齐荣 1朱峰 2何发岐 3姜龙燕 1尹超 1邵隆坎1
作者信息
- 1. 中国石化华北油气分公司勘探开发研究院,郑州 450006
- 2. 中国石化石油勘探开发研究院无锡石油地质研究所,江苏 无锡 214126
- 3. 中国石化华北油气分公司,郑州 450006
- 折叠
摘要
Abstract
The seventh member of the Triassic Yanchang Formation(Chang 7)in the Ordos Basin is abundant in shale oil resources.However,there are significant differences in reservoir characteristics between the basin margin and the basin center.Currently,research on shale oil reservoirs in the western Mahuangshan area at the basin margin remains insufficient,which has constrained shale oil exploration in this area.In this study,a detailed characterization of the shale oil reservoirs of Chang 7 member in this area was conducted using scanning electron microscopy(SEM),high-pressure mercury injection,low-field nuclear magnetic resonance(NMR),nitrogen adsorption,and micro-CT,combined with core observations and thin-section identification.Additionally,carbon and oxygen isotope and major and trace element analyses were conducted to investigate the development mecha-nism of high-quality reservoirs.The results showed that:(1)The shale oil reservoir in the Chang 7 member of the western Mahuangshan area is mainly composed of fine sandstone,siltstone,and mud shale.The mineral compo-sition is characterized by high contents of felsic and clay minerals,with felsic minerals generally exceeding 50%.(2)The reservoir exhibits diverse space types,and the pore development differs among lithologies.In fine sand-stone,intergranular pores and clay mineral intercrystalline pores are dominant,with pore sizes mainly distributed in the 1 to 2 μm range.In siltstone(mainly argillaceous siltstone),both inorganic pores and organic matter pores are developed,with dominant pore sizes near 3 nm and 500 nm.Mud shale is mainly composed of pores with organic-clay composites matter and microfractures,developed with pores below 10 nm and those in the range of tens of nanometers.(3)Analysis of reservoir physical properties and pore structure indicated that interbedded-type fine sandstone reservoirs represent the high-quality reservoir type.During compaction diagenesis,the porosity was reduced by approximately 26%to 33%.Hydrocarbon-generating fluids significantly modified the central parts of the sandstone bodies of reservoirs,and the current porosity generally exceeds 5%.In contrast,the edges of sandstone bodies and laminated-type reservoirs experienced substantial cement sedimentation,resulting in rela-tively poor physical properties.关键词
页岩油/储层特征/控制因素/三叠系/麻黄山西地区/鄂尔多斯盆地Key words
shale oil/reservoir characteristics/controlling factor/Triassic/western Mahuangshan area/Ordos Basin分类
能源科技
