lwd tools vs shows, page-16

My 10c's worth. The update has nothing to do with the drillbit as some one mentioned, so rest easy.

Issue is (or should one say, 'was') with the downhole motor which they should have replaced & gotten back to drilling.

Two mandatory checks performed b4 entering the reservoir include calibration of the gas detectors & the LWD motor.

The motor should have been serviced while they were in the cased section, doesn't matter. Expect the unexpected is the unwritten rule in the oil patch.

As for the seal etc that part is over with the Pagasa shale.

They've just scratched the top of the Limestone rather then drill half way thro' the reservoir & go holy smokes Batman, so there's hopefully more good news to come re: shows etc.

2 separate things here allright, LWD measures the resitivity of the formation fluid, where as the cuttings with the oil-gas r analysed by the chromatograph.

They haven't mentioned any 'Fluorescence' or live oil yet so its mostly C1-C2-C3 with traces of C4-C5 in the drilling mud over the shakers.

So basically they've intersected the top of the NLSt & stopped to replace the LWD motor b4 heading back in.

The upper part of the NLST is tight & then should change over, back & forth. Each segment of the NLSt has a definitive signature & varies in thickness from 10-50m as seen at M'paya. Plenty of articles about this in AAPG bulletins over the years.

The term we r looking for is called 'diagenesis' & Shell have a pretty good idea abt the changing nature of the Lst's properties, having cored MA-2,3, 4, 5, 7 & 9 wells, back in the day.

Basically, it all comes down to the burial history of the reef, its compaction (cementing & matrix) & any vugs.

In even simple terms,

- u have Lst which is calcium carbonate deposited & compacted this gives us a tight Formation with bugger all pores that maynot b inter-connected, hence the 'tight formation'.

- Then we get dissolution of the calcite, creating vugs. This is where u'd found HC's, which should flow when the pores r inter-connected.

So we want pores that r inter-connected & r HC saturated, period.

Note, they'll report gas readings as a combination of C1 (methane) to C5 (pentane).

The later means oil whilst the former denotes gas. What they should b reporting is Fluorescence & live oil, streaming cut etc etc.

For the NLst, the mean P50 OIIP is 634 MMboe not MMbbls, so there is a gas-cap above any insitu oil, as is the case at Malampaya.

All the best lads.