System and method for direct steam injection into slurries
OwnerDuane Serate, Haifeng Liu +2inventors
InventorsDuane Serate, Haifeng Liu, Jose Abreu, John Ajedegba
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Abstract
A system and method is provided for direct condensing steam heating of oil sands process slurry streams including viscous bitumen froth and tailings products streams. Slurry viscosities greater than that of water increase cavitation and vibration issues. High solids content exacerbate component erosions. Difficult, and competing, steam and slurry interactions are managed by steam nozzle arrangements and management of steam injection at sub-sonic velocities based on a ratio of the slurry back-pressure Pb and steam supply delivery pressure Po.
Claims23
A system for direct steam injection to heat a viscous oil sand process slurry, the slurry comprising hydrocarbons, water and solids, comprising:
- a first slurry conduit having a first bore for conducting the slurry therealong at a first pressure;
- and
- a second steam conduit, having a steam outlet situate within the first slurry conduit, for co-injecting superheated steam therefrom and directed downstream into the viscous slurry at a second pressure;
- and
- a steam and slurry distributor section along the first slurry conduit, the steam outlet discharging steam into an upstream portion of the distributor section, at least a downstream portion of the distributor section being erosion resistant;
- wherein the steam is discharged from a nozzle, the nozzle comprising the steam outlet and a conical deflector for forming an annular steam discharge gap therebetween;
- wherein the conical deflector comprises a portion of the distributor section;
- wherein the distributor section further comprises a plurality of axially extending fluid channels circumferentially spaced about the conical deflector;
- and
- wherein each channel of the plurality of fluid channels comprises an upstream inlet and a downstream outlet, and each channel is tapered from the upstream inlet toward the downstream outlet.
A method for direct steam injection to heat a viscous oil sand process slurry, the slurry comprising hydrocarbons, water and solids, comprising:
- flowing the slurry along a first conduit having a first bore for conducting the slurry therealong at a first pressure;
- injecting steam into the slurry via a second steam conduit having a steam outlet situate within the first conduit, the steam being discharged from a nozzle comprising the steam outlet and a conical deflector for forming an annular steam discharge gap therebetween, wherein the steam is injected at a superheated steam supply pressure and temperature;
- discharging the steam from the steam outlet into an upstream portion of a steam and slurry distributor section disposed along the first slurry conduit, at least a downstream portion of the distributor section being erosion resistant;
- wherein the conical deflector comprises a portion of the distributor section,
- wherein the distributor section further comprises a plurality of axially extending fluid channels circumferentially spaced about the conical deflector;
- and
- wherein each channel of the plurality of fluid channels comprises an upstream inlet and a downstream outlet, and each channel is tapered from the upstream inlet toward the downstream outlet;
- measuring the first pressure of the slurry upstream of the steam injection;
- and
- maintaining a velocity of the injected stream from the nozzle to a subsonic to about a sonic velocity.
Dependencies are inferred from the claim text.