摘要
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 fooding 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 fooding. According to the data of pressure-coring wells and water-fooded layers before and after polymer fooding, this paper deepens the understanding of the potentials of remained oil reserves in the strong water-washing layer after polymer fooding 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 fooding, mainly in 4 forms： particle surface adsorption, intergranu-lar adsorption, cluster, pore surface flm. 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 fooding, the bound state residual oil reduced by weak base ASP fooding is 7.1% higher than that of by high concentration polymer fooding, with the obvious effect in reducing flm-like remaining oil on the pore surface, and the ultimate recovery factor enhanced by 4.7% than that of high concentration polymer fooding.
出处
《海洋石油》
CAS
2017年第4期47-52,共6页
Offshore Oil
基金
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)
关键词
聚驱后
水洗程度
强水洗层
微观剩余油
弱碱三元复合驱
after polymer fooding
water-washing degree
strong water-washing rock
microscosmic residual oil
weak base ASP fooding
