analysis of typical data on faults and fractures and its...
TRANSCRIPT
Analysis of Typical Data on Faults and Fractures and Its Application to the Assessment of Potential Migration of Injected CO2 in the Deep Subsurface,
Including Leakage through the Primary Seal(s)
Develop geologically representative DFNs and carry them into flow simulation for iterative history matching
WVUTom WilsonDeng Gao
NETLMark McKoyDuane Smith
Long Term Objective
Develop software and techniques for analyzing borehole logs and seismic data:
for faults and fracture networks in reservoir rock and overlying strata, with emphasis on assessing potential leakage routes through
seals.
Establish procedures to produce DFNs for flow simulation.
Support risk assessment efforts:Migration within reservoirleakage through primary seals.
Provide one or more useful examples that the CO2sequestration industry could follow.
Technical ApproachDevelopment of data processing software and techniques to define field scale DFNs:
1) static-phase waveform (texture) model regression &,2) local Radon (or τ-p) transform for directional analysis of seismic attributes.
n
jyixf
yxfyxr i j∑∑ ++
−=
),(
),(),(
[ ] [ ]( , ) ( , ) ( )pR r x y r x y y px dxdyτ δ τ∞ ∞
−∞ −∞= − +∫ ∫
Technical Approach
For 1 or more selected sites: Use of selected seismic attributes for identification & mapping of faults, fracture zones and general fracture network characteristics in the reservoir, primary seal and overlying strata.
Use of borehole logs for interpretation & assessment of fracture/fault networks in the reservoir and sealing strata.
Use of field observations and aerial imagery to supplement the interpretation & assessment of fracture/fault networks in the deep subsurface.
For 1 or more selected sites: Generate representative DFNs for reservoir and up through
the primary seal.
Use DFNs for flow simulations within reservoir and up through the primary seal.
Assess CO2 plume spread within reservoir plus leakage ratesthrough primary seal.
Technical Approach
Seismic from San Juan Basin CO2 Pilot
Fault and Fracture Zone Interpretations are Difficult in Conventional Amplitude Displays
Defining the reservoir scale fracture systems
1626:Naci
1989:Ojo2018:C12056:Kirt
2690:C2
2826:Fr
2950:UFZ-T2987:UFC-B3056:MFC-T3072:MFC-B3111:LFC-T
0.350
0.400
0.450
0.500
0.550
0.600
0.650
0.700
0.350
0.400
0.450
0.500
0.550
0.600
0.650
0.700
925.0580.0
925.0600.0
925.0620.0
925.0640.0
925.0660.0
925.0680.0
925.0700.0
925.0720.0
925.0740.0
925.0760.0
Line:Trace:
EPNG COM A EC A 300 COM A 300EPNG COM A ING 1 COM A ING1SP-A SP ASP-B SPB SP-C SPC
0.350
0.400
0.450
0.500
0.550
0.600
0.650
0.700
4.1523.9033.6543.4053.1552.9062.6572.4082.1591.9101.6611.4121.1630.9130.6640.4150.166-0.083-0.332-0.581-0.830-1.080-1.329-1.578-1.827-2.076-2.325-2.574-2.823-3.072-3.322-3.571-3.820-4.152
The Kirtland Shale primary seal (caprock)
Fruitland Formation reservoir zone
Seismic Attribute: Absolute value of finite differencePost-stack processing helps enhance seismic discontinuities
The Kirtland Shale primary seal (caprock)
Fruitland Formation reservoir zone
Structure-Oriented Attribute Analysis
1. Structure-oriented seismic attribute analysis: a) characterization of fluid migration pathway, b) caprock sealing capacity.
2. Results promote: a) optimally placing injection and monitor wells,b) using seismic constraints for DFN modeling and flow simulation.
Structure-oriented attribute analysisConstruction of texture model
Mi (i = 1…n)
Retrieval of dataDi (x,y,z) (i = 1…n)
Linear least-squares regressionMi ~ Di (x,y,z)
Output the value of ABSOLUTE gradient g (x,y,z)
Next location (x,y,z)
Mi
Di
∑
∑
=
=
−
−−= n
ii
n
iii
MM
DDMMg
1
2
1
)(
))((
Original Model regression Phase
Reservoir rock with high porosity
Primary caprock with low fracture intensity
Original Structure attribute Phase
Primary caprock with low fracture intensity
Reservoir rock with high porosity
0.5 km0.0 1.0
A
B
Original amplitude
Structure attribute
0.5 km0.0 1.0
A
B
Original
Structure attribute
0.5 km0.0 1.0
A
B
Original
Structure attribute
1 mile
Original
Structure attribute
????
Formation with highstorage capacity
Caprock with potential leaky fractures
Derived from amplitude Derived from structure attribute
N N
1 mile
Improvement in Edge Enhancement
CO2 injection well
Tracer test
????
Migration pathway
Sealingfaults
1.0 km
Complex fracture patterns will cause complex flow and irregular plume geometry of injected CO2
Attribute analysis enhances our ability to detect fracture systems in caprock and reservoir intervals
Interpretation Based on Structure Attribute
Attributes provide plan-view input to DFNs
San Juan Basin Pilot
Attribute Analysis Used to Identify Vertical Continuity in Potential Flow Paths
Kirtland Shale Caprock
Fruitland Coals
480 ms 430 ms 400 ms
NacimientoUpper KirtlandMiddle KirtlandA) B) C)
Orientations of possible fracture systems in the caprock
Use of fracture detection logsN23E σH
Entire Borehole Upper Fruitland Reservoir Zone
Identify drilling induced breakouts and define
present day in-situ stress
Kirtland Shale –Primary Seal
Identify natural fractures in-situ
Note consistency with dominant attribute mapped trend
Use of “sonic scanner” logs & regional/local stress data
Entire Borehole Fruitland Coal Section
Measurements obtained using Schlumberger’s Sonic Scanner
1 23
45
6
7
8 YX
Field-mapped fracturesImage-mapped fractures:
site 1Image-mapped fractures:
site 2
Use surface fracture system information to fill gaps in input data for DFNs
Use of data from ground surface (field observations and areal images (scanner images, aerial photos, fracture maps)
INPUTS: Well logs, outcrop data and seismography determine fracture network statistics.
Conceptual model fills the blanks!
OUTPUTS: Fracture Sets characterized by averages and variances in length, orientations, effective apertures, and locations
Fracture Detection Log
Fracture/Fault Data FRACGEN
2. Axis of Horst1. Seismically Resolved Fold Axes 3. Seismically Resolved Faults
Seismically-resolved features may be input directly into a DFN. Statistical parameters are input for features not directly observed.
Faults & Fractures Zones Define Major Structural Components of Reservoir
Identify fracture sets and their statistical parameters
• FILE IDENTIFICATION (<= 80 CHARACTERS) FRACGEN 6th EDITION• Conceptual Model of Major Flow Paths in Southern Half of Storage Field• X & Y DIMENSIONS OF FLOW REGION• 32000.0 52000.0• EFFECTIVE DEPTH OF MID-LAYER; EFFECTIVE THICKNESS OF FRACTURED LAYER• 6139.0 170.0• NUMBER OF SETS (including MODEL 0 sample trace set)• 8• MODEL -------------------------------------------------------------- SET 1• 1• SET IDENTIFICATION (<= 80 CHARACTERS)• Seismically-Resolved Faults• MEAN AND SDEV OF FRACTURE ORIENTATION (360.0=UNI)• 0.0 0.0• MIN/MEAN AND MAX/DEV FRACTURE LENGTH, DIST. (0=UNI,1=EXP,2=LOG,3=INT)• 0.0 0.0 0• MEAN AND SDEV OF FRACTURE APERTURE• 0.0 0.0• DENSITY OF FRACTURE CENTER POINTS• 0.0• CORRELATIONS (len=F(order), ori=F(len), wid=F(len))• 0.0 0.0 0.0• MAXIMUM PERCENT FRACTURE SHIFT: MODE I, II, III• 0.0 0.0 0.0• SYNTHETIC ANNEALING CONTROLS (pstart,nswaps,swapl,ifreq)• 100.0 0 0 0• RELATIVE FREQUENCIES OF T-TERMINATIONS (T2,T1)• 0.0 0.0• FRACTURE INTERSECTION FREQUENCIES (%): ZERO TO 10+ INTERSECTIONS• 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0• PERCENT FRACS PENETRATING OVERLYING LAYER; CORRELATION TO FRAC LENGTH• 0.0 0.0• NUMBER OF USER-SUPPLIED FRACTURES• 97• FRACTURES: X-LEFT, Y-LEFT, X-RIGHT, Y-RIGHT, WIDTH, SHIFT(%), PERCENT• 2440.00 5200.00 4520.00 9000.00 .350E-02 0.0 0.0• 4520.00 9000.00 6800.00 13800.00 .350E-02 0.0 0.0• 6800.00 13800.00 8960.00 20840.00 .350E-02 0.0 0.0• 8960.00 20840.00 11000.00 27480.00 .350E-02 0.0 0.0• 11000.00 27480.00 11480.00 35280.00 .350E-02 0.0 0.0• 11480.00 35280.00 13560.00 41680.00 .350E-02 0.0 0.0
• MODEL -------------------------------------------------------------- SET 2• 2• SET IDENTIFICATION (<= 80 CHARACTERS)• Sub-Seismic Faults Associated w/ Horst• MEAN AND SDEV OF FRACTURE ORIENTATION• 360.0 6.0• MEAN AND SDEV OF CLUSTER ORIENTATION• 0.0 0.0• MIN/MEAN AND MAX/DEV FRACTURE LENGTH, DIST. (0=UNI,1=EXP,2=LOG,3=INT)• 4000.0 10000.0 0• MIN/MEAN AND MAX/DEV CLUSTER LENGTH, DIST. (0=UNI,1=EXP,2=LOG)• 10000.0 22000.0 0• MEAN AND SDEV OF FRACTURE APERTURE• 0.001390 0.0• MEAN INTRA-CLUSTER FRACTURE SPACING• 2400.0• MEAN AND SDEV OF INTRA-CLUSTER FRACTURE DENSITY• 0.00000010 0.0• DENSITY OF CLUSTER CENTER POINTS• 0.0000000020• .• .• .• RELATIVE FREQUENCIES OF T-TERMINATIONS (T2,T1)• 40.0 40.0• FRACTURE INTERSECTION FREQUENCIES (%): ZERO TO 10+ INTERSECTIONS• 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0• PERCENT FRACS PENETRATING OVERLYING LAYER; CORRELATION TO FRAC LENGTH• 0.0 0.0• NUMBER OF USER-SUPPLIED CLUSTERS• 4• CLUSTERS: X-LEFT, Y-LEFT, X-RIGHT, Y-RIGHT, WIDTH, SHIFT(%), PERCENT• 9360.00 -4600.00 9800.00 11680.00 2400.00 0.0 0.0• 8800.00 7760.00 16960.00 24320.00 2400.00 0.0 0.0• 14600.00 17080.00 19160.00 46440.00 2400.00 0.0 0.0• 16800.00 40480.00 27000.00 56520.00 2400.00 0.0 0.0
• MODEL -------------------------------------------------------------- SET 3• 1• SET IDENTIFICATION (<= 80 CHARACTERS)• Small Sub-Seismic Faults• MEAN AND SDEV OF FRACTURE ORIENTATION (360.0=UNI)• 20.0 8.0• MIN/MEAN AND MAX/DEV FRACTURE LENGTH, DIST. (0=UNI,1=EXP,2=LOG,3=INT)• 2000.0 4000.0 0• MEAN AND SDEV OF FRACTURE APERTURE• 0.000800 0.0• DENSITY OF FRACTURE CENTER POINTS• 0.00000020• CORRELATIONS (len=F(order), ori=F(len), wid=F(len))• 1.0 0.6 0.0• MAXIMUM PERCENT FRACTURE SHIFT: MODE I, II, III• 49.0 40.0 0.0• SYNTHETIC ANNEALING CONTROLS (pstart,nswaps,swapl,ifreq)• 5.0 10 15 2• RELATIVE FREQUENCIES OF T-TERMINATIONS (T2,T1)• 65.0 30.0• FRACTURE INTERSECTION FREQUENCIES (%): ZERO TO 10+ INTERSECTIONS• 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0• PERCENT FRACS PENETRATING OVERLYING LAYER; CORRELATION TO FRAC LENGTH• 0.0 0.0• NUMBER OF USER-SUPPLIED FRACTURES• 0• FRACTURES: X-LEFT, Y-LEFT, X-RIGHT, Y-RIGHT, WIDTH, SHIFT(%), PERCENT•
• MODEL -------------------------------------------------------------- SET 4• 2• SET IDENTIFICATION (<= 80 CHARACTERS)• Right-Lateral Sub-Seismic Oblique-Slip Tear Faults• MEAN AND SDEV OF FRACTURE ORIENTATION• 83.0 6.0• MEAN AND SDEV OF CLUSTER ORIENTATION• 0.0 0.0• MIN/MEAN AND MAX/DEV FRACTURE LENGTH, DIST.
(0=UNI,1=EXP,2=LOG,3=INT)• 8000.0 19000.0 0• MIN/MEAN AND MAX/DEV CLUSTER LENGTH, DIST. (0=UNI,1=EXP,2=LOG)• 11000.0 26000.0 0• MEAN AND SDEV OF FRACTURE APERTURE• 0.000600 0.0• MEAN INTRA-CLUSTER FRACTURE SPACING• 1000.0• MEAN AND SDEV OF INTRA-CLUSTER FRACTURE DENSITY• 0.00000012 0.0• DENSITY OF CLUSTER CENTER POINTS• 0.0000000010• .• .• .• RELATIVE FREQUENCIES OF T-TERMINATIONS (T2,T1)• 20.0 70.0• FRACTURE INTERSECTION FREQUENCIES (%): ZERO TO 10+ INTERSECTIONS• 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0• PERCENT FRACS PENETRATING OVERLYING LAYER; CORRELATION TO FRAC
LENGTH• 0.0 0.0• NUMBER OF USER-SUPPLIED CLUSTERS• 4• CLUSTERS: X-LEFT, Y-LEFT, X-RIGHT, Y-RIGHT, WIDTH, SHIFT(%), PERCENT• 14360.00 -4600.00 14800.00 11680.00 1000.00 0.0 0.0• 13800.00 7760.00 21960.00 24320.00 1000.00 0.0 0.0• 19600.00 17080.00 24160.00 46440.00 1000.00 0.0 0.0• 21800.00 40480.00 32000.00 56520.00 1000.00 0.0 0.0
• .• .• .• MODEL -------------------------------------------------------------- SET 7• 1• SET IDENTIFICATION (<= 80 CHARACTERS)• Regional Extension (Master) Fractures• MEAN AND SDEV OF FRACTURE ORIENTATION (360.0=UNI)• 83.0 8.4• MIN/MEAN AND MAX/DEV FRACTURE LENGTH, DIST. (0=UNI,1=EXP,2=LOG,3=INT)• 4881.6 2140.2 2• MEAN AND SDEV OF FRACTURE APERTURE• 0.000190 0.0• DENSITY OF FRACTURE CENTER POINTS• 0.000000663• CORRELATIONS (len=F(order), ori=F(len), wid=F(len))• 1.0 0.8 0.0• MAXIMUM PERCENT FRACTURE SHIFT: MODE I, II, III• 49.0 40.0 0.0• SYNTHETIC ANNEALING CONTROLS (pstart,nswaps,swapl,ifreq)• 100.0 10 15 2• RELATIVE FREQUENCIES OF T-TERMINATIONS (T2,T1) 20.0 55.0• 50.0 40.0• FRACTURE INTERSECTION FREQUENCIES (%): ZERO TO 10+ INTERSECTIONS• 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0• PERCENT FRACS PENETRATING OVERLYING LAYER; CORRELATION TO FRAC
LENGTH• 0.0 0.0• NUMBER OF USER-SUPPLIED FRACTURES• 0• FRACTURES: X-LEFT, Y-LEFT, X-RIGHT, Y-RIGHT, WIDTH, SHIFT(%), PERCENT•
Multilayer DFNs developed in FRACGEN go directly into NFFLOW for flow simulation and iterative history
matching efforts
Oriskany Well Site
4 layers
1,700 ft x 1,500 ft x 200 ft
10,873 fractures
Time Frame and Costs
Year 1: Initial software development and testing; log, field and image-based fracture analysis (site dependant); preliminary DFN for leakage risk assessment
Year 2: Complete software development; complete 3D seismic analysis; refine/complete model DFN; begin iterative flow simulation efforts through primary seal and reservoir intervals
Depending on project opportunities > refine and continue DFN/flow simulation process.
Annual budgets: $100K -$140K costs will be
site/application dependant
In Summary …
• develop and test of new seismic processing algorithms to support development of realistic caprock and reservoir DFNs.
• produce discrete fracture networks to simulate flow through caprock and reservoir intervals
• work with NETL modelers to evaluate possible leakage risk & reservoir behaviors through
flow simulation <> iterative DFN adjustments
Open Fractures observed in the
wellboreSurface fractures
Shear wave anisotropy
1626:Naci
1989:Ojo2018:C12056:Kirt
2690:C2
2826:Fr
2950:UFZ-T2987:UFC-B3056:MFC-T3072:MFC-B3111:LFC-T
0.300
0.350
0.400
0.450
0.500
0.550
0.600
0.650
0.700
0.350
0.400
0.450
0.500
0.550
0.600
0.650
0.700
925.0580.0
925.0600.0
925.0620.0
925.0640.0
925.0660.0
925.0680.0
925.0700.0
925.0720.0
925.0740.0
925.0760.0
Line:Trace:
EPNG COM A EC A 300 COM A 300EPNG COM A ING 1 COM A ING1SP-A SP ASP-B SPB SP-C SPC
0.300
0.350
0.400
0.450
0.500
0.550
0.600
0.650
0.700
Questions?