Petroleum Science >2015, Issue 1: 129-134 DOI: https://doi.org/10.1007/s12182-014-0012-7
Research into polymer injection timing for Bohai heavy oil reservoirs Open Access
文章信息
State Key Laboratory of Offshore Oil Exploitation, Beijing 100027, China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University,;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, Sichuan, China;State Key Laboratory of Offshore Oil Exploitation, Beijing 100027, China;Research Institute of Exploration and Development, PetroChina Southwest Oil & Gas Field Company, Chengdu 610041, Sichuan, China;State Key Laboratory of Offshore Oil Exploitation, Beijing 100027, China;State Key Laboratory of Offshore Oil Exploitation, Beijing 100027, China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, Sichuan, China
文章摘要
improve oil recovery in the Bohai Oil Field. However,
due to high oil viscosity and significant formation
heterogeneity, it is necessary to further improve the displacement
effectiveness of polymer flooding in heavy oil
reservoirs in the service life of offshore platforms. In this
paper, the effects of the water/oil mobility ratio in heavy oil
reservoirs and the dimensionless oil productivity index on
polymer flooding effectiveness were studied utilizing relative
permeability curves. The results showed that when
the water saturation was less than the value, where the
water/oil mobility ratio was equal to 1, polymer flooding
could effectively control the increase of fractional water
flow, which meant that the upper limit of water/oil ratio
suitable for polymer flooding should be the value when the
water/oil mobility ratio was equal to 1. Mean while, by
injecting a certain volume of water to create water channels
in the reservoir, the polymer flooding would be the most
effective in improving sweep efficiency, and lower the
fractional flow of water to the value corresponding to
D Jmax. Considering the service life of the platform and the
polymer mobility control capacity, the best polymer
injection timing for heavy oil reservoirs was optimized. It
has been tested for reservoirs with crude oil viscosity of
123 and 70 mPa s, the optimum polymer flooding effectiveness
could be obtained when the polymer floods were
initiated at the time when the fractional flow of water were
10 % and 25 %, respectively. The injection timing range
for polymer flooding was also theoretically analyzed for
the Bohai Oil Field utilizing relative permeability curves,
which provided methods for improving polymer flooding
effectiveness.
关键词
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Heavy oil reservoir Mobility ratio Polymer injection timing Injection timing range Timing optimization