Advanced Technology to Improve API Density of Heavy Oils

Eduardo Pacheco1 and Anand Subramanian
(HES) & (KBR)

The incremental demand of oil and gas is driving the world economy, In spite of operator efforts to increase the production we are arriving at limits of the conventional production, Within the next fifteen years, worldwide production of conventional crude oil is projected to peak and decline irreversibly reason why it will be necessary in this decade and the future ones to happen to use the non conventional production where heavy oil plays an important role to minimize the energy crisis.

When petroleum sources are expanded to include heavy hydrocarbons, which include both heavy crude oil and natural bitumen, the outlook for domestic oil supplies is much improved. Worldwide deposits of heavy hydrocarbons are estimated to total almost 5½ trillion barrels, and four-fifths of these deposits are in the Western Hemisphere. In the latest years a values technologies has been development to satisfy the exploration, well construction and completion with exclusive application in this type of hydrocarbons.

With the intention of closing the wheel, in the present work we will show one technology that allows us to improve the API gravity of heavy oils, to obtain better economics benefits and be more profitable in explore and the extraction of this type of hydrocarbons. The upgrading options means are typically designed to convert low value heavy oil into higher values synthetic crude. A solvent extraction process known as ROSE, (Residuum Oil Supercritical Extraction), in which the extraction solvent is recovered as a supercritical fluid.

A conventional method like, solvent recovery in a solvent extraction process consist of evaporating all of the solvent in a series of progressively lower pressures flashes and steam stripping. After the solvent has been vaporized it must be first condensed and them pumped from the condensing pressure back to the pressure required for the extraction. It is well known that the quality of the oil extracted from petroleum residues can be improved by increasing the solvent-to-charge ratio. With conventional solvent recovery system this requires an increased energy demand in the solvent recovery system proportional to increase in the solvent-to-oil ratio.

The rapid increase in the cost of crude and hence energy was not anticipated thirty year ago when ROSE technology was development and introduced in early of 1970.

ROSE process, separate heavy oil into deasphalted oil, and ROSE asphalthenes. The deasphalted oil can be sent to a fluid cat cracker or to a hydrocracker for additional production of transportation fuels. Or, the deasphalted oil can be used for manufactured of lube oil.

The ROSE process uses a light, readily available hydrocarbon as extraction solvent. The choice of hydrocarbon depends on the desired quality and yield of the deasphalted oil. The solvent is recovered as supercritical fluid and recycled. This compares to evaporation, compression and condensation used in conventional deasphalting. A result is lower capital and operating cost for the ROSE unit.

AAPG Search and Discovery Article #90062©2006 AAPG Hedberg Research Conference, Veracruz, Mexico