The shale gale and dash for gas
continues unabated, and with it increasing demand for proppants
required in hydraulic fracturing operations. Its a golden
opportunity for proppant feedstock suppliers - silica
sand, bauxite, kaolin - to pursue this growth market. But
the key questions are: Which material makes the grade? Where
else outside the US is the market likely to catch fire?
American dream
market
North America, and mostly the US,
is where its at, and everyone has been monitoring this
phenomenal development. According to PacWest Consulting
Partners latest proppant market analysis, US onshore
proppant consumption is expected to grow at 9% per annum
through 2015, from 69bn lbs in 2013, to 83bn lbs in 2015.
Naturally, suppliers of US
fracturing sand (frac sand) and ceramic proppants are rubbing
their hands in anticipation of future contracts.
While frac sand remains the
dominant proppant of choice in the US, holding an approximate
80-85% share of the US proppant market, use of ceramic
proppants has risen markedly.
PacWest considers that growth in US
frac sand consumption to 2015 will be perhaps in excess of 9%
per annum, and resin coated sand will grow at 7%. Ceramic
proppant consumption, however, is expected to grow at a rate of
12% per annum. Indeed, ceramic proppant consumption in the US
has risen an impressive 40% since 2011.
One of the main drivers for rising
demand for ceramic proppants has been the increasing practice
of using frac sand and ceramic proppant blends in US fracturing
operations (eg. 65% ceramic: 35% sand in the Bakken).
Ceramic proppants retain their
premium price tag (4-6 times the price of frac sand), but their
superior performance owing to greater strength and uniform
shape and sphericity over frac sand offers greater efficiencies
in oil and gas conductivity (flow through fractured target
formation to recover at well head). Thus exploration and
production (E&P) companies are employing blends of the two
families of proppants to achieve optimum economic
efficiencies.
With their greater crush
resistance, ceramic proppants are also enjoying enhanced demand
from more drilling at greater depths and thus at greater
pressures (>10,000 psi), environments where natural frac
sand fails.
These factors, combined with
drilling operations employing more fracturing stages (40+),
have ceramic proppant producers responding to this market
demand (witness recent expansions/acquisitions by US ceramic
proppant leaders Carbo Ceramics, Saint-Gobain, and Imerys),
while bauxite producers and developers are keen to get in on
the feedstock market.

Which bauxite is best?
The accompanying chart illustrates
the different categories and characteristics of proppants.
With the notable exception of
Russia (using magnesium silicate), most commercial grades of
ceramic proppants are manufactured from calcined
alumina-containing ores, either bauxite or kaolin, or from
blends of each (see table of leading producers).
Georgia and Arkansas, in the US, host unique bauxitic kaolin
deposits which are used to make ceramic proppants.
So which material is best, or even
typical for ceramic proppant manufacture? There does not appear
to be a straight answer, with many different ores being using
to produce different proppant grades.
Terry Palisch, Directory of
Petroleum Engineering, Carbo Ceramics, emphasised that with so
much competitive interest in ceramic proppant development,
feedstock information was naturally highly sensitive. That
said, generally speaking, Palisch offered: If
manufactured correctly, the strength of a ceramic proppant is
directly proportional to the alumina content of the raw
material.ÊImpurities such as silica will affect the end
product.
Ceramic proppants maybe divided
into low density (45-50% Al2O3),
intermediate (70-75% Al2O3), and high
density (80-85% Al2O3) grades,
their predominant feedstock raw materials being kaolin,
bauxite, and bauxite, respectively (see chart).
As important as securing a high
alumina quality raw material, is the correct execution of the
ceramic proppant manufacturing process Ð this is all too
often underestimated. The accompanying diagram outlines the
main elements of the process route, with pelletisation and
sintering being the primary two processes requiring expert
attention.
There are dry and wet pelletisation
variations depending on the feedstock material and desired
proppant end product: the dry process is for calcined ore and
high density grades; the wet process, for low
density/intermediate density proppants, uses uncalcined ore,
and employs slurrying prior to binder mixing, and a fluidizer
sprays slurry onto seed particles prior to sintering.
Concerning bauxite, so-called
abrasive grade bauxite has been the favoured
specification for ceramic proppant manufacture. Typical
specifications of a raw abrasive grade bauxite are min. 55%
Al2O3, max. 5.00% SiO2, max.
Fe2O3, and min. 2.50% TiO2.
Calcination of raw material would normally increase alumina
content to 70-85% Al2O3 depending on raw
material and calcining conditions.
In short, intermediate strength
ceramic proppants have been made from bauxite containing a
significant amount of mullite
(Al6Si2O13), while high
strength ceramic proppants are made from bauxite consisting
mainly of corundum (Al2O3).
Until mid-2007, both Saint-Gobain
and Carbo Ceramics imported calcined abrasive grade bauxite to
their US plants from Comalco in Australia. Carbo Ceramics used
the bauxite for production of its high strength proppant
CarboHSP (83% Al2O3) and intermediate
strength proppant CarboProp (72%
Al2O3).
The raw bauxite used to manufacture
ceramic proppants from deposits mined by Comalco at Weipa,
Queensland, Australia had 60% Al2O3, with
a typical range from 57-63% Al2O3, and an
average 9% SiO2, with a range of typically 7-11%
SiO2. Typical mineralogy comprised 30-50% gibbsite,
22-45% boehmite, 16-24% kaolinite, and less than 1% quartz.
Oxides of iron and titanium totalled about 9-12%.
This raw bauxite yielded a calcined
abrasive grade of 82-85% Al2O3, 6.5-7.3%
SiO2, 5.5-7.0% Fe2O3, and
3.1-3.7% TiO2.
In 2007, Comalco exited production
of abrasive grade bauxite and US proppant manufacturers were
forced to seek alternative supplies: Carbo Ceramics selected a
bauxite source in Guyana among others, and uses locally sourced
bauxite for its Chinese and Russian operations.
In Pocos de Caldas, Minas Gerais,
Brazil, Mineracao Curimbaba produces an intermediate density
bauxite-based proppant, SinterBall containing 73.7%
Al2O3 and 6.4% SiO2, and lower
density grades of 70.5% Al2O3.
Curimbaba has a ceramic proppant
production capacity of 300,000 tpa. Gabriel Warwick, Corporate
Technical Advisor, Curimbaba told IM: By
the end of 2015, beginning of 2016 we will add 70,000 tpa from
a new plant.
China is the largest producer of
bauxite-based proppants, with over 100 plants mainly located in
the bauxite-rich provinces of Henan, Shanxi, Guizhou, and
Sichuan. There are some 20-30 leading producers, with
capacities ranging 20-210,000 tpa, producing low, intermediate,
and high density grades ranging 68-88%
Al2O3.
As is well documented elsewhere,
Chinese bauxite is primarily of the diaspore variety, compared
to the gibbsitic bauxites of Australia and the Americas.
Luoyang Maide Ceramics Co. Ltd, Henan, is bringing on stream a
new production line in early 2014 to double capacity in excess
of 100,000 tpa proppants.
Lucas Xu, export director, Luoyang
Maide Ceramics said: We source local raw bauxite in the
range 75-85% Al2O3 for proppants. The
main competition [for bauxite ore] is Chinalco for aluminium
production.
Many Chinese bauxite producers,
already supplying refractory and abrasive grades, are now
developing and expanding in proppant grade bauxites, have
successfully established an export market in the US and are now
looking elsewhere for the next proppant market.
The development of Chinas
proppant supply market and how it will influence global supply
is the subject of a forthcoming in-depth report from Industrial
Minerals Research (see p.33).
Developers of new bauxite sources
are clearly keen to evaluate the potential of their material
for proppants. First Bauxite Corp. in Guyana is developing the
Bonsika bauxite deposit and last year successfully tested
material for intermediate strength ceramic proppant
applications.
Hilbert Shields, CEO, First
Bauxite, said: The Bonsika deposits are ideal for high
strength ceramic proppants, being gibbsite based with up to 92%
Al2O3 and certain deposits having the
ideal type of iron embedded promoting additional
strength.


Where next?
Outside the North American market,
which is set to continue its stellar growth for some years, the
future potential hotspots for proppant demand, in descending
order, look to be Australia, China, the Middle East/North
Africa, Mexico, and South America. Although a range of factors
could change this order in short notice - including
investor confidence, political willpower, a lowering of cost
risk.
China clearly has a developing
ceramic proppant supply sector, but with the exception of
Mineracao Curimbaba and Mineracao Varginha in Brazil, and
Saint-Gobain in Venezuela, these regions are bereft of major
producers of ceramic proppants.
Australias shale gas industry
seems set for take-off. Santos has brought Australias
second shale-gas well into production after successfully
drilling the Moomba-194 vertical well in the Cooper basin.
Along with coal bed methane (CBM; also requires fracturing),
shale gas could become an alternative feedstock for
Australias fast expanding liquefied natural gas (LNG)
export industry.
Optimism in the Chinese shale gas
market has been tempered by its difficult geology (shales are
generally deeper and faulted), poor pipeline infrastructure,
immature oilfield services, and crucial water supplies are
limited in some areas.
But China has some of the
worlds best source rocks, the government plans to
increase the use of natural gas to around 230 bn cubic metres
by 2015, and foreign interest is growing - oilfield
services giant Schlumberger, already active in five Chinese
basins, is to make China the centre of its global operations.
This market is slowly but surely getting its act together and
promises to rival the US in terms of activity and volume.
In 2012, Saudi Aramco made no bones
about sending its drilling specialists to Texas to learn all
about shale gas and hydraulic fracturing for its future
strategy. In the MENA region Algeria and Saudi Arabia are now
leading the race to exploit shale gas since both countries need
more energy to meet rising domestic power generation needs.
Aramco is soon to invite bids from
firms to build shale-gas processing infrastructure in the
country. However, much work still needs to be done to galvanise
shale gas development into the mainstream. In particular, there
are concerns over water management. Mexico has reformed its oil
industry by promising to open up to foreign investment and
overhaul the state oil monopoly Pemex. This could help direct
activities to Mexicos huge shale gas potential in the
Eagle Ford Basin, which is seeing intense activity within its
US borders.
South America has some of the most
promising shale-gas plays in the world, mainly in Argentina and
Brazil, but exploration in the region remains in the early
stages. Argentina is third after China and the US for hosting
the worlds largest technically recoverable shale gas
resources. The Neuquen basin contains the highly promising Vaca
Muerta formation, but development has stalled and investors,
while interested, remain cautious. A government election in
2015 could create some movement.
Already, ceramic proppant
producers, along with bauxite deposit developers, are trying to
assess the potential demand for proppants in these regions.
That is no surprise, given the future world demand for energy
(increasing by 41% to 2035 according to BPs latest
forecast), and the favouring of natural gas as the fossil fuel
of the future. There is little doubt that there will be
increased demand for ceramic proppants, and thus increased
demand for their raw material feedstock.
Mike ODriscoll is
presenting Chinas ceramic proppant market:
bauxites new bonanza? at the 20th
Bauxite & Alumina Conference, 24-26 February 2014,
Miami.