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Comparison of Mechanical and Fracture Stratigraphy Between Failed Seal Analouges

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Comparison of Mechanical and Fracture Stratigraphy Between Failed Seal Analouges Utah State University DigitalCommons@USU Graduate Student Posters Browse all Graduate Research 2012 Comparison of Mechanical and Fracture Stratigraphy between Failed Seal Analouges Elizabeth S. Petrie Utah State University James P. Evans Utah State University Follow this and additional works at: https://digitalcommons.usu.edu/graduate_posters Recommended Citation Petrie, Elizabeth S. and Evans, James P., "Comparison of Mechanical and Fracture Stratigraphy between Failed Seal Analouges" (2012). EAGE 3rd International Conference on Faults and Top Seals Montpellier 2012. Graduate Student Posters. Paper 10. https://digitalcommons.usu.edu/graduate_posters/10 This Poster is brought to you for free and open access by the Browse all Graduate Research at DigitalCommons@USU. It has been accepted for inclusion in Graduate Student Posters by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. Comparison of Mechanical and Fracture Stratigraphy between Failed Seal Analogues E.S. Petrie & J.P. Evans -- Utah State University 4505 Old Main Hill - Logan, UT 84322-4505 USA [email protected]; [email protected] P1 K2 K2 Qe J2 114°W 112°W 110°W J2 INTRODUCTION 42°N K2 Qa Qa 2 Qe Qao Tununk Mbr. K1 Earthy Entrada Logan K1 P1 J2 J2 K1 K2 J1 The presence of discontinuties in seal lithologies affects their mechanical P1 Qa m m WY J2 Qe 1 Jg J1 4 Tr1 Salt Lake City Qe Tr1 Qe NV J1 P1 and hydro-geologic properties. We examine the mechanical and fracture Qe K2 Curtis Fm. Jg K1 Tr1 8 40°N J2 CO Qe J1 J2 J1 Tr1 Jg J1 J1 60 stratigraphy of failed Paleozoic and Mesozoic seal analogues in J1 Qe Green River Qe P1 Tr1 south-east Utah to understand the nature and distribution of fluid flow San Rafael Moab Uncompaghre Tr1 & Travertine Colluvium Swell Highlands 7 Qe K1 Green River N 38°N J1 pathways in various seal lithologies. Outcrop surveys provide data for Qe K2 J1 PP 0 60 120 K1 50 Km Monument comparison between each locality to identify relationships between Uplift River Colorado J 114°W 112°W 110°W 2 m AZ J2 Jg J1 Qa 6 Jg Qa depositional composition, diagenesis, and loading history. These data K1 Tr1 J1 N J2 Qe P1 W E K2 characterize the distribution and morphology of open mode fractures, with Colorado Plateau N: 36 J2 Mean Direction: 280.5° Qao Counting interval: 10° towns Qe Jg 40 5 changes in lithology and provide input for accurate quantitative Qe uplifts Tr1 J2 maximum edge of Paradox basin salt P subsurface geomechanical and fluid flow models. Qao 0.15 faults P1 50 Qe Ti Tr1 outcrop localities J1 P1 35 Jg 20 J2 Qe Tr1 MEAN: 1.03 MEAN: 6.98 K1 P 45 Tr1 P1 4 30 30 STD DEV: 1.35 STD DEV: 3.21 Tr2 1 Jurassic Earthy Entrada K3 Ti Qa SKEWNESS: 3.1 K2 SKEWNESS: 0.09 PP 25 15 40 0.10 Control Scanline Ti METHODS P1 2 Cretaceous Tununk Member 3 Jg 20 Fracture Scanline Qao Tr2 10 Percent Outcrop 3 Permian Organ Rock Shale K1 35 Percent 15 J1 3 J2 (Darcy) 4 Jurassic Carmel Formation Tr1 Measured stratigraphic sections -- detailed rock descriptions, identification of lithologic eld derived 10 0.05 5 Km 30 Slickrock Mbr. eld permeability 5 changes including grain size, bed thickness, & mineralogy 0 20 40 80 20 strength compressive 25 0 2 0 Scanlines - determine fracture distribution, morphology and interaction types 0 1 2 3 4 5 6 7 0 5 10 15 N Spacing (m) Spacing (m) Rock strength and Permeability - field-derived compressive strength modied from: Hintze, et al., 2000 UGS Digital Geologic Map of Utah 20 0.00 (N-type Schmidt hammer) and permeability (TinyPermII). unbleached 10 bleached 1 Petrography OUTCROP OBSERVATIONS N 2 XRD- mineralogic composition comparison between host and fractured rocks Thinsection - characterization of micro-structures and structural diagenesis All localities show: 0 evidence for mineralization and uid ow in the subsurface 0 Theoretical W E 2 N: 146 1 Mean Direction: 350.7° Burial History & Stress Evolution - burial histories merged with simple Mohr-Coulomb Counting interval: 10° mineralogic dierences between host rock and fracture ll 20 MEAN: 0.52 analysis to constrain Sv, SH, and Sh failure models through time MEAN: 20.9 STD DEV: 0.55 STD DEV: 29.5 SKEWNESS: 1.54 Mohr-Coulomb - stress changes & failure modeled through time where: 15 SKEWNESS: 2.3 σ ρ ν σ σ ν ν Fracture Scanline C=0 & C= 5; Sv= 1= gz, =0.25, SH=Sh= 2= 3=( / -1)(Pp-Sv)+Pp (from Eaton, 1969) meso-scopic fault and fracture orientations which follow 30 10 Control Scanline Percent Percent regional structural trends 20 5 1 10 fracture spacing <0.25-0.5 fractures/meter 0 m Organ Rock Shale 0.00 0.50 1.00 1.50 2.00 2.50 0 Spacing (m) 0 50 100 150 120 White Rim Sst Spacing (m) fracture densities and morphology which vary with lithology From: Doelling, 2002 and bed thickness OUTCROP MECHANICAL STRATIGRAPHY: CARMEL FORMATION 110 Unit 2 -13 Bed Thickness (m) Permeability (m x 10 ) Number KEY 2 m m 0 1 2 3 0 0.5 1.0 1.5 2.0 bed thickness (m) calcareous siltstone Carmel Formation fracture density (frac/m) limestone mudstone Schmidt Hammer Partial Section 35 gypsum sandstone Permeability, K ( m2) 100 m 50 30 Using a modied rock mass ratings, MEAN: 0.202 Windsor STD DEV: 0.306 35 40 0.3m (Bieniawski, 1989; Priest, 1993; Zhang, 2005), SKEWNESS: 3.22 5 0.3m combined with quantitative stratigraphic 90 30 C 25 Fracture Scanline analysis of fracture density distribution Percent 1m 20 (Bertotti et al, 2007) we delineate 10 PLAN VIEW 20 mechanostratigraphic units. 30 Paria River NO DATA NO DATA 80 0 0.00 0.50 1.00 1.50 2.00 2.50 Formation Carmel Spacing (m) Mechano-stratigraphic units have similar: 15 20 MEAN: 2.81 4 STD DEV: 2.32 bed thickness 70 15 SKEWNESS: 1.4 10 cm 25 10 Control Scanline B Crystal Creek 10 Percent C fracture density 3 5 60 5 eld derived permeability 0 0 1 2 3 4 5 6 7 8 9 Spacing (m) 20 2 Co-op Creek eld derived compressive strength 0 1 K > 10x10-12m2 50 Navajo 0 2 4 6 8 10 10 20 30 40 50 60 70 0.5 cm A 0.5 cm Fracture density (frac/m) Schmidt Hammer R- Value From: Petrie, et al., in press Landscape scale alterations associated with faults 15 Cedar Mesa Joint Orientations N 25 N MEAN: 0.31 40 20 STD DEV: 0.27 SKEWNESS: 1.3 INPUT DATA FOR GEOMECHANICAL MODELING Schmidt Hammer Young’s 15 Field Data Based Mechano-stratigraphic Units Compressive Stress Modulus Fracture Scanline 10 70 0 50 Percent 10 30 W E N: 342 10 Estimates of dynamic Young’s Mean Direction: 313.4° W Counting interval: 10° E 5 N: 132 Modulus variability W B Mean Direction: 36.3° 0 Organ Rock Joint Orientations Counting interval: 10° 0.00 0.50 1.00 1.50 derived from wireline logs N Spacing (m) N 80 Well-bore estimates of 20 MEAN: 0.46 70 STD DEV: 0.96 dynamic Young’s Modulus show F2 SKEWNESS: 3.2 5 60 meter scale variability. 50 W E F1 (15-34 GPa) Control Scanline N: 108 A 40 0 10 0 150 normal fault joints modified from: Willis, 2012 Percent 10 m Mean Direction: 303.5° Young’s Fractures/m Gamma Ray Organ Rock Shale 1.5 km Counting interval: 10° 30 10 Cedar Mesa Sandstone N W E Modulus N = 50 20 0 50 Potential Model Layers Based on Mechano- Potential Model Layers Based on Derived Circle = 20 % Stratigraphic Units and Wireline Log Shifts Young’s Modulus Averaged Over 61 cm 10 33 Field-based fracture density and Navajo Sandstone fault deformation 36 band trends, measured on bedding plane 0 compressive strength also show & in cross-section 0 1 2 3 4 5 6 o (mean strike orientation F1 = 21 ) Spacing (m) 29 meter scale variability 0 30 0 Joint trend, measured on Navajo Sandstone Navajo bedding plane (mean strike orientation F2 = 337o) 3 Sst 25 24 Variability in elastic moduli will 19 4 22 be used in future geomechanical modeling 13 17 0 150 Gamma Ray 10 m 10 m MODEL 1 MODEL 2 BURIAL HISTORY AND STRESS EVOLUTION: ORGAN ROCK SHALE From: Petrie, et al., in press Permian Triassic Jurassic Cretaceous Tertiary 0.0 τ μ=0.6 CONCLUSIONS C=5 MPa Stratigraphic variability and resulting changes in mechanical properties inuence the variability Tr-1 μ=0.6 0.5 C=0 MPa of fracture morphology and density over the cm to m scale. 1.0 J-1 21 Mpa 19.5 Mpa Understanding fracture morphology in dierent seal types, across interfaces, and in various Depth (km) 1.5 structural settings is key to understanding how seals respond to hydraulic failure. σn 2.0 T=C/2 10 20 30 40 Calculated variability in elastic moduli correlates to the mechano-stratigraphic variability Laramide COP Sevier B&R TIME observed in outcrop --- the variations in elastic moduli will be modeled to quantify their eects. 2.5 300 250 200 150 100 50 0 Age (Ma) Extensional fractures open by locally applied tectonic stress Increasing Depth Overpressure during burial (lithostatic loading) can induce open-mode tensile failure that can 25 25 or by internal uid pressure (see Laubach, 1988). differential stress hydrostat MPa Fracture Formation: eect future seal integrity: Are most seals fractured then re-cemented/re-sealed in some way? Pp for failure at C=5 1) response to thermoelastic contraction during exhumation 20 20 Pp for failure at C=0 2) due to tectonic stress 21.0 MPa change in effective stress REFERENCES required for failure, C=5 21.0 MPa 3) hydraulic fractures due to overpressure at depth Bertotti, G., N., Hardebol, J.K.
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