Heterogeneity Evaluation Of Tight Sandstone Reservoirs Of Chang6₃ Reservoir In Huaqing Area

The Huaqing area is the main oil-bearing block in the Ordos Basin.The main target layer of this block,Chang 6₃,is a deep-water gravity flow sedimentary.The overall physical performance is low porosity and extra-low permeability.Reservoir Chang6₃ in Huaqing area has a wide range of sand bodies,large differences in thickness and thickness,interlayer interlayers are more developed,and the types of sand bodies are complex.These factors result in strong reservoir heterogeneity and difficult to identify high-quality reservoirs,which restricts favorable areas Formulation of forecasting,well deployment and development measures.Based on previous research,using well logging data,core photos,experimental tests,sand body thickness data,sand body porosity data,etc.,this paper systematically describes the heterogeneity of Chang 6₃ reservoir in Huaqing area from different macro and micro angles.The main controlling factors of reservoir heterogeneity?granularity rhythm,interlayer interlayer,sand body stacking relationship,sand body thickness,porosity and permeability?were artificially modeled and analyzed using artificial neural network technology to predict the area Reservoir heterogeneity.Using Kriging interpolation in Surfer software and scattered points in the study area,a map of the heterogeneity of Chang 6₃ tight sandstone reservoirs in Huaqing area was drawn.The study shows that:?1?Chang 6₃ in Huaqing area has strong heterogeneity,mainly including turbidite,sloping rock,sandy debris flow and argillaceous debris flow.?2?The occurrence frequency of muddy interlayers is relatively high,which has a great influence on the heterogeneity of the sediments.The calcareous interlayers mainly appear in the sandy debris flow.?3?According to the stacking relationship of sediment sand bodies,the heterogeneity from weak to strong is continuous superimposed type,interval superimposed type,lateral spike type,and sand-mud interlayer type.?4?The reservoir area in the study area is mainly composed of fine sandstone,the roundness is mainly subangular,the separation is medium,the contact of detrital particles is mainly linear,and the cementation type is mainly pore cementation.?5?Analyze the distribution of influencing factors such as sand body thickness,sedimentary microfacies,and flow units in the study area,and summarize the plane distribution law of macroscopic heterogeneity of Chang 6₃ reservoir in Huaqing area:the reservoir heterogeneity in the southeast is stronger but the northeast is weaker.