Evaluating Potential Risks for Marcellus Shale - … · Evaluating Potential Risks for Marcellus Shale PTTC-DOE-RPSEA Gas Shales Workshop J. Alexandra Hakala ... air quality; water

Evaluating Potential Risks for Marcellus Shale PTTC-DOE-RPSEA Gas Shales Workshop

J. Alexandra Hakala Geosciences Division, Office of Research and Development

National Energy Technology Laboratory [email protected]

Risk Assessment

Data Science

Base

Platforms/Tools/Diagnostics

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EPACT, RPSEA, & the Complementary Plan

• The Energy Policy Act (EPACT) of 2005 is a bill passed by the United States Congress. – Part of the act established a natural gas supply research

and development program to be funded over the next 10 years

• Research Partnership to Secure Energy for America (RPSEA) is a non-profit consortium – This research consortium was established in support of the

EPACT to help meet the nation's growing need for hydrocarbon resources produced from reservoirs in America.

– The consortium is comprised of U.S. energy research universities, industry and independent research organizations.

• NETL-RUA implements a “Complementary” research plan – A portfolio of oil/natural gas related research conducted by

the NETL-RUA that supports the goals of EPACT/RPSEA but is non-duplicative (complementary)

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FY12 EPACt Complementary Plan - Stakeholders

• Public • RPSEA • DOE HQ • NETL Program

Overarching Mission: Conducting research to help reduce risk and assess environmental impacts associated with oil and natural gas development in sensitive areas

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EPAct Complementary Program: Technical Coordinators: Ultra-Deep Offshore/Frontier Regions: Kelly Rose Unconventional Resources: Alexandra Hakala Federal Project Manager: Jamie Brown

Focus Area Lead: George Guthrie

Focus Area Coordinators: – Reservoirs and Resources: Kelly Rose – Wellbores and Drilling: Brian Strazisar – Water Resources: Dan Soeder – Natural Systems Monitoring: Rick Hammack – Fluid-Rock Geochemistry: Alexandra Hakala – Fluid-Rock Geophysics: Grant Bromhal – Geomaterials Science: Angela Goodman – Integrated Assessment Modeling: Bob Dilmore

Office of Research and Development, NETL-RUA and the EPAct Complementary Program

Risk Assessment

Data Science

Base


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Risk management requires risk assessments

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Risk assessment requires predicting the potential for a deleterious event as well as its consequence.

Risk Assessment

Data Science Base


Risk = probability X consequence

site performance

impact of event

General Risk Approach for Sites • Predict site performance relative to

potential events of concern – probabilistic (uncertainty & heterogeneity)

– science base to ensure confidence

– integrated assessment models to address complexity from coupling of sub-systems

– field data to quantify parameters, to characterize background, and to validate predictions

– identification of monitoring and mitigation to lower uncertainty and risk

• Assess impacts from events of concern – impacts can tie to regulations, economics, etc.

– e.g., air quality; water quality (groundwater, surface waters), induced seismicity

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Risk relates to the probability that an event will occur as well as the consequence of that event; risk can vary over time.

Risk = Pevent x Cevent

consequence of an event

Liability can occur when a consequence is declared a harm.

probability that an event will occur

• impingement on pore space not covered under deed or agreement • impingement on other subsurface resources • change in local subsurface stress fields & geomechanical properties • impact on the groundwater and/or surface water • gas accumulation in poorly ventilated spaces or in low lying areas subject to poor atmospheric

circulation • CH4 or other displaced gases return to the atmosphere

Importance of direct impacts from shale gas development and production vs. indirect impacts (e.g., brines, pressure fronts)

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Case Study of Uncertainty

from Cooper (2009)

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Overarching Risk-Related Issues for Marcellus and Other Shale Gas

Concerns over potential impacts from hydraulic fracturing

–Potential for Inducing seismic events (initiating event, not a risk) and for hydraulic fracturing to go out-of-zone

Concerns over potential impacts from poor wellbore integrity

–Potential for fluid release to groundwater or surface

Concerns over potential impacts to water quality

–Impacts to groundwater or surface water from subsurface release of fracture fluids or produced waters, methane, other hydrocarbons, etc.

–Impacts to streams resulting from surface activities

Concerns over potential impacts to air quality –Impacts due to exploration and production activities

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Performance of the engineered–natural system ties to the behavior of various subsystems.

① Fluid Flow in Reservoir fluid flow (porous flow & discrete fractures) trapping mechanisms heterogeneous and uncertain permeability

③ Wellbore/Seal Integrity flow in pipe/fracture

(coupled to reservoir flow) wellbore/fracture locations & geometries effective permeabilities cement behavior (stemming/completion) geochemical and geomechanical effects

④ Groundwater Protection fluid flow and fluid–rock geochemistry contaminant transport

⑤ Atmospheric Emissions release(s) from subsurface emissions from surface activities

② Ground Motion Response geomechanical response to pressure changes

(induced seismicity; hydraulic fracturing; etc.)

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NETL-RUA’s approach to quantifying system performance relies on integrated assessment models (IAMs).

Fractured Reservoir

Release and Transport

Potential Receptors or

Impacted Media








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General NETL-RUA Approach to Predicting Risk

NR

AP

Syst

em M

odel

(s) Data warehouse

(e.g., EDW)



Impacted Media Anticipated Computational Products

• system model(s) for developing various risk profiles

• reduced-order models for rapid assessment of stochastic properties

• new quantitative relationships for some key risk-related phenomena

• linkages with common simulators

• input/output linkages with data warehouses Fractured

Reservoir

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What tools will be used and developed for risk profiles?

• research simulators for groundwater chemistry

• analytical expressions

• research simulators & analytical representations for wellbores, fractures, porous media

• pressure & saturations from reservoir simulators (research & commercial)

• research simulators & scaling relationships for stress/geomechanics

• system model(s) for integration • statistical methods/models

Tools • statistical analysis of industrial

and natural analogs

Validation Strategy

• field data from industrial and natural analogs (groundwater; atmosphere)

• field data from small tests (e.g., ZERT, EPRI, other)

• field and historical data from industrial and natural analogs

• proposed field test for injection into fault/fracture

• field data from RCSPs and other large scale storage

• field data from industrial analogs • proposed field test for stress-

response relationship



Impacted Media

Fractured Reservoir

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Data Resources for Rapid Assessments Issues

–Wide range of data from a wide range of sources:

• Reservoir properties (DOI, industry)

• Wells (state agencies, industry)

• Aquifers and groundwater (EPA)

–Informing stakeholders (regulators, public, industry) requires accessible presentation of data trends

• Easy to access; clear graphics

–Rapid assessments (e.g., during an event) require immediate access to site-specific data

• Location of diverse data sources; data agreements; protection of proprietary data (Federal role)

Approach –Develop energy data warehouse that includes

data, geoportal, and trends based on data analysis

–Use of data to develop regional trends (i.e., beyond site-specific analysis)

Regional Shallow Aquifers, USGS

Groundwater Atlas Data

Existing Gas Well Distribution Source: West Virginia Geological and Economic Survey

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Energy Data Warehouse

Proprietary Data Store

Available for ORD research but not

released to public

Public/Non-Proprietary Data Store

Externally generated data, open source, publically accessible/distributed

ORD Research 1 Historical Data Store

ORD generated datasets available for public release

ORD Research 2 Active

Data Store ORD generated datasets

not released to public

ORD IT • database management • database architecture • server management

• IT security & backups

• NETL-RUA • Industry

• Government • Private/Public

Institutions

Energy Data Types & Sources

GIS, Geospatial

Analytical systems &

tools

Research

Neural networks

Numerical simulators

Digital Rocks/

Reservoirs Models

Other Systems/

tools

Products Public web

portal Selected data; General

info; Reports; Atlases; Geospatial interface

Publications Journals; newsletters,

whitepapers, etc.

Risk Assessments Environmental and Resource Assessments

Experimental Studies

Reservoir models

Field Studies

Public Access

Databases Proprietary Databases

Lithology

Structural features

Engineering features

Resources

Atmospheric monitoring

Ocean

monitoring

Geographic information

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Integrated Monitoring Approaches and Developing Key Science-Base Issues

– Natural systems have complex baseline signals

–Methods for monitoring subsurface processes relative to safety/environment

–Prediction of materials and fluids behavior under extreme conditions

Approach –Develop comprehensive, quantitative datasets for a variety of

natural conditions, processes and materials behavior

• Baselines pre-development, during development, and during production

• Air quality factors, other environmental signals

• Leverage relationships with operators; coordinate with other government agencies

• Materials properties under extreme conditions

–Natural geochemical signals for use in fingerprinting processes that have impacted groundwater

–Assess utility of geophysical models for predicting the potential of inducing seismic events in shales

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Water Resources and Quality Issues

–Groundwater signals are complex

• Result from natural and anthropogenic processes

• Pre-existing oil/gas operations and coal mining may effects on chemistry and flow

–Variation in chemistry of flowback water and other produced waters

• Challenge to planning for treatment options

–Effect of fluid-rock geochemistry on water quality

Approach –Natural geochemical signals for use in fingerprinting

processes that have impacted groundwater

–Evaluate fluid-gas-rock interactions in shale formations and along potential fluid/gas leakage pathways

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Issues –Assessments for safety/environment require

predictions across a range of scales and processes

• Reservoir to receptors

–Natural systems are heterogeneous, with characteristics that are not completely described

–Simulators that capture detailed physics can be too slow to allow assessment of range of scenarios

Approach –Develop new simulation tools for some

processes (e.g., wellbore and fracture flow)

–Develop reduced-order models that allow rapid simulation for statistical analysis

–Develop integrated assessment models that allow system-level predictions based on linking of simulators for each component of the system (reservoirs; wellbores; fractures/faults; aquifers; etc.)

Fractured Reservoir

Potential Fluid Migration Pathways


Impacted Media

Image adapted from : NETL, Shale Gas: Applying technology to solve America’s Energy Challenge, January 2011

Multiscale Predictive Tools

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NETL-RUA’s approach to quantifying system performance relies on integrated assessment models (IAMs).

Fractured Reservoir



Impacted Media








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Evaluating Potential Risks for Marcellus Shale - … · Evaluating Potential Risks for Marcellus Shale PTTC-DOE-RPSEA Gas Shales Workshop J. Alexandra Hakala ... air quality; water