The Residual Oil Research Of Ling 2 Block In Qiuling Oilfield

Ling 2 Block of Qiuling Oilfield has entered the development stage of extra-high water cut stage,the flooding degree of the reservoir is high and recovery degree of the recoverable reserves are more than90%.At the different stages of development,the object and scale of the residual oil research are different.In recent years,the development practice shows that the residual oil distribution pattern of the target block at this stage is "the overall height is scattered and the local relative enrichment".The key of the study depends on how to find the enrichment in the "dispersion".In this paper,due to the complex geological structure of the target block and the high degree of flooding,four aspects of research work are carried out from the reconstruction of underground geological understanding system: fine structure and fracture system research,single sand body fine characterization study,secondary interpretation and evaluation of logging and comprehensive study of residual oil.The results show that there are three main types of the residual oil in Ling 2 Block: that can not be controlled by the well pattern,that from imperfect injection and production,and that blocked by fault.The recovery degree of the main single sand is 25 to 27%,and non-main single sand just only 17%.The flooding degree of the main single sand is higher,the residual oil here is scattered as a dotted distribution,in the form of residual oil in the layer,and the movable oil saturation is about 10 ~ 15%.In the vicinity of the reservoir,near the fault and the imperfection area of the well pattern,there is still a large amount of remaining oil distribution,where the oil saturation is above 55% on average,even over 65% in some areas,these are the potential focus of the next step.