Drill Pipe Threaded Connection Bevel Diameter Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current drill pipe configurations struggle to maintain connection integrity and tensile capacity at high loads, particularly exceeding 2.5M lbs, leading to stress issues and potential failure in deep well drilling applications.
Innovation Solution
The design incorporates an increased bevel diameter in tubular threaded connections, along with modified diameters and wall thicknesses, to distribute stress more evenly and increase the robustness of the drill pipe segments, allowing for higher tensile capacity and reduced failure rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard FH connection with API bevel diameter is used, then compatibility with conventional equipment is maintained, but connection integrity fails at loads exceeding 2.5M lbs
Solution Approach 1:
The patent applies parameter changes by increasing the bevel diameter from the standard API specification to a larger dimension. This parameter modification allows the connection to withstand higher tensile loads (exceeding 2.5M lbs) while maintaining compatibility with conventional handling equipment through the same external dimensions and threading interfaces.
Solution Approach 2:
The invention introduces a dimensional change by enlarging the bevel diameter in the radial dimension of the connection. This dimensional modification increases the load-bearing capacity and connection integrity without altering the axial dimensions that determine equipment compatibility, effectively adding capacity in another dimensional space.
2Strength
If increased bevel diameter is implemented, then tensile capacity exceeds 2.5M lbs, but manufacturing complexity increases
Solution Approach 1:
The patent applies local quality by modifying only the bevel diameter parameter of the connection geometry while keeping other dimensions and features consistent with standard specifications. This localized modification concentrates the manufacturing complexity only in the bevel area, allowing the rest of the connection to be manufactured using conventional processes and tooling.
3Stress or pressure
If modified diameters and wall thicknesses are used, then stress distribution improves, but device complexity increases
Solution Approach 1:
The patent applies parameter changes by systematically modifying diameters and wall thicknesses to achieve optimized stress distribution. These parameter adjustments create a more uniform stress profile under load, reducing stress concentrations at critical locations while maintaining overall structural integrity and functional simplicity.
Data Source
AI summary
A tubular threaded connection for coupling drill pipe segments to form a drill string is provided. Each of the segments has a tubular pipe body having a wall thickness of >0.5 inches (1.27 cm). The threaded connection comprises a pin end with an external thread, and a box end with an internal thread for threadable engagement with the external thread of the pin end. The pin shoulder extends between a pin base diameter and an outer pin bevel diameter; the box shoulder extends between a box base diameter and an outer box bevel diameter. The outer pin and box bevel diameters are between 7.75-8.688 inches (19.36-22.07 cm). The pin and box shoulders define a contact area such that, when the pin and box ends are threaded together with a make-up torque of >75,000 ft-lbs (10,369 kg-m), a load capacity of >2.0 million lbs (908,000 kg) is provided.