Experimental and analytical studies have been carried out to better understand
production mechanisms of heavy oil under steam injection with propane and petroleum
distillate as steam additives. The studies have been conducted for heavy oil from San
Ardo field (12oAPI, 2800 cp at 53.3oC), under current reservoir conditions.
The experiments consist of injecting pure steam, steam-propane, and steampetroleum
distillate into a vertical cell containing a mixture of sand, water and San Ardo
oil. The injection cell (68.58 cm long with an ID of 7.376 cm) is placed inside a vacuum
jacket, set at the reservoir temperature of 53.3oC. Superheated steam at 230oC is injected
at 5.5 ml/min (cold-water equivalent) simultaneously with propane or a petroleum
distillate slug. The cell outlet pressure is maintained at 260 psig. Six runs were
performed, two runs using pure steam, two steam-propane runs using 5:100
propane:steam mass ratio, and two steam-petroleum distillate runs using 5:100
petroleum distillate:steam mass ratio.
We develop a simplified analytical model that describes steam front
advancement and oil production for the 1D displacement experiments. The model
incorporates heat and material balance, fillup time and DarcyâÂÂs law pertaining to the
injection cell. The analytical model results are compared against the experimental data to
verify the validity of the model.
The main results of the study are as follows. First, experimental results indicate
that compared to pure steam injection, oil production was accelerated by 30% for 5:100
propane:steam injection and 38% for 5:100 petroleum distillate:steam injection respectively. Second, steam injectivity with steam-propane and steam-petroleum
distillate increases to 1.4 and 1.9 times respectively, compared with pure steam injection.
Third, steam front advancement and oil production data are in good agreement
with results based on the new analytical model. The analytical model indicates that the
oil production acceleration observed is due to oil viscosity reduction resulting from the
addition of propane and petroleum distillate to the steam. Oil viscosity at the initial
temperature with pure steam injection is 2281 cp, which is reduced to 261 cp with
steam-propane injection and 227 cp with steam-petroleum distillate injection.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/4308 |
| Date | 30 October 2006 |
| Creators | Simangunsong, Roly |
| Contributors | Mamora, Daulat D. |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | 2744862 bytes, electronic, application/pdf, born digital |
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