Garnet scintillator compositions for downhole oil and gas explorations

Patent metadata

Field	Value
Publication number	US-12429622-B2
Application number	US-202418674421-A
Country	US
Kind code	B2
Filing date	May 24, 2024
Priority date	Mar 12, 2021
Publication date	Sep 30, 2025
Grant date	Sep 30, 2025

Abstract

The use of scintillator compositions having a cubic garnet structure for gamma detection in downhole oil and gas explorations is provided. Specifically, two primary compositions of interest are disclosed, Ca 2 LnHf 2 Al 3 O 12 and NaLn 2 Hf 2 Al 3 O 12 , where Ln is Y, Gd, Tb, or La. Under gamma ray excitation, the electron-hole pairs produced in the garnet lattice structure are trapped by an activator ion to yield an efficient emission in the visible portion of the electromagnetic spectrum. The cubic garnet structure enables the use of these materials as ceramic scintillators with considerable advantages over related single crystals in various ways as disclosed herein, including reduction in cost and improvement in overall performance and durability.

First claim

What is claimed is:

1. A system for detecting gamma radiation in a downhole environment, the system comprising:
a detector positioned in a wellbore extending into a formation;
a scintillator positioned inside the detector, the scintillator being comprised of Ca 2 LnHf 2 Al 3 O 12 or NaLn 2 Hf 2 Al 3 O 12 and wherein Ln is one of Y, Gd, Tb, or La;
a photomultiplier tube coupled to the scintillator; and
a measuring device coupled to the photomultiplier tube for measuring an amount of electrons from the photomultiplier tube.

2. The system of claim 1 , wherein the scintillator is activated by Ce 3+ .

3. The system of claim 1 , wherein the scintillator is a transparent ceramic.

4. A method for detecting gamma radiation in a downhole environment, the method comprising:
positioning a scintillator in a wellbore extending into a formation, wherein the scintillator is comprised of Ca 2 LnHf 2 Al 3 O 12 or NaLn 2 Hf 2 Al 3 O 12 and wherein Ln is one of Y, Gd, Tb, or La;
causing an interaction between the scintillator and the gamma radiation;
converting photons of light emitted from the scintillator in response to the interaction between the scintillator and the gamma radiation into electrons; and
measuring an amount of the electrons.

5. The method of claim 4 , wherein the scintillator is activated by Ce 3+ .

6. The method of claim 4 , wherein the scintillator is a transparent ceramic.

Assignees

• Baker Hughes Oilfield Operations Llc

Inventors

• Srivastava Alok M
• Climent Helene Claire
• Comanzo Holly A

Classifications

• G01T1/1645

  using electron optical imaging means, e.g. image intensifier tubes, coordinate photomultiplier tubes, image converter · CPC title

• G01T1/2026

  Well-type detectors · CPC title

• G01T1/2023

  Selection of materials · CPC title

• G01T1/2006

  using a combination of a scintillator and photodetector which measures the means radiation intensity · CPC title

• C09K11/7774 Primary

  Aluminates · CPC title