Reservoir Evaluation And Percolation Characteristics In Wa 6 Fault Block Of Wazhuang Oilfield In Gaoyou Depression

Reservoir characteristics of Wa6 Block in Wazhuang Oilfield is studied in this project.The corresponding solution measures are put forward base on main control factors of influencing oil recovery and sensitive factors causing reservoir damage analysis.Other factors such as water lock and stress sensitivity of target reservoir and starting pressure are systematically addressed according to the characteristics of low permeability reservoir.On the premise of the basic research,the use of visual physical model test technology to simulate the actual well network to further research,and achieved the following results:1.Based on the analysis of the reservoir rock and mineral characteristics,physical properties and micro pore structure characteristics,summed up the reservoir characteristics of Wa6 fault block in E₁f₁ and K₂t₁.The study shows that the mineral composition in Wa6 fault block is relatively stable,are dominated by quartz,with poor reservoir physical properties,which belongs to the low porosity and low permeability reservoirs,and the properties of K₂t₁is poor than E₁f₁.2.Through the evaluation of reservoir damage test reveals the Wa6 fault block reservoir exhibits a strong water sensitivity,also due to the difference of mineral composition and physical characteristics in E₁f₁ and K₂t₁,showing different reservoir damage,in which the E₁f₁ is in the presence of strong sensitivity,K₂t₁ showed strong acid sensitivity.3.Study on the characteristics of reservoir seepage and water drive oil efficiency evaluation show that Wa6 fault block reservoir belongs to weak hydrophilic layer,relative permeability curve reflects the low permeability reservoir characteristics,bound water and residual oil saturation is high,the water flooding efficiency is low.4.NMR studies show that there is a good linear relationship between the percentage of the movable fluid and the logarithm of the permeability,but it is poor with the correlationPorosity.The E₁f₁ movable fluid percentage is better than the k₂t₁ reservoir,explains the micro flow characteristics are different in the differentreservoirs.5.The empirical formula is established through the starting pressure test,which considers that the starting pressure gradient is closely related with the air permeability,and the minimum starting pressure gradient,the pre-starting pressure gradient and the maximum starting pressure gradient are increasing with the decreasing of permeability.6.Using the visual physical model test technology to simulate the actual well pattern,it is clear that the adjustment of the well pattern or the transformation injection production method can effectively improve the flow field.The effective injection-production well pattern can improve sweep efficiency by more than 10%.