The previous experience on TGD was, well, quite an experience.

After all the excitement about the placing, I found myself slightly surprised by the 90% COS figure that sems to have been blurted out: the guys have given themselves a one-in-ten chance of not only looking a bit embarrassed, but also of having the share-price trashed to well below NAV for some time afterwards.

However, it's all been said and done and in the interim I have been amusing myself by considering the well design. (Yep, some of us do get our kicks that way - no pun intended.) Incidentally, the phrase "over-engineered" has been quoted a couple of times and I think it's been misplaced - it's the well that's going to be over-engineered, not the rig!

 

Background

TGD-1X

We know that in July 2007, pressures of 12,000 were reported when TGD-1X reached 4625m (along-hole depth, I don't believe we know what the True Vertical Depth was.) The well was suspended and in announcing plans for TGD-1X-ST1 in Oct 07 Soco said that they had assembled the proper high pressure drilling equipment which included a 15,000psi BOP.

TGD-1X encountered hydrocarbons in two Oligocene clastic sequences, which were separated by a volcanic layer. Well logs over the upper sequence showed about 30 metres of net pay and they were unble to log the lower section, though at the time they suggested that seismic interpretations show another 300m of sediments above the basement.

As far as I can work out, the section below the volcanics is overpressured; that is to say, instead of the pressure-depth graph being a nice straight line, there is not only a change in gradient just below the volcanics, but quite possibly a step out as well.

TGD-1X-ST1

Holy moley.

Here's a quote from Ed in Oct 2007:

"We are particularly excited to return to the TGD structure. Success in the
deeper objective section of this structure could totally transform this company
and represent a significant milestone in the history of oil exploration in
Vietnam. Accordingly, we are quite anxious to resume our evaluation now that we
have assembled the proper high pressure drilling equipment.

We were all pretty excited too. How did it go?

I'm sure you don't need much reminding. Here's one reaction from June 2008:

Certainly a lot should have been learned from this…

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