Study On Sandstone Migrating System In The Upper Palaeozoic Group Of The Daniudi Gas Filed

In this thesis, by the use of drilling core, formation test, well logging, laboratory analysis and extensive literature, based on the analysis of regional geological background, we analyzed the sand body as a migration system located in the upper Paleozoic group in the Daniudi gas field systematically. Firstly, we carry on the research of the sand body migration efficiency from the marco to micro. And then based on the direction of gas migration we summarize the types of the sand body migration system and predict advantaged migration areas in the Daniudi gas field.Based on the analysis of geological background and sequence stratigraphy, we study the sand body genetic types which include riverbed ,gritty channel bar, coarse sand point bar, braid distributary channel and barrier bar reservoir sands.The distribution of the sand body and the connectivity of them showe the Taiyuan Formation was controlled by barrier flat, sandstone is not developed,Dominated by vertical stacking of sand bodies;Shanxi Formation was offshore delta deposition,sand body large area of devwlopment,the overall north-south trending sand bodies to the main vertical stacking and assembly stacking;Xiashihezi Formation deposit alluvial plain-anastomosed stream-snaking stream,He1 and He2 development sand bodies,He3 is not developed,the overall north-south connectivity to the sand is better than the east-west.He1 to the main vertical stacking and assembly stacking and He3 is dislocation to the main.Sand migration capacity of the sand body was influenced by diagenes, physical poroperties of sandstone and fractures. Ccompaction and cementation are the main factors that lead the sandstone tight. Solution, replacement and alteration improve the migration capacity of sand, particularly, the development of fractures greatly improve the performance of migration in sand body. By analysis of Diagenesis sequence in Daniudi gas field, the migration capacity in the current is the as the period of petroleum accumlation. On the background of the tight sandstone, By analyzing the the plane distribution of the sand body physical properties, we conclude that the sand body having high porosity and permeability is the important channel for oil and gas migrating. Summarizeing the migration system types are sand system and fracture network+sand system in the Upper Palaeozoic of Daniudi gas filed.Xiashihezi formation He3 and He2 the main system are the fracture network + sand migration system;Taiyuan formation,Shanxi formation and He1 the main system are the sand migration system.By analyzing the direction of gas migration,atypical gas reservoir analysis,research the conditions of the effectiveness of migrate oil and gas,predicter the favorable zones of oil and gas distribution.