2014-56
POSIBILITIES OF QUANTITATIVE EVALUATION OF POLISH
SHALE-GAS ROCKS PETROPHYSICAL AND GEOMECHANICAL
PARAMETERS BY LABORATORY ANALYTICAL METHODS
AND WELL LOGS INTERPRETATION
1
Leśniak ,
G.
1
Cicha-Szot ,
1
Stadtmüller ,
1
Mroczkowska-Szerszeń ,
R.
M.
M.
1
2
2
2
1
L. Dudek , G. Tallec , A. Butcher , H. Lemmens , P. Such
and Gas Institute – National Research Institute, Krakow, Poland
2Oil & Gas FEI Visualization Sciences Group, Merignac, France
1Oil
During development of shale gas reservoir exploration there will be less and less parametric wells
from which cores are available and extensive research program covering standard and special core
analyses is performed. It is due to demand of oil and gas companies to reduce drilling time and cost
and their joyful faith in geophysical well logs, despite the cost of well logging is generally more
expensive than laboratory analyses.
Moreover, the possibility of control well trajectory during drilling horizontal wells, based on new sets
of logs, force to perform the same measurements in the vertical sections.
Therefore, calibration of well logs, not only new ones but also classic ones from which we have data
from 70’s and 80’s of 20th century, becomes very relevant. Finding the relationship between well
logs and petrophysical, geomechanical and mineralogical parameters will improve interpretation of
well logs.
Probably in the coming years laboratory analyses will be performed only on side-wall cores or
cuttings. Conducting analyses on cuttings might be problematic because of novel polymeric and oil
based muds which are hard to remove from rocks and small percentage of rock samples from PDP
drill bits which are suitable for analysis. That is why most of the analysis will have to be perform on
side-wall cores from interesting formations like sweet spots and caprocks.
To be ready for this challenge methodology of transferring analytical data, which gave
comprehensive rock characteristic, to well logs parameters has to be developed in order to
estimation geomechanical parametres of separated facies.
Quartz
Plagliokaze
Feldspar
Calcite
Dolomite
Ankerite
Piryte
Marcesyte
Apatite
Illite + Micas
Chlorite
0
10
20
30
40
50
60
70
80
90
100
E
K
Vp
G
Vs
100
90
20
0,36m
80
3nm
10
4,5nm
7,4m
Based on well logs in parametric well geophysical facies (electrofacies) might be distinguished.
Electrofacies can be described as a rock type sediment exhibiting similar set of well log responses.
This classification does not require any artificial data subdivision of data population but follows
naturally based on the unique data values reflecting minerals and lithofacies within the interval.
Procedure of facies isolation is based on finding characteristic value ranges for microelectrical
curve for analyzed interval. Calibration of electrofacies separation procedure was done based on
quantitative laboratory analyses and its accuracy strongly depends on the available data statistic.
Depth [m]
0,92m
5
60
Pore volume [%]
Pore volume [%]
70
15
50
40
30
20
2,2nm
10
0
10000
0
1
10
100
1000
1000
10000
Pore size Diameter (nm)
TOC 0.66 %
100
10
1
0
Pore diameter [nm]
10 20 30 40 50
2000 3000 4000
E,K,G [GPa]
Vp, Vs [m/s]
Total porosity 4.94 % Secondary porosity (TOC) 0.01 %
WELL LOGS,
SEDIMENTOLOGICAL ANALYSIS AND PETROGRAPHICAL
ANALYSIS (THIN SECTION)
0
10
20
30
40
50
60
70
80
90
100
E
K
Vp
G
Vs
100
0,36m
15
90
80
2,57nm
5
7,2m
Depth [m]
70
10
Pore volume [%]
Pore volume [%]
3nm
60
50
40
30
45nm
20
10
0
1
10
100
1000
10000
0
10000
Pore size Diameter (nm)
1000
100
10
1
0
10 20 30 40 50
Pore diameter [nm]
TOC 0.48 %
Depth
SEPARATED ELECTROFACIES
2000 3000 4000
E,K,G [GPa]
Vp, Vs [m/s]
Total porosity 6.49 % Secondary porosity (TOC) 0.13 %
ELECTROFACIES CHARACTERIZATION
AND
CALIBRATION
3.8 nm
5.3 nm
0
10
20
30
40
50
60
70
80
90
100
E
K
G
Vp
Vs
100
0,004
90
3,1nm
80
0,36m
0,002
7,24m
45nm
70
60
50
40
30
0,001
GEOCHEMICAL
ANALYSIS
MINERAL
COMPOSITION
GEOMECHANICAL
ANALYSIS
20
10
1
10
100
1000
XRD, FTIR, ICP
TOC, HI
Vp [m/s]
3500
3520
Depth [m]
0
10
20
30
40
50
60
70
80
90
100
3560
3580
4500
4000
3640
10
3000
3660
0
3700
0
0
3720
0
1
10
100
1000
3
6
10
20
30
40
50
60
70
80
90
100
10
20
30
Pore size Diameter (nm)
40
50
60
70
Mineral content [%]
Quartz
Clays
TOC
[%]
10000
2
4
6
8
10
12
14
TRIAXIAL
COMPRESSION
TEST
Vp, Vs
Total porosity [%]
3680
7,4m
2,2nm
10
10 20 30 40 50
2000 3000 4000
Vp, Vs [m/s]
20
30
40
50
60
70
80
90
100
Carbonates
f1 logs
f2 logs
f3 logs
f4 logs
f5 logs
f6 logs
f7 logs
f1 lab
f2 lab
f3 lab
f4 lab
f5 lab
f6 lab
f7 lab
f1 lab HP
f2 lab HP
f3 lab HP
f4 lab HP
f5 lab HP
f6 lab HP
E
K
G
Vp
Vs
25
100
3,9nm
90
20
80
70
15
Pore volume [%]
5000
3480
Pore volume [%]
3460
3500
0
0
Total porosity 9.45 % Secondary porosity (TOC) 2.42 %
0
3620
4,5nm
1
5500
15
5
10
E,K,G [GPa]
6000
3600
0,92m
100
Pore diameter [nm]
3440
Depth [m]
Incremental Pore Volume (%)
0,36m
3nm
1000
3420
3540
20
10000
Pore size Diameter (nm)
TOC 4.56 %
MERCURY POROSIMETRY
ARGON POROSIMETRY
PERMEABILITY
0
10000
0,000
0,36m
10
45nm
5
Depth [m]
PETROPHYSICAL
ANALYSIS
Depth [m]
1,8m
Pore volume [%]
Pore volume [%]
0,003
60
50
40
30
20
1,8m
10
0
10
100
1000
10000
Pore size Diameter (nm)
100000
0
10000
TOC 4.87 % Total porosity 7.80 %
SEM
FIB-SEM
incremental volume - isotherm adsorption
incremental volume - mercury intrusion
Incremental volume [%]
20
15
10
5
0
1
10
100
Pore size diameter [nm]
1000
10000
3D visualization
of the organic
material
Visualisation
of the separated
organics bodies
Background
Quartz
K-Feldspar
Albite
Calcite
Dolomite
Muscovite
Biotite
Kaolinite
Illite
Smectite
Chlorite
Pyrite
Rutile
Apatite
Zircon
Monazite
Gypsum/Anhydrite
Halite/NaCl Mud
KCl Mud
Others
MINERAL
MAPPING
1000
100
Pore diameter [nm]
10
1
0
10 20 30 40 50
2400 3200 4000
E,K,G [GPa]
Vp, Vs [m/s]
Secondary porosity (TOC) 2.79 %
XRMI data are highest achievable well log resolution and give possibility to correlate laboratory data. Result of
this correlation should be used in upscaling procedure from laboratory analyses to the standard logs and further
for seismic and structural models. Precise work flow planning is essential in order to omit artefacts. Moreover,
statistical representations of analyzed samples, especially in micro scale, is crucial to obtain coherent results
from different analysis.
In order to predict geomechanical parameters in wells from which there is no core material, but geological
formation was characterized before in another parametrical well, extrapolation of petrophysical and
geomechanical data is possible but should be verified on cuttings or side-wall cores by instrumental analysis and
microscopic methods.
The research leading to these results has received funding from the Polish-Norwegian Research Programme, operated by the National Centre for Research and Development under the Norwegian Financial Mechanism 2009-2014, in the frame of Project Contract No PolNor/196923/49/2013 , Blue Gas Programme operated by the National Centre for Research and Development in the frame of Project Contract No BG1/MWSSSG/13 and research project archive number DK-4100/37/2014-01 funded by Ministry of Science and Higher Education