Subsea Riser Dump Joint Fluid Release Gates
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Solution Overview
Problem
In subsea drilling, especially during dual gradient drilling, emergency disconnects can trap seawater or seawater equivalent fluids in the riser, adding weight and stress, which is undesirable, especially in severe weather conditions.
Innovation Solution
A dump joint apparatus with multiple gates and actuator assemblies is used to release fluids from the riser assembly, allowing for efficient and redundant fluid discharge, even in emergency situations, by moving gates from a sealed to an open position in response to hydraulic pressure or signals, ensuring fluid release regardless of system failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the riser is suspended from the vessel during severe weather conditions, then the drilling operation can continue, but the weight of the trapped seawater in the riser adds additional weight and mass, increasing stress on the riser and potential for failure
Solution Approach 1:
The dump joint apparatus is pre-installed in the riser assembly with gates and actuators positioned and ready. When emergency disconnect occurs, the system is already configured to immediately discharge trapped seawater through the pre-positioned gates, eliminating the need for post-emergency water removal operations and reducing overall riser weight burden.
Solution Approach 2:
The invention extracts and removes the harmful trapped seawater from the riser interior space through the dump joint apparatus. By providing a dedicated discharge path with gates that can open to exterior region, the system extracts the unwanted fluid weight, reducing the overall mass of the suspended riser assembly during emergency conditions.
2Reliability
If multiple gates and actuator assemblies are provided for fluid release, then reliable fluid discharge is achieved, but the device complexity increases
Solution Approach 1:
The fluid discharge function is segmented into multiple independent gates (first gate, second gate, third gate) that can operate independently of each other. Each gate is controlled by its own actuator assembly, allowing selective opening based on specific emergency conditions. This segmentation provides redundancy - if one gate fails, others can still discharge fluid - while keeping each individual gate structure relatively simple.
Solution Approach 2:
Different gates are positioned at different locations within the interior space and have different configurations (e.g., first gate with single actuator, second gate with single actuator, third gate with dual actuators). Each gate's specific design and actuation mechanism are optimized for its local function and position, allowing reliable fluid discharge from multiple locations without requiring every gate to be overly complex.
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 apparatus effectively reduces the weight and stress on the riser by releasing fluids close to the lower end, enhancing safety and reliability during emergency disconnects, thereby minimizing the risk of riser failure.
Implementation Method 1
A first actuator assembly may be connected to the first gate and configured for moving the first gate from the sealed position to the open position in response to a signal or hydraulic pressure
Data Source
AI summary
An apparatus, system and method for releasing fluid from a subsea marine riser is disclosed. A housing defines an interior space and an exterior region. The housing includes first and second ends adapted for respective sealed connection in a marine riser assembly. The housing may be defined on its interior space by a central cavity adapted for passage of a drill string. A plurality of ports may be provided for fluid release from the housing upon emergency disconnect of the riser from a subsea well. One or more gates may be provided in mating configuration with the housing. The gates may be moveable from a sealed position that restricts fluid flow through the ports to an open position that facilitates fluid release from the riser through the ports.