在紧密的砂岩水库中自发浸泡时的矿物成分和孔隙结构
1Ministry Education, Key Lab Enhanced Oil & Gas Recovery, Northeast Petroleum University, Daqing, 163318, China.
Scientific reports
|March 3, 2025
概括
在紧密的油库中,复杂的孔隙结构限制了自发的沉浸回收. 在纳米孔中结合的水显著减少了孔径大小和连接性,阻碍了流体流动,缩短了浸泡距离.
科学领域:
- 石油地质科学 石油地质科学
- 储水库工程 储水库工程
- 毛孔结构分析 毛孔结构分析
背景情况:
- 狭窄的油库表现出复杂的孔隙结构,孔隙大小不同,纳米孔隙发达良好.
- 现有的自发浸泡机制研究并不能完全解释这些水库中观察到的低回收和短浸泡距离.
研究的目的:
- 为了研究矿物成分,孔隙类型和狭窄的砂岩中的孔隙结构特征之间的关系.
- 确定孔隙结构和移位相性质对自发浸泡效率和距离的影响.
- 在纳米孔中定量表征自由和结合的水.
主要方法:
- 射线衍射 (XRD) 和扫描电子显微镜 (SEM) 用于矿物成分和孔隙类型的表征.
- 核磁共振 - 碳 (NMR-C),低电场核磁共振 (LF-NMR) 和微型计算机断层扫描 (微型CT) 用于孔径分布分析.
- 通过NMR-C和低温蒸发来定量表征毛孔中的自由水和结合水 (3.33600 nm).
主要成果:
- 最大孔径大小及其比例是通透性的关键;小孔和中孔对于连接性至关重要.
- 微尺度的毛孔与石英含量相关;地和粘土矿物与纳米尺度的毛孔发育有关.
- 大孔比率和移位相粘度显著影响浸泡效率;纳米孔 (>50%) 中的结合水减少了孔径大小和连接性,限制了浸泡距离.
结论:
- 矿物成分影响毛孔结构的发展,石英有利于更大的毛孔和粘土/野有利于更小的纳米级毛孔.
- 纳米孔中的水积累是限制紧密油库中自发浸泡距离的主要因素.
- 了解这些孔尺度和矿物学控制提供了增强在紧密形成中的石油回收的策略.
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