Establishment And Application Of Predictive Model For Oil And Gas Migration Channel

With the development of computer information technology and various artificial intelligence neural network algorithms,numerical simulation has become an important means for oil and gas migration studies.At present,there are mainly fluid potential analysis,percolation model,and numerical simulation method for seepage mechanics,but each There are different limitations.For example,the fluid potential analysis ignores the heterogeneity of the formation.It is difficult to meet the requirements of the percolation model and the seepage mechanics simulation method for all types of relevant stratigraphic data available during the oil and gas exploration stage.Based on the above series of questions,this paper proposes a mathematical model for predicting the migration path of oil and gas based on probabilistic estimation and spatial analysis methods.In theory,the distribution characteristics of oil and gas dominant migration channels under the conditions of single sand bodies and different structural combinations are systematically discussed.And compared with the numerical simulation results of the fluid potential analysis,percolation model and other methods,the actual verification of the model was performed on the Wen'an slope reservoir target optimization proJect.This paper is divided into two parts.The first part is the construction of the theoretical model.Under the control of different combinations of source rock and sand body distribution pattern and structure,the results of the dominant oil and gas migration pathway are predicted and compared.The path of oil and gas migration is mainly determined by the driving force and resistance of oil and gas migration.The oil and gas power is mainly provided by buoyancy and hydrodynamic forces.This will cause oil and gas to always move in the direction with the greatest drop in fluid potential;oil and gas resistance will be transferred from oil and gas during migration.Due to the capillary forces generated,oil and gas will always migrate along the direction of the best permeability and the least resistance in the heterogeneous transmission system.Finally,the oil and gas always tend to have the greatest difference in fluid potential,and the permeability is the best.The direction of migration.Based on the theoretical analysis of oil and gas migration,using ArcGIS as a platform to develop and integrate spatial analysis modules,a predictive model for the migration path of oil and gas is constructed.Through the simulation and analysis of the dominant migration channel of the single sand body and the different structural combination theoretical models,it shows that the oil and gas are under the homogeneous stratum,and the probability of migration of oil and gas to the neighboring unit is zero,and the path is affected by the buoyancy and the shielding surface.Controlling,moving up and down the monoclinic formation,the anticline structure appears to converge along the ridge toward the top of the structure,and the depression structure diverges to the sides of the depression;when we introduce a non-homogeneous stratum of a single sand body,the migration path Controlled by the difference in fluid potential difference and porosity,the migration path appears to be a combination of the two.In the monoclinic structure,there is a tendency toward high-porosity regional aggregation,and the degree of aggregation under the anticlinal structure is greater,and at the same time The path is controlled by the sand body obviously.The sand body under the sag structure has the most obvious influence on the migration path,so that the area that could not be built up is also likely to become a reservoir.Given the initial conditions,the prediction results of this method are basically consistent with the fluid potential model and the percolation model.This paper has been applied and verified in the optimization proJect of shallow reservoir targets in the Wen'an slope.The Wen'an slope is located in the eastern part of the Baxian sag,and the whole is a moderately southwest-facing gentle slope in the northwest.The east-west and north-east direction “Y” is extensively developed.Zigzag is a fault,and the sand body is dominated by sedimentary types such as Binhai Lake beach(dam),meandering river and braided river delta.The simulation results show that the upper and middle oil and gas migration pathways in the upper slope are Jointly controlled by the permeability sand bodies and structural forms,and the industrial oil and gas layers are mostly distributed in the development location of convergent dominant migration channels.