Orinoco油藏泡沫油性能评价研究

Performance evaluation of Orinoco reservoir foam oil

关键词:  Orinoco重油带  泡沫油  稳定性  流变性

Key words:  Orinoco heavy oil belt  foam oil  stability  rheological property

摘要:

Orinoco稠油油藏采用的是压力自然衰竭的开发方式,在开发过程中具有产油量高、产气量低和降压速度慢等特征,在开采过程中会出现“泡沫油”现象。为了研究泡沫油在地层中的稳定性及流变性,利用自主研发的高温高压泡沫油配样器配制泡沫油,分析了黏度、温度、矿化度、溶解气油比等对泡沫油稳定性的影响,并通过流变仪和岩心流动装置分别测量了泡沫油的流变性。实验结果表明:随着脱气原油黏度增大,泡沫油的半衰期变长,稳定性越好；温度越高,稳定性越差；溶解气油比越高,泡沫油稳定性增强；矿化度对稳定性影响并不明显；Orinoco泡沫油具有剪切变稀的性质和轻微触变性；在多孔介质中,随着注入压力的增大,泡沫油黏度先降低后增大,相同压力梯度下,泡沫油的流度明显高于脱气原油流度。该研究提升了人们对泡沫油性能的认识,有利于进一步完善泡沫油性能研究。

Abstract:

The exploitation way of Orinoco heavy oil reservoir is natural pressure failure method. Exploitation process has the characteristics of high oil production, low gas production and low pressure, and the “foam oil” will appear in the exploitation process. In order to study the stability and rheology of foam oil in the formation, we used the self-developed high-temperature and high-pressure foam oil distributor to configure foam oil and research the effects of viscosity, temperature, salinity and dissolved gasoline ratio on foam oil stability and measured the rheological properties of the foam oil by rheometer and core flow device, respectively. The experimental results show that with the increase of the viscosity of degassed crude oil, the half-life of foam oil becomes longer and the stability is better; the higher the temperature, the worse the stability; the higher the dissolved gas oil ratio, the better the foam oil stability; the effect of salinity on stability is not obvious; Orinoco foam oil has the property of shear thinning and slight thixotropy; in porous media, the viscosity of foam oil decreases firstly and then increases with the increase of injection pressure, and the fluidity of foam oil is significantly higher than that of degassed crude oil under the same pressure gradient. This study improves people's understanding of foam oil performance and is beneficial to further improve foam oil performance research.