Scientist warns of environmental, geophysical risks of shale gas development

8/2/2019 Scientist warns of environmental, geophysical risks of shale gas development

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Environmental Impactsand Geophysical Risks of

Shale-gas Development

Chris J.H. Hartnady

Umvoto Africa (Pty) Ltd,Muizenberg

http://www.umvoto.com

SHALE Southern AfricaCape Town, 26-27 March 2012
http://www.umvoto.com/http://www.umvoto.com/


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Presentation overview

Shale-gas development Global perspective

Era of Extreme energy

Environmental impacts

Landscape degradation Water consumption / resource depletion

Surface-water contamination

Groundwater contamination

Geophysical risks Triggered earthquakes

Greenhouse-gas (fugitive) emissions

Energy-cost and other considerations


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Natural gas in US: shale a game-changer?

Shale gasgame-changer

from 2005

M. King Hubbert1903-1989


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EIA 2011 resources assessment

1275862

774

681

485396

388

SA ranked fifth in world,

but ?

TCF = trillion cubic feetFigures refer to

technically recoverableresource (TRR),

not economically recoverablereserve

But note trend in TRR for Marcellus shale:489 TCF (Engelder 2009) 262 TCF (DOE 2009) 84 TCF [P50] or 43 TCF [P95] (USGS, 2011)


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Geological setting of natural gas

Why target thedepleted

source?


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Era of extreme energy

humanity has embarked on the era of extremeenergy, where there are no simple solutions. Theinexpensive, high-yield fossil fuels that powered theindustrial revolution are dwindling, and all of them

emit dangerous levels of greenhouse gases. Whileenormous amounts of natural gas, oil, and coalremain, the portions of those fuels that werecheapest and easiest to produce are now mostly

gone, and producing remaining reserves willentail spiraling investment costs andenvironmental risks.

Richard Heinberg, fellow of Post-Carbon Institute, 2011


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Shale gas impacts and risks

Surface impacts of road and drill pad construction and the requirementfor hundreds of truck trips for each well

Very high water consumption potentially problematic, particularly inarid areas

Contamination of surface water through improper disposal of toxicproduced drilling fluids containing salts, radioactive elements, and othertoxins

Contamination of groundwater directly through hydraulic fracturing andas a result of compromised cementing jobs in near-surface casing

Induced earthquakes through fluid injectionboth during the hydraulicfracturing process and during the disposal of waste fluid through injectionwells

Higher full-cycle greenhouse gas (GHG) emissions

J. David Hughes, 2011.Will Natural Gas fuelAmerica in the 21st Century?Post Carbon Institute, Santa Rosa,CA, USA, 64 pp.

http://www.postcarbon.org/report/331901-report-will-natural-gas-fuel-america


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Environmental Impacts

Hughes (2011) identifies 6 main concerns,including 4 environmental risks:

Surface impacts of road/drillpad/pipeline infrastructure construction,

including 100s to 1000s of truck trips

Very high water consumption, affectingresource quantity, intensifying allocationscompetition and hastening depletion

Contamination of surface water and

groundwater through improper disposal offlowback and produced water

Contamination of groundwater throughhydraulic fracturing, methane migration andcompromised surface casing grouting


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Landscape degradation

Destruction andloss of aestheticsense of place

Industrializationof ruralenvironment

Traffic and

noise pollution

Example of Eolia gas field, Oklahoma

June 2003 April 2008 change


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Water resource competition / depletion

Exploration phase = 2000-9000 m3/well(Shell estimate)

48 000-216 000 m3 over all 3 Karoo areas (24wells)

Require establishment of 40 l/s wellfield to deliversame amount of groundwater in 2-month period?

USA experience:

Marcellus = 12 000, Barnett = 14 000 wells

Similar production in Karoo = ~10 000 wells?

Production phase = 5000-20 000 m3/well

50-200 Mm3 water consumption

Annual groundwater demand in 3 areas = 47 Mm3

Future technology: 50 well pads x 30 wells = 1500

wells = 7.5-30 Mm3 ?


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Produced/flowback water = major qualityhazard Highly saline, acid & corrosive (from pyrite reaction),

radioactive (thorium, uranium, radium), toxic metals(arsenic, mercury), fracking fluid additives

Requires disposal or recycling Transport to wastewater treatment works where

treated and released back to surface streams

Injected into depleted gas fields or deep strata

Recycled and re-used as fracking fluid

Spread on roads for dust suppression

Stored in evaporation pits

Spills hazard during drilling, leakage and overflow from storage

ponds/evaporation pits, pipeline and casing breakage

Surface-water contamination


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Groundwater contamination

Fracking fluids Slickwater = 99% water and proppant (sand, ceramics,

bauxite) 1% fracking additives = hydrochloric acid,biocides, dimethyl formanides, sodium carbonate,ethylene glycol, isopropanol

Do these fluids pose a significant risk to subsurfacecontamination via fracking procedure?

Cross contamination of aquifers Drilling-induced fractures crossing groundwater flowpaths

Casing flaws/failure

Methane contamination from Marcellus Shale(Osborn et al., 2011) Methane (thermogenic origin) 17 times higher in gas

extraction areas, than methane (biogenic origin) in non-extraction areas

Not regulated, but asphyxiation/explosion hazard


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PNAS study (April 2011)

Proceedings of the U.S.National Academy ofScience, online edition


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Well casing and cement failure

Cement has little tensile strength of itsown and fails in tension before lendingsignificant support to the casing. Theassumption of no contact between thecement sheath and borehole is unrealistic,

but illustrates the dangers to crackingthe cement sheath by generating a highinternal pressure in casing, especiallyduring casing pressure tests aftercementing.

(Fleckenstein et al., 2005, AADE-05-NTCE-14; American Association of DrillingEngineers National Technical Conference,Houston, Texas)

Achilles heel at the casing shoe?

How gasgets to

surface byunplanned

route


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Hazards of unconventional

BP Macondowell blow-outin deepwater

Gulf of Mexico Caused by

loss of controlover gas influx

into wellthrough faultycasing andcement seal


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Geophysical risks

Hughes (2011) identifies 2 maingeophysical risks:

Induced earthquakes through fluidinjection during fracking andsequestration of wastewater

Higher full-cycle greenhouse gasemissions

Tulbagh 1969


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In the recent news

Is there a connection to gas-shale fracking?


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Oklahoma epicentres (2009-2011)


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2010-2011 activity near Wilzetta Fault


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Recent pad developments

Google Earthchangeanalysis

1995 Feb 08

2008 Apr 15


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Ohio earthquakes


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Ohio earthquake outcome

Earthquakes last year in Ohio were probablycaused by wastewater from oil and natural-gasdrilling injected into a disposal well, andregulations are needed to address concernabout seismic activity, a state report said.

The Ohio Department of Natural Resourcestoday proposed creating rules for fluidtransportation and disposal that it said would be

"among the nation's toughest," includingbanning drilling into some rock formationsand requiring geological reviews before wellsare approved.

Extract from media report by Mark Niquette, Bloomberg, Mar 9, 2012


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Karoo earthquakes!?

2011 May 14 16:10 SAST

Local magnitude (ML) 4.1

M6.2;1809

M6.3;1969

M7.3;~10.6k BP

USGS


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Lithospheric stress patterns

Dynamic model ofvertical integrated stressanomaly (VISA)

Karoo within N part of

Cape Stress Province(Hartnady, 1998;Wegener Stress

Anomaly of Andreoli)

Reflects high crustalstresses generated bybreak-up of Africabetween Nubia (NU)and Somalia (SO) plates

from Bird, Liu and Rucker, 2008

NU

SO


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Economics of shale gas

With mounting evidence of the environmental and

human health risks of shale gas production,environmental groups are rightfully questioning the

cleanliness of shale gas. But if these groups focus theirarguments only on the contamination of ground watersupplies of shale gas without at the same timequestioning the economics of shale gas drilling, they willhave helped set up conditions for a political battle that

could undermine their own influence and credibility.(cont.)

Richard HeinbergFrom preface to J. David Hughes, 2011.Will Natural Gas fuel America in the 21stCentury?

Post Carbon Institute, Santa Rosa, CA, USA, 64 pp.


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Energy-cost considerations

From Dale et al., 2011


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Financial considerations?

In order to access Wall Street capital, (shale gas)producers have needed to demonstrate that they arebeing successful in exercising a strategy foraggressive wealth creation. That means aggressively

buying acreage and drilling wells. Exercising asuccessful strategy often creates a vicious cyclemore acreage and wells equals increased productionand depressed prices. This cycle will continue as

long as the music (Wall Street's money) continues toflow. Once that stops, we will see how manyproducers can find a chair in the room. In themeantime, the fun continues!

G. Allen Brooks, 2011. Musings: Imaging the future for the shale gas industry.

Rigzone, (Tue Dec 6, 2011), http://www.rigzone.com/news/article.asp?a_id=11314


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Role of political interests

Political interests traditionally funded by the oil and gas

industries will once again claim that environmentalism isthe only thing standing between Americans and energy

security. And if environmentalists are successful inenacting regulations to minimize the risks of watercontamination without clarity about the full lifecyclegreenhouse gas emissions of natural gas, they may

inadvertently exacerbate the very crisis they are trying toaddress.

Richard HeinbergFrom preface to J. David Hughes, 2011.Will Natural Gas fuel America in the 21stCentury?

Post Carbon Institute, Santa Rosa, CA, USA, 64 pp.


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Council of Scientific Society Presidents:Letter on energy & environment, 14 May 2010

(We) represent the leadership of over 1.4 million scientists in over150 scientific disciplines

The production of natural gas (methane) from shale represents amajor new domestic energy resource that can reduce reliance on

imported crude oil ...(but) is anotherexample where policy haspreceded adequate scientific study. Economic recovery requiresthe drilling of long-reach horizontal wells and the high-pressureinjection of with chemical additives to release the gas through aprocess called hydrofracking. Despite the utilization of millions ofgallons of water and the flow back to the surface of these injected

fluids, hydrofracking is exempted from the Clean Water Act.Exploitation of the Marcellus Shale Formation in the AppalachianBasin, recognised as the largest shale-gas reserve in the U.S., couldoccur across a five state region. Prior, thorough science-basedstudies are required to evaluate the impact of massive shaledevelopment on rural land uses, water supply and quality, andfull-cycle greenhouse gas emissions


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Ultimate energy value proposition?

Area(s) ofexcellentdirectnormal irradiance

(DNI) forconcentratingsolar power(CSP) generation

Shale gas versus CSPThank you

for your

attention!

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Scientist warns of environmental, geophysical risks of shale gas development

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