Tectonic Interpretation And Geological Modeling Of Deng-3 In S Block,Shuangcheng Area

Block S is located in Shuangchengnan Sag in the southeast fault depression of the northern Songliao Basin.Only in recent years has exploration breakthrough been made in the third member of the Deng-3 Formation in this area.As the new strata in the old area,the drilling data are relatively few,and the structural characteristics and reservoir distribution of the study area are still unclear.In order to meet the needs of exploration and development,the structural interpretation and geological modeling of the third member of Dengshan Formation are studied in this study area.The fault of Deng3 member in S block is well developed.Due to the influence of seismic data quality and lithology,the continuity of the in-phase axis of reflection of the target layer is poor,the phase is unstable,the amplitude varies greatly,and it is difficult to trace and interpret the seismic horizon.Guided by structural geology and based on the well seismic characteristics of the target strata,this study uses the hierarchical and stratified structural interpretation method to complete the interpretation of the top surfaces of the three sand formations(D?1,D reservoir1 and D reservoir 1)in the third member of Dengjie Formation.Starting with the fault section interpretation,assisted by the coherence volume,time slice and other attributes,the full three-dimensional interpretation of 112 faults was finally completed.Based on the time-depth relationship and the seismic horizon as the constraint of the tectonic trend,the spatial velocity body was established,and finally the structural map of the top surface of the three horizons in the study area was obtained.The average relative error of the reserved post-test Wells was less than 0.3%,which met the research requirements.Based on the results of structural interpretation,sedimentary facies analysis,lithology interpretation and reservoir parameter interpretation,3D geological modeling was carried out using Petrel software.On the basis of fault spatial interpretation and constrained by fault polygons,the spatial positions and intersections of each fault are defined,and a three-dimensional fault model is established.Based on the three tectonic planes and the drilling geological stratification,a structural model of 25m×25m×0.2m with an accuracy of25m×0.2m was established for the third member of the Dengshan Formation,which reached the level of sedimentary units.The deterministic modeling method was selected,combined with sedimentary facies diagram and lithology interpretation,the sedimentary facies model was established,thus indicating the spatial distribution direction and development situation of sand body.Guided by stochastic modeling theory and variation function model theory,the reservoir physical property model is established under the control of phase control model.On the basis of the completion of the attribute model,the volume method is used to predict the petroleum geological reserves in the study area.The calculation error between the predicted results and the 2019 delivery storage report is within 5%.It shows that the model has a high precision,which can provide basic geological data for numerical simulation research,and can also be used to guide the calculation of residual oil distribution and the formulation of development plan.