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First 7-3/4" Vulcan FLEX in Norway

Toolserv AS can now add a further seven operators in Norway to the Vulcan Completion Products track record. In late August the last operator to be added to the list ran the FLEX on their 7-3/4” liner.


Case study on the last 7-3/4” FLEX job:


Historically the operator has had to sacrifice standoff in a tradeoff to low running forces. The 7-3/4” was run through a 9-5/8” casing (8,50” drift) and the OH section was under reamed to 10-1/4”. In addition, there was a rat hole with 8-1/2” OD. The 9-5/8” casing window was at 1920 MD in 46ᵒ and the 7-3/4” landed at TD 3350 MD in 72ᵒ with a 625-meter cemented section.



The loss of hook load is immediate when running oversized centralizers in CH. This has forced the operator to install centralizers that provide poor standoff. This is very unfortunate as the requirement for zonal isolation is high. In previous wells rotation has been used as a means to improve the cement bonding as much as possible. If rotation for some reason stalls out prior to the cement entering the annulus, zonal isolation will most likely be jeopardized.


The standard technical solution has provided a simulated 35%-38% standoff when hook load has been acceptable. The Vulcan FLEX centralizer simulated a minimum 66% standoff (not applicable since in the rat hole), but as seen in the graphs below most of the section is simulated above 80% standoff. FLEX was not run in the rat hole

The operator had reservations about running the Vulcan FLEX centralizer for the first time due to the lack of track records and large OD. The 7-3/4” FLEX for this application has an OD of 10-3/4”. The operator’s concern was that the oversized OD would create too much drag, resulting in loss of hook load.


Due to a lack of satisfactory results from the current provider, it was decided that Vulcan`s FLEX should be tested in a well in August. The result and feedback from the rig and operator could not have been better. The thin blue line represents the simulated hook load. The thicker blue line (dots) are the measured hook load while running in-hole. At TD the liner rotated without any issues and the cement was displaced

The results after running the first well resulted in new orders for the upcoming 2 wells with the same application.


Toolserv would like to extend a big thank you to the operator for being the first Norwegian operator to run the 7-3/4” in Norway and for the confidence in the Vulcan products. We look forward to supporting your future operations.