Laboratory Investigation of Organic-Scale Prevention in a Russian Oil Field
- Ivan A. Struchkov (Saint Petersburg Mining University) | Mikhail K. Rogachev (Saint Petersburg Mining University) | Evgenij S. Kalinin (LLC SamaraNIPIneft) | Pavel V. Pavlov (LLC SamaraNIPIneft) | Pavel V. Roschin (Saint Petersburg Mining University)
- Document ID
- Society of Petroleum Engineers
- SPE Production & Operations
- Publication Date
- February 2018
- Document Type
- Journal Paper
- 113 - 120
- 2018.Society of Petroleum Engineers
- live oil sample, production conditions, organic deposits, wax appearance temperature, wax
- 2 in the last 30 days
- 231 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 10.00|
|SPE Non-Member Price:||USD 30.00|
The objective of this research is a definition of wax-precipitation conditions in waxy oil (a kind of oil that intends to produce high-molecular-weight paraffins during production) at various thermobaric conditions taking place in oil wells, and also proposing a method for the determination of the potential wax-formation depth in a well. In most cases in Russia, many reservoirs are producing oil with high asphaltenes, resins, and wax content that causes the formation of organic deposits in downhole equipment. It reduces the workover period of wells and decreases their productivity. The oil-production system represents the sensitive hydrodynamic system, so any changes in well operational parameters, thermobaric conditions, and oil composition lead to wax and asphaltenes precipitation in oil. Natural surfactants (asphaltenes) stabilize water-in-oil emulsions and change rheological properties of the borehole flow. It demands additional energy consumption for raising reservoir fluid to the surface and for transporting it to gathering and oil-treatment systems.
All laboratory experiments are conducted by use of conventional (standard) techniques. The grain-size-analysis microscopy was performed under high-pressure conditions. Also, a light-scattering method and viscometric analysis were performed, and functional wax-appearance temperature (WAT) vs. the pressure of live and degassed oil are carried out during experimental studies.
The results of our experiments showed that, when the pressure drops below the bubblepoint pressure and the gas starts coming out from the oil, the WAT increases. A significant increase in the viscosity of a live-oil sample with a decrease in temperature and pressure in the range of downhole conditions that can become the reason of decline in the performance of an electrical submersible pump (ESP) is noted. The most technological methods directed on drop in the presented risks—among which are offered (1) the change of well-operation conditions allowing the regulation of the waxing of tubings and (2) the application of inhibitors that demonstrated high efficiency during the laboratory investigations—are mentioned. Mathematical analysis showed that the increase in well flow rate promotes a considerable decrease in potential wax-formation depth in an oil well. The proposed assessment technique of wax-precipitation depth that has been performed in this work can be useful for selecting the well-operation system. Among the studied inhibitors, the experiments showed that Inhibitor A has the highest efficiency in the slowing of the wax-formation process in the borehole conditions.
|File Size||915 KB||Number of Pages||8|
Bello, O. O., Fasesan, S. O., Teodoriu, C. et al. 2006. An Evaluation of the Performance of Selected Wax Inhibitors on Paraffin Deposition of Nigerian Crude Oils. Petroleum Science and Technology 24 (2): 195–206. https://doi.org/10.1081/LFT-200044504.
Bortolin, L. and Uzcategui, E. 1992. New Experience With Electrical Submersible Pumps in Heavy Oil Crude. Presented at the SPE Latin America Petroleum Engineering Conference, Caracas, Venezuela, 8–11 March. SPE-23707-MS. https://doi.org/10.2118/23707-MS.
Brown, K. 1985. Artificial Lift. Tulsa: Oklahoma City USA: Pen Wells Books.
Cazarez-Candia, O. and Vasquez-Cruz, M. A. 2005. Prediction of Pressure, Temperature, and Velocity Distribution of Two-Phase Flow in Oil Wells. Journal of Petroleum Science and Engineering 46 (3): 195–208. https://doi.org/10.1016/j.petrol.2004.11.003.
Cimino, R., Correra, S., Del Bianco, A. et al. 1995. Solubility and Phase Behavior of Asphaltenes in Hydrocarbon Media. In Asphaltenes, pp. 97–130. Springer US.
Dong, L., Xie, H., and Zhang, F. 2001. Chemical Control Techniques for the Paraffin and Asphaltene Deposition. Presented at the SPE International Symposium on Oilfield Chemistry, Houston, 13–16 February. SPE-65380-MS. https://doi.org/10.2118/65380-MS.
Goual, L. 2012. Petroleum Asphaltenes. INTECH Open Access Publisher.
Guozhong, Z. and Gang, L. 2010. Study on the Wax Deposition of Waxy Crude in Pipelines and Its Application. Journal of Petroleum Science and Engineering 70 (1–2): 1–9. https://doi.org/10.1016/j.petrol.2008.11.003.
Hagoort, J. 2004. Ramey’s Wellbore Heat Transmission Revisited. SPE J. 9 (4): 465–474. SPE-87305-PA. https://doi.org/10.2118/87305-PA.
Idris, M. and Okoro, L. N. 2013. A Review on the Effects of Asphaltenes on Petroleum Processing. European Chemical Bull. 2 (6): 393–396.
Kirvelis, R. and Davies, D. R. 2003. Enthalpy Balance Model Leads to More Accurate Modelling of Heavy Oil Production With an Electric Submersible Pump. Chemical Engineering Research and Design 81 (3): 342–351. https://doi.org/10.1205/02638760360596892.
Machado, A. L., Lucas, E. F., and González, G. 2001. Poly (ethylene-covinyl acetate) (EVA) as Wax Inhibitor of a Brazilian Crude Oil: Oil Viscosity, Pour Point and Phase Behavior of Organic Solutions. Journal of Petroleum Science and Engineering 32 (2–4): 159–165. https://doi.org/10.1016/S0920-4105(01)00158-9.
Mansoori, G. A. 1997. Modeling of Asphaltene and Other Heavy Organic Depositions. Journal of Petroleum Science and Engineering 17 (1–2): 101–111. https://doi.org/10.1016/S0920-4105(96)00059-9.
Pedersen, K. S. and Rønningsen, H. P. 2003. Influence of Wax Inhibitors on Wax Appearance Temperature, Pour Point, and Viscosity of Waxy Crude Oils. Energy & Fuels 17 (2): 321–328. https://doi.org/10.1021/ef020142+.
Robles, J. 2001. Application of Advanced Heavy-Oil-Production Technologies in the Orinoco Heavy-Oil-Belt, Venezuela. Presented at the SPE International Thermal Operations and Heavy Oil Symposium, Porlamar, Margarita Island, Venezuela, 12–14 March. SPE-69848-MS. https://doi.org/10.2118/69848-MS.
Sharma, B. K. 2001. Engineering Chemistry. Krishna Prakasan Media (P) Ltd., Meerut, 5.
Singh, P., Venkatesan, R., Fogler, H. S. et al. 2001. Morphological Evolution of Thick Wax Deposits During Aging. AIChE J. 47 (1): 6–18. https://doi.org/10.1002/aic.690470103.
Struchkov, I. A. and Rogachev, M. K. 2016. Risk of Wax Precipitation in Oil Well. Natural Resources Research 26 (1): 67–73. https://doi.org/10.1007/s11053-016-9302-7.
Szilas, A. P. 2010. Production and Transport of Oil and Gas, Vol. 3. Elsevier.
Takács, G. 2009. Electrical Submersible Pumps Manual: Design, Operations, and Maintenance. Gulf Professional Publishing.
Taraneh, J. B., Rahmatollah, G., Hassan, A. et al. 2008. Effect of Wax Inhibitors on Pour Point and Rheological Properties of Iranian Waxy Crude Oil. Fuel Processing Technology 89 (10): 973–977. https://doi.org/10.1016/j.fuproc.2008.03.013.
Venkatesan, R., Singh, P., and Fogler, H. S. 2002. Delineating the Pour Point and Gelation Temperature of Waxy Crude Oils. SPE J. 7 (4): 349–352. SPE-72237-PA. https://doi.org/10.2118/72237-PA.
Venkatesan, R., Wattana, P., and Fogler, H. S. 2003. The Effect of Asphaltenes on the Gelation of Waxy Oils. Energy & Fuels 17 (6): 1630–1640. https://doi.org/10.1021/ef034013k.
Wang, K. S., Wu, C. H., Creek, J. L. et al. 2003. Evaluation of Effects of Selected Wax Inhibitors on Paraffin Deposition. Petroleum Science and Technology 21 (3–4): 369–379. https://doi.org/10.1081/LFT-120018526.
Weingarten, J. S. and Euchner, J. A. 1988. Methods for Predicting Wax Precipitation and Deposition. SPE Res Eng 3 (1): 121–126. SPE-15654-PA. https://doi.org/10.2118/15654-PA.