IVZ - General Discussion, page-967

And just in terms of drilling overbalanced in both the main well and the sidetrack at MK-1. Scott mentioned in a webinar late last year that they were drilling the main well 1700psi overbalanced and they planned to reduce the mud weight by 1500psi in the sidetrack so that they were only just overpressure.

In my chat with Scott last week, from memory he said the main well was drilled with 12ppg mud weight and they were only able to reduce it by 0.5ppg to 11.5ppg.

0.5ppg is equivalent to 200psi at the 2300m depth of the Pebbly Arkose formation.

So instead of reducing the mud weight by 1500psi in the sidetrack, they actually only reduced it by 200psi which is obviously why we saw the same problems in both holes.

By my maths we’ll be drilling MK-2 in the 8-9ppg range.