Genesis Of Remaining Oil In Es1 And Es2 Reservoirs In Wen'an Oilfield

There are mainly four typical fault block reservoirs in Wen'an Oilfield.Through the comparative study of the fault block layers in this paper,a further precise comparison of the small layers is carried out.A unified layering scheme for small layers is established on the premise of the same sedimentary background and the same standard layer..Through the study of the sedimentary facies of each fault block,the sedimentary characteristics of each fault block are described.On the basis of the results of the reunification and sedimentary facies research,the physical properties of the fault blocks are described.The geological reserves of each fault block reservoir were verified,and the geological reserves of each layer were evaluated.Using the production profile data and stratum coefficient,the individual wells were divided by production,the cumulative production curve method was used to calculate the recoverable reserves of the remaining wells,and the remaining oil potential coefficients for single wells and single beds were calculated using Surfer software show.The distribution maps of remaining oil potential coefficients for various small layers were distributed,and then the cause of the remaining oil was analyzed.Finally,using Eclipse numerical simulation software to perform the theory of single layer residual oil tapping measures.The fault blocks in Wen'an Oilfield are far away from the provenance,and the distribution of sand bodies is more developed at the top of each oil group.The reservoir has features of structural and reservoir overlapping in the same direction,with high fault position in the first-line structure and large reservoir thickness.The distribution of sedimentary microscopic properties has a certain degree of control.The average porosity and permeability of the sand body change,the top of each oil group is high and the bottom is low,and it tends to decrease with increasing buried depth.The main strata are located at the top of their respective oil groups.The oil layers are contiguous,with a large oil-bearing area(greater than 0.3876 km~2),a thicker effective thickness(more than 2.05 m),and a higher oil saturation(greater than 50.46%),forming a feature that the top oil is better than the bottom.The main remaining oil generative types include injection and production well pattern imperfect remaining oil,interwell balance residual oil,parallel fault clamping strip residual oil,residual oil of fault-breaking type,fault cross-cut residual oil,lithology fault Composite residual oil,inter-layer interference residual oil and inter-layer rhythmic residual oil.The main remaining oil main controlling factors are the ancient water flow direction orthogonal to the main fault,main fault cutting,fault cross cutting,tight lithologic shelter,narrow and long water injection,no depth,thin sediment thickness due to sedimentation,and insufficient edge water energy.The main floor is poor and the heterogeneity is serious.