致密油源储组合差异富集机制与控藏模式——以酒泉盆地青西凹陷为例

Differential mechanism of tight oil enrichment and reservoir controlling model of source and reservoir combinations: a case study of Qingxi Sag, Jiuquan Basin

罗群 红兰 高阳 邓远 李映艳 王仕琛 马文彧 许倩

LUO Qun HONG Lan GAO Yang DENG Yuan LI Yingyan WANG Shichen MA Wenyu XU Qian

油气资源与探测国家重点实验室, 北京 102249 中国石油大学（北京） 非常规油气科学技术研究院, 北京 102249 中国石油 新疆油田分公司 勘探开发研究院, 新疆 克拉玛依 834000

State Key Laboratory of Oil and Gas Resources and Detection, Beijing 102249, China Unconventional Oil and Gas Science and Technology Research Institute, China University of Petroleum (Beijing), Beijing 102249, China Research Institute of Petroleum Exploration and Development, Xinjiang Oilfield Company, PetroChina, Karamay, Xinjiang 834000, China

源储品质及其空间匹配组合类型是致密油充注成藏与富集的关键因素，然而目前对其认识不足，尤其对不同类型源储组合致密油充注成藏与富集的差异性及其形成机制缺少深入研究，制约了致密油成藏理论的形成与勘探开发进展。以酒泉盆地青西凹陷为例，通过野外观察、岩心描述、钻井分析，总结出下源上储、上源下储、三明治型3种基本类型，源储一体、源储(薄)互层2种特殊类型，下源上储Ⅱ型、上源下储Ⅱ型、三明治Ⅱ型3种复合类型共8种类型的致密油源储组合，其中前5种为常见的源储组合类型。钻探成果统计与核磁共振实验相互验证了源储组合类型与致密油富集的对应关系，即源储一体型致密油富集程度最高，其次是三明治型，上源下储型要好于下源上储型，薄互层型不利于致密油的成藏与富集。揭示了下源上储、上源下储、三明治、源储一体、薄互层5种常见源储组合类型的致密油充注成藏与富集机制及其差异，总结了这5种源储组合致密油充注成藏与富集模式，指出致密油成藏动力、充注方式、保存条件是控制致密油充注成藏机制与富集差异的主控因素，而这些主控因素又与致密油源储组合类型密切相关。

The quality of source and reservoir rocks as well as their spatial assemblage types are crucial factors that controlling the charging, accumulation, and enrichment of tight oil resource. However, there are still deficiencies in the understanding about these factors, especially regarding differences in the mechanism of charging, accumulation, and enrichment of tight oil between different source-reservoir assemblage types, which restricts the formation of theory as well as the process of exploration and development. Taking the Qingxi Sag of the Jiuquan Basin as an example, we have drawn conclusions by field observations, core descriptions, and drilling analyses that there may be eight types of source-reservoir assemblages. Among these, there are three basic types, namely, the lower-generating and upper-reserving type, upper-generating and lower-reserving type, and sandwich-like type. In addition, there are two special types, the self-generating and self-reserving type and source-reservoir interbedding type. Moreover, the other three types are composite types, which are the lowergenerating and upper-reserving type Ⅱ, upper-generating and lower-reserving type Ⅱ, and sandwich-like type Ⅱ. Among the above mentioned eight types, the first five types are common. The results of statistical drilling and nuclear magnetic resonance experiments mutually verify the corresponding relation between source-reservoir assemblage type and tight oil enrichment. The assemblage types can be ranked according to their positive correlation with enrichment in the following order, from the highest to the lowest: self-generating and self-reservoiring type, sandwich-like type, upper-generating and lower-reservoiring type, lower-generating and upper-reservoiring type, and source-reservoir interbedding type. Differences in the mechanism of charging, accumulation, and enrichment of tight oil among the five common source-reservoir assemblage types are revealed and explained. In addition, their accumulation and enrichment patterns are determined and principal controlling factors are proposed, namely, accumulation dynamics, charging patterns, and storage conditions, which are in fact closely related to the source-reservoir assemblage types.

中国石油—中国石油大学(北京)战略合作科技专项 ZLZX2020-01-6

https://doi.org/10.11781/sysydz202301001