Glutenite Reservoir Heterogeneity Study Of Upper Karamay Formation In Wu2Dong Area Of Karamay Oilfield

The frequent horizontal shift of sand bodies,complex superposition of the fan delta make it difficult for effective production.Taking upper Karamay Formation in Wu2 Dong area in Karamay Oilfield as an example,based on principles of sequence stratigraphy,reservoir geology,sedimentology,geostatistics,combining with core,well and sesimic data,the heterogeneity of the fan delta is fully researched.Combining the well and seismic data,based on the principles of hierarchy controlling,the interfaces of the 21 single layers in S1 to S5 are determined,and the results are examined and correlated by data from well pair.According to the sedimentary background,seismic data and horizontal distribution of sand bodies,it is concluded that the current orientation of the study area is northeast and northwest.Combining the data of grain sizes,lithofacies,sand ratio and well logs,the sedimentary facies of the study area is determined as fan delta,and microfacies are identified including braided distributary channel,underwater distributary channel,over bank,inter-channel and so on.The sedimentary model and distributary regulation are further determined.Combining the lab data and well log data,the internal and interlayer heterogeneity as well as horizontal and micro heterogeneity are characterized by statistical parameters.Lorenz parameters and entropy weight method are also used to calculate the heterogeneous parameters.It is concluded that there is strong inter layer heterogeneity between S1 supplement member and S5 main member.All the target members show strong in-layer heterogeneity.The contiguous mud interlayers are widely developed,and the physical and calcareous intercalations are less developed.Using the result of heterogeneity evaluation and production data,4 factors of heterogeneity to production is concluded,including pumping pressure,microfacies distribution,quality heterogeneity and reservoir sensitivity.The results provide guidance for production layer series and Injection-production measures adjustment.