定量荧光技术在页岩油储层研究中的应用——以准噶尔盆地玛湖凹陷二叠系风城组为例

Quantitative fluorescence techniques and their applications in shale oil reservoir research: a case study of Permian Fengcheng Formation in Mahu Sag, Junggar Basin

  • 摘要: 准噶尔盆地玛湖凹陷二叠系风城组页岩油储层具有源储一体的特征,其形成过程受沉积环境、成岩作用和有机质演化等多种因素的影响,导致其烃源岩性质和储层特征异常复杂。目前,无机矿物发育和有机质演化对储层或赋存页岩油性质所造成的影响尚不明确。针对上述问题,将已经广泛应用于常规储层研究的定量荧光技术,如储层萃取液定量荧光分析技术(QGF-E)和全息扫描荧光技术(TSF)等拓展到陆相页岩油储层研究中。将QGF-E和岩石热解相结合发现,热解参数游离烃(S1)与QGF-E强度呈正相关,且变化范围较大,说明含油饱和度的大小主要受S1的控制;TSF分析揭示,在其他检测条件相同的情况下,归一化的TSF光谱最大强度与二维核磁实验结果共同表明,页岩油密度(API)的差异与黏土矿物吸附的含羟基的重质组分密切相关,且黏土矿物含量越高,能够吸附的有机质越多;原油成熟度指标(R1)进一步说明了原始沉积背景下,生烃母质的差异以及成岩改造后孔隙类型以及结构特征是影响储层中页岩油性质的关键因素。这些研究技术和方法可以作为沟通不同参数之间的“桥梁”,有助于进一步认识页岩油储层特征,为后续非常规油气的勘探开发提供参考。

     

    Abstract: The shale oil reservoirs of the Permian Fengcheng Formation in the Mahu Sag of the Junggar Basin are characterized by a source and reservoir integration. Their formation process is affected by various factors, including sedimentation, diagenesis, and organic matter evolution, resulting in highly complex source rock properties and reservoir characteristics. Currently, the effects of inorganic mineral development and organic matter evolution on reservoir and shale oil properties remain unclear. To address these issues, this study extends the application of quantitative fluorescence (QF) techniques, which are widely used in conventional reservoir research, to continental shale oil reservoirs. Techniques such as quantitative grain fluorescence on extract (QGF-E) and total scanning fluorescence (TSF) were utilized. By combining QGF-E analysis and rock pyrolysis, it was found that free hydrocarbon (S1) was positively correlated with QGF-E intensity, and their variation range was significant. This indicated that oil saturation was mainly controlled by S1. Under the same testing conditions, the normalized TSF spectra's maximum intensity and two-dimensional nuclear magnetic resonance (2D NMR) experimental results showed that the differences in shale oil density (API gravity) were related to the adsorption of hydroxyl-rich heavy organic matter by clay minerals. Higher clay mineral content was found to adsorb more organic matter. The crude oil maturity index (R1) further indicated that the differences in bio-precursors under the original depositional environment and the variations in pore types and structures after diagenetic alteration were key factors affecting the properties of shale oil in the reservoir. These analytical techniques and methods serve as a bridge connecting different parameters, facilitating a deeper understanding of the characteristics of the shale oil reservoir and providing valuable references for the exploration and development of unconventional oil and gas resources.

     

/

返回文章
返回