Abstract: A method for killing the parasite plant mistletoe and other photobiotic plants is disclosed. Opaque, heat-absorbing material is provided. The opaque, heat absorbing material is located about a parasitic plant and secured thereabout. The material is left about the plant until the plant dies from lack of light and from elevated temperatures. The material and the dead parasitic plant are then removed from the host plant.

Abstract: An electrode is lowered toward the surface of a liquid column until electrical contact is made between the electrode and a liquid column to establish current flow between the electrode and the liquid column. The electrode is raised from the liquid column. An additional quantity of liquid is added to the liquid column to cause the column to rise. The electrode is lowered toward the surface of the liquid column until electrical contact is again effected. The distance of travel of the electrode is measured as a determination of the rise in height of the liquid column and of the additional volume of liquid added to the column.

Abstract: Electrical contact is made between an electrode and a liquid column to establish current flow between the electrode and the liquid column. The electrode is raised up the liquid column until electrical contact is broken. An additional quantity of liquid is added to the liquid column to cause the column to rise and make electrical contact with the electrode. The electrode is raised up the liquid column until electrical contact is again broken. The distance of travel of the electrode is measured as a determination of the rise in height of the liquid column and of the additional volume of liquid added to the column.

Abstract: A cylindrical core sample of a subterranean formation is place into a sleeve under confining pressure. At least one electrode array extends through the sleeve and makes contact with the core sample. The array is in a plane normal to the core sample and has an even number of electrodes equally spaced about the sleeve. A current is passed through the core sample and voltages are measured across each pair of electrodes that are spaced 180.degree. apart around the sleeve. Such measurements are utilized to identify the radial direction of any electrical anisotropy in the core sample, particularly under differing fluid saturation conditions.

Abstract: A transversely isotropic cylindrical core sample of a subterranean formation is fluid saturated and subjected to a confining pressure. Electrical potential is measured along the core sample and in a plurality of direction through the core sample which are normal to the cylindrical axis of the core sample at a plurality of spaced-apart positions along such axis. From these electric potential measurement tensor conductivity components normal to and lying within the bedding plane of the core sample are determined.

Abstract: A cylindrical core sample of a subterranean formation is fluid saturated and subjected to a confining pressure. Voltages are measured in a plurality of directions through the core sample which are normal to the cylindrical axis of the core sample at a plurality of spaced-apart positions along such axis and utilized to determine resistivities. These resistivities are compared to identify the radial direction of any electrical anisotropy in the core sample for differing fluid saturation conditions.

Abstract: Resistivities are measured for a plurality of subsections of a porous rock following a fluid injection that alters the fluid saturation throughout the porous rock. The measured subsection resistivites are compared to identify an equilibrium in the altered fluid saturation throughout the porous rock when there is a fixed relationship between the measured subsection resistivities. Following the detection of fluid saturation equilibrium, the resistivity of the porous rock is measured.

Abstract: Apparatus is provided for measuring resistivities along the length of a core sample of a porous rock under confining pressure and varying fluid saturations. A confining pressure sleeve surrounds the core sample. Resistivities are measured along the length of the core sample by a plurality of electrodes extending through such sleeve as fluid saturations vary.

Abstract: A low-resistivity, hydrocarbon-bearing subsurface sand formation is logged with an electric logging system. Measurements are taken of formation porosity, water resistivity and formation resistivity. Core samples are taken from the formation water and electrical measurements are made on such core samples that reflect both a free-fluid pore network conductance and a rock matrix conductance. From the measurements, a formation water saturation corrected for rock matrix conductance is determined.

Abstract: A nuclear magnetic resonance logging tool comprises spaced-apart arrays of magnets, oppositely polarized, to produce a homogeneous static magnetic field parallel to the borehole when positioned adjacent the borehole wall. Magnetic material is positioned between the arrays of magnets and the borehole fluid when the logging tool is so positioned against the borehole wall to create a weaker magnetic field within the borehole. Transmitter means produces a radio frequency polarization pulse. Receiver means detects nuclear magnetic resonance in the formation following the termination of the polarization pulse.

Abstract: A method of identifying complex lithologies of subsurface rock formations includes the excitation of at least a portion of the rock formation with a multi-frequency electric current. The voltage resulting in the rock is measured and the phase and amplitude of such voltage is determined for each of the included frequencies. The resistivities are determined for each of the frequencies and are plotted as a function of frequency. The complex lithology of the rock formation is characterized by such plot.

Abstract: A directional epithermal neutron detector for use in well logging employs a plurality of neutron counters and a neutron moderating material. A first thermal neutron shield provides a cylindrical housing for the counters and moderating material. The counters are clustered to one side of the housing and the moderating material fills the remaining portion of the housing. A second thermal neutron shield separates the counters from the moderating material.

Abstract: An accelerator-type neutron source employs a target, an ionization section and a replenisher for supplying accelerator gas. A positive voltage pulse is applied to the ionization section to produce a burst of neutrons. A negative voltage pulse is applied to the ionization section upon the termination of the positive voltage pulse to effect a sharp cut-off to the burst of neutrons.

Abstract: A method for monitoring the ore grade of an uranium bearing fluid mixture. A sample of the fluid mixture is irradiated with neutrons. Delayed fission neutrons resulting from the fission of uranium present in the sample are counted as an indication of uranium ore grade.

Abstract: A gamma ray detector for borehole logging includes a bismuth germanate crystal having a sensitivity to gamma rays and giving off light energy proportional to the energy of detected gamma rays. The bismuth germanate crystal is mounted in a housing which allows the operating temperature of the crystal to be maintained under increasing borehole temperature with depth.

Abstract: A method of logging a subsurface formation surrounding a borehole includes the recording of an induced polarization log, the recording of a nuclear log of delayed gamma-rays from the activation of aluminum in the formation, and the recording of a nuclear log of natural gamma-rays from potassium in the formation. The induced polarization log and the nuclear logs are combined to identify the composition of the lithology of the subsurface formation.

Abstract: A method of logging a subsurface formation surrounding a borehole includes the recording of an induced polarization log, the recording of a nuclear log of delayed gamma rays from the activation of aluminum in the formation, and the recording of a nuclear log of inelastic scattering gamma rays from the activation of iron in the formation. The induced polarization log and the nuclear logs are combined to identify the composition of the lithology of the subsurface formation.

Abstract: A subsurface formation is irradiated with pulsed neutrons and both inelastic scattering and capture gamma-rays are measured in energy level bands characteristic of sulfur and iron. Differentials are determined between such inelastic scattering and capture gamma-rays for both the sulfur and the iron. The iron differential is then compensated by a select multiple of the sulfur differential. The ratio of the compensated iron differential and the sulfur differential is taken as a measure of the pyrite content of the formation.

Abstract: An annular calibration unit employs a steady-state radioactive source. The calibration unit is slidably mounted about a radioactive logging tool and produces radioactive radiation for calibrating the radioactive radiation detectors within the logging tool.

Abstract: A method and system for monitoring the ore grade of an uranium bearing fluid mixture. A sample of the fluid mixture is irradiated with neutrons. Delayed fission neutrons resulting from the fission of uranium present in the sample are counted as an indication of uranium ore grade.