Study On Flow Field Control Of Bohai SZ Ordinary Heavy Oil Reservoir In The Late Stage Of Water Flooding

In the late stage of water flooding development in Bohai SZ oilfield,the distribution of flow field underground is complex,and the development effect in different regions is obviously different.It is necessary to adjust the seepage field of reservoir in order to achieve balanced displacement,and improve development effect further.Streamline distribution between injection and production wells can directly reflect the law of oil-water movement and distribution in reservoirs.Through studying the law of streamline variation,it can provide a strong basis for flow field control in later stage of water flooding.In this paper,the reservoir engineering method,seepage mechanics theory and streamline numerical simulation method are synthesized applied.By establishing suitable streamline model and flow field evaluation method,the flow field variation law and reservoir production law after adjustment measures are studied in deeply,and the control strategy suitable for the characteristics of SZ reservoir in Bohai Sea is determined.The following work is mainly carried out and completed: Firstly,a streamline mathematical model considering the influence of non-Newtonian property of heavy oil and displacement velocity is established,and the numerical simulation of heavy oil streamline under different water flooding conditions is realized.Secondly,based on the study of the variation law and control factors of inter-well flow field,an evaluation method for flow field adjustment is established to characterize the variation of streamline and reservoir production law.Thirdly,research on flow field variation and reservoir utilization law under different well pattern adjustment and hydrodynamic adjustment modes has been carried out.The study shows that,comprehensive considering the effect of well pattern adjustment and the feasibility of field implementation,the comprehensive adjustment mode of reverse nine-point adjustment to row pattern,then production well row infilling and later injection well row infilling is more conducive to improving the overall reservoir utilization effect;the study ofhydrodynamic adjustment under the condition of reverse nine-point pattern and row pattern shows that,with the increase of production ratio between wells in the edge(corner)part and wells in the middle part,the reservoir production effect is gradually improved,and when the ratio is greater than 2,the reservoir production effect is no longer improved obviously by further increasing the ratio of fluid production..Finally,according to the characteristics of actual oilfield and development needs,based on the numerical simulation of streamline,the flow field control strategies of adjust well pattern in stages and assist hydrodynamic measures are determined.The study results will lay a foundation for the deep and well development of Bohai SZ oilfield in the later stage of water development,and provide technical support for the efficient development of such oilfields.