Wax and Asphaltene Deposition on a Chip
Study wax and asphaltene deposit formation and select inhibitors, dispersants and solvents that keep channels open.
| Deposits | wax and asphaltenes |
|---|---|
| Triggers | cooling, depressurization, gas or solvent |
| Fluids | oil, gas condensate, model systems, gas, water, solvents |
| Micromodels | straight and serpentine channels, porous structures, digital core, modified surfaces |
| Chemicals | inhibitors, dispersants, PPDs, crystal modifiers, solvents |
| Video analytics | coverage area, particle size, growth rate, remaining cross-section |
| Deliverables | chemical ranking, minimum effective dose, application regime |
Wax and asphaltene deposits form not only because of oil composition but also due to P–T history, contact with gas and water, shear and equipment surface properties. WAT or deposition onset pressure does not show deposit growth rate or its effect on hydraulic resistance, bottle tests do not reproduce flow, and large-scale rigs consume a lot of crude and chemicals.
The process is reproduced in a transparent microchannel or porous micromodel at set pressure, temperature, flow rate and phase composition. Deposition is triggered by programmed cooling, depressurization, or contact with gas or solvent; video shows particle nucleation, growth, transport, wall adhesion and extended deposit formation.
Inhibitors, dispersants, crystal modifiers, solvents and combined formulations are compared at several concentrations on identical micromodels. Visualization shows whether a formulation prevents particle formation, keeps particles suspended or dissolves an existing layer, and recovery of permeability is assessed after treatment. Contact surfaces can be glass, silicon, metal or modified.
The customer receives a chemical ranking, minimum effective concentration and application recommendations for the specific crude, and only formulations with proven performance move on to large-scale testing.