摘要
致密油储层微观孔喉结构特征是致密油储层研究的重点和难点,也是制约致密油开发的关键。以鄂尔多斯盆地姬塬油田安83区长7致密油储层为例,通过镜下观察和压汞实验对储层微观孔喉结构进行了分析。镜下观察该区孔隙类型主要为长石溶孔和粒间孔,喉道类型以弯片状、片状以及管束状喉道为主;压汞曲线显示排驱压力和中值压力偏高,中间过渡段相对较陡,喉道中值半径偏小,分选较好。孔喉结构的非均质性是决定致密储层渗流特征及其差异的主要因素,通过对孔喉分布、孔喉大小、连通性三方面参数与物性之间的相关性分析,表明孔喉分布特征参数中的分选系数、大小特征参数中的孔喉体积比、连通特征参数中的退汞效率与物性相关性最好,据此建立了适合致密油储层的分类评价标准,以指导致密油储层产能评价及相关措施优化。
The characteristics of micro pore throat structure of tight oil reservoirs are the bottleneck in study of tight oil reservoir. It also holds the key to tight oil development. Take Chang 7 tight oil reservoir in An-83 block of Jiyuan oilfield in Ordos Basin for instance. Based on microscopic observation and mercury intrusion experiment, micro pore throat structure of the reservoir is brought under analysis. Microscopic observation indicate that the main types of pores in this zone are feldspar dissolution pore and intergranular pore, while the types of throat are mainly tortuous sheet shape, sheet shape and bundled tube. The intrusive mercury curves indicate that the expulsion pressure and median value pressure are relatively high, with the curves having a higher pitch of intermediate section and a low throat radius. Heterogeneity of pore throat structure is the main factor to determine the filtration characteristics and differences of tight oil reservoir. The analysis of the correlations between parameters and physical properties in three areas of pore distribution, pore sizes and pore connectivity indicate that the sorting coefficient in the parameters of pore distribution, the pore volume ratio in the parameters of pore sizes and the mercury withdrawal efficiency in the parameters of connectivity have the best correlations with the physical properties. As a result, the appropriate appraisal standards are established to classify tight oil reservoirs, helping appraise productivity of tight oil reservoirs and optimizing the relative measures.
出处
《中国石油勘探》
CAS
2014年第5期73-79,共7页
China Petroleum Exploration
基金
中国石油天然气股份有限公司重大科技攻关项目"鄂尔多斯盆地致密油勘探开发关键技术研究"(2011E-2602)
关键词
鄂尔多斯盆地
姬塬油田
致密储层
微观孔喉结构
毛细管压力
Ordos Basin, Jiyuan oilfield, tight oil reservoirs, micro pore throat structure, capillary pressure
