What Can Microseismic Tell Us About Hydraulic Fracturing? Shawn Maxwell May 2015 Microseismic Geomechanics: Increased understanding; reduced risk 1
Outline Microseismic Introduction Microseismic in Unconventional Reservoirs Learnings after 15 years of Microseismicity Microseismic Source Mechanics Microseismic Geomechanics 2
Hydraulic Fracturing: Where Does It All Go? Fracture Complexity & Natural Fractures Hydraulic Fractures Natural Fractures
IP (MSCFPD) Barnett Shale Development SPE77440: 10000 2000 First Barnett Microseismic Image 8000 6000 N 4000 E 0 100 m Massive Water Fracs Horizontal Wells Microseismic 2000 0 1980 1990 2000 Year 4
Reducing Carbon Emissions 5
Microseismic Hydraulic Fracture Applications Fracture direction Height Length Complexity Optimize Stimulation Design height growth injection rate and volume fluid type, additives, and diverters proppant placement Validate Completion Design completion types and designs stage isolation stage sequencing refracturing Refine Well Plan well orientation landing point well integrity Improve Reservoir Management well spacing well placement induced seismicity and fault activation reservoir characterization production optimization 6
Project Design for Value Eng Obj Landing Point Interpretation Quality Control Cross section Target Up Accurate Processing Pre-Survey Design Quality Acquisition Cross section 7
Eagle Ford Example (Patel, 2013) Cross section Cross section Target Up 8
Project Design for Value Eng Obj Rate/Height Stages 1-2 120 bpm Low Rate Interpretation X-section High Rate Pre-Survey Design X-section Quality Control Up Quality Acquisition Accurate Processing 9
Evolution of Monitoring Geometries Noise Signal Near Surface Surface Borehole Horizontal How do accuracies and sensitivities compare? How do you decide which option? SPE159670 10
Acquisition Footprint Downhole Array Shallow Grid 11
Shale Lessons: Containment 1. Depth Containment Monitor Well Treatment Well Landing Point 12
Environmental Concerns 13
Aquifer Protection 1. Spills 2. Well 3. Frac IEA 14
Fracture Height Growth 0 1000 Height (m) -500-400 -300-200 -100 0 100 200 300 400 Piceance Jonah Horn River Cardium Montney Marcellus Barnett Woodford Eagleford Cotton Valley Spraberry Wolf Camp Bakken Haynesville -500-400 -300-200 -100 0 100 200 300 400 Depth (m) 2000 3000 4000 Piceance Jonah Horn River Montney Marcellus Cardium Barnett Woodford Eagleford Cotton Valley Spraberry Wolf Camp Bakken Haynesville 500 500 15
Induced Seismicity US National Academy, 2012 No damage and rare (several sites and about 70 felt events from 3,000,000 fracs) 16
Shale Lessons: Heterogeneity 1. Depth Containment 2. Fracture Variability Well A Well B Monitoring Well SPE144207 Well C 17
Shale Lessons: Complexity 1. Depth Containment 2. Fracture Variability 3. Fracture Complexity SPE77440 N E 0 100 m Sayers 2010 18
Shale Lessons: SRV 1. Depth Containment 2. Fracture Variability 3. Fracture Complexity 4. Stimulated Reservoir Volume Q Slurry Bank Fluid Microseismic Stage 1 - Yellow Stage 3 - Red Stress Hydraulic Stage 2 Dark Blue Stage 4 Light Blue Propped Wet Events Dry Events Uncertainty 19
Microseismic Interpretation Qualitative/Geometry Stages 1-2 120 bpm Quantitative/Deformation Baig et al, 2012
Microseismic Mechanisms Log S/P 1.5 1.0 0.5 0-0.5 After Rutledge et al., 2013
Mass/Energy Balance M 0 μ = Vol = Ad Stage 1 Stage 2 Stage 3 Stage 4 MS Volume (bbl) 0.82 0.15 0.075 0.30 Frac Volume (bbl) 25300 25300 25300 25300 % 0.0033% 0.00059% 0.00030% 0.0012% MS Area (ft2) 19375 4018 3533 9040 Frac Area (ft2) 7000000-6200000 - % 0.28% - 0.057% - MS Energy (J) 62500 11300 5700 22950 Frac Energy (J) 149040000000 149040000000 149040000000 149040000000 % 0.0042% 0.00076% 0.00038% 0.0015% Maxwell, 2014
Tiltmeters Hydraulic fracture induces a characteristic deformation pattern Fracture-induced surface trough Tilt/microseismic detect elastic strain waves at different frequencies Both Image the geometry and orientation of created hydraulic fracture Fracture Downhole tiltmeters In offset well
Generating Shear during Hydraulic Fracturing Dry Fault Activation Wet Fissure Compression Stress Shadow Shear Wet Fracture Tip Fracture Tension Wet Offset Maxwell, 2014
Complex Hydraulic Fracture Growth Pore Pressure Fracture Opening Fracture Shearing Synthetic Microseismic
Anatomy of Hydraulic Fracture DFN Wet Microseismicity Activated Fractures Primary Fractures Dry Microseismicity
Fracture Growth Wet Microseismicity Dry Microseismicity
Reservoir Drainage Production Forecast 20 Years Pressure (psi) 28
Conclusions Geomechanical interpretation tools key to realize the full value from microseismic Microseismic key technology to image hydraulic fractures Microseismic demonstrated complex fracture networks Microseismic volume oversimplification Microseismic calibration of complex geomechanical fracture model Enables reservoir simulation of well performance Estimates drainage for well spacing 29