Fiber Optic Flow Monitoring Tool for Silent Wellbore Detection
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Solution Overview
Problem
Existing systems for measuring fluid properties in wells, such as venturi meters and passive acoustic sensing, are prone to component failures and struggle with detecting silent flow, leading to costly downtime and inaccurate parameter monitoring.
Innovation Solution
A downhole flow sensing tool utilizing two fiber optic cables for discrete or distributed acoustic signal generation and sensing, allowing for precise measurement of flow parameters by comparing generated and sensed signals, with the ability to detect silent flow and monitor parameters like pressure, temperature, and fluid flow rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If venturi meters and separate electronic sensors are used to measure flow and parameters, then measurement capability is improved, but system complexity and component failure risk increase
Solution Approach 1:
The patent combines multiple measurement functions (flow rate, pressure, temperature) into a single integrated fiber optic sensing system. The distributed acoustic sensing technology along the tubing allows simultaneous measurement of multiple parameters through one continuous sensor system, eliminating the need for separate venturi meters, pressure transducers, and temperature sensors that would otherwise be required.
Solution Approach 2:
The fiber optic cable serves multiple functions simultaneously: it acts as the transmission medium for laser light, the sensing element for acoustic waves, and the measurement tool for flow parameters. This multi-functional approach replaces multiple specialized devices with a single universal sensing system that can measure flow rate, pressure, and temperature along the entire tubing length.
2Device complexity
If passive acoustic sensing is used to monitor fluid flow, then system simplicity is improved, but detection capability for silent flow deteriorates
Solution Approach 1:
The system actively generates acoustic signals along the tubing using distributed acoustic sensing before attempting to detect flow. By creating known acoustic references along the entire tubing length, the system can compare these generated signals against returned acoustic waves from flowing fluid, enabling detection of silent or low-velocity flow that passive sensing would miss.
Solution Approach 2:
The distributed acoustic sensing system utilizes mechanical vibration principles by generating and detecting acoustic waves through the tubing wall. The laser-induced acoustic signals create vibrations that interact with the flowing fluid, and the resulting acoustic responses provide information about flow presence and characteristics, including silent flow conditions where traditional passive acoustic methods fail.
3Measurement precision
If multiple sensors and components are deployed in the wellbore, then measurement accuracy is improved, but system reliability deteriorates due to increased failure points
Solution Approach 1:
The patent extracts and eliminates multiple discrete sensor components from the wellbore system, retaining only the fiber optic cable that runs along the tubing exterior. By removing venturi meters, pressure transducers, temperature sensors, and associated electronics from the wellbore environment, the system achieves comprehensive measurement capability with minimal physical components, thereby reducing failure points while maintaining measurement precision.
Solution Approach 2:
The system replaces traditional mechanical and electronic sensing devices with optical-based distributed acoustic sensing. Instead of using mechanical venturi meters, electronic pressure sensors, and thermal temperature probes, the invention uses laser light transmitted through fiber optic cable to detect acoustic, pressure, and temperature parameters, eliminating the mechanical and electronic components that would fail in the harsh wellbore environment.
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 system provides reliable and accurate measurement of wellbore parameters, reducing the risk of component failure and improving the detection of silent flow, thereby enhancing the optimization of oil and gas production and well performance.
Implementation Method 1
A high power laser is operable to deliver a light to a first fiber optic cable... for producing a generated acoustic signal
Implementation Method 2
producing a generated acoustic signal that propagates outward from the generation gauge and through the tubing
Implementation Method 3
A second fiber optic cable... is operable to receive a resulting signal of the generated acoustic signal so that wellbore parameters proximate to the predetermined location can be determined
Data Source
AI summary
A system for measuring conditions in a wellbore includes tubing extending into the wellbore. A high power laser having a power greater than 1 kW is operable to deliver a light to a first fiber optic cable. The first fiber optic cable extends axially along a fist surface portion of the tubing and has at least one signal generation gauge located at a predetermined location for producing a generated acoustic signal that propagates outward from the generation gauge and through the tubing. A second fiber optic cable extends axially along a second surface portion of the tubing and is operable to receive a resulting signal of the generated acoustic signal so that wellbore parameters proximate to the predetermined location can be determined. The second fiber optic cable is spaced apart from the first fiber optic cable and is operable to transmit data of the resulting signal to a receiver.