January 2003
Aberdeen Formation Evaluation Society
Monthly Newsletter
Archie Quiz
The AFES committee would like to thank
everyone who attended the Christmas Quiz in
support of the Archie Foundation.
Thanks to the support of our members we
managed to raise £1327,72.
We would like to add special thanks to our
sponsors:
Halliburton
Pathfinder
Schlumberger
RML
Helix-RDS
Core Lab
Opus Financial Services
TotalFinaElf
PGL
Baker Atlas INTEQ
February Meeting
5th Feb 2003, Meston Buildings,
Aberdeen University at 6.00pm
The Integrated Formation Evaluation of
a Chlorite-rich Reservoir
Authors:
Burlington Resources; Mr. Iain McNeil, Mr
Andrew Hughes,
Energy Scitech Ltd; Mr. Brian Moss, Dr. Ben
Lowden, Dr. Paul Basan, Dr. Neil Parkinson;
Mr. Partha Biswas
Presented by Iain McNeil
The presentation summarises the results of an
integrated investigation carried out as a team
effort between Burlington Resources (Algeria)
Ltd and Energy Scitech Ltd on a single well in
the Berkine Basin, Algeria. The study focused
on the Carboniferous F1A formation and
revealed the importance of both using all
available data for formation evaluation and
interpreting these data in a consistent manner.
The dataset consisted of: Core data and
descriptions; Conventional Log Suite: NGS/
CNL/ LDT/ AIT/ LSS; Special log Suite: Dipole
Sonic Imager/ MRIL/UBI
Although the overall interpretation from each
data
source
provided
a
consistent
interpretation, the final interpretation model
only evolved after independently crosssubstantiating the interpretation using the
different data sources.
This observation
shows that deriving key parameters necessary
for economic considerations, and detailed
development plans in a complex reservoir like
the F1A sequence, becomes clear only after
assembling the entire “picture” from each data
source.
The study indicates that the F1A sequence is
partitioned
into
alternating
layers
of
hydrocarbon- and water-saturated units.
However, NMR log shows that all water
saturation is irreducible. We also discovered
that the individual reservoir units are thinbedded, but not in the traditional sense.
Instead, variable pore geometry controls
reservoir layering. Grain size (pore size),
cross-stratification,
cementation,
and
lithofacies create the variable pore geometry.
Routine petrophysical analysis failed to
recognise the complexity inherent in the F1A
formation. We therefore turned to statistical
techniques, such as principal components
analysis and cluster analysis, to unmask the
subtle differences created by sedimentological
and mineralogical effects. We normalised the
information from the NMR tools to provide a
consistent interpretation with other logs.
Producing this consistency required using a
unique cutoff model. This model evolves from
using a unique thickness-weighted algorithm
for quantifying the amount of sand, silt, and
shale that contributes to the NMR signal. The
UBI data were used to derive information
about lithology, the internal structure of beds,
bed boundaries, and reservoir structure. The
waveform sonic data were used as a tool to
verify the petrophysical interpretation by
comparing the raw attenuation with core and
NMR permeability.
The team is in the process of testing the F1A
interpretation model developed for this initial
well on three additional wells.
_______________________________
2003 Program
Rupert Hoare & Mike Livingstone,
WesternGeco
5th March: Ronnie Parr (BP) “Using Cased
Hole Logging to calibrate 4-D Seismic”
18th February 2003, Jarvis City Hotel,
Aberdeen
2nd April: Jez Lofts (Baker Atlas/ INTEQ)
"A new Micro-Resistivity Imaging Device for
use in Oil Based Mud."
7th May: Andy Williamson (Core Lab)
" Asphaltenes and their effect on Formation
Evaluation".
4th June: Speaker to be confirmed (University
of Strathclyde) “Plasma-Channel Drilling”
_______________________________
Website of The Month
For all things petrophysical in Australia
www.petrophysics.net
_______________________________
_______________________________
LPS February Meeting
The next monthly meeting of the London
Petrophysical Society takes place on Tuesday
18th February 2003 beginning at 18.00 at the
Geological Society, London. The title is:
New approaches to Russian Log Data
Interpretation
Kirill Shmyglia of Schlumberger, London.
Further information from:
www.lps.org.uk
_______________________________
PESGB London February Meeting
11th February 2003, Burlington House,
Geological Society, London
Amplitudes, Risk and all that
Geophysical Malarkey
Rob Simm1, Andrew Armour2 and Martyn
Millwood Hargrave2, 1Rock Physics
Associates Ltd, 2IKON Science Ltd
_______________________________
PESGB Aberdeen February Meeting
18th February 2003, Jarvis City Hotel,
Aberdeen
Use of multicomponent data to improve
understanding of Tertiary reservoirs in
the Central North Sea