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Wright’s Well Control Services (WWCS) performed a hydrate remediation in the Gulf of Mexico at 7,200’ water depth from a proprietary skid containing a pump and motor. This self-contained subsea unit is powered from the surface through coiled tubing from a Multi-Service Vessel (MSV). Not limited by a Remotely Operated Vehicle’s (ROV) hydraulic energy, the subsea pump can increase volume up to 1 bpm, or reverse flow drawing pressure down to a sub-ambient -12 psi. For this project the integrated skid cleared 15 miles of 12” pipeline removing 9,000 barrels of hydrocarbons, condensate, gases and other fluids.For a subsequent job, a paraffin and asphaltene blockage mixed with hydrates was successfully mitigated reopening four miles of pipeline. To date the skid has cleared a total of 30 miles of pipeline.WWCS Gas Separator - Engineered to Prevent Hydrate Blockages within the Skid and its Coiled TubingA unique WWCS gas separator sits atop the skid and removes the gas mixed in the hydrate to the surface. This approach prevents the formation of additional hydrates in the coiled tubing outtakes used by both the gas separator and the pump for the remaining fluids. The old technique required returning the coiled tubing to the surface for thawing each time hydrates formed and reconnecting to the subsea pump–causing costly delays.This system is further protected from hydrate blockages between the pipeline end termination/flowline end termination and the skid by injecting dispersant chemicals from a ROV panel as needed.Engineered by WWCS to Ensure SafetyWWCS has engineered in a triple-redundant safety system to compensate for a loss of dynamic positioning (DP) or drive-off by the MSV from which the hydrate skid is deployed. An emergency quick disconnect (EQD) removes the skid’s coiled tubing connections via four hot stabs. Accumulators provide an isolated source of hydraulic power for the EQD which can be activated acoustically from the vessel, with ROV manipulators, or as a last resort with wire ropes. This safety system eliminates potential damage to the pipeline asset from the hydrate skid dragging across the seabed or thousands of feet of coiled tubing crashing down on the remediation site.Engineered by WWCS to Protect the EnvironmentThe skid has a number of environmentally friendly features. The pump is powered by filtered sea water avoiding any adverse impact from leaking or severing of the coiled tubing. The fluids the hydrate pump sends to the surface are contained in a specially designed tank on the deck of the MSV. Lastly, in the event of a MSV drive-off or loss of DP, emergency shut-off valves minimize the release of any hydrocarbons from the coiled tubing outtakes after an EQD. WWCS is currently developing a flush loop to eliminate any hydrocarbon release from an EQD deployment.Shallow and Inland-Water CapabilitiesThe WWCS Hydrate Remediation System is also the solution of choice for shallow and inland-water pipelines. Depending on the
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New Developments for Ultra Deepwater Hydrate Remediation Technology in the Gulf of Mexico
Presented by:
Wright’s Well Control Services
David C. Wright President
Fernando C. Hernandez Deepwater Operations Manager
Hydrate Remediation System Recap
At the 2009 Deepwater Intervention Forum, conference delegates learned about a successful hydrate remediation in 7200’ WD in the GoM using Wright’s Well Control Service’s (WWCS) Hydrate Remediation System.
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Hydrate Remediation System Recap
Wright’s designed and built the system in 18 months for a major energy company in response to a hydrate blockage.
On this first deployment, the Wright’s system: • cleared 15 miles of 12” pipeline • removed 9000 barrels of hydrocarbons, condensate and
other fluids
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Hydrate Remediation Update
This year at DIF, we would like to tell you about:
• How the Wright’s Hydrate Remediation System works • What lessons were learned from this first deployment and
the resulting enhancements made to the system • Proven additional uses besides hydrate remediation • Further non-hydrate remediation applications planned • Current R&D and planned enhancements for hydrate
remediation operations • Our thoughts on next generation solutions that go beyond
hydrate remediation
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How the Wright’s Hydrate Remediation System Works - Skid • Self-contained system with pump and motor assembly placed on the
mud line utilizing skirted steel mud mats • Powered by filtered seawater from the surface via coiled tubing
from a Multi-Service Vessel (MSV) or rig, or left on ocean floor for later use
• Not limited by a Remotely Operated Vehicle’s (ROV) hydraulic energy
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How the Wright’s Hydrate Remediation System Works – Skid Deployment at Surface
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How the Wright’s Hydrate Remediation System Works - EQDs
• Subsea accumulators engage Emergency Quick Disconnects (EQD) with acoustic activation from vessel, initiating the following sequence: - Ongoing hydrate operations on the pipeline/subsea asset are shut off by isolating
barriers - All four hot stabs eject at tie in points, thus overcoming differential pressure caused
by a vacuum effect in the pipeline vs. hydrostatic pressure
• EQDs mitigate impact of:
- MSV drive off and/or loss of DP power - Release of hydrocarbons - Sea water flooding the pipeline asset
and hydrates reforming
How The Wright’s Hydrate Remediation System Works – Gas Separator • Deployed in a modular fashion as a independent system that is
designed to interface on the top of the hydrate skid, and separates gas from the fluids
• The first coil tubing line sends gas free
flowing to a surface gas separator and/or flare boom
• The second coil tubing return line receives the processed hydrocarbons and other fluids to the surface for additional processing and containment
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How The Wright’s Hydrate Remediation System Works – Gas Separator • A methanol injection panel prevents the formation of additional
hydrates
• Several injection points throughout the hydrate skid and separator are able to receive methanol
• A ball check in the stack prevents fluid from filling the gas line
• The gas separator has a built in sand trap
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How The Wright’s Hydrate Remediation System Works – Gas Separator Deployment at Surface
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Nine Lessons Learned from the first deployment of the Wright’s Hydrate Remediation System
Lesson #1:
• Needed to add the capability to remove asphaltene and paraffin blockages mixed with hydrates in a pipeline – Installed extra chemical injection lines, so as to treat asphaltene and paraffin during
suction phase of remediation – Developed injection system capable of pumping multiple chemicals independently or
simultaneously as needed at tie in point during suction phase of remediation – Also added injection system for skid and separator to avoid asphaltene and paraffin
blockages forming within the hydrate remediation system
• RESULT: Successfully removed an asphaltene and paraffin blockage at
4,200’ WD from several miles of pipeline
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Nine Lessons Learned from the first deployment of the Wright’s Hydrate Remediation System
Lesson #2: • Needed to enhance ROV friendly features:
– Improve flying lead handling with better parking points – More strategic placement of analog gauges – Paddle vales responsible for flow metering and barrier isolation were redesigned to
better handle an ROV’s force – Installation of visual indicators to improve interpretation of valve actuation
• RESULT: better ROV tooling interface
and actuation of components on system
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Nine Lessons Learned from the first deployment of the Wright’s Hydrate Remediation System
Lesson #3: • Needed to enhance connecting/disconnecting interface points for skid
and separator – Previous male and female connectors were composed of multiple welded components -
each one redesigned as one solid piece to increase connector strength and reduce damage during connecting and disconnecting operations
– A filtration screen on the male connector prevents foreign objects from going into the coil and plugging it
– Repositioned guide posts by moving two post to the back landing area and leaving one in the front area for optimal ROV maneuverability
– Guideposts repositioned closer to the separator allowing for optimal ROV access
• RESULT: improved ROV access and mating points reducing the risk of
possible damage at skid and separator interface points
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Nine Lessons Learned from the first deployment of the Wright’s Hydrate Remediation System
Lesson #3:
ROV visual confirmation of mating point
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Nine Lessons Learned from the first deployment of the Wright’s Hydrate Remediation System
Lesson #4: • Needed to better manage and control nitrogen usage:
– Valve configuration allows for a complete purge of hydrate system on deck of MSV – Isolation valves were installed on the coiled tubing ends used for condensate/fluids
and gas returns – Valves used to remove trapped fluids and gasses in coiled tubing, before and after
connecting or disconnecting – Valve configuration keeps system purged between subsea installation and the start
of remediation operations
• RESULT: less nitrogen wasted and needed on site, as it is
strategically used and controlled to meet job specifications
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Nine Lessons Learned from the first deployment of the Wright’s Hydrate Remediation System
Lesson #5: • Needed a more compact and advance data logging unit
– Designed software/hardware to work in conjunction with WWCS subsea hybrid valve pack to better interpret internals of pipeline, gas separator and skid
– Hybrid valve pack was created with a small footprint making it ROV porch compatible and bypassing the need for an ROV attachable skid
• RESULT: time savings due to:
– Quicker installation – Quicker mobilization – Quicker repair time
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Nine Lessons Learned from the first deployment of the Wright’s Hydrate Remediation System
Lesson #6: • Needed to improve system’s center of gravity and sling configuration
• Skid
– Length of skid (71’) made setting skid on mud mats and retrieval challenging – New sling configuration improves skid’s center of gravity placing less stress on the
frame and critical stress points around the seal assembly
• Gas Separator – The new sling configuration for the separator improves its CG while reducing the
risk of damage to interface points
• RESULT: better overall control and handling in all weather/installation scenarios
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Nine Lessons Learned from the first deployment of the Wright’s Hydrate Remediation System
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Lesson #6:
ROV handling the skid using WWCS sling system
Nine Lessons Learned from the first deployment of the Wright’s Hydrate Remediation System
Lesson #7: • Needed a subsea analog gauge assembly to accurately interpret
vacuum and absolute pressure data from internals of pipeline • RESULT: increased topside reaction time with vessel spread by
utilizing gauges strategically populated on skid to monitor pump inlet, pump outlet, and pressure in the gas separator
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Nine Lessons Learned from the first deployment of the Wright’s Hydrate Remediation System
Lesson #8: • Needed to re‐engineer seal assembly for motor and pump • RESULT: increased operational life of the system
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Nine Lessons Learned from the first deployment of the Wright’s Hydrate Remediation System
Lesson #9: • Needed to enhance environmentally friendly features • RESULT #1: developed subsea flush loop system to flush
hydrocarbons out of the skid and separator with the inclusion of coiled tubing – flush loop also worked as a primer for the pump system
• RESULT #2: hydrocarbons are then placed in a topside containment
system
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Non-Hydrate Remediation Applications Implemented for the Wright’s System
In addition to making improvements from the lessons learned from deploying the system for hydrate remediation, WWCS developed and executed new applications for the skid and gas separator
• The system has successfully flushed several miles of pipeline during
plug and abandonment/decommissioning operations • The system was also reconfigured to allow for the removal of pigs
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So Where Do We Go From Here?
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Current R&D and planned non-hydrate remediation applications
• Dewatering/unloading a pipeline • Flooding and hydro testing a pipeline (max pressure 3600 psi in
current configuration) • Pushing a pipeline pig
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Current R&D and planned enhancements for hydrate remediation operations
• Develop buoyancy system to counter the weight of skid and enable
small crane launch from back of a boat • Reconfigure system for deployment at greater water depths or for
use in shallow water and inland waters
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Conclusion – It’s Time to go Beyond Hydrate Remediation
There is a great emphasis placed in the offshore industry on the entire hydrate remediation process. What we are proposing today is the need for operators to embrace flow assurance as the new solution of choice.
That is to no longer remediate or treat hydrates, but to remove the opportunity for hydrate blockages to form in the first place.
Ashpaltene, paraffin and sand remediation must also be factored into this proposed flow assurance philosophy.
Conclusion – the First Step Toward Flow Assurance
As a first step, Wright’s in conjunction with other service companies is advising its clients on identifying and placing strategic connection points on their assets during pipeline construction or rehabilitation to allow for direct interfacing with the system.
Conclusion – Faster Deployment is the Key to Flow Assurance
By applying its proven technology, which can clear multiple blockages in miles of pipeline at a time, Wright’s can respond at the first sign of a problem and immediately eliminate a possible hydrate rather than deploying after the asset is completely blocked.
The system can also be enhanced so as to lay dormant subsea, adjacent to the asset for even faster deployment.
Questions?
Thank You
David Wright, President
Fernando Hernandez, Deepwater Operations Manager
281-446-0273
www.wwcs911.com
