J. ter Heege - What is going on down there

What is going on down there?
Results from the M4ShaleGas integrated
reviews of best practices of subsurface
operations in U.S.A. and Canada (SP1)
Jan ter Heege (TNO Petroleum Geosciences)
www.m4shalegas.eu
4 Scientific Sub-Programs
M4ShaleGas studies the environmental impact of shale
gas exploitation in 4 sub-programs (SP) on the
subsurface, surface, air & climate, public engagement:
26/05/2016
SP1
Impact of subsurface activities:
hydraulic fracturing, induced
seismicity, well integrity
SP2
Impact of surface activities:
water, soil and well site
activities
SP3
Impact on air quality and climate
SP4
Public engagement and
perceptions of environmental
impacts
Project Outline
/2
SP1: Subsurface impacts & risks
26/05/2016
WP1
Subsurface impact of hydraulic fracturing
WP2
Fault reactivation & induced seismicity
WP3
Seismic monitoring of hydraulic fracturing
WP4
Geochemical monitoring of well leakage
WP5
Drilling hazards and well integrity
WP6
Integration & best practices
SP1 Outline
/3
General Methodology
•
•
2017
•
•
2016
•
practices from U.S.A./Canada
Collection and review of data from
European shales
Model development, simulations and
experimental constraints
Risk and impact assessment
Comparison with conventional gas &
other energy-related industrial activities
Develop science-based best-practice
recommendations
2015
• Review of available data and best
June 2015
November
2017
26/05/2016
Project Approach
/4
Fracture Containment
Data on vertical extent of
fracture disturbed zone:
Vertical extent of fractures mapped by microseismics
(Davies et al. 2012, after Warpinski and Warpinski 2011)
Key data: 1% > 350 m; max. 536 m (Marcellus);
max. 588 m (Barnett)
26/05/2016
•
Data mostly from microseismic monitoring
(estimated 3-5% monitored)
•
Data on maximum vertical
extent show limited height
growth towards aquifers
•
Interaction between natural
and induced fractures or
bedding important
•
Differences European and
North American geological
settings and shale
characteristics important
WP1 Hydraulic Fracturing
/5
Subsurface Impacts Hydraulic Fracturing (BGS)
Study of controls on
fracture disturbed zone in
lab experiments:
•
Hypothesis: Are fractures
lithologically bound?
•
Fractures appear to be
“deflected” by the interface
between two clays of
different rheological
properties
•
Not all fractures deflect and
some do pass through
•
Experiments are on-going
with apparatus being
modified and clay layers
being preformed to create
better interfaces
© NERC All rights reserved
Bowland
shale
Kaolin
Cuss et al. 2016- BGS D1.2, 1.3
Fault Reactivation & Induced Seismicity (TNO)
Study of controlling factors
for induced seismicity:
•
Global database seismic
magnitudes
•
Mechanistic understanding of
problematic seismicity
•
Approach to classify shale
gas sites in terms of seismic
risks
•
Mitigation options (optimum
operations, traffic light
systems)
•
Link subsurface seismic
sources to surface motions
Buijze et al. 2016- TNO D2.2
23/02/2016
WP2 Induced Seismicity
/7
Fault & Fracture Reactivation Models
•
26/05/2016
Characterization of natural
faults and fractures used in
model predictions (coll.
BGS, TNO & SINTEF)
Characterization
of natural fractures at different /8
scales
Project Introduction
(Wassing, TerHeege, Buijze 2015-2016, TNO)
Fault Reactivation Experiments
•
Experiments examining properties of
pre-existing faults and reactivation
potential
•
Using bespoke Angled Shear Rig
(right)
•
Injecting into critically-stressed fault
surface and detecting pressure when
fault reactivates
•
Investigating different lithologies,
pressurisation rate, saturation state of
the gouge
•
Results (right) show that at 100%
saturation, Bowland shale does not
take much pressure to cause
reactivation
– Pressure at which reactivation
occurs is saturation dependent
© NERC All rights reserved
Cuss et al. 2016- BGS D1.2, 1.3
Seismic Monitoring (GFZ)
profile model +
microseismics
Study of optimum seismic
monitoring approaches:
plan
view
•
Network designs
•
Waveform data processing
techniques
•
High precision, real time
monitoring of spatiotemporal fracture growth
•
Application of seismic
monitoring to mitigation of
induced seismicity and
well leakage
microseismic data US plays
fault
profile
WP3 Seismic Monitoring
Warpinski 2014
/10
Seismic Monitoring Networks (GFZ)
Best practice kit for seismic
monitoring:
•
Cost-effective, modular
approach to seismic
monitoring
•
Network design versus
resolution
•
Monitoring of background
seismicity (baseline)
•
Short term monitoring of
stimulation operations
•
Long term monitoring of
production, waste water
disposal and post- well
abandonment period
Bohnhoff et al. 2016- GFZ
/11
Monitoring of Well Leakage (IFPEN)
Study of monitoring well
leakage using chemical
tracers:
Jackson et al. 2015
26/05/2016
•
Geochemical species
suitable for monitoring
•
Baseline concentrations of
potential chemical tracers
•
Properties, detection limits,
sensitivity to leakage of
tracers
•
Optimum deployment of
chemical sensors to detect
tracers in shallow aquifers
•
Classification of species in
terms of alarm function
WP4 Well Leakage
/12
Chemical Tracers For Well Leakage (IFPEN)
Review of chemical tracers:
•
Availability local data on
(baseline) compositions of
ground- & surface water,
hydraulic fracturing fluids &
additives, flow back fluids
•
Methane tracers are complex:
isotope ratios rather than
concentrations (biogenic
sources)
•
Heavy halogens (Br, I), heavy
alkaline earth metals (Ba, Sr)
seem good tracers
•
Isotope ratios of Sr, Br, Li
indicate cross-formational flow
•
Noble gasses can outline
mechanisms of well leakage
Warner et al. 2014
26/05/2016
/13
Drilling Hazards & Well Integrity (SINTEF)
Gawel et al. 2015- SINTEF D5.1
Study well integrity during
drilling, completion,
production & abandonment:
•
Ensuring well integrity during
full life cycle of wells
•
Emerging methods and
materials for drilling and
completion (coll. PGI)
•
Potential differences well
integrity issues between
regions and geology
•
Improving well integrity for
European shale gas wells
WP5 Drilling & Completion
/14
Well Integrity Issues (SINTEF)
Review of shale-specific
issues for well drilling,
completion, production and
abandonment:
Torsaeter 2015
•
Surface environment: Safety
requirements for onshore
drilling near populated areas
•
Borehole stability: Drilling
long sections in non-porous
rocks
•
Hydraulic fracturing: Well
integrity under varying
chemical and pressure
conditions
•
Abandonment: Ensuring long
term containment for
creeping shales
/15
Integration & Risk Assessment (TNO)
Potential hazard
subsurface
loss of zonal isolation or
integrity of wells
migration of potentially
hazardous substances to
surface through fractured
disturbed zoned
induced seismicity related to
hydraulic fracturingd
induced seismicity related to
wastewater disposald
surface
incidents related to well site
storage and transportation
spills and leaks of potentially
hazardous substances
landscape disturbance due to
well site construction
emissions to air
reduction of air quality due to
pollutant emissions
greenhouse gas emissions
affecting the global climate
Key statistics or findings relevant
for the occurrence of incidents
Reported effects, impacts or
concerns
typically <6.3% well integrity
problems, 1.3% leak to surfacea ;
3% lack cement around parts of
casings at groundwater levelsb
vertical extent of fractures above
horizontal well sections from
micro-seismics: typically 1% > 350
m, max. 588 me,f
typically Mw < 1g,h; some examples
of ML > 2g,h; USA: max. Mw = 2.8i,
Canada: max. ML = 4.4j
some examples of problematic
seismicity ML > 2, max. Mw = 5.7
(OK, USA)m
no widespread, systemic impacts on
drinking water resourcesb; some
examples of local drinking water
contaminationc
no documented examples of direct
migration, concerns for shales <
1000 m depth and for effects on
integrity of nearby wellsb
seismicity felt at surface (western
Canada), well damage possiblek,l
likely increase of occurrence, no
quantitative data on comparison of
industriesn
typically 0.4-12.2 spills for every
100 wells, 1% of spills linked to
hydraulic fracturing on or near the
well pad, 0.4% are chemicals,
additives, or fracturing fluidsb
some level of landscape changes
are inevitable, depending on scale
of operations and field development
planningo
impacts linked to local settings,
methods used, scale of operations
and preventive measuresn
9% of chemicals, additives, or
fracturing fluids spills reached
surface water, 64% reached soil,
none reached groundwater (but may
reach groundwater over time)
different levels of ecological,
physical and aesthetic landscape
changes depending on well site
designso
emissions (mg/MJ): CH4 800, VOC
80 (uncaptured venting); NOx 5269, CO 4.6-6.0, PM 0.01
(combustion)p
carbon footprint for generating
electricity: 420-850 CO2-eq/kWhq;
total life cycle GHG emissions for
shale gas: 65-100 g CO2/MJp-r
health effects from smog with
ground-level ozone (VOC+NOx),
CO, fine particles (PM); soil or
surface water acidification (SO2)p
contributes to global warming, level
depends on local energy sources
(impact depends on comparison
with coal, conventional gas, etc.)p-r
Ter Heege 2016 – TNO D21.1
seismicity felt and structural
damage at surfacem
Risk assessment &
recommendations of
best practices:
•
Risk: Combination of
likelihood and effects
of incidents
•
Incident statistics and
effects based on North
American data
•
Comparison of risks
associated with
different activities &
hazards
•
Comparison between
different regions
(North America versus
Europe)
/16
Questions?
Green River Formation, Colorado, USA
(photo: Susanne Nelskamp , TNO)
Disclaimer:
• This presentation is part of a project that has received funding by the European
Union’s Horizon 2020 research and innovation programme under grant
agreement number 640715
• The content of this presentation reflects only the authors’ view. The Innovation
and Networks Executive Agency (INEA) is not Project
responsible
for any use that may
Introduction
23/02/2016
be made of the information it contains