The Study Of The Type And Evaluation Methods Of Low Resistivity Reservoir In B Work Area

As exploration extent advancing,low resistivity reservoirs were widely found in B work area.Low resistivity reservoirs are difficult to be identified in conventional log evaluation methods.Therefore,the study of low resitivity reservoirs is a effective way to understand the regional characteristics of low resistivity reservoir,which provides the foundation of correcting proved reserves in old wells,as we as evaluating reserves precisely in new wells.This study is of great significance for exploration evaluation,development plan and reserves calculation of low resistivity reservoirs in B work area in the future.After summarizing the characteristics of low resistivity reservoirs and high resistivity reservoirs,this paper concludes less than 2 as the regional resistivity index in B work area.It shows low resistivity reservoirs in B work area are found in delta front facies,under weak water dynamic condition.It is also concluded that high salinity of formation water and high shale content are considered as the main cause of the low resistivity reservoirs in B work area.Considering the main cause of low resistivity reservoirs in B area,shale-corrected Wyllie equation is used to calculate porosity,which is proved to improve the accuracy.Comparisons are made when it comes to fluid identification,which shows that neutron-density overlay technique and porosity overlay technique are proved as the best fluid identification methods in B area since they can semi-quantitative identify the fluid directly and correctly.Different saturation calculation models are adopted for different cause to improve the accuracy.Therefore,this paper concludes the techniques suit for low resistivity reservoirs in B work area.