旋回对比技术在河流相地层细分对比中的认识:以南美E油田白垩系储层为例  

Application of Cycle Correlation on Fluvial Stratum Division and Correlation in Cretaceous Reservoir,E Oilfield,South America

作　　者：徐睿[1] 

机构地区：[1]中石化石油勘探开发研究院,北京100083

出　　处：《地质科技情报》2015年第2期36-41,共6页Geological Science and Technology Information

摘　　要：河流相地层细分对比一直是个难点,目前主要使用的对比方法为基准面旋回对比和沉积旋回对比,两者一为动力成因,一为表现形式。基准面旋回对比具有较好的等时性,其中长期旋回和中期旋回可以通过沉积组合来识别,但短期旋回受到异旋回影响难以识别。在开展地层对比时,采用基准面旋回对比和沉积旋回对比有机结合、分层次逐级对比的方法,以最大洪泛面位置发育的分布稳定的泥岩为标志层划分油层组;根据砂体叠置样式划分中期旋回对应砂层组;在中期旋回约束下,充分考虑相变特征,以短期基准面旋回作为指导、以沉积旋回为重点划分小层。以南美E油田白垩系储层为例,采用此方法将储层划分为2个油层组,9个砂层组和50个小层。通过此方法划分的地层格架内砂体平面展布与工区背景物源方向基本一致,比较精准。Base level cycle correlation and sedimentary cycle correlation are always used for fluvial reservoir division but neither one is perfect.Actually,base level cycle is dynamic genesis of sedimentary cycle while sedimentary cycle is material expression of base level cycle.For base level cycle,secular-medium cycle boundary is stable but it is difficult to recognize short cycles because autogenetic cycles are developed in fluvial sedimentary system.For reservoir groups division,secular cycles could be divided under control of isochronous stratigraphic framework.For sand group correlation,medium cycles should be recognized by sedimentary assemblage.For small layer subdivision,it is more considerate to carry out the work by sedimentary cycle under control of isochronous stratigraphic framework,and erosion surfaces or lithological change also could be considered as identification mark.This method would be helpful to improve the correlation accuracy.With application of the correlation method in Cretaceous reservoir in E Oilfield,South America,the fluvial reservoir is subdivided into 2reservoir groups,9sand groups and 50 small layers.Further study on sand bodied correlation and dynamic analysis infers that the result of cycle correlation is relatively accurate.

关 键 词：基准面旋回对比 沉积旋回对比 河流相 

分 类 号：P512.31[天文地球—地质学]