Segmented Drill String Torque and Drag Modeling

Solution Overview

Problem

Current torque and drag modeling in drilling operations is limited by the suitability of models for real-time applications and automation, as soft-string models are fast but inaccurate, while stiff-string and FEA models are accurate but computationally expensive, making them unsuitable for real-time use.

Innovation Solution

Implementing a mixed-modeling technique that selectively applies soft-string, stiff-string, and FEA models to different segments of the drill string based on segment characteristics, balancing computational speed and accuracy to enable real-time torque and drag modeling for drilling automation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If soft-string models are used for torque and drag calculations, then computational speed is improved, but measurement precision deteriorates

Engineering Contradiction:

Improvecomputational speedVSAvoidtorque and drag calculation accuracy

Core Design Contradiction:

SpeedVSMeasurement precision

Solution Approach 1:

The drill string is divided into multiple segments, with different modeling approaches applied to different segments. This segmentation allows the system to balance computational efficiency and accuracy by using simplified models where appropriate and more accurate models where needed.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different modeling approaches (soft-string, stiff-string, FEA) are selectively applied to different segments of the drill string based on local characteristics. This local quality approach ensures that computational resources are optimized while maintaining accuracy in critical areas.

Inventive Principle:

Principle #3Local quality

2Measurement precision

If stiff-string or FEA models are used for torque and drag calculations, then measurement precision is improved, but device complexity worsens

Engineering Contradiction:

Improvetorque and drag calculation accuracyVSAvoidmodeling system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The drill string is divided into multiple segments, with different modeling approaches applied to different segments. This segmentation allows the system to balance computational efficiency and accuracy by using simplified models where appropriate and more accurate models where needed.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different modeling approaches (soft-string, stiff-string, FEA) are selectively applied to different segments of the drill string based on local characteristics. This local quality approach ensures that computational resources are optimized while maintaining accuracy in critical areas.

Inventive Principle:

Principle #3Local quality

3Measurement precision

If stiff-string or FEA models are used for torque and drag calculations, then measurement precision is improved, but productivity worsens

Engineering Contradiction:

Improvetorque and drag calculation accuracyVSAvoidreal-time modeling capability

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The drill string is divided into multiple segments, with different modeling approaches applied to different segments. This segmentation allows the system to balance computational efficiency and accuracy by using simplified models where appropriate and more accurate models where needed.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different modeling approaches (soft-string, stiff-string, FEA) are selectively applied to different segments of the drill string based on local characteristics. This local quality approach ensures that computational resources are optimized while maintaining accuracy in critical areas.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20230100038A1Combined soft and stiff-string torque and drag model

Publication Date: 2023.03.30 LANDMARK GRAPHICS CORP

AI summary

Aspects of the disclosed technology provide techniques for determining frictional forces bearing on a downhole drill string. In some implementations, a method of the disclosed technology can include steps for segmenting a plurality of continuous nodes of the drilling string into a first segment and a second segment, computing a first set of values corresponding with one or more nodes in the first segment using a first model, computing a second set of values corresponding with one or more nodes in the second segment using a second model, and determining a torque of the drill string based on the first set of values and the second set of values. In some aspects, the method can further include steps for determining a drag force on the drill string based on the first set of values and the second set of values. Systems and machine-readable media are also provided.