Re-Evaluation of Asphaltene-Precipitation Risk Depending on Field-Operational-Condition Change/Variation: Case Study Comparing Risks in Past (2008) and Present (2016) for Future Prediction
- Katsumo Takabayashi (INPEX) | Akira Shibayama (INPEX) | Tatsuya Yamada (ADNOC Offshore) | Hiroki Kai (INPEX) | Mohamed Tariq Al Hamami (ADNOC Offshore) | Sami Al Jasmi (ADNOC Offshore) | Hamad Bu Al Rougha (ADNOC Offshore) | Hideharu Yonebayashi (INPEX)
- Document ID
- Society of Petroleum Engineers
- SPE Production & Operations
- Publication Date
- February 2019
- Document Type
- Journal Paper
- 201 - 215
- 2019.Society of Petroleum Engineers
- asphaltene, risk evaluation, gas injection
- 6 in the last 30 days
- 75 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 10.00|
|SPE Non-Member Price:||USD 30.00|
This study aims to improve asphaltene-risk evaluation using long-term data. Temporal changes in asphaltene risks with gas injection were evaluated. In reservoirs under gas injection, the in-situ fluid component gradually changes by multiple contact with the injected gas. Those compositional changes affect asphaltene stability, causing difficulty in risk prediction using asphaltene models. This study aims to reduce the risk uncertainty depending on operational-condition changes.
Periodic upgrading of asphaltene models is essential for understanding the time-dependent changes of asphaltene risks. In a previous study, the asphaltene risk was evaluated for an offshore oil field in 2008 using the cubic-plus-association equation-of-state (EOS) models and using all the available data at the time. Additional experimental data were subsequently collected for a gas-injection plan. An additional study was performed that incorporated and compared the data sets.
According to the previous study recommendation, additional asphaltene laboratory studies were conducted using the newly collected samples. All the asphaltene-onset pressures (AOPs) detected in the new samples were higher than those found in the previous study. A large difference was observed between the past and recent AOPs in the lower reservoir even though the samples were collected from the same well. The asphaltene-precipitation risk increases considerably because the new study detected AOP at the reservoir temperature, whereas no AOPs were detected in the previous study. The difference may be attributed to saturation-pressure increase. Next, the numerical asphaltene models were revised; the re-evaluated asphaltene-risk estimations were higher in the lower reservoir and slightly higher in the upper reservoir than the past ones. The reference sample fluids were collected from two different wells with different asphaltene and methane (C1) contents. The reliability of the new asphaltene laboratory results was increased by applying multiple data interpretation. Thus, the difference between the past and recent results can be attributed to fluid alteration with time. On the basis of the analysis in this study, the risk rating was updated to slightly higher than in the previous evaluation, emphasizing the importance of regular monitoring of asphaltene risks.
This study provides valuable findings of time-lapse evaluation of asphaltene-precipitation risks for a reservoir under gas injection. The evaluations currently conducted in the industry are snapshots of instantaneous risks. Through the entire field life, the risks have varied depending on the operating conditions. This study demonstrates that risk estimates can change in a unique field with identical work flow by analyzing data collected at different times. Finally, this study demonstrates the importance of time-dependent reservoir-fluid properties.
|File Size||1 MB||Number of Pages||15|
ASTM D4124-01, Standard Test Methods for Separation of Asphalt Into Four Fractions. 2001. West Conshohocken, Pennsylvania: ASTM International. Edmonds, B., Moorwood, R. A. S., Szczepanski, R. et al. 1999a. Measurement and Prediction of Asphaltene Precipitation From Live Oils. Presented at the Third International Symposium on Colloid Chemistry in Oil Production, Asphaltenes and Wax Deposition (ISCOP’99), Huatulco, Mexico, 14–17 November.
Edmonds, B., Moorwood, R. A. S., Szczepanski, R. et al. 1999b. A New Method to Give Quantitative Prediction of Asphaltene Deposition From Petroleum Fluids. Presented at the Third International Symposium on Colloid Chemistry in Oil Production, Asphaltenes and Wax Deposition (ISCOP’99), Huatulco, Mexico, 14–17 November.
Edmonds, B., Moorwood, R. A. S., and Szczepanski, R. 1999c. A Unified Framework for Calculating Solid Deposition From Petroleum Fluids Including Waxes, Asphaltenes, Hydrates, and Scales. Fluid Phase Equilibr. 158–160 (June): 481–489. https://doi.org/10.1016/S0378-3812(99)00138-7.
Hirschberg, A. 1988. Role of Asphaltenes in Compositional Grading of a Reservoir’s Fluid Column. J Pet Technol 40 (1): 89–94. SPE-13171-PA. https://doi.org/10.2118/13171-PA.
Høier, L. and Whitson, C. H. 2000. Compositional Grading—Theory and Practice. Presented at the SPE Annual Technical Conference and Exhibition, Dallas, 1–4 October. SPE-63085-MS. https://doi.org/10.2118/63085-MS.
IP 143/01 or ASTM D6560-00, Standard Test Method for Determination of Asphaltenes (Heptane Insolubles) in Crude Petroleum and Petroleum Products. 2001. West Conshohocken, Pennsylvania: ASTM International.
Jamaluddin, A. K. M., Joshi, N., Iwere, F. et al. 2002a. An Investigation of Asphaltene Instability Under Nitrogen Injection. Presented at the SPE International Petroleum Conference and Exhibition in Mexico, Villahermosa, Mexico, 10–12 February. SPE-74393-MS. https://doi.org/10.2118/74393-MS.
Jamaluddin, A. K. M., Creek, J., Kabir, C. S. et al. 2002b. Laboratory Techniques to Measure Thermodynamic Asphaltene Instability. J Can Pet Technol 41 (7): 44–52. PETSOC-02-07-04. https://doi.org/10.2118/02-07-04.
KBC. 2015. Multiflash—PVT Modeling and Flow, Version 6.0. Houston: KBC.
Leontaritis, K. J., Amaefule, J. O., and Charles, R. E. 1994. A Systematic Approach for the Prevention and Treatment of Formation Damage Caused by Asphaltene Deposition. SPE Prod & Fac 9 (3): 157–164. SPE-23810-PA. https://doi.org/10.2118/23810-PA.
Memon, A. I., Qassim, B., Al-ajmi, M. F. et al. 2012. Miscible Gas Injection and Asphaltene Flow Assurance Fluid Characterization: A Laboratory Case Study for Black Oil Reservoir. Presented at the SPE EOR Conference at Oil and Gas West Asia, Muscat, Oman, 16–18 April. SPE-150938-MS. https://doi.org/10.2118/150938-MS.
Riazi, M. R. and Al-Sahhaf, T. A. 1996. Physical Properties of Heavy Petroleum Fractions and Crude Oils. Fluid Phase Equilibr. 117 (1–2): 217–224. https://doi.org/10.1016/0378-3812(95)02956-7.
Schulte, A. M. 1980. Compositional Variations Within a Hydrocarbon Column due to Gravity. Presented at the SPE Annual Technical Conference and Exhibition, Dallas, 21–24 September. SPE-9235-MS. https://doi.org/10.2118/9235-MS.
Sim, S. S.-K., Okatsu, K., Takabayashi, K. et al. 2005. Asphaltene-Induced Formation Damage: Effect of Asphaltene Particle Size and Core Permeability. Presented at the SPE Annual Technical Conference and Exhibition, Dallas, 9–12 October. SPE-95515-MS. https://doi.org/10.2118/95515-MS.
Syed, F. I., Ghedan, S. G, Al-Hage, A. et al. 2012. Formation Flow Impairment in Carbonate Reservoirs due to Asphaltene Precipitation and Deposition During Hydrocarbon Gas Flooding. Presented at the Abu Dhabi International Petroleum Conference and Exhibition, Abu Dhabi, 11–14 November. SPE-160253-MS. https://doi.org/10.2118/160253-MS.
Yonebayashi, H., Masuzawa, T., Dabbouk, C. et al. 2011. Ready for Gas Injection: Asphaltene Risk Evaluation by Mathematical Modeling of Asphaltene-Precipitation Envelope (APE) With Integration of All Laboratory Deliverables. SPE Proj Fac & Const 6 (2): 71–81. SPE-125643-PA. https:// doi.org/10.2118/125643-PA.
Yonebayashi, H., Miyagawa, Y., Ikarashi, M. et al. 2016. How Many Back Up Prepared for Asphaltene Onset Pressure Measurement Using Costly Collected Single Phase Bottomhole Fluid Samples? Presented at the SPE Annual Technical Conference and Exhibition, Dubai, 26–28 September. SPE-181278-MS. https://doi.org/10.2118/181278-MS.