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Surfactant Enhanced Water
Flood Projects (SEWF) |
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There have been twenty-seven known Alkaline Surfactant Polymer,
Surfactant Polymer or Alkaline Polymer projects around the world
since 1980. They have taken place in Alberta, California,
China, Colorado, Indonesia, Louisiana, Oklahoma, Venezuela, and
Wyoming. Thirteen others were being considered in October
of 2001. Some details of the completed or ongoing projects
are summarized in the
Table linked to this page. |
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Most of the
projects are Alkaline Surfactant Polymer (ASP) projects. This
process began to come into use in 1987 after successful projects in Louisiana
and Wyoming. Since then, Surtek
alone has designed and conducted 12 more projects, while other companies
have conducted an equal number. These projects use low (0.1% to
0.3%) concentrations of surfactants. Alkali (sodium carbonate or
sodium hydroxide) is used to produce additional surfactant and to reduce
surfactant adsorption. The chemical cost in most ASP projects is
between $2.50 and $6.00 per barrel of incremental oil recovered.
These chemicals increase the production rate so that the operating cost
per barrel is reduced. An example of this would be a field with
stripper wells. Their production could increase by 500% to 1,000%.
Thus, the profit from the project is really the difference between
the operating cost reduction per barrel and the chemical cost,
i.e. $8.00 to $10.00 per barrel. An economically attractive SEWF
project should last less than 5 years with payout in less than 2 years.
The following figure illustrates that reservoir properties and well
spacing determine how project profitablity. |
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Effect
of Permeability, Depths, and Well Spacing on Earning Power |
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The figure
summarizes the earning power predicted for SEWF projects for fields with
oil cuts below 1% with increasing spacing between wells. The
correlating function is permeability (md) times depth (ft) divided by
the area in square feet. Since allowable injection pressure and
injection volume is a function of depth, this function represents how
fast fluid can be injected. The earning power increases until 0.5
pore volumes of surfactant and chase polymer can be injected in about
two years. Thus, the figure shows that projects will be attractive
for larger well spacing if the feild is deep and there permeability is
higher.
Current SEWF
technology does not require Alkaline chemicals, ultra-low interfacial
tensions or micellar solutions to be successful, so that the chemical
cost will be decreased, and operations will become simpler. One
company Oil-Chem Technologies supplies the surfactants for about half of
the current projects. Several groups can help design the projects.
Please
contact MK Tech Solutions, Inc. for more information and for help in
assessing the EOR potential of a field.
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