Testing & Drilling, page-45

It's an interesting theory that they'r back drilling after the logging, not sure why Cath wont release an update yet.

An operator chooses to drill deeper,

1) based on uncertainity in defining a clear fluid contact or collating more info (assuming the open hole is still stable) or
2) they could plug it, case it, cut a window, drill sideways & do an extended reach section through their 'target zone' & repeat logs/sideway or conventional cores & take fluid samples.

All of the above is worthwhile (at additional AFE costs) whilst the rig is still onsite.

For arguments sake lets say they stopped drilling at 5000m, ran the MDT, resistivity tool, cut sidewall cores (champange cork lookalike plugs), took fluid samples etc etc then looked at the data & realised that

1) hangon we still don't have a clear fluid contact (ie GOC or Oil water contact) &
2) we r not able to define a clear oil pressure gradient,

then that warrants an executive decision to drill deeper & monitor the res from the LWD/MWD tool.

Res change stands out straightaway (ie HC's being high in res compared to water/ mudcake) & helps in establishing the OWC.

Secondly they also shoot VSP (vert seismics) to correct their formation tops & this can take some time.

All this is based on wireline data collated frm a number of logging runs (minimal downtime, maximum output) & assuming that the tool didn't get stuck in the openhole which warrants a fishing job & a few trips. Just my take on this. Hopefully they'll update our market at some point in time.