Nigerian Bentonite

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Nigerian Bentonite

• THE SUCCESS OF THE NIGERIAN BENTONITE
• ByOlukunle Amoo, Bestkamco Resources, Toronto,
  Canada
• Prof.W.O. Emofurieta (Terra Miners Nig, Ltd)

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Nigerian Bentonite

• Records have it that oil drill operations started
  in 1951 using imported bentonite largely from the
  US.
• Before now millions of dollars are spent in the
  procurement of bentonite annually which is not
  healthy for the economy of the country.
• The justification for the importation was based
  on the belief that Na-bentonite did not exist in
  Nigeria particularly being a tropical country
  because Na-bentonite is traditionally a temperate
  mineral.

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Nigerian Bentonite

• But fossil Na-bentonite deposited under reducing
  and alkaline environment can occur in tropical
  countries.
• This issue developed into a long drawn
  controversy and debate among the earth
  scientists, petroleum engineers and the
  multinational oil companies. The matter has
  remained unresolved.
• In 1992, I reported the occurrence of more than 2
  billion metric tons of bentonite reserve in
  Nigeria and the successful development of
  oil-well drilling mud from same but many did not
  believe.As of today, proven reserve has risen to
  more than 4 billion MT.

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Nigerian Bentonite

• The report was subsequently published in Portugal
  in 2001 during the International Conference on
  Clays.This was after more than 15 years of
  continuous fieldwork and laboratory research.
• Results of our findings were made known to the
  Alh. Abdul Kadir-Committee on the Production of
  Bentonite from Nigerian source rocks.
• In 2001, SPDC decided to use the Nigerian
  Bentonite for the drilling of all the SHELL- EA
  Project Wells as a test.

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Nigerian Bentonite

• It is now on record that more than 600 wells have
  been successfully drilled in both east and west
  of the Niger Delta without the slightest hitch
  and it is still drilling at this moment.
• Quite recently, the Nigerian Steel company has
  decided to use our raw bentonite ore as a binder
  in their manufacturing operations. They will be
  needing 100MT/day. This no doubt is a great
  challenge to Terra Miners Ltd. We are currently
  at the pilot test stage after very successful
  laboratory test runs.
• There is therefore, absolutely no need for the
  importation of even a gram of bentonite or Aqua
  Gel into Nigeria anymore.This brings me to the
  thrust of my discussion with you today.
• You are all welcome.

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Geological Summary of the Deposit

• The bentonite deposit occurs as a continuous
  highly fossiliferous sedimentary bed of early
  Mid-Eocene age (SPDC Report, 1999) with an east
  west strike and a dip of 5 to 10 degrees.
• The deposit is secondary in origin.
• It is more than 10km wide, stretches through
  hundreds of kilometres and more than 40m thick on
  the average.
• Pitting, sampling, mineralogical, geochemical
  analyses and geophysical surveys have revealed
  very consistent thickness and composition.

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Geological Summary of the Deposit

• The deposit is capped by one and a half to two
  and a half-meter thick soft layer of combined
  humus soil and a thin gypsum-shale overburden. In
  some places, the deposit is overlain by a massive
  continental sandstone.
• Terra Miners Nig. Ltd is currently quarrying the
  deposit in an open cast mine for oil well
  drilling operations in the Niger Delta of
  Nigeria.

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Sampling, Sample Preparation and Analytical
Techniques

• 40 samples collected from various vertical
  profiles covering the length and breath of the
  deposit were oven-dried, milled and analysed
  mineralogically, geochemically,physically and
  rheologically (see Tables).
• The analyses were done in the Department of
  Geology, Obafemi Awolowo University, Ile-Ife,
  Shell Laboratory , Warri and Baroid Laboratories
  in Warri and Huston.

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Sampling, Sample Preparation and Analytical
Techniques
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Sampling, Sample Preparation and Analytical
Techniques
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Sampling, Sample Preparation and Analytical
Techniques
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Sampling, Sample Preparation and Analytical
Techniques
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Sampling, Sample Preparation and Analytical
Techniques
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Sampling, Sample Preparation and Analytical
Techniques
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Sampling, Sample Preparation and Analytical
Techniques
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Results and Discussion

• Montmorillonitic content in the samples varies
  from 80.39 86.98 in the raw and from 92.56
  95.88 in the clay fraction. These values are
  comparatively much higher than the 58
  montmorillonitic content recorded in an imported
  raw bentonite by the Research and Development
  Unit of NNPC in 1990. Kaolinite and quartz are
  the main impurities and they vary from 4.43
  7.30 and 0.14 0.18 respectively in the
  investigated samples. Some minor amounts of
  illite and attapulgite were also detected in some
  localities.

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• The results also show increase in montmorillonite
  and decrease in illite and attapulgite with depth
  in places.
• The grains are dorminantly clayey with minor
  amounts of silt and sand with high plastic/liquid
  limits and plastic index.
• The geochemical analyses show dorminance of
  SiO2(47.24 53.06), Al2O3(15.09 22.28) and
  H2O(structural water) which varies from 9.36
  11.45. MgO (5.70 9.48), Fe2O3 (5.22 5.73)
  and CaO (3.43 4.23) are subordinate and are
  comparable to the corresponding values of 5.14,
  4.58 and 7.98 respectively in the imported raw
  bentonite and that of a montmorillonite sample
  from France.

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Results

• The high (200 300) Fee Volume Swell FVS) of the
  samples is typical of the expansive clay subgroup
  to which montmorillonite belongs.
• These results closely approximates Wyoming
  bentonite except that CaO and MgO are higher in
  the Nigerian bentonite. Na is much higher in the
  imported bentonite probably due to pre-treatment
  additives.
• Given the above properties, the Nigerian
  bentonitic clays can be successfully treated and
  used as oil well drilling mud.

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Results

• The results also show increase in montmorillonite
  and decrease in illite and attapulgite with depth
  in places.
• The grains are dominantly clayey with minor
  amounts of silt and sand with high plastic/liquid
  limits and plastic index.
• The geochemical analyses show dominance of
  SiO2(47.24 53.06), Al2O3(15.09 22.28) and
  H2O(structural water) which varies from 9.36
  11.45. MgO (5.70 9.48), Fe2O3 (5.22 5.73)
  and CaO (3.43 4.23) are subordinate and are
  comparable to the corresponding values of 5.14,
  4.58 and 7.98 respectively in the imported raw
  bentonite and that of a montmorillonite sample
  from France.

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Rheology

• Rheologically, the samples have 600rpm and 300rpm
  readings of 40 and 30 while the plastic viscosity
  is 10. Yield Point (lb/100sq.ft) is 24. The 10sec
  and 10min Gels are 11 and 33 respectively.
  Filtration Loss varies from 7.4 12 mls. pH is
  9.0 11.06 while the average YP/PV is 2. Calcium
  in filtrate is in trace amount and more often
  below detection limit.
• Sand content on No. 200 sieve is less than 1.40.
• Thus all the Rheological properties fall within
  the API/OCMA specification for oil well drilling
  mud.
• These observations have also been confirmed by
  mud companies such as SPDC, Baker Huges Nig.
  Ltd., Inter-Drill Services, MI Nig. Ltd and
  Baroid Nig. Ltd (see attachments).

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Pilot Test and Results

• About 1000MT were quarried and milled using a
  standard industrial bentonite mill at Warri.
• Rheological tests carried out at intervals
  revealed a drastic reduction in the percentage
  additives by more than 50 which meant reduction
  in production cost.
• More than 600 wells have been successfully
  drilled so far.
• The country is now set for the needed production
  of bentonite for domestic use and export
  purposes.
• This marks a successful bench mark in our quest
  for Technological Development.

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Government Policy

• The current Government policy to ban importation
  of bentonite and barite is best for the
  country.This is rigidly being implemented.
• The policy should be rigidly enforced.
• Government should assist indigenous companies in
  shopping for credible Technical Partners.
• The indigenous companies should be backed
  officially and assisted financially to take off
  properly.
• This will on the long run provide the much needed
  job opportunities for skilled and unskilled
  Nigerians.

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CONCLUSION

• A massive montmorillonitic clay deposit has been
  discovered in Nigeria with an estimated reserve
  of more than 4 billion MT..
• It is suitable for oil well drilling operations
  in all environments, including land, swamp,
  shallow off-shore and deep off-shore.
• Teamwork and patriotism are cardinal to
  technological development.
• Government is encouraged to maintain the ban on
  importation of bentonite.
• Efforts should be directed towards exportation of
  the commodity to boost our foreign reserve.
• The industry, when set up will provide jobs for
  many skilled and unskilled Nigerians and a
  training ground for the younger ones particularly
  now that the Nigerian Steel Company is set to use
  our bentonite ore as a binder in the manufacture
  of steel in Nigeria..

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CHEMISTRY OF BENTONITE

• Bentonite has a chemical formulae of (Na,
  Ca)O,3(Al, Mg)2Si4O10(OH)2.n(H2O). It has a
  molecular weight of 549.07gm. Its chemical
  composition is as follows
•  
• Sodium 0.84 Na
  1.13 Na2O
•  
• Calcium 0.73 Ca
  1.02 CaO
•  
• Aluminum 9.83 Al
  18.57 Al2O3
•  
• Silicon 20.46 Si
  43.77 SiO2
•  
• Hydrogen 4.04 H
  36.09 H2O
•  
• Oxygen 64.11 O
•  
• 100.00
  100.58 Total oxide
•  
• Bentonite being a montmorillonitic clay, assumes
  the empirical formula of montmorillonite which
  is Na0.2Ca0.1Al2Si4O10 (OH)2(H2O)10

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Quarry Site
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Nigerian Bentonite

• THANK YOU ALL !!!