摘要
随着油气勘探的逐渐深入,致密低渗油气藏所占比例越来越高,将是今后油气勘探的一个重要领域。颗粒成分不同导致的成岩差别对致密低渗储层的储集物性具有明显的控制作用。本文以鄂尔多斯盆地上三叠统延长组长8-长6段致密砂岩为例,研究砂岩骨架颗粒、孔隙类型与成岩作用之间的关系。在此基础上,分析由不同类型母岩形成的砂岩成岩作用差别。结果表明,鄂尔多斯盆地长8-长6段物源对砂岩成岩作用具有非常明显的控制作用:(1)石英、长石等刚性颗粒的含量直接影响着压实作用的强度;(2)火山岩屑可以导致绿泥石环边和浊沸石胶结物的形成,火山岩屑和浊沸石胶结物的溶蚀较强,易形成次生孔隙;(3)黑云母可以导致强压实形成致密层,但黑云母水解可以提供大量的铁和镁,利于绿泥石环边的形成;(4)碳酸盐岩岩屑的溶解可以为碳酸盐胶结物的形成提供额外的物质来源。所以,物源研究可以有效地预测深层致密碎屑储层的成岩作用及成岩强度,进而对高效储层的发育作出预测。
Tight lithologic reservoirs occupy an increasing percentage with development of petroleum exploration, and will be an important exploration target in the future. Diagenesis resulted from varied grain compositions exerts a strong control on the quality of tight siliciclasfic reservoirs. This paper stud-ies the relationship among framework grains, pore types and diagenesis in the upper Triassic Chang 8 to 6 members in the Ordos basin, and analyzes the di-agenesis differences resulting from various kinds of provenance. The results show that the diagenesis is controlled significantly by the source rocks of Chang 8 to 6 members in the basin. （ 1 ） Rigid framework grains,like quartz and feldspars,have crucial influences on mechanical compaction. （2） The formation of laumontite and chlorite coats cement is controlled by volcanic rock fi＇agmcnts largely,and the dissolution of volcanic rock fragments and laumontite ce-ment can ibrm secondary pores. （ 3 ） The hydrolyzation of biotite can offer abundant iron and magnesium favorable for the formation of chlorite coats,while biotite can result in extensive mechanical compaction because of ductile deformation. （4） Dissolution of carbonate fragments can offer additional material for forming carbonate cement. Therefore,studies of provenance can help to forecast dlagenesis for deeply - seated tight siliciclastic reservoirs.
出处
《地质与勘探》
CAS
CSCD
北大核心
2013年第2期384-392,共9页
Geology and Exploration
基金
国家自然科学基金项目松辽盆地松科1井碎屑岩埋藏过程中的成岩事件及水岩反应机理(40972098)
博士后基金项目碎屑岩地层中大气淡水淋滤形成次生孔隙的识别标志(2012M511941)联合资助
关键词
成岩作用
物源
储层
延长组
鄂尔多斯盆地
diagenesis, provenance, reservoir, Yanchang Formation, Ordos basin
