Water treatment method for heavy oil production
US6733636B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | May 8, 2000 |
| Grant date | May 11, 2004 |
| Priority date | — |
| Expiry date | May 8, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S203/17
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
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) trea…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.