Most of the old oil fields in China have reached high water cut stage, in order to meet the booming energy demanding, oil production rate must be kept in the near future with corresponding IOR (Improving Oil Recovery) methods. Z106 oilfield lies in Shengli Oilfields Area at the Yellow River delta. It was put into development in 1988. Since the oil belongs to heavy oil, the oil-water mobility ratio is so unfavourable that water cut increases very quickly. Especially for reservoir Ng21, the sand rock is sediment from river channel, the permeability heterogeneity and heavy oil properties together lead to extremely poor water flooding efficiency. In order to improve the oil recovery, IOR methods are needed urgently. Considering all practical situations for this reservoir and present technique level, polymer flooding method has been selected as an IOR test with numerical simulation. For polymer flooding, since polymer resolution has the capability of enlarging water viscosity, it controls the mobility of water phase and at the same time improves the driving efficiency. During polymer flooding simulation, many factors must be taken into account for the construction of mathematical model, such as inaccessible pore volume, polymer shear thinning effect, polymer adsorption, relative permeability reduction factors, etc. All simulations were done with black oil model with polymer option in ECLIPSE. Simulation results for a theoretical river channel reservoir with serious permeability heterogeneity and heavy oil, and simulation results for practical reservoir Ng21, both have shown that polymer flooding is a feasible method for IOR. For reservoir Ng21, with polymer slug size of 0.235 PV, polymer concentration at 1.5 kg/m3, the final oil recovery after polymer flooding could reach 12.8%, the enhanced oil recovery is about 5%. If only the developable oil reserve being taken into account, the final oil recovery is about 34%, and enhanced oil recovery from polymer flooding is more than 12%. For such heavy oil river channel reservoir to reach such a final oil recovery, it could be concluded as a great success. Since there are still many such oil reservoirs in Shengli Oilfields Area, polymer flooding will be of great importance for improving oil recovery in this area in the near future.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa.de:swb:105-8869557 |
| Date | 13 July 2009 |
| Creators | Lu, Hongjiang |
| Contributors | TU Bergakademie Freiberg, Geowissenschaften, Geotechnik und Bergbau, Prof. Dr. habil. F. Häfner, Prof. Dr. habil. F. Häfner, Prof. Dr. Köckritz, Dr.-Ing. Voigt, Prof. Dr. Geistlinger |
| Publisher | Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola" |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | doc-type:doctoralThesis |
| Format | application/pdf |
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