Research On Fracture Characteristics And Prediction Of Tight Sandstone Reservoirs In Badaowan Formation, Baka Area

Based on the current research achievements of Baka region,combining with the core observation,FMI interpretation,test and analysis,the seismic data,with the theoretical guidance of structure geology,oil geology and mathematical statistics,in this paper,the fracture development characteristics,imaging logging interpretation,the causes and main controlling factors of fractures in Jurassic sandstone of Baka region were studied,three different kinds methods were used to predict the fractures in this area,finally,carries on the comprehensive evaluation of fractures,on the basis of analyzing the fracture effectiveness,study the distribution of effective fractures.The following knowledge and achievements have been obtained in this thesis:On the plane,the faults in the Jurassic of the Baka region give priority to the near NWW direction,the plane combined styles of the faults include parallel-aligned,broom-like,skew-type;the reservoir lithology give priority to medium grained sandstone,secondly,is the fined grained sandstone and coarse grained sandstone,the porosity and permeability are small,the fracture system is the main reservoir space and seepage channel of the Jurassic reservoir of the Baka region,fractures characterized by medium scale,medium propagation(5?15cm),medium angle(>45°),varying width(<1mm),larger density(average of density is 0.2n/m?0.3n/m).The main orientations of the fractures in Jurassic of the Baka region are NWW direction,secondly is the NNE direction,the NNW direction and the NEE direction.There are two stages of fractures in the study area.The first stage is the NNW and NWW direction plane shear fractures and a few NW direction extensional fractures,The second stage is the NEE and NNE direction plane shear fractures and a few NE direction extensional fractures;there are two kinds of influencing factors of fractures in the Baka region,including external and internal factors.Based on the three different kinds methods to evaluate this area,on the plane,the fracture development zones are mainly distributed in Ke20?Ke23 well area,the high place of the footwall of the KEKEYA fault,the area between the well Ke22 to well Ke19,Ke34 well area,the area of south of Ke21,the slope area of west of Ke26,around Ke32 well area and Ke24 well area.The effective fractures mainly distributed along the south-north faults and the middle area of east-west faults,mainly distributed in well Ke22?well Ke 19?well Ke20,the north zone and around well Ke23,The favorable targets of fractures of the study area are the areas of well Ke22?well Ke 19 and around well Ke23.