|
鄂尔多斯盆地H地区长8段致密砂岩储层成岩演化研究 |
Study on Diagenetic Evolution of Tight Sandstone Reservoirs of Chang 8 Member in H Area, Ordos Basin |
投稿时间:2025-05-06 修订日期:2025-06-13 |
DOI: |
中文关键词: 致密砂岩 储层特征 成岩演化 长8段 鄂尔多斯盆地 |
英文关键词: Dense sandstone Reservoir characteristics Diagenetic evolution Chang 8 Member Ordos Basin |
基金项目:陕西省科技厅自然科学基金项目“有机质类型及热成熟度对页岩层系生排烃过程孔隙演化约束机制研究”(2023-JC-QN-0320);陕西省教育厅科研计划项目“基于岩心可视化模型的页岩孔隙介质超临界CO2-水岩反应机理及物性演化规律研究”(23JK0595)。 |
|
摘要点击次数: 49 |
全文下载次数: 0 |
中文摘要: |
通过铸体薄片、扫描电子显微镜等多种测试和测井数据综合分析,H地区长8段储层以致密砂岩为主,岩石类型以长石岩屑砂岩和岩屑长石砂岩为主,石英含量高(>70%),结构成熟度中等。储层孔隙以原生粒间孔和混合粒间孔为主(>65%),整体呈低孔-特低渗特征(孔隙度均值10.81%,渗透率均值0.45mD),孔喉中值半径小(0.01~0.4μm),由研究区关键层位砂地比、孔隙度和渗透率等值线图可知潜在“甜点区”分布在该区砂体发育较好的河道中部。成岩作用研究表明,压实作用(孔隙损失35~45%)和胶结作用(碳酸盐、黏土矿物)是该区储层致密化主要因素,溶蚀作用(长石、岩屑溶解)形成次生孔隙但对渗透率改善有限。储层演化经历早成岩A期(绿泥石胶结保孔)→早成岩B期(有机酸溶蚀增孔)→中成岩A期(碳酸盐胶结致密化),原油充注与成岩作用交替进行。有效储层受孔隙度-渗透率-孔喉协同控制,但高产需结合其他因素分析。 |
英文摘要: |
Through comprehensive analysis of multiple tests such as cast thin sections and scanning electron microscopy, as well as well logging data, it is found that the Chang 8 section reservoir in the H area is mainly composed of tight sandstone, with feldspar lithic sandstone and lithic feldspar sandstone as the main rock types. The quartz content is high (>70%), and the structural maturity is medium. The reservoir pores are mainly primary intergranular pores and mixed intergranular pores (>65%), presenting an overall low-porosity and ultra-low-permeability characteristic (average porosity of 10.81% and average permeability of 0.45 mD). The median radius of pore throats is small (0.01 - 0.4 μm). From the isogram of sand-to-shale ratio, porosity and permeability of key layers in the study area, it can be seen that the potential "sweet spots" are distributed in the middle of the well-developed channel sand bodies in this area. Diagenetic studies show that compaction (35 - 45% pore loss) and cementation (carbonate, clay minerals) are the main factors for the tightness of the reservoir in this area. Dissolution (feldspar, lithic dissolution) forms secondary pores but has limited improvement on permeability. The reservoir evolution has gone through the early diagenesis A stage (chlorite cementation and pore preservation) → early diagenesis B stage (organic acid dissolution and pore increase) → middle diagenesis A stage (carbonate cementation and tightness). Crude oil charging and diagenesis alternate. Effective reservoirs are controlled by porosity-permeability-pore throat synergy, but high production requires analysis in combination with other factors. |
View Fulltext
查看/发表评论 下载PDF阅读器 |
关闭 |