扇三角洲储层质量差异特征及控制因素研究

Quality Variations and Control Factors of Fan Delta Reservoirs

许允杰 吴胜和 张可 熊绮聪 余季陶

XUYunjie WUShenghe ZHANGKe XIONGQicong YUJitao

中国石化石油勘探开发研究院, 北京 海淀 100083 中国石油大学(北京)油气资源与探测国家重点实验室, 北京 昌平 102249 振华石油控股有限公司, 北京 西城 100031

Petroleum Exploration and Production Research Institute, SINOPEC, Haidian, Beijing 100083, China State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Changping, Beijing 102249, China Zhenhua Oil Co. Ltd., Xicheng, Beijing 100031, China

扇三角洲沉积作为一种重要油气储集场所，其储层质量差异特征对剩余油分布具有重要影响。前人认为砂岩储层的物性韵律和粒度韵律变化一致，粒度较粗的扇三角洲砂砾岩储层质量韵律和粒度韵律是否一致尚不清楚。以滦平盆地桑园剖面为研究对象，通过无人机拍摄、人工观测及室内岩石分析化验的方法，研究扇三角洲储层质量差异特征及控制机理。结果表明： 1）小砾岩和粗砂岩分选适中，泥质含量低，原始孔隙高且更抗压实，储层物性最好；粒度变粗分选变差，粒度变细泥质含量增高，均会导致其储层物性变差。2）在正韵律分流河道和正韵律河口坝中，垂向上从底部向上由中—细砾岩变细至中—细砂岩，储层物性先变好再变差，横向上从中部向两侧粒度变细，储层物性变差；反韵律河口坝垂向上从底部向上由细砂岩变粗至粗砂岩、小砾岩，物性变好，横向上从中部向两侧粒度变细，储层物性变差。

Fan delta is the important reservoir, and its reservoir quality variations strongly influence the distribution of residual oil. It was previously believed that the physical property rhythm and particle size rhythm of sandstone reservoirs were consistent. But it was not clear whether the physical property rhythm and particle size rhythm were consistent for fan delta glutenite reservoirs with coarse grain size. Field survey, unmanned aerial observation and indoor experiments were used to investigate the fan delta of Sangyuan outcrop within Xiguayuan Formation of Lower Cretaceous in Luanping Basin, aiming to analyze the quality variations and control mechanism. The results show that: the small conglomerates and coarse sandstones with moderate sorting and low argillaceous content have the higher original pores and more compaction-resistant, and have the best physical properties; when granularity becomes coarse with worse sorting, and the argillaceous content increases with the granularity finer, the physical properties of the reservoir become worse. In the positive rhythmic distributary channel and the positive rhythm mouth bar, the vertical upward as the medium-fine conglomerate becomes to the medium-fine sandstone, reservoir physical properties from the bottom to the top become better to worse, and as the lateral granularity from the middle to sides becomes finer, the physical properties of the reservoir become worse. The anti-rhythm mouth bar from the bottom to the top becomes from fine sandstone to coarse sandstone and small conglomerate, the physical properties become better, and as the lateral granularity from the middle to sides becomes finer, the physical properties of the reservoir become worse.

10.11885/j.issn.1674-5086.2023.06.05.02