Structural Interpretation And Reservoir Prediction Of Jurassic Reservoirs In Aryskum Oilfield

Aryskum Oilfield is located in the South Turgay Basin in Kazakhstan and discovered in September 1986.At present,the large-scale structure in the oilfield have been studied and it has entered the stage of exploring complex small structures and lithologic reservoir.In order to better excavate reservoir potential,it is necessary to explain the structure of the target layer?J₃ak and J₂kr?in detail,and to predict the favorable targets of reservoirs.In this study,the structure,sand body and hydrocarbon distribution of J₃ak and J₂kr are explained in detail,and the favorable hydrocarbon-bearing targets are predicted,which provides a basis for the Aryskum oilfield to increase production capacity.In the study,the logging lithology and fluid identification models are built with Boosting Tree algorithm by using the logging data and the logging and oil test results,then the models are used to predict lithology and fluids of each wells and it achieved satisfactory results;then the Jurassic reservoirs are divided into small layers and the small layers was calibrated on the seismic section according to the logging interpretation results;then we explained the large structure and the secondary fracture of the target layer by utilizing coherent body technology;by establishing the forward model,the seismic reflection characteristics of different geological models are obtained to establish the pattern of lithologic trap on the seismic data;the seismic amplitude is used to predict the lateral distribution of the reservoir.Finally,the favorable oil and gas targets are predicted.According to the structure explanation result,a series of NE-trending pinante faults are derived from the northwest-south strike-slip fault.The west side of the main fault is gentle and the eastern side is steep.According to the sand explanation result,J₃ak is river sedimentation and the sand dam is represented by a“sick”reflection on the seismic section.Its oil&gas is controlled by the river sand distribution;J₂kr is turbidite delta front deposit and the distribution of sand bodies is mainly"seat"and"lens".The oil&gas is controlled by secondary faults and lithology.What's more,this study identified well lithology and reservoir fluid properties by utilizing a new method named Boosting Tree algorithm,which not only improves the interpretation efficiency but also achieves satisfactory results.