The Shell Thermal Conversion technologies, jointly licensed by Shell and CB&I Lummus, reduce viscosity and produce high quality, stable fuel oil (or residue) and distillates from atmospheric and vacuum residues and solvent deasphalter pitch.

The core of these technologies, the Shell Soaker Visbreaking process, reduces heavy fuel oil product by reducing residue viscosity and maximizing distillates production. Feeds include atmospheric and vacuum residues and solvent deasphalter pitch. Its advantages include significantly lower fuel requirements, increased heater run-length, and higher conversion operation with better viscosity reduction. With typically 20% of the vacuum residue feed converted to distillate and lighter products, the Shell Soaker Visbreaking process is one of the lowest cost conversion options. Since 1985, over 70% of new visbreaking capacity has been based on the Shell Soaker Visbreaking technology because of its high conversion to distillates, low fuel requirements, and low investment cost.

The Shell Thermal Gasoil process, which upgrades atmospheric residue and waxy distillate, is a combination of three Shell technologies: Soaker Visbreaking, Vacuum Flashing, and Thermal Cracking. The Shell Vacuum Flashing technology was developed to recover distillates from thermal conversion residue. The design of the distillate Thermal Cracking heater is based on Shell's experience and know-how in the field of thermal cracking in general.

The Shell Deep Thermal Conversion process fills the gap between visbreaking and coking. The process yields a maximum of distillates by applying deep thermal conversion (i.e., Shell Soaker Visbreaking process) to the vacuum residue feed and vacuum flashing the cracked residue. High distillate yields are obtained while producing a stable liquid residual product. The Shell Deep Thermal Gasoil process is a combination of the Shell Deep Thermal Conversion and the Shell Thermal Gasoil processes. In this high conversion scheme, the heavy gasoil (HGO) from the atmospheric fractionator and the vacuum gasoil (VGO) from the vacuum flasher are cracked in a distillate thermal cracking heater into lower boiling point gasoil.