A successful cross-linked polymer flooding has been implemented in JD reservoir, an ordinary heavy oil reservoir with high permeability zones. For all that, there are still significant volumes of continuous oil remaining in place, which can not be easily extracted due to stronger vertical heterogeneity. Considering selective plugging feature, polymer enhanced foam (PEF) flooding was taken as following EOR technology for JD reservoir. For low cost and rich source, natural gas was used as foaming gas in our work. In the former work, the surfactant systems CEA/FSA1 was recommended as foam agent for natural gas foam flooding after series of compatibility studies. Foam performance evaluation experiments showed that foaming volume reached 110 mL, half-life time reached 40 min, and dimensionless filter coefficient reached 1.180 when CEA/FSA1 reacted with oil produced by JD reservoir. To compare the recovery efficiency by different EOR technologies, series of oil displacement experiments were carried out in a parallel core system which contained cores with relatively high and low permeability. EOR technologies concerned in our work include further cross-linked polymer (C-P) flooding, surfactant-polymer (S-P) flooding, and PEF flooding. Results showed that PEF flooding had the highest enhanced oil recovery of 19.2 % original oil in place (OOIP), followed by S-P flooding (9.6 % OOIP) and C-P flooding (6.1 % OOIP). Also, produced liquid percentage results indicated PEF flooding can efficiently promote the oil recovery in the lower permeability core by modifying the injection profile.

中文翻译：

---

普通稠油油藏交联聚合物驱后聚合物增强泡沫驱优化研究

在高渗区普通稠油油藏JD油藏成功实施了交联聚合物驱。尽管如此，仍有大量连续石油残留在原地，由于垂直非均质性较强，这些石油不易开采。考虑到选择性封堵的特点，JD油藏采用聚合物增强泡沫（PEF）驱作为后续EOR技术。由于成本低、来源丰富，本工作中采用天然气作为发泡气体。前期工作中，经过一系列配伍研究，推荐表面活性剂体系CEA/FSA1作为天然气泡沫驱的泡沫剂。泡沫性能评价实验表明，CEA/FSA1与JD油藏产出油反应时，起泡量达到110 mL，半衰期达到40 min，无量纲过滤系数达到1.180。为了比较不同三次采油技术的采收率，在含有相对高渗透率和低渗透率岩心的平行岩心系统中进行了一系列驱油实验。我们工作涉及的三次采油技术包括进一步交联聚合物（CP）驱、表面活性剂-聚合物（SP）驱和PEF驱。结果表明，PEF 驱的采收率最高，为 19.2% 原始石油地质储量 (OOIP)，其次是 SP 驱 (9.6% OOIP) 和 CP 驱 (6.1% OOIP)。此外，产液百分比结果表明，PEF驱可以通过修改注入剖面有效地促进低渗透岩心的石油采收率。