Abstract

The field development for (A)SP requires a staged approach, from a single-well test (Stage I) to a multiwell pilot (Stage II) to a full-scale project (Stage III). Surfactant quantity at 100% active concentration increases from ~1 ton (I) to ~1,000 ton (II) to 10,000s of ton per year (III). The industry is currently at Stage II and the EOR surfactants manufacturing/supply chain is being developed in parallel with field development. This paper describes how chemicals supply is being aligned with field projects.

Best practices from existing large-scale surfactant manufacture (for household and industrial applications) are being applied to EOR surfactants:

  • Improve the manufacture and handling characteristics of surfactant concentrates that can be viscous, making them difficult to pump and dilute. In addition, dilution of the concentrate in the field facilities needs to avoid the formation of viscous phases.

  • Use existing surfactant manufacture processes and plants that use standard industry petrochemical building blocks (ethylene, propylene oxide and ethylene oxide) to make products that are costeffective and can be readily scaled up.

  • Larger projects (in Stage II and III) are supplied via 20 ton ISO-tanks, a standard bulk industry container.

The main findings are:

  • For small field projects, it is usually advantageous to ship less concentrated products (e.g. ≤ 30% active matter, AM), for ease of mixing and dilution in the field.

  • More concentrated (≥ 65% AM) products that are more viscous can be manufactured with a viscosity modifier to reduce viscosity and/or handled with the appropriate mixing equipment at the project facilities. In addition, the delivery of a mixed surfactant blend can be an option as this can be easier to handle than the single surfactant component due to reduced viscosity.

  • For large projects, two strategies can be used to reduce logistics costs:

    • Supply a concentrated product (to minimise shipping of water) and/or

    • Manufacture the product (or part of the product) in country/region and near the field.

  • A realistic supply chain was used to estimate the logistics costs to transport low and high %AM products from a USA point of manufacture to an EOR project destination in the Middle East. This calculation assumed an equal manufacturing cost for the low and high %AM products and transportation by 20 ton ISO-tanks, a standard bulk industry container. The transportation cost for the high %AM product is around 52% of the low %AM product. Additional logistics savings are achievable through manufacturing the product (or part of the product) in country/region, and the cost can be reduced to 34% of the low %AM product.

  • Reduction in bulk chemical volume transport, achievable by the strategies above, gives a reduction in overall project costs as well as lower HSSE transport risks via fewer miles traversed per ton of product.

More general learning for EOR projects are:

  • Experience from the wider, bulk chemicals industry can be usefully applied for EOR projects.

  • The need to align surfactant manufacture/supply logistics with reservoir management and the field life plan is important as significant lead time is required for supply of larger surfactant volumes.

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