Transcript oil and gas float

Geological background to
Shale-gas in New Brunswick
Dr. Adrian F. Park
Outline
1. Conventional & unconventional petroleum
2. Fracking
3. Shale gas potential in NB
4. Outstanding issues
CLASTIC SEDIMENTS
Classified by composition and grain-size
Environments of deposition
(Sediments sorted by grain-size and energy of water flow)
Sand and gravel in river channels
Fine sand and silt on delta front
Mud plumes
Deltas - Lake Ayikum, Tibet
Environments of deposition (organics)
Delta-top swamp/forest (peat)
Organic detritus
(sapropelic mud)
Off-shore algal blooms & detritus
(sapropelic mud)
Mississippi delta, Gulf of Mexico
4. Traps
trap
gas
oil
Impermeable layer (aquitard)
Permeable layer with water (aquifer)
(oil and gas float)
Conventional Oil and Gas
Unconventional Oil and Gas - directly exploiting the ‘source rocks’
(the trick is extracting the hydrocarbon content)
OIL SHALE - the first petroleum industry
Scotland 1780s to 1860s
The ‘bings’ of West Lothian c. 2000
AND A LITTLE CLOSER TO HOME
Albert Mines, NB
1840s to 1880s
North America’s first petroleum industry
Abraham Gesner
1797 - 1864
Images courtesy
NB Museum and NB Archives
US EIA
RESERVE
v.
RESOURCE
Frederick Brook, NB
Horton Bluff, NS
Estimated reserve
Proven reserve
Recoverable reserve
1 GJ ≈ 0.5 bbl oil ≈ 28m3 gas
?
?
?
Marysville
subbasin
Courtesy Steven Hinds, NB DNR, 2013
With unconventional oil and gas the problem is
getting the oil and gas out
In 19th century this
involved mining and
major environmental
degradation
21st century this
involves ‘fracking’
‘Fracking’ (also ‘fraccing’) - enhancing permeability by fracturing
Oil workers ‘fracking’ an oil well with nitroglycerine, 1903, NB
Images courtesy of NB DNR
‘Hydraulic fracturing’ or ‘hydrofracking’
(first used 1948, last two decades more
widespread
alongside horizontal drilling)
Natural pressure gradient with depth
(between 2.6 and 3.0 tons/metre2
for each metre down)
Between 250 and 300 m depth fractures are
naturally sealed by lithostatic load
Drinking water aquifers usually lie above this zone
Deep aquifers where water pressure = load
usually salty and non-potable
Fractures created in one rock layer generally do
not spread into other layers because of
different mechanical properties between rock
types (even within rock types)
Corridor hydrofracturing tight sandstone reservoir
at McCully, Sussex since c. 2003
Causes for concern (shale-gas):
1. Leakage of gas (or oil) in drinking water aquifers through induced fractures
2. Leakage of wells into aquifers
3. Hydrofracturing liquids and possible toxic effects
4. Hydrofracturing noise and air quality
5. Surface leakage and contamination (waste water disposal)
6. Hydrogen sulfide, heavy metals, radioactive materials
7. Earthquakes induced by hydrofracturing and deep well injection disposal
Hydrofracturing operations
Waste water
Seismicity
‘Hydraulic fracturing’
or ‘hydrofracking’
Freshwater
aquifers
2 + km
Hydrofractured shale
CANDOR – this is a hydrofrac operation
Pumps & compressors
Slickwater
storage
Producing
well-pad
Well-pad
FULL DISCLOSURE
Fracking additives from the Apache/Corridor Elgin project
Sodium hydroxide
Carboxymethyl cellulose
Bentonite
Xanthan gum polymer
Sodium bicarbonate
Barite
Base oils (e.g. HT 40)
Calcium chloride
Polyamide/fatty acid blend
(Novamul)
Calcium hydroxide
Glutaraldehyde
used in manufacturing soap (lye, caustic soda)
ingredient in laxatives and toothpaste
clay - used in water filters
food additive and food processing
component of baking powder
medical uses as an X-ray blocker (barium meals)
synthetic oil and mineral oil
food preservative, de-icing fluids, electrolyte drinks
comparable to linseed oil
‘lime’ – whitewash and fertilizer
biocide, surgical & dental disinfectant
Manufactured by Petrocan
under Federal license
(proprietory)
Some concern as carcinogen
Used to prevent formation of H2S
Waste water
Recovered hydrofracturing liquids
Production water
Drilling fluids
Hydrogen sulfide, radionuclides, heavy metals
have not been an issue thus far.
Waste water is a strong brine (2 – 3X seawater)
Treatment and disposal:
Until 2012 – waste water treatment and disposal at Debert, NS
Currently transported by road to Levis, Quebec
Deep-well injection currently not an option
Alternatives to slick water hydrofracturing
Liquid propane, nitrogen foam, carbon dioxide
Remove hydrofracturing water from consideration
Microseismic monitoring
during hydrofracturing
Required in North Dakota,
and BC
(used at Elgin)
Microseismic activity during a hydrofracturing
process, Barnet Shale, Texas
18 July – 18 August
2015
Seismicity in Canada
UK draft regulations
consider
‘acceptable levels’
of seismic activity
?