Downhole Near-Infrared Spectrometry for Real-Time Fluid Identification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current downhole fluid analysis methods are limited in their ability to accurately and efficiently identify the type of formation fluid, such as oil, gas condensate, wet gas, or dry gas, in real-time without the need for sample retrieval to the surface.
Innovation Solution
The implementation of near-infrared optical spectrometry within downhole tools to determine the optical density of formation fluids at multiple wavelengths, calculating an optical density ratio which is then used to identify the fluid type, facilitated by a fluid analysis module and controlled by processors using algorithms or lookup tables.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If fluid samples are retrieved to the surface for analysis, then fluid type identification can be performed, but time delay occurs and real-time analysis is not achieved
Solution Approach 1:
The patent replaces the mechanical system of physically retrieving fluid samples to the surface with an optical measurement system that analyzes fluids in situ downhole. Near-infrared spectrometry is used to measure optical properties of the fluid directly at the wellbore, eliminating the need for sample transport and enabling real-time fluid type identification without time delay.
Solution Approach 2:
The patent introduces optical properties (absorbance, optical density) as an intermediary parameter to indirectly identify fluid type. Instead of directly analyzing fluid composition through physical sampling, the system measures optical absorption characteristics at specific wavelengths, which serve as a mediator to determine fluid type (oil, gas condensate, wet gas, or dry gas) in real-time.
2Productivity
If downhole fluid analysis is performed, then real-time fluid type identification is achieved, but measurement complexity increases
Solution Approach 1:
The patent utilizes changes in optical parameters (absorbance, optical density) at specific near-infrared wavelengths to identify fluid type. By measuring how different fluid types absorb light at characteristic wavelengths, the system translates complex fluid composition analysis into simpler optical parameter measurements that can be performed downhole in real-time.
Solution Approach 2:
The patent employs a universal optical measurement approach that can identify multiple fluid types (oil, gas condensate, wet gas, dry gas) using the same downhole spectrometry system. The near-infrared spectrometry method serves multiple functions: measuring optical density, determining fluid type, and providing real-time analysis capability, reducing the need for multiple specialized devices.
3Speed
If optical spectrometry is used for fluid analysis, then measurement speed increases, but measurement precision requirements increase
Solution Approach 1:
The patent applies partial action by measuring optical density at only a few specific, strategically selected near-infrared wavelengths rather than analyzing the entire spectrum. This selective wavelength approach (e.g., 1600 nm, 1670 nm, 1720 nm) provides sufficient precision for fluid type identification while enabling faster measurement and reducing the complexity of the spectrometry system.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables real-time downhole fluid analysis, allowing for immediate identification of fluid types, improving the speed and accuracy of formation evaluation without the delay associated with surface sampling, and providing reliable characterization of formation fluids.
Implementation Method 1
optical spectrometry may be employed to determine the optical density of the fluid at two or more wavelengths
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for identifying the type of a sampled formation fluid, such as a hydrocarbon, is provided. In one embodiment, the method includes measuring absorbance by a sample of a formation fluid at multiple wavelengths of electromagnetic radiation with a spectrometer. The method also includes distinguishing between multiple fluid types to identify a fluid type of the sample most likely to match an actual fluid type of the sample based on the measured absorbance at two or more wavelengths of the multiple wavelengths. Additional systems, devices, and methods are also disclosed.