流花油田礁灰岩储层微观性质及驱替特征研究

Study on the Displacement Characteristics and Microscopic Properties of the Reef Limestone Reservoir in Liuhua Oilfield

宁玉萍 王峻峰 罗东红 张伟 戴宗

NINGYuping WANGJunfeng LUODonghong ZHANGWei DAIZong

中海石油(中国)有限公司深圳分公司, 广东 深圳 518000 中国石化西南油气分公司川西采气厂, 四川 德阳 618000 西南石油大学石油与天然气工程学院, 四川 成都 610500

Shenzhen Branch of CNOOC Ltd, Shenzhen, Guangdong 518000, China Western Sichuan Gas Production Plant, SINOPEC Southwest Branch Company, Deyang, Sichuan 618000, China School of Oil & Natural Gas Engineering, Southwest Petroleum University, Chengdu, Sichuan 610500, China

与碎屑岩储层相比，礁灰岩储层的微观孔隙结构复杂且具有油湿性，其水驱油机理主控因素尚不明确。采用“岩芯扫描电镜、铸体薄片、压汞、润湿性”等静态资料与“微观驱替及岩芯驱替实验”等动态测试相结合的分析方法，建立了“静态数据动态化”的渗流机理研究新方法，明确了礁灰岩储层的微观性质与流体驱替特征的关系以及不同孔隙结构的剩余油分布规律。研究表明，流花礁灰岩储层微观孔隙结构可分为4类，其中，I、Ⅱ、Ⅲ类为有利储层，具有低排驱压力、低退汞效率及强非均质性的特点，储层渗流能力与储层类型关系密切，主控因素有储层类型、孔喉半径比和润湿性3个关键因素。水驱前后的油水分布特点及不同岩芯驱替动态与驱替效果受储层微观性质控制并有直接的相关性。

Compared to clastic reservoirs, reef limestone reservoirs are oil wettable and their microscopic porous structure is complex. Furthermore, the main factors controlling their water flooding mechanism are still not clear. This study combined static data from rock core SEM, casted rock thin sections, mercury injection, wettability tests, and dynamic experiments, such as microscopic displacement and core displacement, in analysis and established a new method to study the seepage mechanism that involves the dynamic usage of static data. The microscopic properties and fluid displacement characteristics of the Liuhua reef limestone reservoir, and the distribution pattern of residual oil in different porous structures were also identified. The microscopic porous structure of the reservoir was classified into four types, of which type I, Ⅱ and Ⅲ are favorable reservoirs with low displacement pressure, low mercury withdrawal efficiency, and strong heterogeneity. Percolation in the reservoir is closely related to the reservoir type, and controlled by three key factors:reservoir type, pore throat radius ratio, and wettability. The distribution characteristics of oil and water before and after water flooding, and the displacement dynamics and effects in different cores are controlled and directly linked to the microscopic properties of reservoirs.

10.11885/j.issn.1674-5086.2017.09.04.02