陆表海碳酸盐岩台地沉积期微地貌恢复方法研究——以四川盆地磨溪气田嘉二~2亚段A层为例  

Research on the Method of Recoverying Microtopography of Epeiric Carbonate Platform in Depositional Stage:A case study from the layer A of Jia 2~2 Member in Moxi Gas Field,Sichuan Basin

作　　者：谭秀成[1,2] 聂勇[2] 刘宏[2] 周彦[2] 李凌[2] 赵路子 张本健[4] 冯钰[4,5] 

机构地区：[1]油气藏地质及开发工程国家重点实验室西南石油大学,成都610500 [2]西南石油大学资源与环境学院,成都610500 [3]西南油气田分公司勘探处,成都610051 [4]西南油气田分公司川西北气矿,四川江油621709 [5]西南油气田分公司川中油气矿,四川遂宁629000

出　　处：《沉积学报》2011年第3期486-494,共9页Acta Sedimentologica Sinica

基　　金：四川省重点学科建设项目(编号:SZD0414)资助

摘　　要：陆表海碳酸盐岩台地沉积期微地貌起伏差异小,难于确定。分析了沉积期微地貌控制着颗粒滩储层的发育及分布,因此,可通过对颗粒滩储层的研究,反演微地貌起伏。按此原理,建议具体研究步骤为:颗粒岩沉积为主体的等时地质体选取、储层成因确定、暴露时间确定、沉积期地貌恢复,以及成果检验应用。以四川盆地磨溪气田嘉陵江组嘉二2亚段A层为例,利用丰富的钻孔取心资料进行了实例研究,取得良好效果,表明该方法值得推广应用,尤其适用于钻探程度高、资料老、缺乏三孔隙度测井系列的盆地老区,这对于储层预测和新层挖潜具有重要参考意义。The microtopography difference of the epeiric carbonate platform in the depositional stage is so tiny,as a result, it is too hard to identify. This paper is then, firstly, mainly based on the development dominating factors of the grain shoal within the platform, and then points out that the microtopography highland tends to be beyond the wave base in the relative-regression stage,where the grain shoal develops. The depositional rate is higher than any other mi- crofacies area within the platform,hence,the topography difference was enhanced at that stage. Besides,after the sedimentation of the grain shoal, the grain-supported framework forms under the influence of physical compaction, where the compaction rate is much lower than the finer sediments,so the depositional thickness resulted from the topography difference of various microfaeies areas is also further enhanced,which shows that the grainstone thickness within a cer- tain period of time can be used, approximately,in recovering its microtopography prominence when it began to present, and that the compaction correction can be ignored when approximately recovering the microtopography within the platform at the depositional stage. It then further analyses the effects on the grain shoal construction and reservoir development by the exposure process during the depositional stage,and it divides the shoal within the epeiric platform into three genetic types：unexposed shoal,short-medium-term exposed shoal and long-term exposed shoal, meanwhile, pointing out that the method of grainstone gross-thickness which is used,approximately,in recovering the depositional palaeogeomorphology of epeiric carbonate platform is preferable for the unexposed and short-medium-term exposed shoals, where the main characteristics of the short-medium term exposed shoal can be concluded as follows（contrarily be long-term exposure ） ：①unconformity characteristic limited,palaeosol lacks;②irregular karren and corroded fissure lack;③intargranular solution extremely develops ; �

关 键 词：陆表海 碳酸盐岩台地 沉积期微地貌 颗粒滩 嘉陵江组 三叠系 磨溪气田 四川盆地 

分 类 号：P512.2[天文地球—地质学]