Abstract—Some blocked phenomenon happened since the Surfactant/Polymer (SP) flooding field experiment began in the China Karamay oilfield Qizhong district which is a conglomerate reservoir, for instance, worse flow ability and low liquid production capacity. We carried out a series of flow ability experiments for different SP flooding systems in natural cores with different permeability under reservoir condition. Even more important, We determined the polymer`s distribution in cores by nitrogen element calibration using EPMA (Electron probe micro-analyzer). The flowing experiment results showed that the SP flooding system can continue to flow in the district with a permeability above average level by reducing polymer molecular weight and concentration. The district with a permeability under average level should replace SP flooding with water flooding. According to the EPMA results, polymer was mainly distributed in pore edge, clay and fragment abundance area and the pore channels. The retention volume in pore channels was the main factor that affected flow ability. Once the polymer content in the pore channels approached to that in the other two areas which were saturated by polymer during the flooding, the mainstream channels will be blocked by polymer. That’s the mechanism for the polymer blocking.
Index Terms—Nitrogen element calibration, polymer blocking, SP flooding, microcosmic distribution.
The authors are with China University of Petroleum, China (e-mail: 515947931@qq.com, lyq13504598848@163.com).
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Cite: Chen Sun and Yiqiang Li, "Polymer Blocking Distribution and Causes Analysis during Surfactant/Polymer Flooding in Conglomerate Reservoir," International Journal of Chemical Engineering and Applications vol. 7, no. 5, pp. 336-339, 2016.
