鄂尔多斯盆地南梁西区长4+5油层组微观渗流特征及影响因素

Micro-flow characteristics and controls of Chang 4+5 reservoirs in the western Nanliang oil field, Ordos Basin

任江丽 朱玉双 刘林玉 王伟 王振川 陈大友

Ren Jiangli Zhu Yushuang Liu Linyu Wang Wei Wang Zhenchuan Chen Dayou

西北大学 地质学系 大陆动力学国家重点实验室(西北大学), 西安 710069 2. 陕西延长石油集团 油气勘探公司, 陕西 延安 716000 3. 兰州城市学院 培黎石油工程学院, 兰州 730070

State Key Laboratory of Continental Dynamics/Department of Geology, Northwest University, Xi'an, Shaanxi 710069, China 2. Oil and Gas Exploitation Company, Yanchang Petroleum, Yan'an, Shaanxi 716000, China 3. Bailie School of Petroleum Engineering, Lanzhou City University, Lanzhou, Gansu 730070, China

为了提高鄂尔多斯盆地南梁西区长4+5油层组的注水效率，对目的层砂岩模型进行渗流实验，观察其渗流特性，探讨储层特征、实验参数与驱油效率之间的关系，目的是找到制约驱油效率的重要因素。应用扫描电镜、铸体薄片等测试资料对储层微观结构进行细致研究，再通过砂岩微观模型渗流实验，总结储层特性、渗流实验参数与驱油效率的关系。结果表明，长4+5油层组主要驱替类型是均匀驱替，局部存在指状和网状驱替，饱和油的最终驱油效率中均匀状驱替最高。驱油效率内部影响因素中非均质性对驱油效率影响最大；储层润湿性也是主要影响因素之一；物性中的渗透率与驱油效率正相关，孔隙度对驱油效率的影响较弱。驱替压力和注入水体积倍数这2个外部影响因素，亦可提高驱油效率，相对来说驱油效率受注水压力的影响更明显。

A model of real sandstones was applied to study the micro-flow characteristics and oil displacement efficiency of the Chang 4+5 reservoirs in the western Nanliang oil field to improve the efficiency of water flooding. The micro-structure was studied with casting thin sections, scanning electron microscopy and mercury injection in order to estimate the influences of reservoir characteristics and micro-flow experiment factors on water flooding efficiency. The results showed that the Chang 4+5 reservoirs were dominated by homogeneous seepage, while finger-type seepage and net-type seepage also existed locally. The homogeneous seepage resulted in the highest final oil saturation and final displacement efficiency. For the internal factors affecting displacement efficiency, heterogeneity played a key role, and reservoir wettability was also important. Permeability was positively related to oil displacement efficiency, while porosity had a weak influence on oil displacement efficiency. Two external factors, water injection pressure and volume multiple, could enhance displacement efficiency, and the influence of pressure was more significant.

国家科技重大专项（2008ZX05013-005）资助。

https://doi.org/10.11781/sysydz201706805