孔南地区高凝油藏化学复合驱最佳流度界定实验研究

发布时间：2018-10-08 11:11

【摘要】：近年来,随着石油消费量增加和新增探明储量减少,石油公司开始重视高凝油藏开发工作。实践表明,流度控制作用对常规油藏开发十分重要,它对高凝油藏开发作用如何成为石油科技人员十分关心的问题。大港油田孔南地区属于高温高盐高凝油藏,前期研究工作确定采用无碱聚/表二元复合驱作为提高采收率技术。本文以大港孔南地区储层地质和流体为模拟对象,开展了聚/表二元体系基本性能特征和驱油效果及其影响因素研究。结果表明,目标油藏注入水中钙镁离子浓度较高,它们对聚/表二元体系流度控制和洗油能力都存在不利影响。建议清除注入水中钙镁离子,这不仅可以提高聚/表二元复合体系黏度,而且能够降低界面张力,增油降水效果十分明显。疏水缔合聚合物是通过聚合物分子链上疏水基团间缔合作用来形成网状分子聚集体,进而达到增加聚合物溶液黏度目的,但这也可能带来聚合物分子聚集体与岩石孔隙间匹配关系变差、增油效果降低的技术风险。在岩心渗透率变异系数Vk和原油黏度μ_o一定条件下,随聚/表二元体系与原油黏度比(μ_(sp)/μ_o)增大,驱油效果增加,但增幅逐渐减小。在黏度比(μ_(sp)/μ_o)相同条件下,随渗透率变异系数Vk增加,采收率增幅增加,但最终采收率减小。在黏度比(μ_(sp)/μ_o)和渗透率变异系数Vk一定条件下,随岩心平均渗透率增加,驱油效果增加,但增幅呈现“先增后降”变化趋势。在黏度比(μ_(sp)/μ_o)和岩心参数(Kg和Vk)一定条件下,随原油黏度μ_o增加,水驱和化学驱增油效果变差。从技术和经济角度考虑,目标油藏均质储层聚/表二元复合驱合理黏度比范围为0.5~1.0,非均质储层为1~2。与洗油能力相比较,聚/表二元复合体系流度控制能力对化学驱采收率的贡献率较大,通常可以达到50%以上。因此,矿场在进行驱油剂组成设计时应首先确保其具有充足流度控制能力,只有这样才能确保其洗油能力发挥作用。
[Abstract]:In recent years, with the increase of oil consumption and the decrease of new proven reserves, oil companies began to attach importance to the development of high-condensable reservoirs. Practice shows that mobility control is very important for conventional reservoir development, and how to develop high condensate reservoir becomes a very important issue for petroleum scientists and technicians. The Kongnan area of Dagang Oilfield belongs to high temperature and high salt and high solidification reservoirs. In the previous research work it was decided to adopt alkaline free polymer / surface binary composite flooding as the technology of improving oil recovery. Taking reservoir geology and fluid in the south of Dagang Kongnan area as simulation objects, the basic performance characteristics, oil displacement effect and influencing factors of polymer / surface binary system are studied in this paper. The results show that the high concentration of calcium and magnesium ions in the injected water of the target reservoir has adverse effects on the mobility control and oil washing ability of the polymer / surface binary system. It is suggested that the removal of calcium and magnesium ions in the implanted water can not only increase the viscosity of the polymer / surface binary composite system, but also reduce the interfacial tension and the effect of increasing oil and precipitation is very obvious. Hydrophobically associating polymers form reticular molecular aggregates by associating with hydrophobic groups on polymer chains, thus increasing the viscosity of polymer solutions. However, this may also lead to the technical risk that the matching relationship between polymer molecular aggregates and rock pores becomes worse and the oil increasing effect decreases. Under certain conditions of core permeability coefficient of variation (Vk) and crude oil viscosity 渭 _ 0, the displacement effect increases with increasing the ratio of polymer / apparent binary system to crude oil viscosity (渭 _ (sp) / 渭 _ o), but the increase decreases gradually. Under the same viscosity ratio (渭 _ (sp) / 渭 s _ o), with the increase of permeability coefficient of variation (Vk), the oil recovery increases, but the final recovery decreases. Under certain conditions of viscosity ratio (渭 _ (sp) / 渭 -man _ o) and coefficient of variation (Vk) of permeability, the displacement effect increases with the increase of average permeability of core, but the increase shows a trend of "increase first and then decrease". Under certain conditions of viscosity ratio (渭 _ (sp) / 渭 -tio) and core parameters (Kg and Vk), with the increase of viscosity 渭 _ O of crude oil, the effect of water flooding and chemical flooding becomes worse. From the point of view of technology and economy, the reasonable viscosity ratio range of homogeneous / surface binary flooding in target reservoir is 0.5 ~ 1.0 and that in heterogeneous reservoir is 1 ~ 2 ~ 2. Compared with the oil washing ability, the mobility control ability of the polymer / surface binary composite system contributes more than 50% to the chemical flooding recovery. Therefore, in the design of oil displacement agent composition, the sufficient mobility control ability should be ensured first, only in this way can the oil washing ability play its role.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE357.46

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