Abstract: Systems, methods, and devices for inelastic gamma-ray logging are provided. In one embodiment, such a method includes emitting neutrons into a subterranean formation from a downhole tool to produce inelastic gamma-rays, detecting a portion of the inelastic gamma-rays that scatter back to the downhole tool to obtain an inelastic gamma-ray signal, and determining a property of the subterranean formation based at least in part on the inelastic gamma-ray signal. The inelastic gamma-ray signal may be substantially free of epithermal and thermal neutron capture background.

Abstract: A scintillator type radiation detector package is provided including a scintillation crystal directly coupled to the window of a photomultiplier. A scintillator package is also provided having a longer life at wellbore temperature with minimal deterioration of a hygroscopic scintillation crystal(s). Direct optical coupling of the scintillator to the photomultiplier reduces the amount of light lost at coupling interfaces and improved detection resolution over the conventional structures having separate packages for crystal and photomultiplier.

Abstract: Methods for pre-treating packaging materials of particular composition for use in conjunction with a scintillation crystal are disclosed. The packaging materials may comprise a reflecting material, an elastomer, a reflecting fluorocarbon polymer, a polymer or elastomer loaded with a reflecting inorganic powder (including a reflecting inorganic powder comprising a high reflectance material selected from the group comprising Al2O3, TiO2, BN, MgO, BaSO4 and mixtures thereof), or a highly reflective metal foil selected from the group comprising Ag and Al that is chemically compatible with the scintillator crystal. The scintillator crystal may comprise a crystal selected from the group comprising NaI(Tl), LaBr3:Ce, La—Cl3:Ce, La-halides, and La-mixed halides.

Abstract: The present disclosure describes a scintillation crystal having the general formula RE(1?y)MyF3XA3(1?x), wherein RE includes; A is selected from Cl, Br or I; and M is an activator ion selected from the Ce3+, Pr3+ or Eu3+; x is greater than 0.01 mole% and strictly less than 100 mole%, and y is greater than 0.01 mole% and strictly less than 100 mole%; and wherein the at least one activator ion is further combined with ions from the group of Ho3+, Er3+, Tm3+, or Yb3+.

Abstract: Methods and systems are provided that enable the removal or reduction of moisture and any other volatile substances within downhole tools. A purging gas can be allowed to flow into the downhole tool, where it begins to interact with and dry the moisture present as well as dilute the gaseous environment therein. Then purging gas then can exit the tool, thereby removing the moisture and any other potentially polluting or corrosive gases in the tool. A vacuum pump and desiccant jar assembly also can be used to further remove moisture from the tool.

Abstract: Methods for pre-treating packaging materials of particular composition for use in conjunction with a scintillation crystal are disclosed. The packaging materials may comprise a reflecting material, an elastomer, a reflecting fluorocarbon polymer, a polymer or elastomer loaded with a reflecting inorganic powder (including a reflecting inorganic powder comprising a high reflectance material selected from the group comprising Al2O3, TiO2, BN, MgO, BaSO4 and mixtures thereof), or a highly reflective metal foil selected from the group comprising Ag and Al that is chemically compatible with the scintillator crystal. The scintillator crystal may comprise a crystal selected from the group comprising NaI(Tl), LaBr3:Ce, La—Cl3:Ce, La-halides, and La-mixed halides.

Abstract: The present disclosure provides a protective scintillator package for enclosing a scintillator wherein at least one component in the package is at least partially formed from a viscoelastic material. The protective package may comprise both elastic and viscoelastic materials, which may both be included in one component or may be in differing components. The present disclosure further provides radiation detectors using such scintillator packages, as well as logging tools, and methods for oil exploration.

Abstract: The invention provides a hermetically sealed scintillation crystal package with a window made of a ruggedized material such as ALON (aluminum Oxynitride) or Spinel ceramic (MgAl2O4) where the window is sealed to an external metallic housing part by a brazing or soldering process and the external housing part is welded to the housing containing the scintillation crystal.

Abstract: Systems, methods, and devices for inelastic gamma-ray logging are provided. In one embodiment, such a method includes emitting neutrons into a subterranean formation from a downhole tool to produce inelastic gamma-rays, detecting a portion of the inelastic gamma-rays that scatter back to the downhole tool to obtain an inelastic gamma-ray signal, and determining a property of the subterranean formation based at least in part on the inelastic gamma-ray signal. The inelastic gamma-ray signal may be substantially free of epithermal and thermal neutron capture background.

Abstract: The present disclosure describes a scintillation crystal having the general formula RE(1?y)MyF3XA3(1?x), wherein RE is selected from the group consisting of La, Gd, Y, Lu, or mixtures thereof; A is selected from Cl, Br or I, and M is an activator ion selected from the group consisting of Ce3+, Pr3+ or Eu3+ and combinations thereof containing two or all three activator ions and further optionally comprising Ho, Er, Tm, or Yb also in the 3+ oxidation state. We also disclose a scintillation detector including a scintillation crystal, and downhole tools and methods of oil exploration utilizing such scintillation crystals.