Research And Application Of Flow Field Optimization Adjustment Method In Water-driven High Water-cut Reservoir In Jianghan Oilfield

At present,most oilfields in China are mainly developed by water drive,and most water drive reservoirs have been transferred to high water cut or even extra high water cut stage.However,high water cut and extra high water cut stage are still one of the most important research and development stages.Due to the complex geological structure of various unconventional oilfields and the frequent adjustment of reservoir engineers and oil companies in the long-term research and development process,the remaining oil in many water-driven oilfields is seriously dispersed,the reservoir parameters have changed obviously,and the overall pattern of underground oil-water distribution has also changed greatly,resulting in problems such as low completeness of injection-production well pattern,weak reserve control level,serious interlayer interference and large inter layer difference deviation,and few remaining oil exists in layers or contiguous layers.To a great extent,the optimization and adjustment of the development plan directly determines the scale of the production base,the production cycle and life of an oil and gas field at this stage,and the social and economic benefits of these oil and gas field enterprises;Reasonable research and production plan design can significantly improve the degree of water-driven control and the ultimate recovery effect.General oilfield development optimization is mainly through reservoir engineering method calculation,numerical simulation analysis,combined with actual development adjustment experience to complete the optimization design of development scheme or adjustment scheme.In recent years,with the progress and development of modern computer science and technology,some optimization algorithms combined with modern computer science and technology development indicators have appeared.Most of the existing optimization methods only optimize one or two of the indicators such as well location,well type,perforation,injection-production parameters,etc.However,the research on optimization methods of overall reservoir development indicators is limited to theory and model,and no executable calculation program has been quantified and formed.The existing optimization methods have shortcomings: optimizing a single index can not consider and reflect the displacement status of other parts of the reservoir at the same time;the displacement degree of affected parts is different,and the difference of oil saturation is large,which can not guarantee the displacement balance in the development process,and will make the remaining oil more dispersed and aggravate the uneven displacement degree.In order to meet the diversified development practice,based on the advantages of various methods,this paper brings the core development optimization indexes such as well location,well type,perforation and injection-production parameters into the optimization index system,and establishes the genetic algorithm for optimizing oilfield development scheme considering multiple variables;Aiming at the practical constraints in the optimization process,a population validity test method is proposed The genetic coding method of each index is established,and then the genetic coding of the whole development scheme is established,and the corresponding computer software is compiled.Taking the H2 well area of Huangchang Oilfield in Jianghan Oilfield as the test object,the optimization results show that the oil production curve of the optimized scheme is significantly higher than that of the unadjusted scheme,which proves the feasibility of the optimization software.