Abstract: A ground penetrating antenna apparatus and method are provided for locating underground objects via radar, sonar, or similar methods. The apparatus includes one or more antennas that are rotatably affixed to support extensions that also rotate, but about an axis that is different from each of the antenna axes. The apparatus includes a linear propulsion mechanism, and the support extensions may be coupled to the linear propulsion mechanism via a transmission mechanism. In one embodiment, the supporting extensions rotate at a constant rate and each antenna rotates at that same constant rate but in the opposite direction.

Abstract: An apparatus and method for combining a survey measurement dataset and a position dataset into a single dataset containing both measurement and position data is disclosed. The survey measurement data may be obtained from a ground penetrating radar, an inductometer, a magnetometer, or an optical camera. Positioning information is collected and merged with the survey information so that the position of the survey tool is known at each data point. Also provided are channel-equalization filters, spiking deconvolution filters, and frame filters that can be used in conjunction with the positioning information to enhance the quality of the images obtained from the data collected by the survey tool.

Abstract: An apparatus and method for combining a survey measurement dataset and a position dataset into a single dataset containing both measurement and position data is disclosed. The survey measurement data may be obtained from a ground penetrating radar, an inductometer, a magnetometer, or an optical camera. Positioning information is collected and merged with the survey information so that the position of the survey tool is known at each data point. Also provided are channel-equalization filters, spiking deconvolution filters, and frame filters that can be used in conjunction with the positioning information to enhance the quality of the images obtained from the data collected by the survey tool.

Abstract: A ground penetrating antenna apparatus and method are provided for locating underground objects via radar, sonar, or similar methods. The apparatus includes one or more antennas that are rotatably affixed to support extensions that also rotate, but about an axis that is different from each of the antenna axes. The apparatus includes a linear propulsion mechanism, and the support extensions may be coupled to the linear propulsion mechanism via a transmission mechanism. In one embodiment, the supporting extensions rotate at a constant rate and each antenna rotates at that same constant rate but in the opposite direction.

Abstract: A ground penetrating antenna apparatus and method are provided for locating underground objects via radar, sonar, or similar methods. The apparatus includes one or more antennas that are rotatably affixed to support extensions that also rotate, but about an axis that is different from each of the antenna axes. The apparatus includes a linear propulsion mechanism, and the support extensions may be coupled to the linear propulsion mechanism via a transmission mechanism. In one embodiment, the supporting extensions rotate at a constant rate and each antenna rotates at that same constant rate but in the opposite direction.

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 tool which contains a pulsed accelerator neutron source and means for making timing measurements of the thermal neutron response in a localized portion of the environment immediately surrounding the borehole. Formation sigma is determined by parameterizing the detected thermal neutron decay curve, preferably with a diffusion model similar to that known in the art for determining formation sigma on the basis of gamma ray time distributions. In a more comprehensive embodiment of the present invention, which includes a gamma detector in the tool, formation sigma can be measured in parallel using both gamma ray and thermal neutron decay characteristics. Deviations between the neutron and gamma-based signals that occur as the tool traverses the borehole, provide useful indications of local effects immediately surrounding the borehole.

Abstract: A nuclear detector and a circuit connect in a feed back loop to stabilize gain. The circuit defines two intervals about the capture reaction peak of a pulse height spectrum of neutron counts made by the detector and determines the number of counts occurring within the two intervals. The circuit connects to a high voltage source that powers the detector and adjusts the voltage to compensate for any shift of the pulse height spectrum due to electronic drift, for example. The circuit comprises discriminator circuits, a microprocessor, or a digital processor, for example.

Abstract: In the illustrative embodiments of the invention disclosed, a neutron porosity well logging tool includes a D-T neutron accelerator, a fast-neutron monitor for monitoring accelerator output, near and far epithermal neutron detectors for deriving a primary porosity measurement, a neutron detector array intermediate to the near and far epithermal detectors for providing enhanced spatial resolution, and a far-spaced thermal neutron detector. The epithermal neutron detectors are shielded and spaced relative to the accelerator to optimize tool response to formation porosity, whereby the tool affords accurate porosity sensitivity over the entire range of porosities of interest. The source monitor may additionally be employed to measure capture gamma ray intensity vs. time between neutron bursts for deriving formation sigma. Also, the detector array may include both epithermal and thermal neutron detectors to afford an epithermal/thermal comparison measurement.

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.