沥青质沉积对轻质油藏CO2驱的影响

为了解沥青质沉积对轻质油藏CO_2驱的影响,以CO_2及延长轻质原油为介质,在不同压力、不同CO_2与原油物质的量比的实验参数下,研究了CO_2对沥青质的沉积规律以及沥青质沉积对油水界面性质、原油组成、储层渗透率及采收率的影响。研究结果表明:当压力从0 Pa升至20 Pa时,沥青质沉积量从0.17%增至6.27%;沥青质沉积导致的储层渗透率损害程度从1.87%增至13.64%,油水界面张力原来的2.40 mN/m增至16.80 mN/m。压力在25 MPa时原油采收率最大,达到11.83%。

Effect of Asphalt Deposition on CO2 Flooding in Light Oil Reservoir

In order to study the effect of asphalt deposition on CO₂ flooding in light oil reservoir, based on the indoor experiment method, the CO₂ and light crude oil from Yanchang oilfield was used to study the effect of CO₂ on the regularity of asphaltene deposition, and effect of asphaltene deposition on characteristics of oil-water interface, crude oil composition, reservoir permeability and oil recovery under different pressure and different molar ratio of CO₂-crude oil. The experiment results showed that when the pressure of the CO₂ injection was increased from 0 Pa to 20 Pa, the amount of asphaltene deposition increased from 0.17% to 6.27%, which leaded to a increase of the reservoir permeability damage from 1.87% to 13.64%, and oil/water interfacial tension increased from 2.40 mN/m to 16.80 mN/m. Oil recovery reached to maximum when the pressure was of 25 MPa, being of 11.83%.