What is Asphasol?

Sulfonated asphalt is produced by using an asphaltic material such as gilsonite, blown asphalt or bitumen derived from lignite. The asphalt is sulfonated with a liquid sulfonating agent, then the sulfonic acids are neutralized with a basic neutralizing agent, such as caustic soda, separating solvent from the sulfonated asphalt,

First of all, Asphasol is a sodium sodium sulfonate of asphalt that is made water-soluble by a unique sulfonation process using sodium. It is a versatile, total mud conditioner that stabilizes shale formations, significantly increases lubricity, lowers water loss as a result of high-hemperature high-hressure fluid loss (HTHP) and enhances filter cake properties in both oil-based drilling fluids and water-based drilling fluids.

Sulfonated asphalt produces thin and tenacious mud cakes in both oil and water based drilling mud systems, also it can be mixed in most water-based, all oil-based and synthetic muds. Asphasol additive is available in two different forms: Regular and potassium enhanced, so potassium sulfonated asphalt additive is a specially prepared potassium salt of sulfonated asphalt.

Finally, sulphonated asphalt can help drilling fluids maintain low shearing rate during HTHP drilling well process, stabilize and clean wellbores that have many collapsing shales. Unlike some shale control additives, it’s not necessary to pre-mix the gilsonite Asphasol inhibitor with oil and it contains no surfactants.

Advantages of Uses

  • It is compatible with all water based mud systems.
  • Improves lubricity thereby reducing torque and drag of the drilling string.
  • Seals small fractures in stressed shale formulation.
  • Prevents bit and down hole assembly bailing by preferentially wetting the drill string with oil.
  • Reduces the fluid loss down hole due to temperature and contributes to corrosion inhibition.
  • Controls high temperature water loss.
  • Reduces high temperature-high pressure (HTHP) Fluid Loss
  • Improves filter cake quality and helps seal micro fractures
  • Contains no surfactants
  • Premixing is not required
  • Reduces torque and drag
  • Inhibits swelling and water-wetting of shales
  • Finally sulfonated asphalt acts fully as an emulsion in water while Gilsonite will remain on top.

How to Use Sulfonated Asphalt

  • Shale control 
  • Fluid loss improvement 
  • Torque and drag reduction 
  • Inhibition of swelling clays in all water based muds.
  • Shale stabilizing by controlling HTHP fluid loss.
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