1. Petrophysical evaluation of Rotliegend Formation in K15-FA-104A
K15-FD development well
Oscar Kelder
March 2010
Doc. Nr. EP

2. K15-FA-104A well objectives
Develop Field K15-FD
Appraised by K15-7 (1978)
Expected Reserves (L-M-H):
0.5 – 0.7 – 1.0 Bcm
K15-FD
L13-FA
K15-FL
K15-FE
K15-FJ
K15-FDW
K15-FA

3. Logging in the K15-FA-104A reservoir section:
Hole conditions: 6” hole, VCM oil based mud, Temp. 129 deg. C., Deviation 18 deg.
LWD Vision Impulse GR-Resistivity & ADN Density-Neutron
Schlumberger D&M
Logging date February 2 to February 7, No operational issues
Additional QA/QC on ADN data by Schlumberger DCS
Reference log for wireline cement log & perforations.
Wireline GR-SCMT (logged in completion brine)
Schlumberger Wireline
Logging date February 18, No operational issues.

4. JOINED log : Hole Size: 20“ 24m - 627m 17“ 627m - 1462m
Missing downhole data from to m and to m bit depth due to demodulation problems.
Missing Gamma Ray data from to m due to change in BHA length and sensor offsets.
Missing Gamma Ray data from to m due to change in BHA length and sensor offset.
Created by Anne Doek, Geological Data Management Team, EPT-IT-ED

5. Petrophysical Parameters K15-FA-104A:
PORSHDEN user program used (joint evaluation of porosity and HC saturation) with p=0.3, f=0.3, fw = 1.10 g/cc, mf = 0.90 g/cc, HC = 0.2 g/cc
ma from core plugs: 2.73 g/cc (from K15-7 core, see next slide) !
JDA Archie parameters m = 2 (slightly higher due to higher ma), n = 1.65 and with Rw = m, Qv = 9.71 E-5 * porosity ^ -3.6 (with a maximum of 1) and B = 19.
GR cutoff 60 API for net sand calculations.

6. K15-7 core grain density versus porosity

7. K15-FD permeability classes (low/base/high)
1. Low Case phi-K relationship (low perm facies)
2. Base Case phi-K relationship (regional)
3. High Case phi-K relationship (K15-15A) L B H

8. K15-FA-104A sums & averages Net sand cutoff GR < 60 API
Arithmetic average for log permeability based on regional por-perm transform (see previous slide)
Log KH across perforated interval 80 mD.m
FWL at 3763m TVDSS (4947m MD). Similar to K15-7
Bottom row reflects the ROSLU gas column only

9. K15-FA-104A

10. Density standoff images
2MHZ Resistivities
PEF images
+PEF bottom and Up
Density standoff images
Density images
Density Qaudrants
Washout
Thin layer of a different lithology
PEB<PEU
Slight difference between ROBB and ROBU
QA/QC results from reprocessed LWD Vision field data by Vanessa Garnier from Schlumberger DCS
ADN tool was in good contact with the formation bottom and the density /resistivity measurements are not affected by mud or washout (except top 4790m).
PEF, with only 1inch depth of investigation, is affected by mud (4% barite) at the top side of the hole (PEU) but the bottom measurement looks fine (PEB).
Minor invasion effects from resistivity inversion (see next slide). Rt inversion not requested.

11. ARCWizard Resistivity inversion
Invasion flag

12. K15-Falcon Saturation height model
New regional model based only on Hg-Air cap curve data.
Less subjective
Not affected by uncertainty in log saturation
No corrections applied (e.g. for clay, stress, closure)
Generally provides optimistic results
K15-15A
Sw=Power(10, *POR)*((HAFWL/517)^-( *POR))

13. K15-FA-104A
3763m TVDSS
Log
Model

14. SCMT cement evaluation 5” liner:
Assuming a proper cement strength development before running the log, the
top-to-bottom interpretation looks as follows:
Free pipe down to 4195m AHORT
Increase to fair bonding down to 4310m AHORT
Patchy bonding with alternating good and fair bond down 4450m AHORT
Good bond down to 4560m AHORT
Patchy bonding with alternating good and fair bond down 4730m AHORT
Fair bond with minor good bond streaks across reservoir and down to well TD.
The fair bonding amplitudes are medium to low so may still provide hydraulic seal but as
the casing arrival gets stronger it indicates some poorer bonding between cement and
liner. The low amplitude good bonding is supported by increased traveltime (cycle skipping).

15. SCMT snapshot across reservoir section
Good bond

16. PQ update 11 March 2010 CITHP=300bar 1st 1150km3/d@120bar
2nd
3rd
A=100 bar^2/e3m3/d
F= bar^2/(e3m3/d)^2
Pressure 395 bar
Gas sg. = 0.664
CO2 = 3.2%
WGR = 8 m3/Mm3
CGR = 6m3/Mm3
FTHT = 70 degC
Openhole log PQ equals welltest data with following assumptions in the model:
- no perforation damage
- 70% of remaining permeabilities
- 6" fluid invasion
- 10" depth of penetration

17. Conclusions:
A full set of LWD Gr-Den-Neut-Res logs (Schlumberger Vision) were successfully acquired in K15-FA-104A.
The logs have been evaluated in line with general JDA processing procedures and parameters. The resulting average porosity (9.0% in the ROSLU) is lower than expected compared to the K15-7 offset well (11.5%).
Matrix density of 2.73 g/cc based on K15-7 core data is higher than regional K15 matrix density (2.68 g/cc).
Most of ROSLU in K15-FA-104A is gas-bearing and the FWL in the lower part of ROSLU is picked at the same depth of 3763m TVDSS as in K15-7.
Well clean-up confirmed gas bearing section and no pressure depletion (395 BHP bar)
Reasonable match between K15 regional saturation height model and K15-FA-104A log saturation.
The initial well performance matches the predicted well performance based on a log derived Kh of 100 mD.m across the perforated interval. Initial well rate 1.2 mln m3/d at 120 bar FTHP

18. K15-7 (K15-FD) ROCLT/ROSLU TVDSS depths 3722m RFT gas point
3782m first RFT water point
3722m RFT gas point
3756m FWL from RFT
3763m FWL Base case +/- 10m