Achieving a Well Transfer in 40 Minutes- A North Sea Operator's First Use of the WellHOP™
After completing onshore trials in Q4 last year, the WellHOP™ Shallow Application Slickline System is already bringing significant time and cost benefits to North Sea Well Integrity and DHSV Remedial Operations.
This includes Wellvene’s recent work with a major North Sea Operator where the WellHOP™ was used to drift the wellbore to TRSSSV depth and set an Interwell bridge plug and junk catcher on two wells as part of a temporary suspension workscope.
Ensuring Well Integrity
When one of the Operators platforms went into COP, it was identified that the stormchoke on two wells were not closing as expected, and therefore required replacement or a bridge plug installation to provide the required well barrier/integrity. The clients objective was to set and test a bridge plug above the existing storm choke on each well. To do this, they required a system that would allow the workscope to be carried out as safely and efficiently as possible in a single campaign.
WellHOP™ - Challenging Traditional Slickline Rig Ups
Wellvene’s WellHOP™ is a Shallow Application Slickline System that reduces operational risk, time, cost and personnel, whilst simplifying the overall pressure control equipment rig up, for operationally-efficient repairs. Eliminating the need for a mast and separate wireline winch, the WellHOP™ can be rigged up onto the well in two lifts and moved between further wells in a single lift.
Its operation eliminates the rig down, repositioning and rig up required with more traditional slickline methods. For this operation, the WellHOP™, and its associated equipment was planned for a 13-day campaign. Successfully mobilised in just four main lifts, the complete equipment package included:
- The WellHOP™ transportation frame with the WellHOP™ system
- A tool container with a pressure test package
- Two open-top containers with pre-assembled PCE package, well control panel, power pack and associated spares
The operations were carried out in March 2022, with equipment and only four WellHOP™ engineers mobilised to cover 24-hour operations.
Operating WellHOP™ on the Platform
The WellHOP™ system and associated PCE was spotted and prepared on the skid deck level. Reduced lifts compared to conventional slickline activities resulted in a smaller working area, and ultimately safer and more efficient operations. Upon well handover from production, the WellHOP™ system was rigged up and pressure-tested successfully before any runs in the well.
A 7” nominal Interwell simulated drift was then deployed to a depth of 1729ft RKB to confirm the depth of the previously-set storm choke in the TRSSSV nipple profile. Once the drift was complete, operations moved to setting a 7” nominal Interwell ME bridge plug. Following the setting of the bridge plug, a junk catcher was also installed prior to bleeding down the tubing above and performing a successful, four-hour inflow test.
After a swift 40-minute transfer of the complete WellHOP™ system directly from the first well to the second well, the same operational steps were completed using 5.5” nominal Interwell drift, bridge plug and junk catcher, with a setting depth of 920ft. A successful inflow test was then completed prior to full rig down and backload of equipment.
All operations were carried out with zero incidents, equipment failure or impact on the environment, with the client confirming their full appreciation and delight at the operational results.
WellHOP™ Results
The main benefit of the WellHOP™ for the completed workscopes was the time-saving. A well transfer using traditional slickline methods can easily range from 12 – 24 hrs. With the WellHOP™ in action, well transfer was completed in just 40 minutes.
With WellHOP’s™ pressure control equipment arriving offshore pre-assembled, significant time savings were confirmed during the spot and prepare stage (typically 18 hours for traditional slickline methods) The WellHOP™ performed this stage of the operation in less than 9 hours. Upon completion of operations, and with just a few lifts, all equipment was packaged for backload in no time at all allowing for a swift de-mob of equipment and personnel.
Beyond time and cost savings, the WellHOP™ also brings a reduction in personnel and operational risk. Through simplicity of design and use, the system can be operated with only 2 WellHOP™ personnel per shift (conventional slickline typically has 3 per shift) and requires less footprint and lifts on both the transport vessel and platform.