The Sedimentary Environment And Microfacies Research Of Gaotaizi Reservoir In The Yingtuo Region

According to core,logging and seismic data,this paper divides all levels cycle.Based on the analysis of all levels cycle,taking the method of well pattern contrast and multiwell correlation,this paper establish isochronous time stratigraphic framework of Gaotaizi reservoir of Yingtuo region.Based on establishing isochronous time stratigraphic framework,the analysis of heavy mineral and the distribution characteristic of sand body,determining the qingshankou formation source direction is the northwest.Using the facies marks,such as the characteristics of petrology features,sedimentary rock structure types and geophysical well logging curve,this paper determine the sedimentary environment of Gaotaizi reservoir of Yingtuo region is braided river delta facies.The sedimentary environment of the first member of the Qingshankou For mation is prodelta of braided stream-braided delta front subfacies.The sedimentary environment of the second member of Qingshankou Formation is prodelta of braided stream-braided delta front subfacies.The sedimentary environment of the third member of Qingshankou Formation is braided delta front subfacies.The microfacies types are sheeted sand,mouth bar,underwater distributary channel,underwater distributary interchannel and prodelta.Based on determining the type of sedimentary facies and sedimentary microfacies,Combining with the data of exploratory well,this paper draw Sand bo dy thickness of the floor and sedimentary microfacies planegraph of single layer and drew many highly detailed studies of distribution characteristic of sand body and sedimentary microfacies.It Provide a reliable geological basis for the next step of oilfield development.At last,on the basis of drawing many highly detailed studies of distribution characteristic of sand body and sedimentary microfacies,this paper analyzing the effect of depositional system to the oil and gas accumulation pattern of pool-formingand predicting favorable areas of Gaotaizi reservoir of Yingtuo region.This paper analyzing the source rocks of Yingtuo region are low in maturity and are not capable of raw oil.The main oil source was Qingshankou Formation source rock of the eastern Qijia-Gulong depression.The sedimentary background of the Qingshankou Formation of Yingtuo region was braided stream delta front-lacustrine deposition.Frequent water retreats let the sealing rocks or cap rocks growth.The sand body of prodelta,distributary channel,mouth bar and sheeted sand is configured with NNE fault letting reservoir types of Yingtuo region are structure-lithology and lithology reservoir.According to Source direction of oil and gas,migration paths,the main control factor of the reservoir and prospecting data,this paper predicting favorable areas of Gaotaizi reservoir of Yingtuo region.The quantity of favorable of the first member of the Qingshankou was 2.The quantity of favorable of the second member of the Qingshankou was 3.The quantity of favorable of the third member of the Qingshankou was 3.