region to flow in a flow line of the logging device, and providing a measurement cell in the logging device which receives the sample of formation fluid via the flow line.

Abstract: A differential pressure flow rate measurement apparatus comprises: a conduit having a flow passage for conveying a fluid flow, the conduit being adapted for connection to a downhole fluid flow line having a bore of predetermined transverse cross-sectional area; a flow energy dissipator which partially obstructs the flow passage and which is capable of imparting an angular velocity to the fluid flow and thereby causing a dissipative pressure drop in the fluid; and a pressure sensor for measuring said pressure drop. The flow passage, when viewed in the axial direction of the flow passage, projects an unobstructed transverse cross-sectional area which is at least 25% of the transverse cross-sectional area of said bore.

Abstract: A preferred method for determining the flow fraction of a mixture of water, gas and oil in a hydrocarbon reservoir includes measuring pressure and density of the mixture over time, determining a function which approximates a relationship between the density and pressure measurements, calculating a derivative of the function over time, and determining flow fraction based, in part, on the derivative. Preferably, transient data points are eliminated and the remaining set of data points are weight averaged to improve signal to noise ratio. Bubble point pressure, bubble point density and molecular weight and density of the liquid portion of the mixture are also used in the determination.

Abstract: A flow meter for multiphase flows, includes a holdup measuring device having a Venturi located upstream thereof and separated therefrom by a distance that results in flow through the holdup measuring device being at least partially homogenized by the effect of the Venturi on the fluids flowing therethrough.

Abstract: In accordance with an embodiment of the present invention, a method of processing large volumes of data to allow for real-time reservoir management is disclosed, comprising: a) acquiring a first data series from a first reservoir sensor; b) establishing a set of criteria based on reservoir management objectives, sensor characteristics, sensor location, nature of the reservoir, and data storage optimization, etc.; c) identifying one or more subsets of the first data series meeting at least one of the criteria; and optionally d) generating one or more second data series based on at least one of the subsets. This methodology may be repeated for numerous reservoir sensors. This methodology allows for intelligent evaluation of sensor data by using carefully established criteria to intelligently select one or more subsets of data. In an alternative embodiment, sensor data from one or more sensors may be evaluated while processing data from a different sensor.

Abstract: A differential pressure flow rate measurement apparatus comprises:

Abstract: A gravity measuring apparatus is provided comprising a gravitational force detector including a test mass and which produces measurements related to gravitational force exerted on the test mass, characterized in that the gravitational force detector is adapted for use downhole and includes a compensator to compensate for errors in measurements made whilst downhole. The compensator may comprise a guide rail along which the gravitational force detector is moveable over a calibrated distance. Where the test mass is biased toward an equilibrium position about which measurements are made.

Abstract: A method of and apparatus for determining a physical property of a material. The method includes: attaching nanoparticles to a substrate; positioning the substrate near the material; illuminating the nanoparticles with photons having wavelengths that stimulate surface enhanced Raman emissions; detecting photons emitted as a result of the illumination; and determining said physical property of said material using said detected photons. The apparatus includes: a substrate; nanoparticles attached to the substrate; a light source, connected to the substrate, for illuminating the nanoparticles with photons having wavelengths that stimulate surface enhanced Raman emissions; a photodetector, connected to the substrate, for detecting photons emitted as a result of illumination of the nanoparticles; and a processor, connected to the photodetector, for determining a property of material near the nanoparticles from the detected photons.

Abstract: A method of and apparatus for determining a physical property of a material. The method includes: attaching nanoparticles to a substrate; positioning the substrate near the material; illuminating the nanoparticles with photons having wavelengths that stimulate surface enhanced Raman emissions; detecting photons emitted as a result of the illumination; and determining said physical property of said material using said detected photons. The apparatus includes: a substrate; nanoparticles attached to the substrate; a light source, connected to the substrate, for illuminating the nanoparticles with photons having wavelengths that stimulate surface enhanced Raman emissions; a photodetector, connected to the substrate, for detecting photons emitted as a result of illumination of the nanoparticles; and a processor, connected to the photodetector, for determining a property of material near the nanoparticles from the detected photons.

Abstract: A flow meter for multiphase flows, includes a holdup measuring device having a Venturi located upstream thereof and separated therefrom by a distance that results in flow through the holdup measuring device being at least partially homogenized by the effect of the Venturi on the fluids flowing therethrough.

Abstract: There is provided downhole power generation apparatus with a first electrode, a second electrode and an electrolyte, wherein the first electrode comprises a casing within a borehole. The first electrode and the second electrode are formed from dissimilar metals and by appropriate selection of the two dissimilar metals, the casing functions as the cathode. Typically the first electrode is formed from a steel casing and the second electrode is of zinc. The second electrode is provided on an insulated connector joining at least two sections of casing. Power is extracted in an electrical load connected between the casing and the second electrode. Where a cement holds the casing in place within the borehole, it serves as the electrolyte. The cement is provided with additives to improve its conductivity. The first electrode is provided with oxide coatings, such as iron (III) oxide, to mediate the electrolytic reaction at the cathode.

Abstract: Once an oil well has been drilled and is producing, it is desirable to monitor the rate at which oil or gas is being delivered. It is particularly useful to know when there is a change in a fluid's output rate, for that can indicate problems with the well. This monitoring is known as “production logging”. Prior to the introduction of horizontal well drilling, most wells were either vertical or only slightly deviated. However, many present-day wells have long horizontal or nearly-horizontal portions, and the techniques used to measure flow in vertical wells are not applicable to horizontal wells. Moreover, any flow rate measurement technique to be used downhole should take account not only of the several sorts of “lined” wells but also the “barefoot” ones.

Abstract: An x-ray generator provides a continuous bremsstrahlung photon spectrum for determining the water to liquid ratio in a mixture of oil/water/gas flowing through a pipe located a distance from the generator. A plurality of detectors measure photons passing along a beam path from the generator through the fluid. A detector is also provided to monitor the energy distribution of the generator. A time interval for measuring the output of each detector is established such that small changes in the gas to liquid ratio occur during this interval. An energy bin width is selected to provide a linear approximation of the water to liquid ratio. After binning the counts for each detector, a multi-phase flow characteristic such as the water to liquid fraction, liquid density, or liquid fraction along the beam path is determined.

Abstract: A method of measuring flow velocities in flowing fluids includes injecting into the flow a non-radioactive tracer having a neutron capture cross section higher than that of the flowing fluids, for example a gadolinium compound, and measuring the neutron capture cross section in the fluid downstream of the injection point to detect the passage of the tracer and hence determine the time of flight. By making the tracer miscible with only one phase (typically the continuous phase) of a multi-phase fluid, it is possible to measure the flow velocity of that phase. The neutron capture cross section can be measured by irradiating with neutrons from a pulsed neutron generator and measuring capture .gamma. rays with a scintillation detector.

Abstract: Measurement-while-drilling apparatus includes a 14 MeV neutron accelerator, a near-spaced neutron detector which primarily senses source neutrons and whose output is proportional to source strength, one or more intermediately-spaced epithermal neutron detectors eccentered against the drill collar wall and primarily responsive to formation hydrogen concentration, and a third far-spaced radiation detector, either gamma ray or neutron, primarily responsive to formation density. The intermediately-spaced and far-spaced detector outputs, normalized by the near-spaced detector output, are combined to provide measurements of porosity, density and lithology and to detect gas. A thermal neutron detector and/or a gamma ray detector may also be provided at intermediate spacings to provide additional information of interest, such as standoff measurements and spectral analysis of formation composition. Tool outputs are related to the angular or azimuthal orientation of the measurement apparatus in the borehole.

Abstract: A method of determining a characteristic of an underground formation including the steps of irradiating the formation with high energy neutrons and detecting neutrons scattered by the formation having energies above epithermal to determine the nature of the formation matrix. Epithermal neutrons can also be detected to determine formation porosity. Apparatus includes a high energy neutron source, typically a D-T accelerator producing 14 MeV neutrons, and detectors such as .sup.4 He filled proportional counters for detecting neutrons having energies above epithermal and .sup.3 He filled proportional counters for detecting epithermal neutrons.

Abstract: Measurement-while-drilling apparatus includes a 14 MeV neutron accelerator, a near-spaced neutron detector which primarily senses source neutrons and whose output is proportional to source strength, one or more intermediately-spaced epithermal neutron detectors eccentered against the drill collar wall and primarily responsive to formation hydrogen concentration, and a third far-spaced radiation detector, either gamma ray or neutron, primarily responsive to formation density. The intermediately-spaced and far-spaced detector outputs, normalized by the near-spaced detector output, are combined to provide measurements of porosity, density and lithology and to detect gas. A thermal neutron detector and/or a gamma ray detector may also be provided at intermediate spacings to provide additional information of interest, such as standoff measurements and spectral analysis of formation composition. Tool outputs are related to the angular or azimuthal orientation of the measurement apparatus in the borehole.