Cement Bond Log Analysis Using VDL-SDT Correlation
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Solution Overview
Problem
The heavy reliance on registered professional engineers for interpreting cement-casing bond logs leads to inconsistent interpretations, necessitating improved systems and methods for bond log analysis.
Innovation Solution
A modular, library-driven bond log analysis system that interfaces with toggleable data libraries, enabling compatibility with various manufacturers' tools and adaptable to field conditions, performs real-time parallel analysis, and generates integrity reports using a processor that correlates VDL and SDT data to identify cement discontinuities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If registered professional engineers interpret bond logs manually, then expert judgment and flexibility are applied, but interpretation consistency deteriorates
Solution Approach 1:
The patent replaces the mechanical system of manual human interpretation with an automated computer-based system that processes bond log data through standardized algorithms. The processor executes predefined rules and criteria to evaluate cement bonding quality, eliminating human subjectivity while maintaining expert-level analysis capabilities through programmed expertise.
Solution Approach 2:
The system transforms qualitative expert judgment into quantitative parameter-based evaluation. By defining specific thresholds and criteria for cement bond assessment (such as amplitude ratios, frequency characteristics, and signal patterns), the system converts subjective engineering judgment into objective, measurable parameters that ensure consistent interpretation across different logs and operators.
2Adaptability or versatility
If multiple data libraries are maintained for different manufacturers' tools, then compatibility and adaptability improve, but system complexity increases
Solution Approach 1:
The system implements a universal processor-based platform that can handle multiple data libraries for different manufacturers' logging tools. The single processor executes different software modules or algorithms corresponding to various tool types, allowing one system to perform multiple functions and support diverse data formats without requiring separate dedicated systems for each manufacturer.
Solution Approach 2:
The patent introduces a standardized data interface and processing layer that acts as an intermediary between different manufacturers' proprietary data formats and the core analysis engine. This intermediary layer translates various tool-specific data structures into a common format that the processor can analyze uniformly, reducing the complexity of direct multi-format support.
3Measurement precision
If comprehensive multi-stage analysis is performed on all depth modules, then measurement precision improves, but analysis time increases
Solution Approach 1:
The system applies partial analysis by focusing comprehensive multi-stage evaluation only on depth modules flagged as potential discontinuities by the initial VDL assessment. Rather than performing exhaustive analysis on every depth module, the system selectively applies additional analysis stages (SDT correlation, library matching, pattern recognition) only where needed, maintaining high detection precision for anomalies while minimizing unnecessary processing time for normal sections.
Solution Approach 2:
The analysis process is segmented into hierarchical stages: initial rapid VDL screening of all depth modules, followed by detailed multi-stage analysis only of flagged suspicious sections. This segmentation allows the system to maintain high overall processing speed while applying comprehensive precision analysis selectively to critical areas, optimizing the balance between detection accuracy and analysis time.
Data Source
AI summary
A bond-log interpretation system, apparatus, and computer-implemented method are disclosed. The system ingests a cement-bond log (CBL) containing variable-density log (VDL) data and at least one secondary data track (SDT). A processing core, coupled to toggleable lithology, casing-tally, cementing-data, and prior-CBL libraries, first executes a VDL-only assessment at each depth to flag possible discontinuities. For every flagged depth, the core correlates the concurrent SDT data with selected library information to confirm or clear the discontinuity, delineate imperfect intervals, and identify probable causes. Results are synthesized into an annotated integrity report that includes audit-trail metadata listing which libraries were enabled. In a multi-well deployment, multiple field units synchronize their libraries with a central repository over a secure network, allowing real-time, parallel analysis and fleet-wide visualization. The modular architecture permits on-the-fly enabling, disabling, and versioning of libraries while maintaining a single interpretation engine adaptable to diverse tools and formations.