Patent EA-001665-B1 (EA)
Title: Process for upgrading heavy crude oil production
Inventor: OHSOL ERNST O
IPC: C10G53/04
Filed: 1998-10-08
Abstract: 1. A process for upgrading heavy, high viscosity, crude oil produced as a crude oil/water emulsion comprising the steps of: adding a sufficient amount of a light hydrocarbon diluent having a boiling point of from about 10 degree  to about 180 degree F (from minus 12 degree C to 82 degree C) to said crude oil/water emulsion to form a mixture having a viscosity of less than about 50 cP; heating and pressurizing said mixture to suitable conditions for breaking said crude-oil/water emulsion contained in said mixture by flashing; breaking the crude oil/water emulsion and forming a vapor effluent and a liquid effluent by flashing said mixture to a sufficiently low pressure to vaporize at least about 5 percent by volume of said mixture; separating crude oil from said liquid effluent; and  recovering said separated crude oil. 2. The process of claim 1 further comprising the step of removing gross solids from said crude oil/water emulsion prior to the flashing step and said separating step includes introducing a stream of additional hydrocarbon diluent to enhance the removal of asphaltic material from the crude oil. 3. The process of claim 1 wherein the amount of hydrocarbon diluent is from about 10 to about 35 percent by volume of the oil in the crude oil/water emulsion. 4. The process of claim 1 wherein the hydrocarbon diluent is selected from the group consisting of C3 to C7 paraffinic or naphthenic hydrocarbons C6 to C8 aromatic hydrocarbons, casinghead gas condensate, light aromatic distillate and mixtures thereof. 5. The process of claim 1 wherein the hydrocarbon diluent is a mixture of more than one light hydrocarbon boiling at a temperature of from about 10 degree  to about 180 degree F (from minus 12 degree C to82 degree C). 6. The process of Claim 1 for upgrading a heavy, high viscosity crude oil containing asphaltenes and resins including the steps of: flashing the crude oil to break emulsions; adding additional solvent after the emulsion-breaking step, using 200 to 800 volume percent based on the separated oil content, selecting the solvent from the group of C4 through C7 paraffinic or naphthanic hydrocarbons at a moderate temperature obtain a continuous single phase oil-solvent solution; gently warming the blend to a temperature within about 5 degree  to about 25 degree  F (2,8-13,9 degree C) below the critical temperature of the solvent causing a substantial part of the asphaltic or asphaltenic content of the crude oil to precipitate, causing the asphaltic solid or semi-solid material to settle from the lighter solvent-oil solution; separating the solvent from the oil for recycling; and recovering the extracted crude oil product. 7. The process of Claim 6 which includes the step of separating the solvent from the asphaltic material for recycling. 8. A process as in Claim 7 which includes the step of precipitating asphaltic material in a continuous  countercurrent contacting device, with the solvent introduced near the asphalt removal end and solvent-oil solution removed at the opposite end. 9. A process as in Claim 8 in which, by suitable heat transfer means, a temperature gradient is maintained with a higher temperature at the solvent-oil discharge end. 10. A process as in Claim 8 using a Rotating Disc Contactor. 11. A process as in Claim 6 in which the solvent is normal butane or isobutane. 12. A process as in Claim 6 in which the solvent is a pentane. 13. A process as in Claim 6 in which the solvent is a heptane. 14. A process as in Claim 6 in which the solvent is a mixture of C3 - C5 hydrocarbons. 15. A process as in Claim 6 in which the solvent is a C5 - C7 blend (including C6). 16. A process as in Claim 6 which includes the step of recovering the solvent from the oil in a plurality of stages, using progressively lower pressures and supplying heat to vaporize the solvent. 17. A process as in Claim 6 which includes the step of steam stripping the solvent from the oil, condensing the vapors and decanting the condensed water from the recovered solvent. 18. A process as in Claim 8 which includes the step of recovering solvent from the separated asphaltic material. 19. A process as in Claim 18 which includes the step of treating the separated asphaltic material, while still containing some solvent, to a countercurrent washing with water containing a chelating agent for removal of heavy metals from the asphalt. 20. A process as in Claim 19 in which the chelating agent is EDTA or one of its partial salts. 21. A process as in Claim 19 in which the chelating agent is nitrilotrisacetic acid. 22. A process as in Claim 19 in which the chelating agent is a glycolic acid.