Wellbore DAS Inflow Detection for Continuous Fluid Phase Identification
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Solution Overview
Problem
Existing production logging systems (PLS) provide inaccurate and discontinuous measurements of fluid inflows in hydrocarbon wells due to their intrusive nature and brief exposure times, leading to skewed data and inability to monitor dynamic fluid changes over time.
Innovation Solution
A method using distributed acoustic sensors (DAS) to obtain acoustic signals across wellbore depths, analyze frequency domain features, and develop a fluid flow model for real-time identification of gas, aqueous, and hydrocarbon liquid inflows, enabling continuous monitoring and accurate fluid discrimination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a Production Logging System (PLS) is used to measure fluid inflows, then fluid profile and inflow rate can be assessed, but the measurements are skewed due to the intrusive nature of the tool and brief exposure time
Solution Approach 1:
The patent replaces the mechanical intrusive PLS tool with a DAS system that uses acoustic signals transmitted through the wellbore environment. This substitution eliminates the mechanical interference that skews measurements while maintaining the ability to detect fluid inflows through acoustic signature analysis.
Solution Approach 2:
The DAS system enables continuous monitoring of fluid inflows over extended periods, unlike the brief exposure time of PLS tools. The system continuously captures acoustic signals that can be analyzed to detect and track fluid inflow events throughout the wellbore, providing ongoing reliable data.
2Loss of time
If a PLS tool is run through a well once or a few times, then cost is reduced, but the sensors are exposed to conditions for only a brief period of time
Solution Approach 1:
The DAS system allows continuous exposure and monitoring of fluid conditions over time, eliminating the brief exposure limitation. Acoustic signals are continuously captured and analyzed, enabling the system to track fluid inflow events, changes in flow regime, and temporal variations in fluid composition throughout the wellbore.
Solution Approach 2:
The system performs preliminary characterization of acoustic signatures for different fluid types and flow regimes during training phases. This preliminary action enables the system to recognize and identify fluid inflow events in real-time without requiring repeated tool runs, preserving information over extended periods.
3Adaptability or versatility
If PLS sensors are distributed along the length of the tool, then circumferential flow profile can be assessed, but data is skewed by variability in flow regime caused by intrusive measurements
Solution Approach 1:
The patent replaces the intrusive mechanical sensors with acoustic sensing that passively captures flow information through the wellbore environment. This substitution maintains the ability to assess flow profiles while eliminating the mechanical interference that causes data skewing and variability in flow regime measurements.
Solution Approach 2:
The system uses acoustic signals as an intermediary to transmit information about fluid flows and flow regimes without direct mechanical contact. The acoustic signals serve as a mediator that captures flow characteristics while avoiding the intrusive effects of physical sensors in the flow path.
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 and continuous monitoring of fluid inflows, allowing for targeted remediation actions to optimize production and reduce operational risks by providing precise fluid flow rates and locations.
Implementation Method 1
obtaining an acoustic signal from a sensor within the wellbore, wherein the acoustic signal comprises acoustic samples across a portion of a depth of the wellbore
Data Source
AI summary
A method of identifying inflow locations along a wellbore comprises obtaining an acoustic signal from a sensor within the wellbore, determining a plurality of frequency domain features from the acoustic signal, and identifying, using a plurality of fluid flow models, a presence of at least one of a gas phase inflow, an aqueous phase inflow, or a hydrocarbon liquid phase inflow at one or more fluid flow locations. The acoustic signal comprises acoustic samples across a portion of a depth of the wellbore, and the plurality of frequency domain features are obtained across a plurality of depth intervals within the portion of the depth of the wellbore. Each fluid flow model of the plurality of fluid inflow models uses one or more frequency domain features of the plurality of the frequency domain features, and at least two of the plurality of fluid flow models are different.