fracman improved oil production - golder breakfast series jan 2015 - full
TRANSCRIPT
The worlds premier DFN software
www.fracman.com © Golder Associates Inc, 2015
Golder Houston Breakfast Series – Jan 2015
Improving Oil Production: Understanding Natural, Induced, and Reactivated Fractures
Bill Dershowitz, Technical Director FracMan Technology Group [email protected]
Golder Associates – Geomechanics and Environment
Golder – Mining, Oil and Gas, and Environment
FIRL 3%
Land Development 9%
Manufacturing 8%
Mining 36%
Oil & Gas 20%
Power 7%
Transportation 9%
Waste Management 5%
Water Resources 1%
Other 2%
Percentage of Global Revenues by Client Sector
FIRL
Land Development
Manufacturing
Mining
Oil & Gas
Power
Transportation
Waste Management
Water Resources
Other
Unconventional Oil and Gas Project Lifecycle
Appraisal Exploration Development Production
Asset Retirement
Resource Evaluation
Seismic, Drilling &
Stimulation
Vertical/ Horizontal Drilling &
Stimulation
Production, Workover & Enhanced Recovery
Restoration &
Closure
Reservoir Engineering/FracMan Stakeholder Mapping and Consultation
Planning and Permitting
Environmental Monitoring and Compliance
Reclamation Golder
Services &
Solutions
Remediation
Play Selection &
Siting
Pre-Development
Due Diligence
Integrated Water Management and Planning
Pipeline & Infrastructure Design & Engineering
Geotechnical Engineering
4
Golder Unconventional Oil and Gas Services
Wednesday, January 28, 2015
Some of Golder’s Fractured Reservoir Projects Over the Past 20 Years
Unconventional Reservoir Experience
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Barnett Haynesville Eagle Ford Permian Bakken Appalachian Marcellus Niobrara Mesaverde Monterey Woodford Wolfcamp Horn River Grosmont La Vaca Muerte
Morocco Poland Russia Australia Kuwait (Najmah & Makhul)
FracMan® Discrete Fracture Network Modelling
Explicitly represent discrete fractures in 3D Space
Build a model of key fracture geometry, mechanical properties, storage and permeability
Transform geological, geotechnical and well testing data into quantitative parameters to describe fracture network
Generation of Geologically Realistic DFN models based on parameters derived from field data
Stochastic process allowing probabilistic assessment to be carried out
Provides direct data to geomechanical simulators
DFN Model
DFN models can be used directly or
upscaled to equivalent properties
.
Formation Analysis &
Geo-Modelling
Geo- mechanics
Seismic Analysis & Geophysics
Dynamic Analysis & simulation
Advanced seismic processing Unique VSP processing & imaging Micro-seismic monitoring and
analysis
Hydraulic fracturing Critical stress analysis Sanding issues Wellbore stability Subsidence
Data analysis, integration & synthesis Conceptual model development DFN & Petrel model building DFN Volumetrics
Interpretation of dynamic data Multi-porosity Flow Simulation Calibration of DFN models Reservoir simulation
FracMan Carbonate and Unconventional Reservoir Analyses
January 28, 2015 8
Natural Fractures Matter!
Few natural fractures HF defines drainage
Natural fractures but most are healed
HF essential for opening up healed fractures and increasing drainage
Persistent, open, natural fractures
HF may not greatly increase production in all wells or stages
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Eagle Ford
Utica
Hydraulic Fracture Geometry
• What is the interaction between hydraulic fractures and • in situ stress field
(local and regional) ? • pre-existing natural
fractures and faults ? • Geomechanical units
and their heterogeneity (both vertical and lateral) ? All these questions relate to discrete features and
heterogeneities. Can we rely on a simple continuum solution ?
σhmin
σhmax
Induced Hydrofracs, Inflated Natural Fractures, and Hydrosheared Natural Fractures
Stress grid: Sigma 3 direction shown
Identify fractures that are connected to the perf zone and whose state of stress is such that they will take fluid and/or pressure
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(c) Golder Associates Inc. 2014
Field Development Issues Addressed by DFN Hydraulic Fracture Modeling
With a DFN model we can address the following field development issues:
Landing depth Well spacing Lateral length Stage spacing Vertical drainage contribution Well sequencing Geologic differences within the lease area Completions optimization EUR
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Hydroshearing
Hydroshearing: microseismic events are simulated and assigned to fractures which are sheared and critically stressed beyond inflated fractures due to pressure diffusion.
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Plan View
Hydraulic Fractures & Natural Fractures Scenarios
TYPE A: Hydraulic fracture propagation provides the only flow pathway to the well TYPE B: Hydraulic fracture propagation provides the primary flow pathway to the
well, but is supplemented by fractures that are critical stressed by frac fluids (esp. rough fractures)
TYPE C: Frac fluid “leakoff” to natural fractures is extensive, and production is through a combined network defined by the hydraulic fracture and natural fractures (or perhaps by the natural fractures alone!)
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Do these have unique signatures?
Type A – Hydrofracs Provide only Flow
Implies that Gas/Oil Storage is Exclusively in Rock Matrix Classic “1-D” Linear Flow Signature from Rock Matrix to
Fracture Typical Reservoir – Some parts of Barnett
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Well
Hydraulic Fractures
Pressure Response
Type B – Hydrofracs and Natural Fractures Provide Flow and Storage
Natural fracture - particularly those reactivated by fracing can provide both flow and storage
More extensive, higher dimension network delivering gas to the well – not necessarily linear flow!
Natural fractures can dramatically increase tributary drainage volume of each well – increasing both IP and EUR
Or.. Rapid decline as natural fractures are depleted Typical Reservoir – Fayetteville
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Well
Natural Fractures
Pressure Response
Hydraulic Fractures
Type C – Natural and Reactivated Natural Fractures Dominate Production
Hydraulic Fractures primarily provide connection to and enhancement of pre-existing natural fracture network
Low apparent hydraulic efficiency of fracing, as frac-fluid is diverted to natural fracture
Wide, diffuse microseismic response Flow dimension depends on geometry of natural
fracture network – 1D, 2D, or 3D ! Dynamic stress effects can be very important Typical Reservoir – Appalachian Basin
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“Leakoff” from Hydrofrac to Natural Fractures
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0
1000
2000
3000
4000
5000
6000
0 2 4 6 8 10 12 14 16 18
psi
Square Root Time
0500
100015002000250030003500400045005000
1 10 100 1000
psi
Time, seconds
3D DFN Model and Hydraulic Fracturing Simulation
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Induced Hydraulic Fracture
Propped Natural Fractures
Stimulated Natural Fractures
Discrete Fracture Network (DFN)
Simulated Microseismic Events
FracMan Discrete Fracture Network Workflow
Propped Natural Fractures
Hydrosheared Natural Fractures
Induced Hydraulic Fractures and Stimulated Natural Fractures
Hydraulic fracture (HF) initiates at the well in the direction of σHmax
Natural fractures intersected by the HF are checked for dilation criterion:
Dilatable fracture = fracture pore pressure > fracture
normal stress
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Induced Hydraulic Fracture
Volume of the stimulated fractures is solved in time steps and is determined by the: elastic properties of the rock; in situ stress regime; internal fracture pore pressure
At each time step a fraction of slurry is pumped to the HF, as the HF grows the intersected natural fractures are checked for their injection possibility
Movie of Hydraulic Fracturing – Induced Fractures and Stimulated Natural Fractures
Inflated Natural and induced fractures
January 28, 2015 73
Induced hydraulic fractures
Inflated Natural Fractures
Simulated and Measured Microseismic
Microseismic point is generated for each element having a critical stress, which can be used to compare with observed microseismic data
January 28, 2015 74
Simulated Microseismic
Simulated Microseismic with hydraulic and reactivated natural fractures
Measured Microseismic
Simulated and Measured Microseismic
Production from Stimulated Natural Fractures DFN Dual Porosity Dynamic Simulation
January 28, 2015 75
Tributary Drainage to well is a combination of induced, inflated, and hydrosheared natural fractures
Rock Drainage Concepts
Reservoir volumetric reports, including EUR, Stimulated Reservoir Volume (SRV) or Tributary Drainage Volume (TDV).
January 28, 2015 76
FVFRFSNTGSRVEUR matrixoil /∗∗∗∗= φ
Tributary Drainage Volume (TDV) Fractures Contributing to Flow and their Connected Rock Matrix
Stimulated Reservoir Volume (SRV) Microseismic Cloud
Induced Fractures, Inflated Natural Fractures, and Hydrosheared Natural Fractures
1/28/2015
(c) Golder Associates Inc. 2015
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Induced hydraulic fractures only
Induced hydraulic fractures and inflated natural fractures
Hydrosheared natural fractures
Stress Shadow Effects in Zipper Fracing Comparison
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Overlapping Zones
Stress Shadow Effect No Stress Shadow Effect
Grid Stiffness Increase due to Frac inflation
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DFN Dual Porosity Match to Well Test (Early Time)
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Hydraulic Fractures with 350 Feet Well Spacing
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Hydraulic Fractures with 500 Feet Well Spacing
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Hydraulic Fractures with 650 Feet Well Spacing
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Pressure Derivatives
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500ft 350ft
650ft
Designing Completions and Well Spacing Using FracMan DFN 3D Dynamic Simulation
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Pressure Map – 350 Feet Well Spacing
Pressure Map – 500 Feet Well Spacing
Pressure Map – 650 Feet Well Spacing
Perspective view – fractures can be seen in 3D
Natural Conductive Fractures – Appalacian Basin Gas Shale Example
Rich Data Set Conventional
microseismics Image logging Flow logging using %
natural gas in the drilling returns from quadrupole mass spectrometer
Tracer testing Tomographic Fracture
Imaging (TFI)
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Drilling Gas Monitoring and Production Log
PLT (Green) Natural Gas Returns (Red)
Tomographic Fracture Imaging (TFI)™
Method of Global Geophysical Services Passive seismic method Employs surface arrays imaging responses of both artificial and natural
fractures Total trace energy mapped by voxels and summed over periods ranging
from minutes to hours
TFI Shows Affected Volume Larger than That Shown by Conventional Microseismics
Conventional Microseismics
3 miles
Tracer Responses
3 miles
All Conductive Fractures
•Hydrofracs
•Conductive Fractures in Well
•TFI Lineaments
•Stochastic TFI Lineaments
3 miles
Pressure From Production
108 second ~ 1100 days
Increasing Permeability
Natural Fractures Matter Appalachian Basin Case Study
1. The most successful wells can be expected where stress concentrations ensure large hydraulic fractures. This can be determined by geomechanical modeling of faults, stratigraphy, and topography
2. Orientation of horizontal wells should be adjusted to local stress conditions
3. Reactivated natural fractures frequently contribute to production, such that higher natural fracture intensity can be an indication of better well locations
Reactivated Natural Fractures and Hydraulic Fractures
Reactivated Natural Fractures and Hydraulic Fractures
January 28, 2015 111
FracMan Discrete Fracture Network Workflow