Experimental investigation of molecular deposition filming flooding in a low-permeability oil reservoir
Experimental investigation of molecular deposition filming flooding in a low-permeability oil reservoir
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低渗透油藏分子沉积成膜驱实验研究
DOI：
10.1021/acs.energyfuels.0c00819
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发表时间：
2020
期刊：
影响因子：
5.3
通讯作者：
Zhang Mingxing
中科院分区：
文献类型：
--
作者：
Yao Chuanjin;Zhan Guangxian;Zhao Jia;Wang Na;Lei Guanglun;Zhang Kai;Gu Jianwei;Zhang Mingxing
分子沉积（MD）膜驱已被证明是一种有效的提高采收率（EOR）的方法，在油藏的开采相对困难。胜利油田B425低渗透区块实施MD膜驱后，取得了明显的效果。然而，该区块提高采收率的主要机理及影响因素尚不清楚。通过室内实验研究了不同条件下MD膜驱提高采收率的机理及其在低渗透油藏提高采收率方面的应用。还进行了自发渗吸、微观模型驱替和油水相对渗透率实验。结果表明，分子量较小的MD膜驱剂（MDFFA）能更有效地降低界面张力，改善润湿性。当MDFFA的分子量小于1000 g/mol时，渗透能力的提高明显增加。低分子量的MDFFA对大口径毛细管中的自发自吸有较好的促进作用，提高MDFFA的浓度可以促进这一过程。较低的注入速度和注入浓度有利于降低注入压力，提高采收率。岩心渗透率越小，水驱与MD膜驱的相对渗透率差越大。岩心渗透率越低，越有利于低渗透油藏MD膜驱提高采收率机理的发挥。
Molecular deposition (MD) filming flooding has proved to be an effective enhanced oil recovery (EOR) method in reservoirs where recovery was relatively difficult. The B425 block with a low permeability in Shengli Oilfield, China, has reaped the benefits of MD filming flooding. However, the main EOR mechanisms and the influencing factors in this block are still not clear. In this work, laboratory experiments were conducted under various conditions to investigate the EOR mechanisms of MD filming flooding and its potential use in enhancing the recovery of low-permeability reservoirs. Spontaneous imbibition, micromodel displacement, and oil–water relative permeability experiments were also performed. The results indicate that a MD filming flooding agent (MDFFA) with lower molecular weight can more effectively reduce the interfacial tension (IFT) and perform better in wettability alteration. The improvement of seepage capacity is obviously increased when the molecular weight of the MDFFA is less than 1000 g/mol. The low molecular weight MDFFA has a better effect on the spontaneous imbibition in a capillary with a larger diameter, and increasing the concentration can enhance this process. Lower injection rate and lower injection concentration are beneficial to reduce the injection pressure and improve oil recovery. The smaller the permeability of cores, the greater the relative permeability difference between water flooding and MD filming flooding. In addition, lower core permeability is more conductive to the EOR mechanisms of MD filming flooding in the low-permeability oil reservoirs.