Abstract
A liquid-liquid centrifuge was tested for possible application as a downhole method for separating crude oil from produced water. The centrifugal separator investigated at Oak Ridge National Laboratory will extend the application of remotely operated equipment, which was developed for the nuclear industry, to in-well recovery of oil, with in situ recycling of produced water. The on-off cycle imposed by rod pumps makes it less likely of successful coupling with this type of lifting system. Coupling of the centrifugal separator with an electric submergible pump or hydraulic pump is feasible. From a standpoint of equipment simplicity, the use of a centrifugal submergible pump or a progressing cavity pump seems to be the best choice for a baseline equipment choice for pushing the fluid through the centrifugal separator. Water/oil feed ratios of 10:1 to 1:19 were tested with a light Gulf of Mexico crude oil, and the separator operated efficiently for the full range of feed ratios. Air was added to the oil stream in one test to model the effect of gas in the oil. Air additions ≤ 20% of the feed flow rate did not have any impact on the performance of the separator. The separator also effectively processed a very viscous North Sea heavy crude oil. Increasing the temperature of the oil and water feed stream improved overall performance and decreased the concentration of oil in the water discharge stream. Preliminary estimation about full-scale design appeared reasonable, suggesting the separation of 1500-3000 bpd of oil/water mixtures would be possible in standard wells.
| Original language | English |
|---|---|
| Pages (from-to) | 1143-1159 |
| Number of pages | 17 |
| Journal | Petroleum Science and Technology |
| Volume | 22 |
| Issue number | 9-10 |
| DOIs | |
| State | Published - Sep 2004 |
Keywords
- Centrifugel separator
- Gravity separation
- Hydrocyclones
- In-well separator
- Water-to-oil