Ann: Lockyer Deep-1 Operational Update, page-159

I did some calculations on volumes inside casing and volumes in the annulus. I made some assumptions for the calculations (for the amount of cement to actually pump) that the top of cement was to be around 1000m inside the 9 5/8" intermediate casing. I assumed 15% excess in the open hole to cover some washouts.
I assumed casing was run to TD....4274m or thereabouts.

Casing capacity is approximately 311 barrels if they ran 20 lb/ft casing. Annular volume is approximately 320 barrels...So if they pumped 320 barrels of cement slurry through the ruptured bottom plug stuck in the wellhead area into the casing, it is in theory possible that there is some cement in the annulus as it U-tubed down the casing and equalised inside and outside of the casing. If they did use 20 lb/ft casing then they would have to find a drill bit (hopefully a 4 1/2" PDC) that can fit in the ID which 4.778", 3 1/2" drill collars and around 4,000m of 2 7/8" drill pipe.......maybe with a casing scraper on this run or maybe a separate run with casing scraper. Hopefully they find out that all of the cement is inside the casing and once drilled out they can lay out this string and regain circulation through the 5 1/2" casing and up the annulus....and get back to planning and executing the production casing cement job......as several have eluded to (Ya and Jopdha and others), if there is cement in the annulus, the next operation(s) becomes a little more complicated......!!!!