To reveal the complex crude oil-CO_(2) interaction mechanism and oil mobilization behavior during CO_(2) huff-n-puff in shale-type shale oil reservoirs,CO_(2) huff-n-puff experiments with on-line nuclear magnetic reso...To reveal the complex crude oil-CO_(2) interaction mechanism and oil mobilization behavior during CO_(2) huff-n-puff in shale-type shale oil reservoirs,CO_(2) huff-n-puff experiments with on-line nuclear magnetic resonance monitoring were conducted on Gulong shale cores,combined with the prediction model of CO_(2) dynamic diffusion coefficient,the flow mechanism and factors influencing oil mobilization during CO_(2) huff and puff in Gulong shale oil reservoirs are studied,and the diffusion and mass transfer behavior of CO_(2) in shale is investigated.The results show that at the injection stage,CO_(2) invades into macropores near the injection end,and drives part of the crude oil to micropores in the deep part of the core.At the shut-in stage,the crude oil gradually reflows to macropores near the injection end and is redistributed in the core.At the production stage,the oil mobilization zone is gradually expanded from the production end(injection end)to the deep part of the core.The contribution ratio of produced oil from macropores and micropores is about 8︰3 after production.The diffusion coefficient of CO_(2) in shale porous media gradually decreases with the advance of diffusion front at shut-in stage.The better the porosity and permeability of core samples,the higher the CO_(2) concentration at diffusion front,the greater the CO_(2) diffusion coefficient,and the slower the diffusion decline rate is.Increasing the huff and puff cycles could effectively enhance oil displacement efficiency,though its impact on the crude oil mobilization zone remains insignificant.The crude oil in small pores of the small layer with undeveloped laminae is difficult to be produced during CO_(2) huff and puff,and the oil recovery is only 12.72%.The crude oil in macropores and micropores of the small layer with developed laminae can be effectively mobilized during CO_(2) huff and puff,and the oil recovery can reach 39.11%.展开更多
复杂地形风电场流动具有强烈的非定常现象和多尺度特征,其准确模拟是风资源精细化评估的难点。为兼顾宏观中尺度大气环流和微观非定常流动细节,该文结合中尺度气象研究与预报(weather research and forecasting,WRF)模式和微尺度计算流...复杂地形风电场流动具有强烈的非定常现象和多尺度特征,其准确模拟是风资源精细化评估的难点。为兼顾宏观中尺度大气环流和微观非定常流动细节,该文结合中尺度气象研究与预报(weather research and forecasting,WRF)模式和微尺度计算流体动力学(computational fluid dynamics,CFD)技术,构建一套WRF-CFD模式耦合的复杂地形风电场非定常仿真方法。以国际经典案例Askervein山和Bolund岛为验证对象,研究复杂地形流场中平均风速和湍流强度的分布特征,并简要分析复杂地形中风力机布置策略。结果表明,基于WRF-CFD模式的数值模拟结果与实验观测值有较好的一致性,且优于中尺度数值模拟结果,在选取的特征点位置,风速绝对误差均在2 m/s以内。结果可为风力机的设计、布局、载荷评估及风电场运行控制提供一定参考。展开更多
基金Supported by the National Natural Science Foundation of China(520743198)Scientific and Technological Problems Tackling Project of Heilongjiang Province(DQYT-2022-JS-761).
文摘To reveal the complex crude oil-CO_(2) interaction mechanism and oil mobilization behavior during CO_(2) huff-n-puff in shale-type shale oil reservoirs,CO_(2) huff-n-puff experiments with on-line nuclear magnetic resonance monitoring were conducted on Gulong shale cores,combined with the prediction model of CO_(2) dynamic diffusion coefficient,the flow mechanism and factors influencing oil mobilization during CO_(2) huff and puff in Gulong shale oil reservoirs are studied,and the diffusion and mass transfer behavior of CO_(2) in shale is investigated.The results show that at the injection stage,CO_(2) invades into macropores near the injection end,and drives part of the crude oil to micropores in the deep part of the core.At the shut-in stage,the crude oil gradually reflows to macropores near the injection end and is redistributed in the core.At the production stage,the oil mobilization zone is gradually expanded from the production end(injection end)to the deep part of the core.The contribution ratio of produced oil from macropores and micropores is about 8︰3 after production.The diffusion coefficient of CO_(2) in shale porous media gradually decreases with the advance of diffusion front at shut-in stage.The better the porosity and permeability of core samples,the higher the CO_(2) concentration at diffusion front,the greater the CO_(2) diffusion coefficient,and the slower the diffusion decline rate is.Increasing the huff and puff cycles could effectively enhance oil displacement efficiency,though its impact on the crude oil mobilization zone remains insignificant.The crude oil in small pores of the small layer with undeveloped laminae is difficult to be produced during CO_(2) huff and puff,and the oil recovery is only 12.72%.The crude oil in macropores and micropores of the small layer with developed laminae can be effectively mobilized during CO_(2) huff and puff,and the oil recovery can reach 39.11%.
文摘复杂地形风电场流动具有强烈的非定常现象和多尺度特征,其准确模拟是风资源精细化评估的难点。为兼顾宏观中尺度大气环流和微观非定常流动细节,该文结合中尺度气象研究与预报(weather research and forecasting,WRF)模式和微尺度计算流体动力学(computational fluid dynamics,CFD)技术,构建一套WRF-CFD模式耦合的复杂地形风电场非定常仿真方法。以国际经典案例Askervein山和Bolund岛为验证对象,研究复杂地形流场中平均风速和湍流强度的分布特征,并简要分析复杂地形中风力机布置策略。结果表明,基于WRF-CFD模式的数值模拟结果与实验观测值有较好的一致性,且优于中尺度数值模拟结果,在选取的特征点位置,风速绝对误差均在2 m/s以内。结果可为风力机的设计、布局、载荷评估及风电场运行控制提供一定参考。
