THE CHALLENGE
This offshore well in Northeast Java had a high inclination of up to 70° to total depth. Washout intervals created restrictions for the casing to pass through. The customer needed a solution to aid cement placement and to achieve acceptable zonal isolation for future production.
The customer initially ran casing with a zinc-alloy solid-body centralizers from a different supplier. During the initial run the casing was pulled out of hole (POOH) as the customer planned to clean the bottom hole assembly to clear out the ledges/restrictions. During POOH, the casing got stuck due to casing parting near the reamer shoe connection and the solid body centralizers and stop collars broke up and were lost downhole.
Following an unsuccessful fishing operation, 19 solid-body centralizers and stop collars from the 9 5/8 in. × 12 1/4 in. application remained downhole. Although some components were recovered, the remaining equipment could not be retrieved. The wellbore was therefore abandoned, and the customer drilled a sidetrack.
THE SOLUTION
To avoid any further costly delays the customer SME recommended the Centek S2 9 5/8 in. x 12-1/4 in. single-piece bow spring centralizers and 9 5/8 in. 00SO stop collars. The customer SME chose Centek products as they are well-known for their performance and would be highly suited to mitigating the challenges of the well design. The customer’s aim was to deliver an average stand-off of 80% at the HC zone up until previous shoe
With in-country stocking, our suppliers in Indonesia were able to deliver the required number of products in the extremely limited time frame required.
THE RESULT
Simulations run by Centek using their proprietary LatLoad software showed that the S2 provided the required standoff and better flow-by area compared to the solid-body centralizers. Using the correct type of centralizer, the Centek single-piece, bow spring, the customer achieved a good cement job, with no failures.
