Seismic Reservoir Prediction Of Huangliu Formation In Y Area Of Yinggehai Basin

In recent years,large gas fields have been found in Yinggehai Basin.The sedimentary environment in the basin is complex,and gravity flow deposits are mainly developed.Submarine fan reservoirs are mostly developed secondarily.The lateral heterogeneity of the reservoirs is strong.Most of the reservoirs are small-scale sand bodies,which are limited by seismic resolution,making it more difficult to accurately predict the reservoirs.Based on 11 drilling and logging data and 500 km2 high resolution seismic data in the study area,this paper first establishes sequence framework,determines sequence classification level,and divides target strata into I and II gas groups.On the basis of petrophysical analysis,the geological-geophysical response of section I of Huangliu Formation in the study area is studied,which integrates seismic facies,seismic attributes and earthquakes under the guidance of forward simulation results.Inversion technology carries out reservoir prediction and favorable regional prediction research.This paper draws the following conclusions through research:(1)The sedimentary period of the first member of Huangliu Formation in the study area determines the basis for dividing the fourth-and fifth-order sequences,and divides the first member of Huangliu Formation into two fourth-order sequences and four fifth-order sequences.(2)The gas-bearing reservoirs of I and II gas formations in Huangliu Formation I of Yinggehai Basin are characterized by low natural gamma,low wave impedance and low density.Using natural gamma ray curve,resistivity curve and density curve,the gas-bearing sensitive curve is reconstructed.(3)Taking well Y-4 and well Y-5 as examples,the seismic facies in section H1 I and H1 II of Huangliu Formation I in Yinggehai Basin are classified by intercepting seismic profiles through wells.Four main sedimentary units are identified: confined channel configuration,confined multi-body configuration,non-confined multi-body configuration and non-confined multi-body configuration.(4)The inversion result profile(through Y-7,Y-3,Y-6,Y-2 wells)obtained from inversion of H1I?H1IIgas groups has high matching accuracy with the model,and there is a relatively thick low impedance area between Y-3 and Y-6 wells.In addition,according to the inversion results,the enrichment of sand bodies in different intervals is predicted.(5)By combining seismic multi-attribute analysis,inversion results and sand body characterization results,and connecting with stratigraphic structure,this study depicts favorable areas for different periods of H1 I and H1 II,totaling 7 sets.