Study On Characteristics Of Sedimentary Facies At Xishanyao Formation Of Block Ha Qian 20-22 In Allard Oil Field

Allard oilfield in junggar basin is one of the important exploration targets.Based on the Aallard oilfield Ha Qian 20-22 block for research purpose,from the block have some problem of a few Wells were drilled in the study area,the low degree of research,the study of sedimentary facies,sand body distribution is not clear,and carried out fine stratigraphic correlation,sedimentary facies and reservoir characteristics research,then carry out favorable reservoir evaluation within the study area(block: Ha Qian 20-22).At the outset,focuses on the study of the fine sedimentary facies by the comprehensive application of sequence stratigraphy,reservoir geology and sedimentology and based on previous researches,used the "sediementary cycle comparison,classification control" as the principle,we carried out small segmented layers with careful comparison.The results reveals that the study area developed into two second-order sequence interface and a third-order sequence interface.On the basis of these interpretations we divided into three sand layers.Secondly,on the basis of stratigraphic division and correlation,the comprehensive utilization of core,thin section,well logging and seismic data,conduct the study of sedimentary microfacies in the reservoir.In based on the analysis of the regional sedimentary background,from the perspective of the core observation,through the research of sedimentary facies marks,think that the period from the study area for the fan delta facies,Xishanyao formation second and third stages in braided river delta deposition.Fan delta facies of Xishanyao set further subdivided into five main microfacies:(1)channel and flood plain,(2)braided channel,(3)distributary bay,(4)mouth bar and(5)sheet sand microfacies.Xishanyao formation second and third stages in braided river delta facies divided into braided river delta plain and braided river delta front subfacies,that are further subdivided into(1)flood plain,(2)braided river channel,(3)distributary bay,(4)mouth bar and(5)sand sheet between the sedimentary microfacies.And then carried out in 4 Wells single well facies analysis,2 profile phase contrast analysis,and 4 phase plane analysis,confirmed the small layer of sand body distribution characteristic;And the period of fan delta and from the established two period,three period of braided riverdelta sedimentary facies model.On the basis of the above research,through reservoir lithology,pore types,physical property and oil content research,combined with the layers of different sedimentary microfacies of sand body distribution,carry out the favorable reservoir evaluation of the Xishanyao formation.