利用压汞资料进行低渗储层孔隙结构特征分析——以W11-7油田流沙港组三段储层为例

Analysis of pore structure characteristics of low permeability reservoir with mercury injection data——taking El reservoir in W11-7 oilfield for example

汪新光 李茂 覃利娟 蒋利平 李明 孙婷

Wang Xinguang Li Mao Qin Lijuan Jiang Liping Li Ming Sun Ting

中海石油(中国)有限公司湛江分公司, 广东湛江 524057

Zhanjiang Branch of CNOOC Ltd., Zhanjiang Guangdong 524057

储层孔隙结构是影响低渗储层微观孔隙内流体运移与聚集的主要因素,决定了储层的优劣。以W11-7油田流沙港组三段储层为例,应用压汞资料定性与定量研究储层孔隙结构特征。研究结果表明,孔隙结构分为三类,总体上具有"喉道细、分选差、连通性差"的特点,这种较差的孔隙结构发育特征是造成储层呈低渗-特低渗的核心因素。在此基础上应用多元判别方法优选出排驱压力、中值压力、最大孔喉半径、孔喉半径均值、分选系数五类孔隙结构分类评价参数,并结合常规物性将储层分为三类,其中Ⅱ、Ⅲ类是广为发育的储层。

Pore structure is the principal factor influencing the fluid migration and accumulation in microscopic pore of low permeability reservoir, by which, the quality of reservoir can be directly determined.Taking E2l3 reservoir in W11-7 oilfield as an example, mercury injection data can be applied to qualitative and quantitative examination of the reservoir pore structure characteristics.The results show that the pore structure can be classified into three types, and characterized by small throats, poor sorting and poor porethroat connectivity, the bad pore structure is the principal factor causing low or super-low permeability of E2l3 reservoir.Based on the multiple discriminant analysis method, the displacement pressure, median capillary pressure, max pore-throat radius, mean porethroat radius and sorting coefficient are optimally selected as pore structure classification evaluation parameters, and combining with property parameters, the E2l3 reservoirs are classified as types I, Ⅱ and Ⅱ I, and the reservoir of Ⅱ and Ⅲ types is widely developed.

https://doi.org/10.3969/j.issn.1008-2336.2011.01.042