Riser Pipe Section With Inner Locking Ring And Sliding Pivot
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Deep-sea oil reservoir drilling risers face challenges due to excessive weight and length, leading to high tensile stresses in auxiliary lines, which increases the mass and cost of the riser system, and requires longer assembly times.
Innovation Solution
A compact connector design featuring a sliding pivot connection with a clearance adjustment mechanism, utilizing a locking ring and flanges to distribute stresses and reduce the thickness of auxiliary lines, allowing for reduced mass and faster assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the auxiliary lines are fastened rigidly to the main tube to withstand tensile stresses, then the strength and reliability are improved, but the auxiliary line thickness increases, leading to increased mass and cost
Solution Approach 1:
The patent applies a sliding pivot connection that allows dynamic relative motion between the auxiliary line and main tube, transforming the rigid static connection into a dynamic adjustable one. This enables the system to adapt to stress variations without requiring excessive thickness, thereby reducing mass while maintaining strength.
Solution Approach 2:
The clearance adjustment means allows modification of the gap between auxiliary line and main tube, changing the mechanical parameters of the connection. By adjusting the clearance, the system can optimize the distribution of tensile stresses, enabling thinner auxiliary lines that still meet strength requirements.
2Length of moving object
If the riser length is increased to reach greater water depths, then the operational capability is improved, but the weight and assembly time increase significantly
Solution Approach 1:
The riser is divided into modular sections that can be assembled separately and connected using the standardized connector with sliding pivot connection. This segmentation allows for optimized distribution of stresses across multiple sections, enabling the use of thinner auxiliary lines in each segment while maintaining overall structural integrity for deep water applications.
3Reliability
If the auxiliary line thickness is increased to withstand high tensile stresses, then the reliability is improved, but the mass of the floaters and total riser increases, leading to higher cost
Solution Approach 1:
The sliding pivot connection acts as an intermediary mechanism between the auxiliary line and main tube, distributing the mechanical stresses through a controlled interface. This intermediary structure protects the auxiliary line from excessive direct tensile loads, allowing for reduced thickness while maintaining reliability.
4Productivity
If the riser assembly time is decreased for operational efficiency, then the productivity is improved, but the complexity of the connector design may increase
Solution Approach 1:
The connector design merges multiple functions into a single integrated structure: the locking mechanism, the sliding pivot connection, and the clearance adjustment means are combined in one compact assembly. This integration reduces the number of separate components and assembly steps, thereby improving assembly speed without excessive complexity.
Data Source
AI summary
The present invention relates to a riser section (4) equipped with an inner locking ring (11). According to the invention, auxiliary line elements (7) are secured to one end of main tube (6) and they are mobile with respect to the other end of main tube (6) through the agency of a sliding pivot connection, whose relative translational motion is limited by a clearance adjustment means (15). The invention also relates to a riser consisting of several sections (4) and to the use of the riser for carrying out an offshore drilling operation.