Sedimentary Features And Favorable Sandbodies Prediction In The Third Member Of Funing Formation Of Huazhuang Oilfield

For the characteristics of super-low-permeability reservoir in the third member of Funing formation of Huazhuang area,The study started with the high resolution stratigraphic correlations of 105 wells of Huazhuang oilfield.Based on the result of structure interpretation,sedimentary micro-facies feature,reservoir feature,comprehensive reservoir evaluation and production performance,the favorable targets had been determined,and the following conclusions had been obtained:(1)The regional maker beds and sedimentary cycle feature of each sub-layer in the third member of Funing formation of Huazhuang oilfield has been identified by the high resolution stratigraphic correlations.The stratigraphic classification plan and subdivision plan had been worked out.The main oil-bearing sandbodies had been filtered out,and it shows thin sand-shale interbed series,and high degree of heterogeneity.The favorable reservoir is mainly distributed in the mid-bottom of the E1f31 and E1f32.(2)The sedimentary micro-facies distribution feature of 14 main sub-layers had been worked out by the analysis of single well,section and plane facies.Seven of these developed relatively thicker and extended underwater distributary channel sandbodies,and the channel developed shorter in the other sub-layers.The main channel area shows inherited in vertical.(3)By analysis the correlation of the deposit feature and hydrocarbons enrichment regularity.The sedimentary micro-facies is the main factor of the favorable sandbodies distribution.The main channel area show great development potential,but the mouth bar and sheet sand are relatively lower.(4)The sandstone reservoir of this area is characterized by medium-low porosity and super-low permeability in the third member of Funing formation.The micro-pore structure study shows the low throat pore coordination number and thin throat.The permeability of channel is much better than the others.(5)The main diagenesis is strong compaction,cementation and solubility.The overall poor reservior caused by the compaction and cementation,but the relatively good reservoir is affected by the solubility and microfracture.The diagenetic facies had been classified into 2 two major categories and subdivided into five categories in the third member of Funing formation.(6)The prediction of favorable sandbodies distribution had been worked out by the study of reservoir characteristic.In the certain part area of Hua32,Hua22 blocks,it developed great reservoir according to the result of deposit study,and it's the favorable area of progressive exploration and development next.