Fiber Optic Sensor for Sour Oilfield Fluid Composition
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Solution Overview
Problem
Conventional electronic sensor systems are not suitable for sour oilfield applications due to the hazardous environment, which limits the opportunity for deploying or replacing sensing tools to measure hydrocarbon fluid composition, especially when hydrogen sulfide and other gases are re-injected into the reservoir.
Innovation Solution
A fiber optic sensing tool is deployed in the wellbore to measure fluid composition using a fiber optic sensor assembly that includes a heated section and a reference section, allowing for remote electronic interrogation and acquisition, thereby overcoming the harsh conditions and providing durable and reliable measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electronic sensor systems are used to measure fluid composition, then measurement capability is provided, but the system is not suitable for sour oilfield environments due to corrosion and reliability issues
Solution Approach 1:
The patent replaces conventional electronic sensor systems with an optical fiber sensing system. The optical fiber uses light propagation instead of electrical signals, eliminating the corrosion and electromagnetic interference issues that plague electronic sensors in sour oilfield environments. The optical fiber sensor measures fluid composition through optical absorption spectra without being affected by hydrogen sulfide or other corrosive gases.
Solution Approach 2:
The optical fiber sensing system creates an inherently inert measurement environment. Since optical fibers transmit light rather than electrical signals, they are immune to chemical reactions with sour gas components. The fiber optic cable itself acts as a chemically inert transmission medium that can withstand prolonged exposure to corrosive conditions without degradation.
2Measurement precision
If production is stopped for well intervention procedures to deploy sensors, then fluid composition measurement opportunity is created, but production loss occurs and the process is impeded by sour gas presence
Solution Approach 1:
The optical fiber sensing system enables continuous production monitoring without requiring well shutdowns. The sensor can be deployed and begin measurements while the well remains in production, allowing real-time fluid composition analysis. The system serves itself by providing measurement capability that does not interrupt normal operations, eliminating the need to stop production for sensor deployment.
Solution Approach 2:
The patent enables continuous fluid composition measurement during ongoing production. The optical fiber sensor maintains measurement capability throughout the production process, providing uninterrupted data on fluid composition changes. This continuous monitoring capability eliminates the intermittent measurement approach that requires production stoppages, maintaining both production continuity and measurement accuracy.
3Measurement precision
If electronic components are placed in the wellbore for sensing, then measurement capability is achieved, but noise interference and durability issues occur in harsh environments
Solution Approach 1:
The patent substitutes electronic sensing components with optical fiber sensing elements. Instead of using electrical signals that are susceptible to electromagnetic noise and interference, the system uses optical signals transmitted through fiber. This substitution eliminates noise interference while maintaining high measurement precision for fluid composition detection in harsh wellbore environments.
Solution Approach 2:
The optical fiber acts as an intermediary medium that transmits measurement information from the wellbore environment to the surface without being affected by environmental noise. The fiber optic cable isolates the sensitive measurement process from electromagnetic interference and other harmful factors present in harsh wellbore conditions, delivering clean measurement data to the surface.
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
The fiber optic sensing system effectively measures fluid composition and characteristics in sour oilfields, offering increased durability and reliability by avoiding electronic components in the wellbore and minimizing noise interference, enabling accurate data collection even in acidic environments.
Implementation Method 1
an optical fiber sensor assembly (114) deployed within a wellbore (102) of a sour oilfield
Implementation Method 2
a heated section and a reference section
Data Source
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AI summary
A fiber optic sensing tool assembly is deployed in a wellbore that penetrates a hydrocarbon-bearing formation of interest to measure fluid composition and other fluid characteristics. This measurement is implemented by deploying the tool in a region in which there is substantially no fluid flow and by heating the tool through an optical delivery system. Parameters of the fluid are monitored as a function of the heating of the tool to derive information that is indicative of fluid composition and other fluid characteristics.