Use of an activate-able scraper in a drilling or cleanout BHA

Dear all,

Here's another item that keeps cropping up.

A well re-entry is being planned. The well has was temporarily-suspended with a cement plug inside 11¾" liner and the shoetrack had not been drilled out.  

The re-entry plan requires  a USIT/CBL to be conducted to investigate the bond outside the liner.

Due to drilling out a cement plug, and - possibly part of the shoetrack - the wireline company has requested that we scrape the casing. The team are looking at various options, which include:
  1. Incorporate a 'drilling scraper' in the BHA (ODfjell's DrillRdillo comes to mind): these are run in the 'collapsed' state and after drilling is finished, they are activated (ball) and then the casing can be scraped.
  2. Incorporate a 'non-rotating' scraper in the BHA (MI-Swaco's Razorback comes to mind), and anticpating that the drilling bit/mill will grind the cement up small enough so as not to cause a problem
  3. Don't bother running a scraper at all (after all scrapers are hardly ever run before bond logs)
We'd really value your experience in any of the three (3) options above, plus any other options you can think of.


Note added later: The reason that we need to know about the cement bond is because the contingency plan (if we cannot re-use the old hole below the liner) is to conduct a cased-hole sidetrack.

6 Answer(s)