Subsea Riser Sealing Device Debris Removal via Fluid Jet
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Debris and cuttings tend to collect on top of the riser sealing device (RSD) in subsea riser operations, leading to operational troubles such as particle entry into small spaces, wear on the riser wall, and difficulties in retrieving the RSD.
Innovation Solution
A novel flushing arrangement and method that inject a fluid jet into the space immediately above the RSD, creating a swirling fluid motion to stir up and lift debris off the RSD surface, preventing accumulation and facilitating debris removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If debris traps are installed to prevent particle accumulation on the RSD, then debris collection is reduced, but the device complexity increases and operations may be hindered requiring trap removal
Solution Approach 1:
The invention extracts the harmful function of debris traps by removing them entirely from the system. Instead of using physical traps to capture debris, the patent employs a fluid jet system that actively removes particles from the RSD surface through hydrodynamic forces, thereby eliminating the need for complex trap structures that would interfere with operations.
Solution Approach 2:
The patent applies hydraulic principles by using a jet of fluid (water or drilling mud) directed at the RSD surface to remove accumulated debris. The high-velocity fluid jet creates shear forces and lift that detach particles from the sealing element surface and transport them away, replacing the need for mechanical debris traps with a hydraulic cleaning mechanism.
2Device complexity
If debris is allowed to accumulate on the RSD, then the device complexity remains low, but operational reliability deteriorates due to particle intrusion, wear, and retrieval difficulties
Solution Approach 1:
The invention implements preliminary action by continuously or periodically directing fluid jets at the RSD surface to prevent debris accumulation before it reaches harmful levels. This proactive cleaning approach maintains the RSD in a clean state throughout operation, preventing particle intrusion into sealing surfaces and avoiding the reliability issues that would arise from allowing debris to accumulate.
3Object-affected harmful factors
If a fluid jet system is implemented to remove debris from the RSD, then debris accumulation is prevented, but the device complexity and system requirements increase
Solution Approach 1:
The patent achieves multi-functionality by utilizing the existing boost line, which is already part of the riser system, to deliver the cleaning fluid. The boost line serves both its original purpose of providing hydraulic support and the additional function of debris removal through the jet system. This eliminates the need for separate dedicated cleaning infrastructure, thereby reducing overall system complexity.
Solution Approach 2:
The system employs self-service principles by using the circulation system's own fluid (drilling mud or water) to clean the RSD surface. The fluid that is already circulating in the system is redirected through jets to perform the cleaning function, eliminating the need for separate cleaning fluids or additional complex fluid delivery systems.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively prevents debris accumulation on the RSD by creating a swirling fluid motion that keeps particles in suspension, ensuring smooth operation and easy retrieval of the RSD.
Implementation Method 1
inject a fluid jet into the space immediately above the RSD, creating a swirling fluid motion to stir up and lift debris off the RSD surface
Implementation Method 2
inject a fluid jet into the space immediately above the RSD
Implementation Method 3
creating a swirling fluid motion that keeps particles in suspension
Data Source
AI summary
An arrangement and a method for preventing collection of debris on or for removing debris, such as cuttings, from the top of a closed riser sealing device (215) in a subsea riser (1). The arrangement comprises a flushing line and at least one flushing fluid inlet (294) to direct a jet of flushing fluid into said riser (1). The inlet (294) directs flushing fluid into a space in the riser (1) immediately above said closing element. The invention also relates to a swirl element (351) located immediately above the riser sealing device (215) and being rotationally coupled to a drillstring (11).