Research On Low Permeability Reservoir Characteristics Of Bannansha 3 2+3 Oil Group In Dagang Oilfield

Used the Sha three 2+3 oil group in southern area of Banqiao in Dagang oilfield as research destination,guided by the theories of sedimentary,sequence stratigraphy,reservoir geology,logging geology,based on the extensive literature research,according to macroscopic and microscopic observation about drilling cores,combined with kinds of analyses or test materials such as analysis of mercury intrusion capillary pressure,thin section observe,Logging identification and so on,this article has studied the characteristics of formation,sedimentary facies and reservoir in Sha three 2+3 oil group in southern area of Banqiao,analyzed main controlling factors,divided the reservoir level,forecasted the favorable block of reservoir distribution.The studies of formation and sedimentary facies indicate that Sha three 2 oil group is divided into two small layer and Sha three 3 oil group is divided into 9 small layer.Sha three 2+3 oil group development fan deltaic sediments,turbidite fan,lakes three depositional systems,the microfacies types include:fan delta the underwater distributary channels,fan delta underwater distributary channel between Bay and mouth bar,cloud the alluvial fan,shallow lake mud folder sandy sediments,the inherited sexual development of these depositional systems in Shasan during the deposition.Reservoir studies show that the Sha three 2+3 oil group in southern area of Banqiao main is lithic sandstone,followed by feldspar lithic sandstone.Most of the sandstones in the middle diagenetic A1 and A2,a few in the middle diagenetic stage B;,the diagenesis main types of compaction,cementation,dissolution and metasomatism four.Reservoir pore primary porosity and secondary porosity two secondary intergranular dissolved pores,intragranular dissolved pore and mold pore-based.Reservoir physical properties by sedimentary facies,rock composition and diagenesis three aspects,underwater distributary channel and turbidite fan is favorable sedimentary facies hydrocarbon accumulation in the study area,the dissolution affecting reservoir properties,is to improve the reservoir properties most critical factor.On the basis of research on the purpose of the study area layer Sedimentary facies and reservoir characteristics,reservoir pore morphological characteristics of the sand thickness,porosity,permeability,mercury intrusion curve characteristics,sheet and cast sheet division,the reservoir is divided into good reservoir(class ?),the general reservoir(class ?)and poor reservoir(class ?)three types of the study area reservoir ?,? class.Proposed the Bin 85 well to Ban 65 well area,Banshen 5-1 well area and Banshen 78-1 well area three favorable reservoir development areas.