Study Of Flow Field Characterization Of Gudong Oilfield In High Watercut Stage

Nowadays many old oil fields of China has entered the late stage and are in high water cut or even extra high water cut period.The distribution of remaining oil is highly dispersed as well as local centralized.Development of high permeability sandstone reservoirs in Shengli oil field have entered extra high water cut stage,however Multidisciplinary information indicates that the remaining oil still has considerable exploitation potential.However,long team water flooding worsen the heterogeneity of those reservoirs,and now there are strong and weak drive parts in current reservoir,leading to an even worse displacement difference.Therefore,in order to further improve the water flooding recovery,it is very urgent to carry on the study of flow field characterization in extra high water cut stage,which can provide the further development of reservoirs with guidance,and it has broad application prospects.In this paper,the characteristics of remaining oil distribution at high water cut period and problems of flow field characterization are defined based on the development features of Gudong oil field,and investigations are focused on the characterization methods on the flow field during extra high water cut stage.Firstly,static factors and dynamic factors of Gudong oilfield and their influence on flow field are analyzed.The surface flux was chosen as the only one index of flow field based on the screening principles and logical analysis method.The accuracy of surface flux are proved from static factors and dynamic factors.the flow field strength is determined depend on the reasonable membership function,The optimal number of classification and the standard for flow field level are determined by the fuzzy C-means clustering methods and clustering validity analysis,which can provide guidance to the flow field reform and polices of tapping potential.In this paper,we identified the definition and properties of flow field,and the surface flux is chosen as the only index of flow field.Besides,the strength of flow field and the field level are determined by ring type membership function and the fuzzy C-means clustering,respectively.Finally the flow field evaluation system is established,which can be used to analysis the laws of remaining oil distribution under different flow field level.It is proved that the flow field evaluation system has broad practicability and guidance by verifying two typical block of Gudong oilfield.The establishment of theoretical system of flow field lay the foundation for the development of flow field reform and parameter time-variance numerical simulation technology.