Fiber optic refractometer
AssigneeBaker Hughes Incorporated
InventorRocco DiFoggio
Life of this patent
Estimating the term…
Abstract
A downhole refractometer apparatus and method include a light source, an optical fiber that receives light emitted from the light source and a fluid cell that receives a downhole fluid. A metalloid interface member is disposed to provide an interface with the downhole fluid in the fluid cell, and a light detecting device detects a light reaction at the metalloid interface member, the downhole fluid property being estimable at least in part based on the light reaction.
Claims24
An apparatus for estimating a downhole fluid property comprising:
- a light source;
- an optical fiber that receives light emitted from the light source;
- a fluid cell that receives a downhole fluid;
- a metalloid interface member disposed to provide an interface with the downhole fluid in the fluid cell;
- and
- a light detecting device that detects a light reaction at the metalloid interface member, the downhole fluid property being estimable at least in part based on the light reaction.
A method for estimating a downhole fluid property comprising:
- emitting a light from a light source;
- conveying the emitted light in an optical fiber toward a metalloid interface member disposed to provide an interface with a downhole fluid in a fluid cell;
- detecting a light reaction at the metalloid interface member using a light detecting device;
- and
- estimating the downhole fluid property at least in part using the detected light reaction.
A refractometer with downhole calibration, comprising:
- a light source that emits at least two wavelengths of light to an optical fiber;
- a fluid cell that receives a downhole fluid;
- a metalloid interface member disposed to provide an interface with the downhole fluid in the fluid cell, the metalloid interface member reflecting a first wavelength of the at least two wavelengths to a return optical fiber and transmitting a second wavelength of the at least two wavelengths to the downhole fluid, at least a fraction of the second wavelength being reflected by the downhole fluid and to the return optical fiber;
- and
- a light detecting device that detects the first wavelength and the reflected fraction of the second wavelength, the detected first wavelength being indicative of a light source characteristic and the detected fraction of the second wavelength being indicative of a downhole fluid characteristic.
A method for calibrating a refractometer downhole, comprising:
- emitting at least two wavelengths of light from a light source to an optical fiber;
- receiving a downhole fluid in a fluid cell, a metalloid interface member being disposed to provide an interface with the downhole fluid in the fluid cell;
- reflecting a first wavelength of the at least two wavelengths to a return optical fiber;
- transmitting a second wavelength of the at least two wavelengths to the downhole fluid;
- reflecting at least a fraction of the second wavelength at the downhole fluid and to the return optical fiber;
- detecting the first wavelength and the reflected fraction of the second wavelength with a light detecting device, the detected first wavelength being indicative of a light source characteristic and the detected fraction of the second wavelength being indicative of a downhole fluid characteristic;
- and
- calibrating the refractometer in-situ using the light source characteristic and the downhole fluid characteristic.
Dependencies are inferred from the claim text.