致密储层孔隙结构表征技术有效性评价与应用

Evaluation and application of porous structure characterization technologies in unconventional tight reservoirs

非常规致密储层类型多,孔隙结构复杂,非均质性强,研究难度大。针对已有致密储层孔隙结构评价技术,重点探讨了CT扫描、气体吸附与压汞分析等技术的有效应用范围,厘定了不同技术应用时需注意的关键问题,指出兼顾分辨率与代表性、提高表征维度、实现动态与静态同步表征是致密储层孔隙结构评价技术优选的关键。通过系统解剖常规砂岩、致密砂岩、致密混积岩、沉凝灰岩、介壳灰岩及泥页岩6种储层,明确不同级别孔隙系统的差异性,针对性地提出了不同储层对应的关键表征技术系列。非常规致密储层孔隙结构研究应加强多尺度数据融合,加强与可动流体评价结合,加强与储层改造研究结合,通过多领域、多学科、多视角联合攻关,实现储层有效性评价,为寻找预测规模有效"甜点区"提供技术支撑。

Unconventional tight reservoirs pose a great challenge to researchers because of their complex porous structures and great heterogeneities. In this study, key issues of CT scanning, gas adsorption and MICP application in unconventional tight reservoirs were investigated. Optimization of these techniques led to higher resolution and multi-dimension representation in porous structure characterization by using a combination of static description and dynamic modeling. Six typical reservoir rocks, including conventional sandstones, tight sandstones, peperites, tuffs, shelly limestones and marine shales were analyzed systematically to understand the structural differences and define appropriate characterization methods for different porous structures. Moreover, the effects of pore size on physical property, resource economic and development technologies are discussed. Future research should be focused on integrating porous structure characterization performed at different structural scales, and evaluating the relationship between porous structure and mobile fluids ＆ reservoir stimulation. Based on our multi-field, multi-discipline and multi-view study, the reservoir effectiveness can be assessed to provide technological support for the large-scale ＂sweet spot＂ predictions.