Deepwater Riser Intervention System with Emergency Disconnect
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Solution Overview
Problem
Current subsea well intervention systems are heavy, bulky, and costly, requiring semi-submersible platforms for operation, which are slow and inefficient, often resulting in significant fluid leakage during emergency disconnections.
Innovation Solution
A lightweight and compact deepwater riser intervention system with a subsea hydraulic power unit and closed loop control system, featuring a lower riser package and emergency disconnect package that can be controlled independently, eliminating the need for external hydraulic pressure and allowing for quick installation and removal, with at least three well barriers for cutting and sealing functions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a subsea drilling BOP intervention system is used, then the system can perform any type of desired work, but the system becomes very heavy and bulky, weighing 500,000 to 1,000,000 pounds
Solution Approach 1:
The intervention system is divided into separate functional modules: a subsea tree with intervention tools, a hydraulic power unit, and control systems. This segmentation allows each component to be optimized independently, reducing overall system weight while maintaining full intervention capabilities through modular reconfiguration.
Solution Approach 2:
The subsea tree is designed with multi-functional capabilities, integrating production, intervention, and emergency shutdown functions into a single unified structure. This eliminates the need for separate heavy-duty BOP systems, as the same tree performs multiple functions including well control, production flow management, and intervention operations.
2Weight of moving object
If a semi-submersible platform is used to deploy the intervention package, then the heavy system can be lowered and installed, but the operation becomes slow and requires anchoring
Solution Approach 1:
The intervention package incorporates buoyancy modules and flotation devices that counterbalance the system's weight, enabling deployment from lighter, faster vessels without requiring heavy semi-submersible platforms. This anti-weight approach allows the system to be lowered and raised quickly without anchoring operations.
Solution Approach 2:
The system employs dynamic positioning capabilities with adjustable buoyancy and ballast systems, allowing real-time weight compensation during deployment. This enables rapid installation and removal operations from agile vessels, eliminating the slow anchoring and positioning procedures required by static heavy systems.
3Reliability
If prior art emergency disconnect systems are used, then the well can be sealed in emergency situations, but the systems are slow to operate and allow significant fluid leakage
Solution Approach 1:
The emergency disconnect system is pre-positioned with sealing elements and cutting tools already in place within the subsea tree. Hydraulic actuators are pre-charged and ready for immediate operation. This preliminary preparation enables instant well isolation upon emergency detection, eliminating the time required for system deployment or configuration.
Solution Approach 2:
The emergency disconnect mechanism utilizes high-pressure hydraulic actuators with rapid response valves that can seal and cut within seconds. The hydraulic system incorporates accumulator chambers pre-filled with pressurized fluid, providing immediate actuation force without requiring external hydraulic supply lines, thus achieving fast well isolation.
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 system enables rapid and environmentally friendly subsea interventions by reducing system weight and size, minimizing fluid leakage, and allowing for independent operation of the lower riser package and emergency disconnect package, enhancing operational efficiency and safety.
Implementation Method 1
The first control includes a first hydraulic power unit. The first hydraulic power unit includes a first hydraulic fluid reservoir and a first hydraulic pump.
Implementation Method 2
The first hydraulic power unit includes a first hydraulic fluid reservoir and a first hydraulic pump
Data Source
AI summary
The present invention discloses apparatus and methods for a lightweight subsea intervention package. In one embodiment, the system comprises a lower riser package for controlling the subsea well which utilizes a plurality of hydraulically activated well barriers. An emergency disconnect package is secured to the lower riser package and is electrically connected to the lower riser package. The emergency disconnect package is operable to seal the bottom of a riser and minimize environmental leakage of fluid from the riser. The lower riser package and emergency disconnect package each contain a closed loop system of fluid operable to control the system without fluid from the surface. Each is operable to control the well barriers. Either an electrical connection or an acoustic control system may be utilized to control the system. The lower riser package can be operated from the surface when the emergency disconnect package has been disconnected.