The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 11, 2004
Filed:
May. 08, 2000
William F. Heins, Redmond, WA (US);
Ionics, Inc., Watertown, MA (US);
Abstract
A method of treating produced water from heavy oil production to provide feedwater for the production of high quality steam. A produced water from heavy oil recovery operations is initially treated by first removing oil and grease to a desired level, preferably to about twenty parts per million, or less. The pH is then adjusted, normally downward and by acid addition, to release at least some carbonate alkalinity as free carbon dioxide. Preferably, all non-hydroxide alkalinity is removed, or substantially so, by introducing the feedwater into a decarbonator. In some cases, the pH may be raised (without, or subsequent to decarbonation, depending upon water chemistry) preferably by caustic addition, to maintain silica solubility in the feedwater. Next the feedwater is introduced into an evaporator, and the feedwater is evaporated to a pre-selected concentration factor to produce (1) a distillate having a small amount of residual hardness therein, and (2) a concentrate containing residual solids (dissolved solids and in some cases, suspended solids). The distillate is then cooled, and is subsequently introduced into a hardness removal step, preferably an electrodeionization (EDI) treatment unit, to remove the residual hardness from the distillate. Finally, the substantially hardness free treated water stream is sent to packaged boilers, for production of high quality steam. The hardness containing stream from EDI is recycled to the evaporator feed, for further treatment.