基于CO置换的低渗透储层岩心饱和方法研究

Saturation method of low-permeability reservoir cores based on CO displacement

韩学辉 李峰弼 戴诗华 张娟娟 唐俊 王雪亮 王洪亮

Han Xuehui Li Fengbi Dai Shihua Zhang Juanjuan Tang Jun Wang Xueliang Wang Hongliang

中国石油大学(华东) 地球科学与技术学院, 山东 青岛 266580 2. 中国石油西部钻探工程有限公司 测井公司, 新疆 克拉玛依 834000

School of Geosciences, China University of Petroleum, Qingdao, Shandong 266580, China 2. Logging Company, CNPC West Drilling Engineering Company Limited, Qaramay, Xinjiang 834000, China

针对低渗透储层岩心的饱和难题, 基于CO2置换吸附气的原理开发了低渗透储层岩心饱和方法和实验装置, 通过饱水法孔隙度测量考察了该方法在26块低渗透储层岩心的应用效果。研究发现, 该方法饱和后饱水法孔隙度比常规饱和方法饱和后的饱水法孔隙度平均增加0.54%, 平均比氦气法孔隙度小0.14%左右, 饱和效果有明显改善并近于完全饱和;饱水法孔隙度相对增量与泥质含量存在正相关关系, 而与平均粒径、孔隙度、渗透率存在负相关关系, 表明该方法在消除致密岩心吸附气对饱和影响方面有很好的针对性, 可用于低渗透储层岩心的饱和。

In order to improve the saturation of low-permeability reservoir core, the saturation method and experimental device were developed based on CO2 displacement of absorbed gas. The saturation effect was investigated by the measurement of saturated porosity with the employment of 26 cores from low-permeability reservoirs. It was demonstrated that saturation effect was significantly improved and was close to complete saturation because the saturated porosity of the new saturation method was 0.54% on average larger than that of the traditional saturation method and 0.14% on average smaller than helium porosity. Also, it was illustrated that the new saturation method had highly pertinence in reducing the effect of absorbed gas in tight cores and was able to be widely used for the saturation of low-permeability reservoir cores because the relative increment of saturated porosity by the new method increased positively with shale content and negatively with average grain size, helium porosity and permeability.

国家油气专项(2011ZX05009-003)资助。

https://doi.org/10.11781/sysydz201406787