Post on 07-Dec-2021
Tariq Mattar RDC, Snr.PE
10 Mar 2021
Downhole Fluid Sampling, Contamination Estimation
CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICESVirtual Workshop Series (Feb, Mar & Apr 2021)
SPWLA SAUDI ARABIA CHAPTER (SAC)9th Topical Workshop
Agenda
2 SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES
Basic Theory of Optical Density
DFA (Down Hole Fluid Analysis); Main Measurements
OCM (Oil Contamination Monitoring) Theory
WCM (Water Contamination Monitoring) Theory
Cases
Q&A
Objective
3 SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES
TM
“To Understand the Down Hole Fluid Analysis Physics of Measurements & Fundamentals of Optical Contamination Monitoring & Water Contamination Monitoring to enable assessment of the Sample Quality & the Hydrocarbon / Water Characteristics InSitu Conditions”
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES
Wireline Formation Tester
Down Hole Fluid Analysis is an Application within the Formation Tester
Sampling / Downhole Fluid Analysis (DFA):
o To confirm the presence of Hydrocarbon / Water bearing zones (clear any OH logs & Gradients uncertainties)
o PVT Studies (Reservoir Simulations, SARA, FDP, Facilities, Flow Assurance etc..)
o Determine Hydrocarbon / Water Type and Characteristics
o Determine Fractions of Fluid
o Assess Vertical & Lateral Communication (Composition, GOR, RFG)
o Estimate Contamination to Determine Sample Quality & Accurate Fluid Characteristics InSitu Conditions
TM
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES
MRSMS – Multi-sample (carries 6 Bottles)
Fluid Analyzer Main
Pump Out Standard
Pump Out H/X/XX
Fluid Analyzer 2
Dual Packer
Saturn
Sample Chamber (pH)
Single Probe
Pow
er Cartlidge
Formation Tester ModulesBasic DFA/Sampling
String
Inlet Port
Pump Out
Power Cartlidge
Carrier SC/MS
Advanced Sampling String
2 Press Gauges3 Temp GaugesResistivity Cell
TM
Fluid Analyzer Main
Fluid Analyzer Main
Entry
Ports
Entry
Ports
Entry
Ports
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES
Formation Testing ModulesFluid Analyzer; EYES Downhole
Fluid A
nalyzerF
luid Analyzer
To wellbore
TM
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES
Formation Testing ModulesFluid Analyzer; Optical Density Spectrometry
Fluid A
nalyzerF
luid Analyzer
0
10logI
IOD
TM
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES
Formation Tester ModulesFluid Analyzer; Optical Density Spectrometry
Fluid A
nalyzerF
luid Analyzer
C1
C2C3-C5
C6+
C1C3-C5
C6+
C1
C6+
CO2C3-C5C2
TM
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES
Formation Tester ModulesFluid Analyzer; Fluorescence, Resistivity, Gas Detection, H2S & DV
Fluid A
nalyzerF
luid AnalyzerGas Detection Density-Viscosity RodH2S Coupons
TM
ResistivityFluorescence
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Formation Tester ModulesSpectroscopic pH Determination
Fluid A
nalyzerF
luid Analyzer
TM
0.8
0.6
0.4
0.2
0.0
OD
700600500400
Wavelength (nm)
pH > 9 base only
6 <pH < 9acid-base mixture
pH < 6acid only
1.2
1.0
0.8
0.6
0.4
0.2
0.0
OD
700600500400
Wavelength (nm)
1.2
1.0
0.8
0.6
0.4
0.2
0.0
OD
700600500400
Wavelength (nm)
experimentpredicted
pH=7.4
A B
pH Sensitive Dye
Accuracy ~ 0.1 unitRange extended by using dye mixturespKa’ is function of T, P and IS
Optical Contamination Monitoring OCM
SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES 11
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES
Fluid Miscibility; Fluid Fractions Vs Contamination
Miscibility is the property of liquids to mix in all proportions, forming a homogeneous solution
Miscible fluids− OBM filtrate & oil − OBM filtrate & gas Condensate − WBM filtrate & formation water
Immiscible fluids− OBM filtrate & water− WBM filtrate & oil − WBM filtrate & gas condensate− WBM filtrate & dry gas
OCM is not applicable to immiscible fluids Fluid fraction or fluid cut is more applicable
when sampling/DFA immiscible fluids
TM
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
-0.1
0.9
1.9
2.9
3.9
4.9
500 700 900 1100 1300 1500 1700 1900
Clean up monitoring: 15 mins (after Mud)OBM & Oil
Formation Tester
Flowline
Fil
trate
Filtr
ate
Early Time
Crude Oil
Light Color
Formation Tester
Flowline
Filtr
ate
Filtr
ate
Late Time
Fo
rmati
on
Crude Oil
Dark Color
Fo
rmati
on
Methane Channel
Oil Peak/OBM
Wavelength (nm)
Optical Density
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
-0.1
0.9
1.9
2.9
3.9
4.9
500 700 900 1100 1300 1500 1700 1900
Clean up monitoring: 1 hr
Wavelength (nm)
Optical Density
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
2.9
3.9
4.9
1500 1700 1900-0.1
0.9
1.9
500 700 900 1100 1300
Wavelength (nm)
Optical Density
Clean up monitoring: 2 hrs
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
3.9
4.9
-0.1
0.9
1.9
2.9
500 700 900 1100 1300 1500 1700 1900
Wavelength (nm)
Optical Density
Clean up monitoring: 3 hrs
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
4.9
2.9
3.9
1100 1300 1500 1700 1900-0.1
0.9
1.9
500 700 900
Wavelength (nm)
Optical Density
Clean up monitoring: 3.5 hrs
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
4.9
3.9
-0.1
0.9
1.9
2.9
1500500 700 900 1100 1300 1700 1900
Wavelength (nm)
Optical Density
Clean up monitoring: 4.5 hrs
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
-0.1
0.9
1.9
2.9
3.9
4.9
500 700 900 1100 1300 1500 1700 1900
Wavelength (nm)
Optical Density
Clean up monitoring: 5.5 hrs
20
SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
-0.1
0.9
1.9
2.9
3.9
4.9
500 700 900 1100 1300 1500 1700 1900
Wavelength (nm)
Optical Density
Clean up monitoring: 6.5 hrs
21
SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
-0.1
0.9
1.9
2.9
3.9
4.9
500 700 900 1100 1300 1500 1700 1900
Wavelength (nm)
Optical Density
Clean up monitoring: 7 hrs
22
SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
-0.1
0.9
1.9
2.9
3.9
4.9
500 700 900 1100 1300 1500 1700 1900
Wavelength (nm)
Optical Density
Clean up monitoring: 8 hrs
23
SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES
-0.1
0.9
1.9
2.9
3.9
4.9
500 700 900 1100 1300 1500 1700 1900
Wavelength (nm)
Optical Density
Clean up monitoring: 9 hrs
Flowline
Filtr
ate
Filtr
ate
Early Time
Crude Oil
Light Color
Flowline
Filtr
ate
Filtr
ate
Late Time
Form
ati
on
Crude Oil
Dark Color
TM
24 SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES
Beer – Lambert Law of Mixing Fluids
TM
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
Linear relationship between absorbance and concentration of species
In the color region the OD of filtrate is normally zero
oilfil ODODOD ,, 1
- contamination
oilfil
oil
ODOD
ODOD
,,
,
Beer – Lambert Law of Mixing Fluids
26
SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
0, filOD
oilfil
oil
ODOD
ODOD
,,
,
oilOD
OD
,
1
aOD oil ,
12/5)(
v
bavOD
Single Channel OCM
2/3
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
Color
ac bc
1.88 44.10
Methane
am bm
0.14 1.93
Fitting Methane & Color Channels
Color Channel
Methane Channel
Volume
Colo
r Channel / M
eth
ane C
hannel
12/5)(
v
bavOD
OD meas 1.65
OD meas0.128
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
88.11 OD
Color
ac bc
1.88 44.10
14.01 OD
Methane
am bm
0.14 1.93
oilOD
OD
,
1
Contamination plotting
Color (12%)
Methane (8%)
No Correction to methane
1.65
0.128
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
-0.1
0.9
1.9
2.9
3.9
4.9
500 700 900 1100 1300 1500 1700 1900
Wavelength (nm)
Optical Density
Linear relation between channels
OD filtrate @ methane channel ≠ 0
Methane Channel offset: 15 mins
OD filtrate @ color channel is often 0
30
SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
When Ch4 (Color) = 0Ch0 (Methane) = 0.051Filtrate OD = 0.051
Cross Plot between Methane & Color
Meth
ane C
hannel
Color Channel
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
oilfil
oil
ODOD
ODOD
,,
,
88.11 OD
Color
ac bc
1.88 44.10
Methane
am bm
0.14 1.93 14.0051.0
14.0
OD
Color (12%)
Methane (8%)
Methane Corrected (11%)
1.65
0.128
Water Contamination Monitoring WCM
SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES 32
33
SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
Density (�) and Conductivity (C) change linearly with contamination (h)
• h =�����
��������, density mixing rule at constant P & ~T
• h =��,�����
��,�����,���, Conductivity mixing rule
Mixing rules for Downhole WCM
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
Exponent selection:• Single probe : = 5/12th
• Radial probe : = 2/3rd
Fluid property changes with cleanup can be modeled with a power law:
� = ��� + �����
�� = ��,�� + �����
� → ∞
Formation fluid property determination
35
SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
Volume (cm3)
Densi
ty [
g/cc
]Conduct
ivit
y [m
S/m
]
Flow regime identification
From regression:������ = ��� + �����
Assume:��������� = ��������
��������� = ��� + �����
log�������������
��= − � log �
������ = 1.0125+ 6.2���/�
��,����� = 16470+ 1422134���/�
Example 2
Paper #27291 • Adriaan Gisolf
36
SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES TM
0.2
[g/cc]
End point plotting & QC
Filtrate end point can be achieved from:
• Surface measurement
• Conductivity Vs Density Cross plot
Measured fluid properties all:
• Vary linearly with contamination
• Vary linearly together
Any properties cross-plotted
• Should generate a straight line
• Linear function can be fitted
• End point should fall on the linear fit
Paper #27291 • Adriaan Gisolf
Measured data
Data eliminated from regression
Linear regression
Conductivity [mS/m]D
ensi
ty [
g/cc
]
10,000 [mS/m]
Filtrate
Formation water
h =�����
��������h =
��,�����
��,�����,���
Summary
Accurate Contamination Estimation is crucial for Sampling Quality which affects PVT studies, FDP, Facilities Design etc..
Determining Contamination in Real time saves unnecessary Pumping hours & rig time
Using all sensors available & accurate modeling will minimize the contamination uncertainty
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES
Thank You
www.spwla-saudi.org
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SPWLA SAC WORKSHOP - CORING AND CORE ANALYSIS: CHALLENGES AND BEST PRACTICES