This study represents the petrophysical evaluation of Bentiu Formation-Muglad basin, 
Diffra west oil field block (4) using well logs, A successful petrophysical interpretation for any 
hydrocarbon  system  still  motivates  the  researchers,  to  conduct  more  studies  to  discover  a  new 
productive zones as well as to sustain their continuity productivity.  
In this study petrophysical evaluation had been done for five wells using Interactive Petrophysics 
software  to  detect  the  petroleum  parameters  and  reservoir  characteristics  in  the  study  area, 
Focusing  on  Bentiu  formation  Evaluation  which  is  the  main  reservoir  at  this  part  of  Muglad 
basin manually compared with interpretation for all logs have been done to confirm the software 
results. 
Many  reservoirs  in  addition  of  many  determination,  water  cut  had  had  been  determined,  which 
were considered to be negatively affection on the future   production rates. The solution of this 
reduction impact was already proposed. 
Comprehensive  results  were  achieved  after  calculating  the  amount  and  distribution  of  shale 
throw  all  the  layers  of  Bentiu  Formation  using  single  curve  method  determination,  the  average 
porosity of Bentiu Formation about 15%, and average water saturation had also been determined 
by  62%  these  values  were  considered  to  be  very  compatible  with  the  characteristics  of  the 
reservoirs  but  some  different  cases  had  been  noted,  such  as  high  water  cut  in  Diffra1  about 
(93%) and in Diffra5 about (94%)