Modeling of Micro-Bubble Drilling Fluid Stability

Micro-bubble surfactant multi-layer (MBSML) drilling fluids are included in the drilling operation of low pressure reservoirs. These fluids contain tiny dispersed micro-bubbles coated with two surfactant layers. For the stability evaluation of these fluids in operational conditions surfactant type concentration pressure and temperature effects on the size of micro-bubble fluid should be scrutinized. For investigating these variables a diffusion model for solute transport in micro-bubble fluids was proposed with the mass transfer concept. The model included mass transfer resistance of fluid phases and interfaces. It was observed that the bubble sizes decrease as a result of adding surfactant to the fluid. However there were pressure temperature and surfactant concentration thresholds for the bubble stability.