| Three-dimensional geological modeling is one of the important technologies in oil and gas exploration and development.Its ultimate goal is to establish a geological model that can characterize the structure,facies and physical properties of underground reservoirs.Accurate geological model is the premise of accurate development of oil and gas reservoirs.The accuracy of the single phase-controlled modeling method is seriously restricted by the well pattern density.In the dense well area,the accuracy is high.In the less well area,due to the less deterministic well control information,the inter-well model mainly depends on the modeling algorithm,so the accuracy is greatly reduced.Seismic data has the advantage of high lateral resolution.The introduction of seismic inversion data collaborative constraints to establish geological models can improve the accuracy of geological models and reduce the risk of reservoir development decisions.Y block of D oilfield is an important oil and gas exploration and development block in the southern Songliao Basin.It develops typical low-permeability thin sand bodies with strong reservoir heterogeneity.The well pattern of Y block is sparse and there are few well areas,and the accuracy of well control modeling model is low.In order to solve this problem,this paper takes the Y block of D oilfield as the research target area to carry out the research on the three-dimensional geological modeling method of seismic inversion constraints.The three-dimensional inversion data volume is used to constrain the model,control the cross-well modeling,and improve the model accuracy.Guided by geophysics,sedimentology and geostatistics,this paper establishes a high-precision inversion framework model by using four seismic reflection layers in the first member of Qingshankou formation.Based on the data of82 wells in the study area,the wave impedance curve is optimized,and the waveform indication inversion method which can reflect the phase-controlled characteristics is adopted to determine the inversion parameters and reduce the uncertainty of the inversion results.On the basis of the above research,using the geological modeling software Petrel,combined with the data of well,seismic and sedimentary,the structural model of 16 faults and 16 sedimentary units in the Qingyi section of Y block is established;The digital sedimentary facies model was established by assignment method,and the lithofacies model was established by sequential indicator simulation method using the well sandstone data;The wave impedance inversion body after time-depth conversion is used as the second variable,and the phase-controlled sequential Gaussian simulation method under the collocated co-Kriging algorithm is adopted.At the same time,the porosity data are analyzed and the porosity model is established by using the results;Under the constraint of porosity model,permeability and oil saturation models are established;The geological reserves of Qingyi member in Y block are calculated,and the error between the geological reserves and the oilfield geological reserves is less than 5 %.It is proved that the geological model established by this method has high accuracy,which is in line with the existing geological understanding and can accurately describe the reservoir characteristics,which provides a strong guidance for the next development of the reservoir.The three-dimensional geological modeling method constrained by seismic inversion also provides a research method for geological modeling in few well areas. |
