Patent ID: 8899321

Claim:
A method of reducing surface solvent storage need for a solvent-dominated process for recovering hydrocarbons from an underground reservoir, the method comprising: (a) injecting a viscosity-reducing solvent into the underground reservoir; (b) allowing the viscosity-reducing solvent to reduce a viscosity of the hydrocarbons, wherein at least 50% of the reduction in the viscosity of the hydrocarbons is due to chemical solvation; and (c) producing the reduced viscosity hydrocarbons from the underground reservoir; and (d) minimizing a volume of the viscosity-reducing solvent in a surface solvent storage tank by selecting a schedule that minimizes variation in a net solvent injection rate before jointly injecting and producing, wherein the schedule comprises injecting the viscosity-reducing solvent into a first group of wells, while producing the hydrocarbons from a second group of wells, wherein a net solvent injection rate is a difference between a total solvent injection rate and a total solvent production rate for a set of wells, and wherein the surface solvent storage tank comprises a tank having a volume of at least 500 cubic meters.