松辽盆地古龙地区青山口组泥页岩成岩演化与储集性能

The diagenesis evolution and accumulating performance of the mud shale in Qingshankou Formation in Gulong area,Songliao Basin

泥页岩成岩演化、孔隙结构及其连通性是页岩油储层评价的关键。通过运用岩心观察及精细描述、薄片鉴定、X射线衍射、场发射电镜、微—纳米CT扫描、氮气吸附等技术,对松辽盆地古龙地区青山口组泥页岩岩性与组构特征、成岩演化特征、孔隙类型及储集特征进行分析。研究认为:古龙地区青山口组主要发育页岩、泥岩、粉砂质岩、灰质岩、云质岩5种岩性,微米—毫米级纹层构造与页理缝发育;泥页岩主体处于中成岩A2期,局部为中成岩A1期和中成岩B期;储层孔隙分为基质孔和裂缝2大类6类12亚类,纹层状页岩中的纹层构造、页理构造和层状页岩、纹层状页岩中的页理缝有效改善储集能力,为油气横向运移的良好通道,层状页岩和纹层状页岩是最有利的储集岩性。该研究明确了松辽盆地古龙地区青山口组泥页岩成岩演化规律与储集特征,为松辽盆地页岩油的规模勘探提供了有力支撑。

Shale diagenesis evolution,pore structure and their connectivity are the key to the shale oil reservoir evaluation.With the help of the following techniques:core observation and fine characterization,thin section identification,X-ray diffraction,field emission electron microscopy,micro-nano CT scanning,nitrogen adsorption and so forth,the characteristics of the lithology and fabric,diagenetic evolution,pore type and accumulating performance were studied in Qingshankou Formation mud shale in Gulong area,Songliao Basin.The studies show that 5 kinds of lithology are mainly well-developed in Qingshankou Formation in Gulong area,including shale,mudstone,silty rock,calcareous rock and dolomitic rock with micro-millimeter scale laminated structure and shale bedding fracture.The mud shale is mainly in the middle diagenetic stage A2,and the local shale is in the middle diagenetic stage A1 and middle diagenetic stage B.The reservoir pores are divided into matrix pores and fractures,including 2 big classes,6 classes and 12 sub-classes,and the laminated structure and lamellation structure developed in the laminated shale and the shale bedding fractures in the layered shale and laminated shale can effectively improve the reservoir accumulating capacity,so they are the most favorable accumulating lithologies and can provide the good channels for the lateral migrations of the oil and gas.The studies have made clear of the diagenetic evolution laws and accumulating characteristics of the mud shale in Qingshankou Formation in Gulong area,Songliao Basin,which provide the favorable support for the scale exploration of the shale oil in Songliao Basin.