Research On Sedimentary Characteristics And Reservoir Heterogeneity Of Ng₁₊₂ In Zhong Er Area Of Gudao Oilfield

After 40 years of Gudao oilfield waterflood development,now in high water cut stage,the main layer production continues to decline,oil and gas development direction gradually extended to non-major reservoirs.In Gudao oil field area,the second upper GuanTao 1+2 sand group(Ng₁₊₂)for the non major reservoirs,sand bodies scattered distribution and thickness thin,brings many difficulties to the development.Therefore,the study of the sedimentary characteristics and reservoir heterogeneity of the purpose of the study area,reveals the influence of reservoir heterogeneity on the distribution of oil and gas,and provides the geological basis for the later development of oil field.Paper utilization geology,well logging,laboratory testing and analysis of production performance data,focusing on the study area revealed the sedimentary microfacies and reservoir heterogeneity characteristics Ng₁₊₂,mainly achieved the following and understanding:?1?set up the island oilfield in the area of Ng₁₊₂ fine stratigraphic framework,it consists of three level 4 depositional cycle and 14 sublayer,14-10 sublayers for the first cycle,9-6 for the second cycle,5-1 for the third cycle.?2?the Ng₁₊₂ for braided river sedimentary,divided into 4 types of subfacies and eight kinds of microfacies,mainly include river,river edge,flood plain,abandoned channel4 kinds of subfacies;And each microfacies profile and plane distribution rule,the reservoir microfacies are mainly braided channel microfacies and mesh river sand dam microfacies.?3?From the inner layer,layer,layer plane of the three point of view of the purpose of reservoir heterogeneity:intraformational interlayer is given priority to with argillaceous interlayer,intraformational heterogeneity stronger;Significant difference between layers.Plane heterogeneity is mainly controlled by sedimentary microfacies,high permeability zone along the paleocurrent direction distribution.Braided channel sand dam reservoir property is best,heterogeneity,the weak channel microfacies,poor physical property,on the edge of the river channel heterogeneity is strong.?4?the vertical distribution of oil and gas in a single reservoir associated with the rhythmicity of reservoir sand body;Interlayer heterogeneity in vertical uneven distribution of oil and gas in the study area in the main body and the main layer;Plane distribution sand body shape,physical properties of the sand body plane change rule and the distribution law of sedimentary microfacies and plane distribution regularity of oil and gas in the studied area have different degree influence.