缝洞型油藏单裂缝中气驱油规律

Mechanism of gas flooding in single fracture of fractured-vuggy carbonate reservoir

 吴颉衡 5 赵凤兰 4 侯吉瑞 4 宋兆杰1 4 汪勇 3 杨柳 3

中国石油大学（北京）提高采收率研究院，北京 102249 中国石油三次采油重点实验室低渗油田提高采收率应用基础理论研究室，北京 102249 中国石油大学（北京）石油工程教育部重点实验室，北京 102249 中国石化海相油气藏开发重点实验室，北京100083 中国石油测井有限公司长庆事业部，陕西 西安710200）

EOR Research Institute, China University of Petroleum, Beijing 102249, China Basic Theory Laboratory of Enhanced Oil Recovery in Low Permeability Oilfield, Tertiary Oil Recovery Key Laboratory, PetroChina, Beijing 102249, China MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing 102249, China Key Laboratory of Exploration and Production for Marine Reservoirs, SINOPEC, Beijing 100083, China Changqing Division of CPL, Xi′an 710200, China)

 为探索缝洞型碳酸盐岩油藏注气过程中气驱油特征及气体窜逸规律，文中从分析裂缝中油气流动特征着手，设计制作了不同开度的单裂缝可视化有机玻璃模型，开展缝洞型碳酸盐岩油藏单裂缝注氮气驱油实验。结果表明：对于一定开度的裂缝，随着注气速度的增加，驱替形态逐渐从活塞驱变为非活塞驱，注气换油率也随之降低；对于不同开度的裂缝，窜逸系数与注气驱替拟线速度的关系均可用分式方程变形式拟合，且随着拟线速度的增加，窜逸系数趋于一个极限值，裂缝开度越大，窜逸系数极限值越小。基于窜逸系数建立的单裂缝气驱油流体流动区域识别图版，可用来分析不同裂缝开度与驱替拟线速度时气体在裂缝中的窜逸规律，也为深入研究缝洞型碳酸盐岩油藏油气流动规律和分析开发动态提供支持。

 In order to explore the rule of gas channeling in gas flooding of the fractured-vuggy carbonate reservoir, based on the oil and gas flow characteristics in a single fracture, several visual fracture models with different apertures were designed using organic glass, and the nitrogen injection experiments were carried out to model the gas flooding in fractured-vuggy carbonate reservoirs. The results show that, for a given fracture aperture, as the gas injection rate increases, the displacement shape changes from piston-like displacement to non-piston displacement, and the gas replacing oil ratio decreases. The gas channeling factor and pseudo-linear-velocity of gas displacement can be well fitted with fraction equation regardless of the fracture aperture, and the gas channeling factor could reach a maximum value. The larger the fracture aperture is, the lower the maximum value of gas channeling factor is. The prediction plate of fluid flow region during gas displacing oil in single fracture was built based on the gas channeling factor. It could be used to research the gas channeling in fracture at different fracture apertures and gas injection rates, and also it could serve as an essential tool to study the fluid flow mechanisms and production performance in fractured-vuggy carbonate reservoirs.

10.6056/dkyqt201606018