页岩油气地质评价方法和流程

我国页岩油气勘探开发刚刚起步,为了有效而快速地评价页岩油气的潜力,基于国内外10多个页岩油气项目评价的工作实践,综合出了一套适合我国条件的页岩油气地质评价流程和方法,并通过实例说明其应用过程及效果。所提出的页岩油气地质评价流程包括页岩区域评价、页岩评价和页岩油气储量评估。其中页岩区域评价包括建立地层格架、区域构造演化及古地理演化研究、地理地貌分析,目的是确定盆地内是否存在形成富含有机质页岩的古地理环境,评价中强调含有机质页岩沉积环境稳定分布及构造变化稳定性的确定;页岩评价的目的是确定页岩油气发育的有利区,评价中重点要确定"五度",即页岩深度、页岩储层厚度、页岩中有机质丰度、页岩中有机质成熟度、页岩的脆性度等指标,这是快速评价页岩油气有利区的关键;页岩油气储量评估的目的是确定形成页岩油气的核心区或"甜点"区,该评估反映了页岩油气藏连续分布的特点。结论认为,所建立的页岩油气地质评价流程和方法便捷有效,为页岩油气快速评价提供了一种方法。

A method and workflow for shale oil and gas geological evaluation

For quickly and efficiently evaluating the potential of shale oil and gas resources in China, based on the actual practices from over 10 projects of shale oil and gas resource assessment at home and abroad, a new method and workflow is summarized especially for Chinese shale oil and gas geological evaluation, and its application process and sound effects are also reiterated with case histories. This specific workflow includes shale regional evaluation, shale rock assessment and shale oil & gas reserve appraisal. The shale regional evaluation consists of building a stratigraphic framework as well as the analysis of regional tectonic evolution, paleogeographic evolution and geography & landforms. This workflow aims to determine if there is a paleogeographic environment with organic matter rich shales, focusing on the determination of steady distribution of sedimentary environment with organic rich shales and the stability of tectonic evolution. The shale rock assessment will achieve the goal of delineating the favorable zones for shale oil and gas reservoirs, concentrating on the following key indicators for a rapid evaluation: shale depth, reservoir thickness, TOC, Ro, brittle strength, etc. The shale oil and gas reserve appraisal will define nuclear areas or the so called sweet spots of shale oil and gas plays, reflecting the characteristics of shale reservoir's continuous distribution. It is finally concluded that this method and workflow is simple but feasible, providing a new approach for shale oil and gas rapid evaluation.