CO_2在多孔介质中的运移规律研究

A Study of the Migration Rule of Carbon Dioxide in the Porous Media

低渗透油藏的储量是油田难动用储量的主要部分,提高这部分油藏的采收率是研究的重点。注CO2提高原油采收率技术由于其独特的优点,已经在国内外多种油藏和各种地质条件下得到了成功应用。通过室内模拟研究CO2在地层中运移机理,得出如下结论:多孔介质中填充水相后对CO2扩散速度影响巨大,水相溶解CO2后与矿物反应损耗是CO2扩散的限制因素;渗透率对扩散的影响程度比温度的影响大;高压下气体扩散速度增加缓慢。根据单相渗流规律结合实验,推出与CO2扩散相关联的温度、压力、渗透率三者之间的关系。

The resource of low-permeability oilfield takes up the dominate positions for difficult-to-produce reserves, which is the stress for study. Enhancing oil recovery by carbon dioxide injection has been used in many reservoirs successfully home and abroad. This paper does some research on the migration rule of carbon dioxide in the porous media in the lab. Some results are got. For example, water phase will affect the diffusion rate for CO2 seriously, at the same time, the aqueous phase reacting with mineral blocks the diffusion velocity of CO2. The permeability affecting diffusion is more serious than the temperature does. The rate of gas will increases slowly in high pressure. In the end, combing the rule of the single phase flow with the experiment results, this paper deduces the relational expression with respect to temperature, pressure and permeability, which lays a foundation for predicting migration law of carbon dioxide in the reservoir.