Subsea Umbilical Flushing Vessel with Dual-Mode Flow Control
Solution Overview
Problem
Existing methods for flushing subsea fluid conduits, such as umbilicals and hydraulic control lines, are not economical or convenient for deployment and operation, particularly in offshore hydrocarbon exploration and production systems, where blockages or contamination can occur, necessitating effective flushing procedures.
Innovation Solution
An apparatus comprising a vessel with expandable interior volume, connectors for coupling to subsea fluid conduits and production systems, and a flow control system that operates in two modes: directing flushing fluid into the vessel and diverting it to the subsea production system, with pressure relief circuits providing detectable signals for surface indication of flushing completion and system status.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If flushing fluid is directed into a vessel for collection, then contamination is contained, but the system requires immediate surface intervention for disposal
Solution Approach 1:
The patent introduces an intermediary storage bladder positioned between the subsea conduit and the surface system. This bladder temporarily holds flushed fluid and contaminants, allowing the subsea system to resume operations immediately while the bladder is gradually filled. The intermediary eliminates the need for immediate surface intervention, resolving the contradiction between containment reliability and operational downtime.
2Extent of automation
If a complex flow control system with multiple valves is used, then flushing operations can be automated, but device complexity increases
Solution Approach 1:
The patent implements self-service automation where the system automatically switches between flushing mode and diversion mode based on pre-programmed sequences or sensor inputs. The flow control system uses automated valve actuation and monitoring without requiring continuous manual intervention, achieving high automation while keeping the control logic relatively simple through standardized components and sequences.
3Productivity
If flushing fluid is diverted back to the production system, then operational continuity is maintained, but contaminated fluid re-enters the system
Solution Approach 1:
The storage bladder acts as an intermediary barrier between the contaminated flushing fluid and the clean production system. When diverting flushed fluid back to the production system, the bladder gradually empties its contents into the sea environment rather than directly into the production system, preventing contaminant re-entry while maintaining operational continuity. This resolves the contradiction by providing a buffer zone that enables both productivity and safety.
Data Source
AI summary
An apparatus and method for collecting fluid during flushing of a subsea fluid conduit such as a subsea umbilical. The apparatus comprises a vessel configured to receive fluid from the subsea fluid conduit, and a first connector for fluidly coupling the vessel to the subsea flowline. In one aspect, the apparatus comprises a second connector for fluidly coupling the apparatus to a subsea production system and a flow control system. The flow control system is configured to operate in a first mode in which flushing fluid is directed from the subsea fluid conduit into the vessel, and is configured to operate in a second mode of operation in which the fluid is diverted from the subsea flowline to the subsea production system. In another aspect, the apparatus is configured to provide a detectable signal to surface when a pre-determined volume of flushing fluid has been received in the vessel.