Sedimentary System Research And Geological Modeling Of A'nan Oil Field In Erlian Basin

A'nan oilfield is located at the east of Magni Dpression in Erlian basin.It has went on strem in 1988.As a result of oil reservoir by a variety of sedimentary systems superimposed,by intermittent activity of Arershan Fault and periodical aggression and retrogression of the lake,sedimentary cycle is complex,the rhythm is changeable and the physical property difference is big.At present,the evolution of sedimentary facies is not fully understood,and there is no complete geological model,these affect the development of latter adjustment work.It is of great significance to study geological characteristics and 3-D geology modeling.According to the regional geological background of A'nan oilfield and based on the former research works.Though the combination of the High-resolution sequence stratigraphy and traditional facies analysis.The geological characteristics of the study area is analyzed by using the basic geology,laboratory analysis,well logging and seismic data,the high resolution stratigraphic sequence is accurately divided and the isochronous stratigraphic framework is established.Through the characteristics of core and well logging facies,identified six kinds of sedimentary mircrofacies,it included underwater distributary channel,underwater distributary interchannel,underwater overflow shore,mouth bar,distal bar,and blanket sand at the lower A? oil formation;distributary channel of fan and the edge of the fan sheet sand at the upper A? oil formation;T? oil formation developed beach sand,beach bar and lacustrine mudstone,on the basis of the study area is analyzed the planar distribution of microfacies and vertical evolution.According to the evolution of the sedimentary microfacies and sedimententary microfacies of each period which have a good inheritance in the evolution of each period,sand body contiguous and thickness is bigger.The study area has experienced the sedimentary evolution of the braided of delta,underwater fan and shore shallow lake,among the sedimentary facies,the delta is formed along the steep slope with sufficient sediment supply in intermittent period of the fault activity of Aershan,the subaqueous fan is formed growth fault in the deep lake of rapid subsidence,eventually with the cessation of the rupture of the Aershan fault and the lake level rising into the shallow lake,and then establish the regional sedimentary evolution model.On the basis of sequence stratigraphy,division and correlation of sedimentary facies and sedimentary microfacies.Application of Petrel2009 geological modeling software,based on the geological statistics,under the constraint of phase and variable parameters,determined a reasonable algorithm.The stochastic modeling method is used to establish sedimentary microfacies model,porosity model and permeability model by petrel geological modeling software at A? oil formation and T? oil formation in A'nan oil field.