Study On Sequence Stratigraphy And Sedimentary Microfacies Of The He8 Member In The Chao 30 Area,Sulige Gas Field

Sulige gas field is located in the north of ordos basin,Geological prospecting has been going on in this area since the Paleozoic era,The gas bearing layer exists in C2b?Pls and P1-2s,The Chao Well block district lies to the east of sulig.The main gas producing strata of the gas field in Pls and P1-2s,Among them,the eight sections of the lower stone box are the most important,Is the main research and development of the key block.The strata of the upper paleogas reservoir in the study area have typical continental fluvial sedimentary characteristics,which are remarkable in different periods,and the sand bodies overlap with each other in different periods,resulting in serious heterogeneity and difficulties in gas field development.Therefore,it is of great significance to study its sequence and sedimentary development characteristics.This thesis for gas east toward the Chao 30 in a he 8 segments,using sedimentology sequence stratigraphy method,based on the basis of predecessors'research results by observing the core using the comprehensive logging data such as data,the areas of single well sequence stratigraphy source and even well facies and sedimentary microfacies in sedimentary facies marks classification were studied,A high resolution sequence stratigraphic framework was established to characterize the plane and longitudinal distribution of sand bodies and sedimentary microfacies.Under the guidance of strata,and gradually identified as well as a sign of the lower reservoir sand formation interface,using cycle sequence and lithologic-thickness was method he 8 period of sand body of subdivision,From top to bottom,he 8 is divided into h8s1,h8s2,h8x1 and h8x2.in turn,create fine stratigraphic framework in the study area.Through the study of sandstone composition distribution and mudstone color,sedimentary environment water level changing reaction,water is often in the transformation between oxidation and reduction environment,can draw source direction from the northeast direction according to the characters of petrology characteristics of sedimentary structure granularity characteristics and logging facies marks,etc.The results of the analysis,judge the box of 8 period of development in the study area meandering river,can identify the channel flood plain dam and sedimentary microfacies such as swamp;The braided river is developed in the lower section of box 8,and sedimentary microfacies such as overland composite dam and overland can be identified,and the spatial distribution of sand body and sedimentary microfacies is described.On this basis,the sedimentary evolution model is established.