Virtual Wellbore Torque and Drag Analysis for Multi-Layer Drill Strings
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Solution Overview
Problem
Conventional techniques for torque and drag analysis of multi-layer drill strings are inadequate, often failing to accurately account for the complex interactions between inner and liner strings, leading to computational challenges and inaccuracies.
Innovation Solution
A torque and drag system that partitions the inner and liner strings, generating a virtual wellbore based on the liner string's diameter and trajectory, allowing for separate analysis of each layer using single-layer FEA models to simulate interactions and determine forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a global model is constructed to account for all interactions between inner and liner strings, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent divides the multi-layer drill string system into separate single-layer models, analyzing each layer independently rather than as a complex global model. This segmentation reduces computational complexity while maintaining accuracy by treating the inner string and liner string as separate entities with their own force balances.
Solution Approach 2:
The patent introduces a virtual wellbore as an intermediary construct that represents the space occupied by the liner string. This virtual wellbore allows the inner string to be analyzed as if it were drilling alone, simplifying the model while still accounting for the presence of the liner string through force transfer mechanisms.
2Measurement precision
If an intricate global model is constructed to represent both inner and liner strings, then measurement precision is improved, but productivity decreases
Solution Approach 1:
By segmenting the analysis into separate single-layer models for the inner and liner strings, the patent avoids the computational burden of solving a complex global model. Each segment can be analyzed independently and more efficiently, then combined through force transfer to produce accurate results.
Solution Approach 2:
The patent creates a virtual wellbore that copies the geometry and trajectory of the actual wellbore, allowing the inner string analysis to proceed in a simplified virtual environment rather than requiring complex interaction modeling with the physical liner string.
3Device complexity
If conventional techniques analyze the system as a single-layer drill string, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent segments the multi-layer system into separate single-layer models that can be analyzed with simpler methods, then combines the results through force transfer. This approach maintains the simplicity of single-layer analysis while capturing the complexity of multi-layer interactions.
Solution Approach 2:
The virtual wellbore acts as an intermediary that allows the inner string to be analyzed in isolation while still accounting for its interaction with the liner string. This mediator enables accurate multi-layer analysis without requiring a complex global model.
4Measurement precision
If all complexities of interactions between layers are accounted for, then measurement precision is improved, but loss of time increases
Solution Approach 1:
By dividing the analysis into separate time-independent single-layer models, the patent eliminates the need for iterative solving of complex interaction equations. Each layer can be analyzed independently and quickly, then combined through force transfer to produce accurate results without excessive computational time.
Data Source
AI summary
A method of analyzing torque and drag of a drill string in a wellbore includes receiving wellbore data including a trajectory of the wellbore, and receiving drill string data for the drill string, at least a portion of the drill string including an inner string positioned inside of the drill string. The method includes generating a virtual wellbore associated with the inner string based on an inner diameter of the drill string and based on the trajectory of the wellbore, and determining a set of inner forces for the inner string including an axial force based on the weight of the inner string and a set of contact forces between the inner string and the virtual wellbore. The method includes identifying a set of normal forces between the drill string and the wellbore based on simulating the inner forces as applied forces to the drill string.