This paper aims to conduct an experimental investigation of the fluid phase behavior of a highly opaque Brazilian pre-salt crude oil-CO2 system, specifically focusing on the occurrence of highly dispersed liquid-liquid transitions. The study involves examining the phase behavior of five global mole compositions [zCO2= (37.9, 50.0, 76.6, 80.6, and 84.2) mol%] by using conventional PVT techniques as light scattering, pressure-volume curve, and direct fluid observation through sapphire windows. When other techniques were ineffective, a high-pressure microscope coupled with a short-wave infrared apparatus (SWIR camera and light source) was used for complex fluid inspection.