聚驱后强水洗油层微观剩余油量化分布及挖潜研究

Study of Distribution and Potentiality Exploiting of Microscosmic Residual Oil in Strong Water-washing Layer after Polymer Flooding

陈文林

CHEN Wenlin

大庆油田有限责任公司勘探开发研究院, 黑龙江大庆 163712

Exploration and Development Research Institute of Daqing Oilfield Company Ltd., PetroChina, Daqing 163712, China

聚驱后油层剩余油分布高度零散，水洗程度严重且分布比例逐年增大，如何挖潜聚驱后强水洗油层剩余油对于聚驱后进一步提高采收率至关重要。此文通过统计聚驱前后密闭取心井和二类上返井水淹层解释资料，深化了聚驱后强水洗层剩余储量潜力认识及微观剩余油量化分布特征。利用现代物理模拟和激光共聚焦扫描显微分析等方法，在前期统计聚驱后剩余油饱和度数据为基础建立强水洗天然岩心模型，开展聚驱后不同驱油体系对微观剩余油的动用效果室内实验。结果表明：聚驱后强水洗层段自由态、束缚态微观剩余油比例相差不大，以颗粒吸附状、粒间吸附状、簇状、孔表薄膜状为主。中水洗层段自由态较强水洗层高3.7%；聚驱后强水洗岩心弱碱三元复合驱降低束缚态剩余油能力强于高浓度聚驱，多降低7.1%，降低孔表薄膜状剩余油效果明显，最终采收率增幅较高浓度聚合物驱多提高4.7%。

The distribution of residual oil after polymer flooding becomes highly dispersed, the degree of water-washing is gradually aggravated in the reservoir and distribution proportion increases year by year. How to dig the potential of residual oil in the strong water-washing layer is very important to further enhance oil recovery after polymer flooding. According to the data of pressure-coring wells and water-flooded layers before and after polymer flooding, this paper deepens the understanding of the potentials of remained oil reserves in the strong water-washing layer after polymer flooding and the quantitative distribution of the microscopic residual oil. Based on the previous statistic data of residual oil saturation, together with the application of modern physical modeling and laser confocal scanning microscope techniques, the author established the model of strongly-watered natural core, performed the laboratory experiment of the oil increment effect by different oil displacement systems. The results show the bound state remaining oils in strong water-washing layers were similar to free residual oils after polymer flooding, mainly in 4 forms:particle surface adsorption, intergranular adsorption, cluster, pore surface film. The percentage of free residual oils in medium water-washing rock is 3.7% higher than that of in strong water-washing rock; In the strong water-washing core samples after polymer flooding, the bound state residual oil reduced by weak base ASP flooding is 7.1% higher than that of by high concentration polymer flooding, with the obvious effect in reducing film-like remaining oil on the pore surface, and the ultimate recovery factor enhanced by 4.7% than that of high concentration polymer flooding.

国家科技重大专项课题“聚合物驱后进一步提高采收率新技术”（2011ZX05010-005）。

https://doi.org/10.3969/j.issn.1008-2336.2017.04.047