Abstract: The invention relates to methods and apparatus for determining downhole mud flow rates and other downhole parameters. A method for determining a downhole parameter includes operating a pulsed neutron generator (6), pulsing the pulsed neutron generator (6) off, detecting a substantially unactivated drilling fluid slug at a known distance (d) from the pulsed neutron generator (6), and determining a time-of-flight (t) for the unactivated drilling fluid slug to travel from the pulsed neutron generator (6) to a detection point.

Abstract: An apparatus and method for determining the density and other properties of a formation surrounding a borehole using a high voltage x-ray generator. One embodiment comprises a stable compact x-ray generator capable of providing radiation with energy of 250 keV and higher while operating at temperatures equal to or greater than 125° C. In another embodiment, radiation is passed from an x-ray generator into the formation; reflected radiation is detected by a short spaced radiation detector and a long spaced radiation detector. The output of these detectors is then used to determine the density of the formation. In one embodiment, a reference radiation detector monitors a filtered radiation signal. The output of this detector is used to control at least one of the acceleration voltage and beam current of the x-ray generator.

Abstract: An x-ray tool for determining a characteristic of an oilfield fluid. The tool may include a generator portion housing a collimator about a target from which x-rays are emitted. In this manner x-rays may be attenuated right at the target such that a majority of shielding otherwise necessary for safety concerns may be eliminated. Rather, by employing the target within the collimator, shielding of the generator may be limited to a single shielding plate within the generator portion that is positioned parallel to the target at the opposite end of an x-ray tube therebetween. As a result of this configuration, an x-ray tool for analysis of oilfield fluids may be provided with a minimum weight of shielding material. Thus, hand-held user friendly embodiments may be safely employed at the oilfield.

Abstract: An X-ray downhole imaging tool is provided and includes an X-ray tube capable of operating at least at 50 KeV and emitting at least one hundred micro-amperes of continuous electron current and a radiation detector axially displaced from the X-ray tube, at least partially shielded therefrom and radially directed. In certain embodiments, the radiation detector includes a microchannel plate and a resistive anode. In certain embodiments, a second detector which is axially directed is also provided.

Abstract: An apparatus and method for determining the density and other properties of a formation surrounding a borehole using a high voltage x-ray generator. One embodiment comprises a stable compact x-ray generator capable of providing radiation with energy of 250 keV and higher while operating at temperatures equal to or greater than 125° C. In another embodiment, radiation is passed from an x-ray generator into the formation; reflected radiation is detected by a short spaced radiation detector and a long spaced radiation detector. The output of these detectors is then used to determine the density of the formation. In one embodiment, a reference radiation detector monitors a filtered radiation signal. The output of this detector is used to control at least one of the acceleration voltage and beam current of the x-ray generator.

Abstract: An apparatus and method for determining the density and other properties of a formation surrounding a borehole using a high voltage x-ray generator. One embodiment comprises a stable compact x-ray generator capable of providing radiation with energy of 250 keV and higher while operating at temperatures equal to or greater than 125° C. In another embodiment, radiation is passed from an x-ray generator into the formation; reflected radiation is detected by a short spaced radiation detector and a long spaced radiation detector. The output of these detectors is then used to determine the density of the formation. In one embodiment, a reference radiation detector monitors a filtered radiation signal. The output of this detector is used to control at least one of the acceleration voltage and beam current of the x-ray generator.

Abstract: A method for operating a pulsed neutron generator includes adjusting a target current of the neutron generator to a preselected value. A parameter related to a neutron output of the neutron generator is measured. A target voltage of the neutron generator is adjusted to maintain the measured parameter within a predetermined range.

Abstract: An apparatus and method for determining the density and other properties of a formation surrounding a borehole using a high voltage x-ray generator. One embodiment comprises a stable compact x-ray generator capable of providing radiation with energy of 260 keV and higher while operating at temperatures equal to or greater than 125° C. In another embodiment, radiation is passed from an x-ray generator into the formation; reflected radiation is detected by a short spaced radiation detector and a long spaced radiation detector. The output of these detectors is then used to determine the density of the formation. In one embodiment, a reference radiation detector monitors a filtered radiation signal. The output of this detector is used to control at least one of the acceleration voltage and beam current of the x-ray generator.

Abstract: An apparatus for determining fractional amounts of each phase of a multiple phase fluid includes an x-ray generator includes a sample chamber is configured to admit therein a sample of fluid for analysis. The chamber is disposed in a radiation path output from the generator. A filter is disposed in the radiation path between the output of the generator and the radiation input of the sample chamber. A first radiation detector is positioned in a radiation path from the sample chamber after radiation has passed through the sample chamber. A thickness and a material of the filter are selected to optimize resolution of radiation detected by the first detector to changes in volume fraction of oil and water in the fluid sample when a gas fraction thereof is between about 90 to 100 percent.

Abstract: An X-ray downhole imaging tool is provided and includes an X-ray tube capable of operating at least at 50 KeV and emitting at least one hundred micro-amperes of continuous electron current and a radiation detector axially displaced from the X-ray tube, at least partially shielded therefrom and radially directed. In certain embodiments, the radiation detector includes a microchannel plate and a resistive anode. In certain embodiments, a second detector which is axially directed is also provided.

Abstract: The invention relates to methods and apparatus for determining a downhole parameter in an underbalanced drilling environment which include: selectively activating a first fluid flowing from the formation through a wellbore while under balanced drilled; detecting the activated first fluid, and determining a depth at which said fluid enters the wellbore.

Abstract: A method and apparatus for determining the density and phase fractions of well services fluids is shown including an x-ray generator, a sample cell, and a radiation detector. Radiation is passed through the sample cell and fluid and the attenuated radiation signal is used to evaluate the fluid. In one embodiment, a reference radiation detector measures a filtered radiation signal and controls the acceleration voltage and/or beam current of the x-ray generator using this information. The apparatus may be permanently affixed for long term monitoring or temporarily clamped on to a pipe in production.

Abstract: A fluid density determination apparatus and method comprising an X-ray generator emitting a high energy radiation signal and a low energy radiation signal; a sample cell housing a sample of interest and at least one of the high energy and low energy radiation signals being directed through the sample cell; and a radiation detector measuring the output radiation from the sample cell. Data gathered at the radiation detector using the high and low energy signals are used to calculate the density of the fluid sample of interest.

Abstract: The invention relates to methods and apparatus for determining a downhole parameter in an underbalanced drilling environment which include: selectively activating a first fluid flowing from the formation through a wellbore while under balanced drilled; detecting the activated first fluid; and determining a depth at which said fluid enters the wellbore.

Abstract: An apparatus and method for determining the density and other properties of a formation surrounding a borehole using a high voltage x-ray generator. One embodiment comprises a stable compact x-ray generator capable of providing radiation with energy of 260 keV and higher while operating at temperatures equal to or greater than 125° C. In another embodiment, radiation is passed from an x-ray generator into the formation; reflected radiation is detected by a short spaced radiation detector and a long spaced radiation detector. The output of these detectors is then used to determine the density of the formation. In one embodiment, a reference radiation detector monitors a filtered radiation signal. The output of this detector is used to control at least one of the acceleration voltage and beam current of the x-ray generator.

Abstract: An x-ray tool for determining a characteristic of an oilfield fluid. The tool may include a generator portion housing a collimator about a target from which x-rays are emitted. In this manner x-rays may be attenuated right at the target such that a majority of shielding otherwise necessary for safety concerns may be eliminated. Rather, by employing the target within the collimator, shielding of the generator may be limited to a single shielding plate within the generator portion that is positioned parallel to the target at the opposite end of an x-ray tube therebetween. As a result of this configuration, an x-ray tool for analysis of oilfield fluids may be provided with a minimum weight of shielding material. Thus, hand-held user friendly embodiments may be safely employed at the oilfield.

Abstract: A tool for formation logging includes a support configured for movement in a borehole; a neutron source disposed on the support; a neutron monitor disposed on the support and configured to monitor an output of the neutron source; a gamma-ray detector disposed on the support and spaced apart from the neutron source; and a shielding material disposed between the gamma-ray detector and the neutron source.

Abstract: A method and apparatus for determining the density and phase fractions of well services fluids is shown including an x-ray generator, a sample cell, and a radiation detector. Radiation is passed through the sample cell and fluid and the attenuated radiation signal is used to evaluate the fluid. In one embodiment, a reference radiation detector measures a filtered radiation signal and controls the acceleration voltage and/or beam current of the x-ray generator using this information. The apparatus may be permanently affixed for long term monitoring or temporarily clamped on to a pipe in production.

Abstract: An x-ray tool for determining a characteristic of an oilfield fluid. The tool may include a generator portion housing a collimator about a target from which x-rays are emitted. In this manner x-rays may be attenuated right at the target such that a majority of shielding otherwise necessary for safety concerns may be eliminated. Rather, by employing the target within the collimator, shielding of the generator may be limited to a single shielding plate within the generator portion that is positioned parallel to the target at the opposite end of an x-ray tube therebetween. As a result of this configuration, an x-ray tool for analysis of oilfield fluids may be provided that is no more than about 50 lbs. in total weight. Thus, hand-held user friendly embodiments may be safely employed at the oilfield.

Abstract: An apparatus and method for determining the phase fraction of a fluid collected downhole is shown comprising an x-ray generator, a filter, a sample cell, and a radiation detector. The filter produces a radiation spectrum with a high energy portion and a low energy portion. Filtered radiation is passed through a sample fluid and the resulting attenuated radiation signal is used in calculating the phase fractions of oil, water, and gas in the sample fluid. In one embodiment, a second reference radiation detector measures the radiation directly from the x-ray generator and this measurement is used in normalizing the fraction result. The ratio of the high energy signal to low energy signal of the reference detector is used in controlling the input voltage of the x-ray generator thus ensuring a stable spectrum.