Multi-channel source assembly for downhole spectroscopy

A downhole fluid analysis tool, comprising:

• a tool housing deployable downhole and having a flow passage for a fluid sample;
• and
• a fluid analysis device disposed in the tool housing relative to the flow passage,
• the fluid analysis device at least including—
• a plurality of individual light emitting diode (LED) sources generating optical signals across a spectral range of wavelengths,
• a routing assembly spectrally filtering the generated signals, optically combining the spectrally filtered signals of each of the LED sources into a combined signal, and routing the combined signal into a reference channel and one or more measurement channels, and
• control circuitry electrically coupled to the LED sources and operable to electronically modulate each of the LED sources at an independent frequency.

A downhole fluid analysis method, comprising:

• deploying a fluid analysis device downhole;
• obtaining a fluid sample downhole;
• generating a plurality of optical signals across a spectrum of wavelengths by electronically modulating each of a plurality of light emitting diode (LED) sources at an independent frequency;
• spectrally filtering the generated signals from one or more of the LED sources;
• combining the spectrally filtered signals into a combined signal;
• and
• routing the combined signal concurrently into one or more measurement channels for interacting with the fluid sample and into a reference channel for dynamically scaling the measurement channel.

A source assembly for downhole spectroscopy, comprising:

• a plurality of individual sources generating optical signals across a spectral range of wavelengths and spatially configured on an array topology arranged in one or more dimensions;
• a routing assembly having a grating optically coupled to the generated signals of the spatially configured sources, the routing assembly routing a first order reflection of the generated signals on the grating to one or more measurement channels and routing a second order reflection of the generated signals on the grating to a reference channel;
• and
• control circuitry electrically coupled to the sources and operable to electronically modulate each of the sources at an independent frequency.

A downhole fluid analysis method, comprising:

• deploying a fluid analysis device downhole, the fluid analysis device having a plurality of individual sources spatially configured in one or more dimensions;
• obtaining a fluid sample downhole;
• generating a plurality of optical signals across a spectrum of wavelengths by electronically modulating each of the sources at an independent frequency;
• optically coupling a grating to the generated signals of the spatially configured sources;
• routing a first order reflection of the generated signals on the grating to one or more measurement channels for interacting with the fluid sample;
• and
• routing a second order reflection of the generated signals on the grating to a reference channel for dynamically scaling the measurement channel.