Discrete Sensor Array for Coiled Tubing Acidizing Monitoring

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Solution Overview

Problem

Current methods for evaluating matrix acidizing in subterranean hydrocarbon formations, such as distributed temperature sensing (DTS) technology, face challenges including the need for immobile fiber placement and high data processing costs, which are not reliable and expensive.

Innovation Solution

A system with an array of sensors located on the outer radial surface of a matrix acidizing bottom hole assembly, capable of detecting operational parameters like temperature, pressure, and flow rate, which can be moved past a location to detect changes at different times, providing data for effective acidizing performance evaluation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If distributed temperature sensing (DTS) technology is used for real-time monitoring, then temperature data acquisition sensitivity is improved, but data processing complexity and cost increase

Engineering Contradiction:
Improvetemperature data acquisition sensitivityVSAvoiddata processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the continuous DTS fiber into discrete sensor segments positioned at specific intervals along the coiled tubing. Instead of processing continuous temperature data from the entire wellbore, the system uses a limited number of discrete sensor points, significantly reducing data volume and processing complexity while maintaining effective monitoring capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts only the essential temperature measurement function from the complex DTS system by using simpler discrete temperature sensors. This extraction eliminates the need for complex optical fiber processing while retaining the core functionality of monitoring temperature changes during matrix acidizing operations.

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If DTS fiber is placed inside coiled tubing for continuous monitoring, then real-time temperature monitoring is achieved, but operational reliability decreases due to fiber mobility requirements

Engineering Contradiction:
Improvereal-time monitoring capabilityVSAvoidfiber placement stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the monitoring function into discrete sensors that can be independently positioned and secured at specific locations along the coiled tubing. This segmentation allows each sensor to be firmly attached at its measurement point without requiring the entire fiber to remain immobile, enhancing reliability while maintaining real-time monitoring.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a static continuous fiber system to a dynamic discrete sensor system that can accommodate coiled tubing movement. The discrete sensors are positioned to measure temperature at critical points without requiring continuous fiber stability throughout the entire wellbore, allowing the system to adapt to operational dynamics.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If multiple sensors are used to detect operational parameters at different locations, then measurement coverage is improved, but data volume and processing time increase

Engineering Contradiction:
Improvespatial coverage of operational parametersVSAvoiddata interpretation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies sensors strategically at specific locations where temperature and pressure changes are most indicative of matrix acidizing effectiveness. Rather than uniformly distributing sensors throughout the wellbore, the system places sensors at critical zones such as the bottom hole assembly and key formation intervals, reducing total sensor count while maintaining measurement quality where it matters most.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses a limited number of sensors positioned to capture the essential temperature and pressure gradients during acidizing. This partial monitoring approach focuses measurements on the most critical parameters and locations, providing sufficient data for evaluation without the excessive data burden of comprehensive full-wellbore sensing.

Inventive Principle:
Principle #16Partial or excessive action

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

This solution reduces data volume and interpretation time, lowers operational costs, and allows for more accurate evaluation of matrix acidizing performance by using robust conduits and single-point sensors, enabling faster data acquisition and processing.

Implementation Method 1

The acid temperature in the formation depends on the convective heat transfer as the acid flows through the formation and on the reaction heat transfer due to the acid-mineral reaction.

Methodology Applied
Scientific EffectConvective heat transfer: Convection

Implementation Method 2

The acid temperature in the formation depends on the convective heat transfer as the acid flows through the formation and on the reaction heat transfer due to the acid-mineral reaction.

Methodology Applied
Scientific EffectReaction heat transfer: Exothermic Reaction

Implementation Method 3

the local pressure drops due to the change in flow area (such as from the annulus area to the wormhole area)

Methodology Applied
Scientific EffectPressure drop: Pressure Drop

Data Source

PatentEP3074593B1Systems and methods for real-time evaluation of coiled tubing matrix acidizing
Publication Date: 2023.01.04 BAKER HUGHES CO
  • EP3074593B1 patent drawingFigure 1
  • EP3074593B1 patent drawingFigure 2~3
  • EP3074593B1 patent drawingFigure 4~5

AI summary

A matrix acidizing monitoring system wherein a sensor array is operably associated with a matrix acidizing bottom hole assembly and contains first and second sets of sensors that detect a matrix acidizing operational parameter at different times at one or more particular locations along the wellbore. This allows the effectiveness of the acidizing to be modeled.