Atlas BA Consulting Inc is one of the few EPCM that has extensive experience with Underground Salt Caverns. Salt caverns are large vessels created underground by solution mining techniques.

Salt caverns can typically store upwards of 600,000 barrels of hydrocarbon product two kilometers below the surface.

Salt caverns are developed by washing out rock salt formation with pure river water. While wash water is being sent down into the cavern, unsaturated brine from the cavern is sent to disposal well(s) or existing brine system.

Once a salt cavern is developed it can be used to store hydrocarbon product. Product can be injected to the cavern from injection pumps and rejected from the cavern through displacement using brine to displace the product.

Atlas has been involved with Front End Engineering Design (FEED), Detailed Design, HAZOP studies through to construction turnover for salt cavern storage facilities involved in the wash and production phase of the salt caverns.

 Cavern Production

General Description
Once the Salt Cavern is developed, the cavern can be used to store hydrocarbons. This is known as the Cavern Production Phase. The components of a salt storage cavern during production are:

  • Brine String
  • Production Casing
  • Casing Shoe
  • Wellhead
  • Injection Equipment
  • Brine System (Brine pond, Brine Separator)

Projects

Single Completion Cavern
Single Completion Cavern has one wellhead. Typically the brine will be injected/rejected in the string. Whereas, the product will be injected/rejected in the annulus.

Dual Completion Cavern
Dual Completion Cavern has two wellheads. For a dual completion Cavern the wellhead configuration will vary depending on the application.

 Cavern Wash

General Description
Salt Caverns are developed by washing out rock salt formations with pure river water.

A wellhead is installed at a proposed site and a hole is drilled suitable for production requirements. String arrangements and configurations of new caverns are based on flow rate injection requirements.

During Cavern Wash (Leaching Phase) fresh water enters the cavern through the wash string and due to its less specific gravity the fresh water goes up in the cavern and mixes

with the surrounding brine. Finally, the diluted brine reaches the cavern wall and dissolves the salt. The re-concentrated brine drops down along the wall driven by it high specific gravity and is then sent out of the cavern through the annulus.

For this whole process to work there must be enough pressure to push water into the cavern and a brine disposal system to send the displaced unsaturated brine.