Reserve Evaluation Of The Non-producing Area Of Wuerhe 2+3 Segment In Lower Wuerhe Reservoir Of District No.8

As the Xinjiang oilfield annual production scale largest reservoir,Lower Wuerhe Reservoir of District No.8 in Karamy's early water-flooding development is poor.The type?reservoir with a large thickness is developed in the Wuerhe 2+3 Segment of the lower plate of the 256 fault.Considering that there are non-producing intervals in Lower Wuerhe Reservoir,areas on the plane that are not controlled by the well pattern,Reservoir also has potential for further utilization of horizontal wells for production.so The reserve evaluation of the unused area of Wu2+3 Segment of the Lower Wuerhe Formation reservoir in the eight districts was carried out.By comprehensive analyzing of core data,seismic data,logging curves and other related data in non-producing area,Using various methods to study the stratigraphic,sedimentary,structural,and reservoir characteristics of Wuerhe 2+3 Segment in the study area,we conclude the following conclusions.Wuerhe 1 to Wuerhe 5 Segments developed in the study area,Wuerhe 2+3 Segment gradually thickened from south to north,from 240m to 360m.Lower Wuerhe Formation is a fan delta,Wuerhe 2 Segment and Wuerhe 3 Segment mainly develop fan head deposit and middle desposit.The fan head mainly develops near the South Baijiantan fault,and the middle desposit continuously distributed in the southern and central regions.The newly explained east-256-well fault is reliable,and the extension length on the plane is larger which play an extremely important role in oil and gas accumulation in the study area.Reservoir lithology is dominated by glutenite and sandy small conglomerate.Interstitials are mainly analcite,calcite and volcanic dust.Pore types are mainly intergranular pores and zeolite dissolved pores,and the cementing types are mainly press-fit and contact-porous.The overall pore permeability of the reservoir is poor that it is a conglomerate low porosity and ultra-low permeability reservoir.The physical properties of the Wuerhe 3Segment are slightly better than that of the Wuerhe 2 Segment.The comprehensive performance of the reservoir is strong heterogeneity with low porosity and ultra-low permeability,weak-medium weak sensitivity,medium-strong hydrophilicity.Type of the formation water is sodium bicarbonate.After clarifying plane distribution of reservoir thickness,we use volume analysis method calculating the oil in place of Wuerhe 2 Segment and Wuerhe 3 Segment which totally 3001.26×10~4t.The vertical reserves are mainly concentrated in Wuerhe 3 Segment,accounting for 78.8%of the geological reserves of the entire research area,and the overall recovery is low.The abundance of remaining geological reserves in Wuerhe 2 Segment is near the small well distance in the south and near the fault in the north.Wuerhe 3 Segment has a large abundance of remaining geological reserves in the southern part of the unused area,the northern fault clamping area,and the northern large well spacing area.On the whole,it has good development adjustment potential and benefits.