| Autor: |
Yixiu Chen, Louis M. Castanier, Anthony R. Kovscek, Rongping Huang, Renbao Zhao |
| Rok vydání: |
2015 |
| Předmět: |
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| Zdroj: |
Journal of Petroleum Science and Engineering. 127:82-92 |
| ISSN: |
0920-4105 |
| DOI: |
10.1016/j.petrol.2015.01.005 |
| Popis: |
In-situ combustion (ISC) is an effective thermal recovery process that provides an alternative to steam injection. Air is injected into a reservoir to oxidize a small portion of the hydrocarbons present thereby generating heat and pressure that enhance recovery. ISC suffers from fewer limitations than steam injection, but is not applied widely. One factor that has limited application of ISC is the difficulty of evaluating ISC candidates in the laboratory to obtain critical information such as crude-oil oxidation kinetics, combustion front propagation, and the burning qualities of various crude-oil components. The Karamay Field (Xinjiang, China) has crude oil that is roughly 12.0°API and is a potential candidate for ISC. We have conducted a screening study to evaluate the likelihood of the success of ISC in Karamay. Questions of interest for Karamay include the fraction of the crude oil that is converted to fuel and the particular crude-oil components that become fuel for ISC. To investigate ISC properties of the oil, true boiling point fractions were collected from Karamay crude oil and the kinetics of oxidation of each fraction in porous media were measured using ramped temperature oxidation (RTO). The isoconversional approach is used to interpret the RTO results of each boiling point fraction. The approach obtains the reaction kinetics for a given rock/oil sample at identical reaction extent from multiple experiments with different heating rates. The 500+°C boiling point fraction presents reaction kinetics most similar to the whole crude oil indicating that the crude-oil components in this fraction contribute the most to fuel production. Reaction kinetics of the whole oil appeared to be favorable for successful propagation of a combustion front. This prediction was validated by conducting displacement tests in a 1 m long combustion tube using reservoir sands. The Karamay crude oil demonstrated significant in-situ upgrading as a result of ISC. The initial gravity was 11.8 °API whereas the average gravity of the produced oil was 19.3 °API. Importantly, our results add to the knowledge base of both conditions for successful ISC as well as significant upgrading. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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