摘要:
Methods are disclosed which provide for determining in situ the characteristics of hydrocarbons including oil API gravity in a formation traversed by a borehole. The vanadium content in the formation is determined from a logging tool. The total vanadium content is then systematically separated into an oil vanadium content and a formation matrix or clay vanadium content. From the oil vanadium content and a determination of formation bulk density, porosity and oil saturation, the vanadium concentration of the oil is derived in parts per million, from which the API gravity is determined.
摘要:
A method for producing lutetium aluminum perovskite crystals includes heat aging the crystal melt and maintaining the interface between a crystal and the melt from which it is pulled substantially flat as the crystal is grown. In a Czochralski growth method, the rate of rotation of the crystal and its diameter are typically controllable to provide the flat interface as the crystal is pulled. Crystals produced by this method exhibit less variability in scintillation behavior which allows larger crystals to be produced from a boule making them particularly suitable for spectroscopic uses. Such crystals find uses in borehole logging tools.
摘要:
Improved borehold logging methods and apparatus for detecting and measuring photon and other radiation from earth formations. Such radiation may be, for example: natural; generated by a source and modified by interaction with formation constituents; produced during or immediately following interactions between neutron irradiation and formation constituents; or produced by decay of constituents rendered artificially radioactive by prior neutron activation. The radiation is detected by a scintillator and photomultiplier tube, the scintillator comprising one or more crystals containing gadolinium, for example gadolinium orthosilicate doped with cerium. Such a detector provides advantageous operating characteristics, including relatively high detection efficiency and energy resolution and the ability to operate in the borehold environment without special protection against contamination or temperature effects. Depending upon the origin of the radiation to be measured, the crystal may be surrounded with a layer of material for attenuating low-energy gamma radiation, such as lead, and/or a layer of neutron absorbing material such as boron-10. The crystal may be shaped by truncating its corners parallel to the axis of the photomultiplier tube, thereby improving the usage of space and obtaining an improvement in energy resolution.
摘要:
In the illustrative embodiments of the invention disclosed, the lithology and salinity of an earth formation traversed by a well bore are investigated by irradiating the formation with a neutron source and generating an energy spectrum of the activation gamma rays resulting therefrom. From the spectrum thus obtained, the level of the activation gamma radiation emitted by .sup.24 Na and that emitted by .sup.38 Cl are determined. The two intensity measurements are then combined, e.g., by forming a cross-plot or ratio thereof, to provide an indication of the lithology and salinity of the earth formation.
摘要:
A method of determining the flood front profile created during the production flooding of an oil-bearing formation utilizes cased observation boreholes located between the injection wells and the producing wells. The time and depth of arrival of the flood front at an observation borehole are detected by gamma ray spectroscopy examination of the formation. Tracer elements having characteristic gamma ray emission energies are employed to facilitate detection of the flood front and its direction of travel. The tracer elements may be naturally radioactive substances or they may be normally stable elements which are rendered radioactive by neutronbombardment. Elements having interfering spectral lines may be separated on the basis of half-life measurements, selective detection periods or the response of the elements to different energy neutrons. By repeating the detection process at different depths and times, the profile of the flood front as it approaches the producing wells may be developed. This information may be used to control the flooding operating to prevent or localize premature breakthrough to the producing wells.
摘要:
A method and apparatus is disclosed for inspecting a wall to evaluate the remaining thickness of the wall as well as the extent to which the wall has been infiltrated by another material. The disclosure discusses directing photons of radiation and/or neutrons into the wall and measuring and analyzing the radiation emitted from the wall as a result of Compton scattering, pair production, photoelectric absorption and/or neutron absorption. The invention is particularly well suited for inspecting a carbon hearth-wall liner of an iron-smelting blast furnace.
摘要:
A single crystal scintillator and apparatus for prospecting underground strata using the scintillator is described. The single crystal scintillator is a cerium doped gadolinium silicate compound of the formula:Gd.sub.2-(x+y) Ln.sub.x Ce.sub.y SiO.sub.5wherein Ln is Sc, Tb, Lu, Dy, Ho, Er, Tm, or Yb; 0.03.ltoreq.x.ltoreq.1.9; and 0.001.ltoreq.y.ltoreq.0.2.
摘要翻译:描述了使用闪烁体探测地下地层的单晶闪烁体和装置。 单晶闪烁体是下式的掺铈钆硅酸盐化合物:Gd2-(x + y)LnxCeySiO5其中Ln是Sc,Tb,Lu,Dy,Ho,Er,Tm或Yb; 0.03 = x <= 1.9; 和0.001≤y≤0.2。
摘要:
Logging apparatus and methods for detecting first signals indicative of the absolute concentrations of the first category of elements in the rock matrix, for irradiating the formation with a pulse of high energy neutrons and for detecting a second signal indicative of the relative concentrations of a second category of elements in a rock matrix. The absolute and relative concentrations of a plurality of elements are determined, and this information is used to transform at least one of the relative concentrations into an absolute concentration. One of the measured absolute concentrations is for aluminum, from which correlations are used to determine the absolute concentrations of other, non-measured elements. A tool system for measuring the absolute aluminum concentration includes a californium-252 source and a gamma ray detector having a plurality of windows from which the aluminum count rate can be compensated for interference by manganese activation. A further correction to the aluminum count rate has a functional dependence on the neutron slowing down length in the formation, the formation macroscopic cross section, the borehole microscopic cross section, the bulk density of the formation, and the borehole diameter. When used in conjunction with a density tool sensitve to the effects of photoelectric absorption of gamma rays in the formation, the techniques of the invention allow the magnesium concentration to be determined.
摘要:
A method for producing lutetium oxyorthosilicate crystals includes maintaining the interface between a crystal and the melt from which it is pulled substantially flat as the crystal is grown. In a Czochralski growth method, the rate of rotation of the crystal and its diameter are typically controllable to provide the flat interface as the crystal is pulled. Crystals produced by this method exhibit less variability in scintillation behavior so making them particularly suitable for spectroscopic uses. Such crystals find uses in borehole logging tools.
摘要:
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.