Sduty Of The Sedimentary Facies And Reservoir Characteristics For Shanxi Formation In Su76, Su77Area, Sulige Gas Field

This thesis selects Shanxi formation as studied object,which sit in the north of Su76, Su77Area in Sulige gas field in Ordos Basin.Using the theory of sedimentology、petroleum geology and geophysics,combined with regional geological data, cores,flakes and logging data,we try to study the sedimentary micro-facies and Reservoir Characteristics of Shanxi formation. The following results and understanding are got:1. Shanl section and Shan2section in study area deposited during structure uplift, so braided river which vertical erosion is greater than the lateral erosion is its main sedimentary face. According to the profile structure features, it can be divisioned into fluvial subfacies and flooding subfacies, and its micro-facies contain channel bar flooding plain、natural levee、peat swamp and so on. Carrying out a detailed studying of sedimentary micro-facies in the depositional system,setting up a deposition model for it. Arenaceous channel bar and arenaceous conglomeratic channel bar in braid channel is the most important reservoir sands of this area at the target formation.2.Systemly studied reservoir characteristics of Shanxi formation:rock type of reservoir sands, Which Mainly Include quartz sandstone、lithic quartz sandstone and lithic sandstone. From the physical property on look, reservoir petrophysical property changes greatly. Porosity by5-10%give priority to, The biggest porosity can reach20.17%.Permeability by0.1—1mD give priority to, The biggest permeability can reach34.02mD.The pore types of the sandstone of reservoir in study area comprised primary intergranular pores, intergranular corrosion pores, secondary pores. According to physical parameters,reservoir sand of porosity and permeability is positively correlated. Sandstone reservior of study area mainly are especially low porosity and reservoir with extremely low permeability.3.The reservoir physical properties are mainly controlled by sedimentation, sedimentary fabrics,diagenesis. Different sandstone types,fabrics have obviously effect on physical property.With the high content of quartz and coarse grain,the physical properties become better.The important diagenesis of effecting reservoir quality is compaction,agglutination and dissolution. Some of them are destructive, some are constructive.4.The favorable prospect areas of Shanxi formation were predicted,combining with the research results of sedimention and reservoir, according a forecast and screen. The study results are useful to provide important geologic data for oil and gas exploration and further development of Shanxi formation in Sulige gas field, provides a powerful guarantee for productivity construction of Sulige gas field.