Treatment of brackish water
AssigneeFrancis Hankin & Co. Limited
InventorEdmund J. Ciepiela
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Abstract
Brackish water resulting from steam extraction of heavy crude oils, including oil sands bitumen, is processed for reuse by removing hydrocarbon contamination and removing mineral contamination. The purified water can be boiled in conventional boilers without scaling or fouling occurring. Heat economy is used in carrying out the process.
Claims8
A method of treating hydrocarbon- and mineral-contaminated brackish water from the steam extraction of a heavy oil from a subterranean deposit thereof to render the same susceptible of reuse in steam regeneration, which comprises:
- (a) removing hydrocarbon contamination from the brackish water by:
- (i) causing a substantial proportion of said hydrocarbon contamination to separate from the brackish water as a substantially continuous phase,
- (ii) separating the continuous phase from the hydrocarbon contamination-depleted brackish water, and
- (iii) oxidizing any residual hydrocarbon contamination in the hydrocarbon contamination-depleted brackish water;
- and
- (b) subsequently removing mineral contamination from the brackish water by subjecting hydrocarbon contamination-free brackish water to reverse electrolysis to remove all mineral contaminants therefrom except for silica and removing silica from the electrodialyzed aqueous phase, thereby to form decontaminated water suitable for boiling to form steam.
A method of treating hydrocarbon- and mineral-contaminated brackish water from the steam extraction of a heavy oil from a subterranean deposit thereof to render the brackish water suitable for use in steam formation for use in said steam extraction, which comprises:
- (a) feeding hot brackish water from separation of steam-extracted heavy oil into heat-exchange relationship with purified decontaminated water to heat the same, partially recover the heat value of said hot brackish water and form a partially-cooled brackish water,
- (b) feeding the partially-cooled brackish water into heat exchange relationship with mineral-contaminated hydrocarbon-free brackish water to heat the same, recover heat value from the partially-cooled brackish water and form cooled brackish water,
- (c) subjecting the cooled brackish water to air flotation to separate at least a substantial proportion of said hydrocarbon contamination from the brackish water in the form of a surface layer of hydrocarbon contamination floating on a subsurface layer of hydrocarbon-depleted brackish water,
- (d) removing said surface layer from said subsurface layer,
- (e) subjecting said hydrocarbon-depleted brackish water to ozone stripping to oxidize any residual hydrocarbon contamination and thereby remove the same from the brackish water and form said mineral-contaminated hydrocarbon-free brackish water,
- (f) passing said mineral-contaminated hydrocarbon-free brackish water into said heat-exchange relationship with said partially-cooled brackish water to form warmed mineral-contaminated hydrocarbon-free brackish water,
- (g) subjecting said warmed mineral-contaminated hydrocarbon-free brackish water to electrodialysis reversal to remove mineral contaminants from the same with the exception of silica to form a silica-contaminated water,
- (h) subjecting said silica-contaminated water to silica removal to form said purified decontaminated water, and
- (i) passing said purified decontaminated water into said heat-exchange relationship with said hot brackish water to form warmed purified decontaminated water suitable for boiling to form steam.
Dependencies are inferred from the claim text.