If the condensing temperature is 30°C (86°F) and you have 100°C (212°F) discharge temperatures the discharge superheat of the compressor is 70° (or 126° on the F Scale). That is very high!

At the same time you say the discharge pressure is 150 psi, which is fairly close to the saturation temperature of your condensing temperature.

You either have extremely high suction superheat or no oil cooling based on what this seems to be.

Another possible cause for high volumes of oil loss is if the discharge pressure suddenly decreases. Do you have hot gas defrost on the evaporators? When the coils go into defrost, what happens to the discharge pressure?