Segmented Capacitance Probe for Horizontal Well Water Level
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Solution Overview
Problem
Current production logging tools face challenges in accurately monitoring multiphase fluid mixtures in highly deviated or horizontal wells due to harsh downhole conditions, including high pressure, temperature, and corrosive fluids, which affect sensor accuracy and tool durability, and require a flexible and cost-effective solution for water level measurement.
Innovation Solution
A production logging tool with an articulated dual arms deploying arrangement and segmented water level capacitance probes, featuring multiple water level capacitance sensors positioned along the arms to cover the internal diameter of the well, allowing for precise water level measurement and phase identification, with a pantographic mechanism ensuring sensors remain perpendicular to the well axis for accurate capacitance sensing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional production logging tools are used in highly deviated or horizontal wells, then they can operate in harsh downhole conditions, but they fail to accurately measure water level due to phase segregation and well deviation effects
Solution Approach 1:
The capacitance probe is divided into multiple discrete sensing elements arranged vertically along the wellbore. Each sensing element independently measures capacitance at its specific location, enabling accurate water level detection despite phase segregation and well deviation by providing distributed measurement points rather than a single averaged measurement
Solution Approach 2:
The invention transitions from traditional single-point or averaged measurements to multi-dimensional spatial measurement by arranging capacitance sensors at different vertical positions along the wellbore. This dimensional expansion allows the system to capture the vertical distribution of phases and accurately determine water level in deviated and horizontal wells where gravity-induced phase segregation occurs
2Measurement precision
If multiple sensors are deployed to improve measurement accuracy in complex wells, then measurement precision improves, but device complexity and cost increase
Solution Approach 1:
The capacitance sensing elements serve multiple functions: they detect water level, map phase distribution, and characterize flow regime. By using a single type of sensor (capacitance probe) for multiple measurement objectives, the system achieves high measurement precision without proportionally increasing device complexity, as the same sensor technology addresses various measurement needs
Solution Approach 2:
The invention measures changes in capacitance parameter along the vertical arrangement of sensors to infer water level and phase distribution. By monitoring parameter variations across multiple sensing points rather than using complex mechanical or optical sensor arrays, the system achieves accurate flow profile mapping with relatively simple capacitive sensing technology
3Length of stationary object
If tools are made longer and heavier to cover more well section, then measurement coverage improves, but tool deployment difficulty and risk increase
Solution Approach 1:
The deploying arms are designed to be movable and adjustable rather than fixed, allowing the capacitance probe to be positioned at optimal locations along the wellbore. This dynamic positioning capability enables comprehensive measurement coverage without requiring the entire tool assembly to be excessively long, as sensors can be deployed to specific zones of interest
Solution Approach 2:
The capacitance sensing elements are arranged in a compact vertical configuration along the deploying arm, with sensors nested within the structural framework of the tool. This nested arrangement maximizes measurement coverage within a compact tool footprint, reducing overall tool length and weight while maintaining extensive sensing capability along the wellbore
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 tool achieves high-resolution water level measurement and phase identification with a simple, compact, and cost-effective design, minimizing measurement errors and tool damage, while maintaining operational reliability in harsh conditions.
Implementation Method 1
each water level capacitance sensor comprising a conductive body forming an electrode covered by a protective cap forming an insulator
Implementation Method 2
the capacitance between the electrodes depends on the dielectric properties of the fluid in contact with the electrodes
Data Source
AI summary
A production logging tool comprises an elongated cylindrical body of longitudinal axis, the body carrying an articulated dual arms deploying arrangement comprising two deploying arms, the deploying arms being operable from a retracted configuration into a vertically extended configuration. At least one arm carries a segmented water level capacitance probe comprising multiple water level capacitance sensors sensitive to a water content of a multiphase fluid mixture flowing in a hydrocarbon well. The water level capacitance sensors are positioned along the arm such as to be positioned at different height from a bottom to a top of a highly deviated or horizontal section of the hydrocarbon well.