Study On The Type And Distribution Of Sand Micro-facies Of The Toutunhe Formation In Block 4 Of Central Junggar Basin

The reservoir types of the Toutunhe formation in block 4 of central Junggar Basin are mainly dominated by lithologic traps,so the distribution of sand bodies has become an important reservoir-control factor.Through the study of this paper,the meandering river channel,delta diversion channel and Binhai shallows beach dam are the main types of sand body microfacies in the Toutunhe Formation.It is determined that the vertical direction(from bottom to top)of the study area is in line with the lake sedimentary evolution sequence of “Beach shallow beach dam – delta front – delta plain – meandering river”.Longitudinal fine-scale calibration of sand bodies and seismic sand body sections were used to explore the longitudinal and planar distribution of sand bodies in different intervals.In the longitudinal study of the sand body,due to the generally low-speed characteristics of the river sand bodies in the work area,coupled with the analysis results of the “de-sanding experiment”,the sand bodies of the 10 wells were longitudinally finely portrayed.The accuracy rate is close to 90% and it has a very good application effect.In the study of the plane distribution of the sand body,the sand body was longitudinally finely scribed and the sand body slice and the stratum slice were made to jointly analyze and predict the plane distribution of the sand body.Beach shallow beach dam sand body and delta front sand body are concentrated in the first section of Toutunhe Formation.The delta front sand body and delta plain sand body are concentrated in the second section of Toutunhe Formation.The delta plain sand body and meandering river sand body are concentrated in the third section of Toutunhe Formation.Finally,the distribution regularity of sand bodies in the Toutunhe Formation in the construction area and the development patterns of different micro-facies sand bodies are summarized.