HFDT and Array Induction Tool Joint Inversion
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Solution Overview
Problem
Existing resistivity logging tools, such as high-frequency dielectric tools (HFDT) and array induction resistivity tools (ART), face limitations in depth of evaluation and precision, leading to incomplete and inaccurate formation parameter estimation due to interference from mud and mud cakes in wellbore environments.
Innovation Solution
A method combining data from HFDT and ART tools to generate enhanced formation evaluation data sets, using joint inversion algorithms and iterative processing to refine estimates of resistivity and anisotropy, accounting for mud and invasion effects, and applying corrections for anisotropic and dipping effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If HFDT is used to estimate formation resistivity, then the depth of evaluation is limited to shallow depths, but the tool can operate in certain wellbore conditions
Solution Approach 1:
The patent combines HFDT and ART tools into a single logging system, allowing the HFDT to provide shallow depth information with high resolution while the ART provides deeper depth information, together covering a broader depth range with improved overall accuracy
2Length of stationary object
If ART is used to estimate formation resistivity, then the depth of evaluation is improved, but the precision and detail of the data logs are inferior
Solution Approach 1:
The patent merges the data from ART and HFDT tools, using the ART data for deeper evaluation and the HFDT data for higher precision measurements at shallow depths, achieving both deep penetration and high precision simultaneously
3Device complexity
If traditional resistivity logging is performed, then the process is simple, but the estimates are inaccurate due to mud and mud cake interference
Solution Approach 1:
The patent uses an iterative joint inversion algorithm as an intermediary processing step that takes raw measurements from both HFDT and ART tools and produces corrected formation parameter estimates by accounting for mud and mud cake effects
Solution Approach 2:
The patent implements an iterative processing approach where the joint inversion algorithm repeatedly refines the formation parameter estimates by comparing predicted responses with actual measurements and adjusting parameters to minimize differences, thereby improving accuracy
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 approach improves the accuracy and efficiency of formation property estimation by leveraging combined data from HFDT and ART tools, providing more precise resistivity and anisotropy measurements, and reducing the impact of mud and invasion interference.
Implementation Method 1
transmitting electrical signals into the formation, detecting returns of the electrical signals
Implementation Method 2
array induction resistivity tool...transmitting electrical signals into the formation, detecting returns of the electrical signals
Data Source
AI summary
In some aspects, systems and methods are provided for determining formation properties using data from both a high-frequency dielectric tool (HFDT) and an array induction tool (AIT). The system includes a controller in communication with at least one HFDT, at least one ART (which may be a multi-component AIT), and a processing unit. The acquired ART formation data can be processed and used to set constraints on the processing of the acquired HFDT formation data. In aspects, a set of processed HFDT data can be used to reinitialize the ART data processing, to allow for a repeated or iterative evaluation process. The system and method generate values used to determine one or more formation properties such as a resistivity of the formation, the presence of an invasion in the formation, mud resistivity or permittivity, anisotropy characteristics of the formation, and dipping characteristics of the formation.