Helical Torque Shoulder Tubular Connection Design

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Solution Overview

Problem

The Oil & Gas upstream production industry faces challenges in creating threaded connections for deep, high-pressure, and deviated wells that offer high-torque resistance while maintaining ease of machining and production cost, as existing premium connections are difficult to manufacture and measure, especially for wedge threads.

Innovation Solution

A tubular connection featuring a pin member with a first thread structure and a helical torque shoulder, and a box member with a second thread structure and a second helical torque shoulder, where the helical torque shoulder is designed to increase the surface area for enhanced torque resistance by engaging only after initial thread contact, allowing for easier assembly and increased manufacturing simplicity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If wedge threads are used to increase torque resistance, then torque resistance is improved, but manufacturing difficulty and measurement complexity increase significantly

Engineering Contradiction:

Improvetorque resistanceVSAvoidmanufacturing difficulty

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The torque resistance function is segmented into two independent components: the thread structure (for basic engagement and torque transmission) and the torque shoulder structure (for enhanced torque resistance). This segmentation allows each component to be optimized independently, with the torque shoulder being a simple cylindrical feature that is much easier to manufacture and measure than wedge threads.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention merges the torque resistance function into a separate structural element (the torque shoulder) that is combined with the basic thread structure. This merging provides the torque resistance benefit of complex thread designs while maintaining the manufacturing simplicity of standard cylindrical features.

Inventive Principle:

Principle #5Merging (Combining)

2Strength

If conventional premium connections with torque shoulders are used, then torque resistance is improved, but the torque shoulder area is limited by the axial clearance requirement

Engineering Contradiction:

Improvetorque resistanceVSAvoidtorque shoulder area

Core Design Contradiction:

StrengthVSArea of stationary object

Solution Approach 1:

The invention transitions from a conventional axial torque shoulder to a helical torque shoulder that extends in the circumferential dimension. This helical configuration allows the torque shoulder area to be increased by utilizing the circumferential wrap-around feature, effectively adding a dimensional aspect that increases the contact area without requiring additional axial clearance.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The helical torque shoulder employs a curved, spiral geometry that wraps around the connection interface. This curved configuration increases the effective surface area for torque resistance compared to a flat or simple cylindrical shoulder, while the helical path allows for gradual engagement that maintains assembly ease.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Strength

If larger torque shoulder area is used to increase torque resistance, then torque resistance is improved, but the connection complexity increases

Engineering Contradiction:

Improvetorque resistanceVSAvoidconnection complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The connection is segmented into distinct functional zones: the thread engagement zone and the torque shoulder zone. This segmentation allows the torque shoulder to be designed as a separate, simplified feature that can be independently manufactured and does not complicate the threading process, thereby increasing torque resistance without proportionally increasing overall connection complexity.

Inventive Principle:

Principle #1Segmentation

4Ease of operation

If axial clearance is provided for easy assembly, then ease of operation is improved, but the torque shoulder area is reduced

Engineering Contradiction:

Improveease of assemblyVSAvoidtorque shoulder area

Core Design Contradiction:

Ease of operationVSArea of stationary object

Solution Approach 1:

The helical torque shoulder utilizes the circumferential dimension to increase its effective area, compensating for the reduced axial dimension caused by the clearance requirement. The helical wrap-around geometry allows the torque shoulder to achieve sufficient contact area while maintaining the necessary axial clearance for easy assembly operations.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS9869139B2Tubular connection with helically extending torque shoulder

Publication Date: 2018.01.16 HYDRIL CO

AI summary

A tubular connection includes a pin member and a box member. The pin member has a first thread structure and a helical torque shoulder spaced axially along the pin member from the first thread structure. The box member has a second thread structure and a second helical torque shoulder spaced axially along the box member from the second thread structure. The first thread structure and the second thread structure are sized and located to control a stab position of the tubular connection, and in the stab position the first helical torque shoulder does not engage or axially overlap with the second helical torque shoulder. A method of joining tubular members utilizing a helical torque shoulder is also provided.