摘要
为明确纹层发育程度对页岩储层的影响,以渤海湾盆地东营凹陷沙四上—沙三下亚段页岩为研究对象,采用岩心观察、铸体薄片、扫描电镜、高压压汞和低场核磁共振等方法,分析不同岩相页岩的储集空间类型及孔隙结构特征,研究页岩纹层发育程度对储集空间及渗流通道的影响因素。结果表明:渤海湾盆地东营凹陷沙四上—沙三下亚段页岩油储层的储集空间类型由孔隙及裂缝组成,其中孔隙类型主要为粒间孔、粒间微缝、晶间孔和溶蚀孔,裂缝包括层间裂缝、异常压力裂缝和构造裂缝;纹层状页岩的孔隙结构为大孔细喉型,层状页岩的孔隙结构为中孔中喉型;纹层状页岩T_2谱呈“三峰”特征,层状、块状页岩T_2谱主要呈“双峰”特征,纹层状页岩样品孔裂隙发育好于层状、块状页岩样品的;纹层发育程度一方面影响页岩储层的孔隙度,页岩的纹层越发育,孔隙度越高,含油性越好;另一方面页岩纹层改善页岩储层的渗流能力。该结果为渤海湾盆地东营凹陷沙四上—沙三下亚段页岩油勘探开发提供参考。
To investigate the influence of lamination development on shale reservoirs,this study takes the shales of the Upper E s 4 and the Lower E s 3 in the Dongying Sag of the Bohai Bay Basin as an example.Through experiments including core observation,casting thin section,scanning electron microscopy,high-pressure mercury intrusion,and low-field nuclear magnetic resonance,the study analyzed the storage space types and pore structure characteristics of different lithologies in shale and researched the factors affecting storage space and seepage channel caused by lamination development.The results show that the storage space types of the oil reservoir in the studied shale are composed of two parts:pore and fracture.The pore types mainly include intergranular pores,intergranular fractures,intercrystalline pores,and dissolved pores,while the fractures include interlayer fractures,abnormal pressure fractures,and structural fractures.The pore structure of the layered shale is characterized by medium pores and throats,and the pore structure of the laminated shale is characterized by large pores and small throats.The T 2 spectrum of the laminated shale shows a“triple peak”feature,while the T 2 spectrum of the layered and blocky shale samples mainly shows a“double peak”feature,indicating that the pore and fracture development of the laminated shale samples is better than that of the layered and blocky shale samples.The degree of lamination development affects both the porosity and the oil content of the shale reservoir.The more developed the lamination,the higher the porosity and oil content of the shale,and the bedding also improves the seepage capacity of the shale reservoir.These results provide a reference for oil exploration and development in the Dongying Depression of the Bohai Bay Basin.
作者
窦伟
孙丕臣
欧阳哲远
张贝希
王海超
DOU Wei;SUN Pichen;OUYANG Zheyuan;ZHANG Beixi;WANG Haichao(Xinjiang Key Laboratory for Geodynamic Processes and Metallogenic Prognosis of Central Asian Orogenic Belt,Xinjiang University,Urumqi,Xinjiang 830047,China;School of Geological and Mining Engineering,Xinjiang University,Urumqi,Xinjiang 830047,China;CBM Engineering Technology Research Center,Xinjiang University,Urumqi,Xinjiang 830047,China)
出处
《东北石油大学学报》
CAS
北大核心
2023年第4期14-28,106,I0002,共17页
Journal of Northeast Petroleum University
关键词
纹层
页岩油
储集空间
含油性
渗流通道
沙河街组
东营凹陷
渤海湾盆地
lamina
shale oil
reservoir space
oil-bearing capacity
seepage channel
Shahejie Formation
Dongying Depression
Bohai Bay Basin
