Research On Development Strategy Of L Oilfield In Super-high Water Cut Stage

Water flooding is used in most oil fields at home and abroad,especially sandstone reservoirs.With the progress of water injection development,most of the old oil fields have entered the period of extra-high water cut.In the high water cut stage fields,there is a continuous state of underground crude oil in a highly dispersed.Relatively enriched oil mostly exists in the near poor reservoir or the edges and corners near the fault,tapping the potential of the work is very difficult.Therefore,it is of great significance to study the development strategy in the extra-high water cut period.L reservoir is a typical waterflooding development reservoir.Its water cut has reached more than 90%.It has entered the extra-high water cut stage.The current water injection works cannot meet the needs of reservoir development in extra-high water cut stage.Based on the analysis of geological conditions,current development status and distribution of remaining oil in L reservoir,this paper analyzes the problems existing in its development,and puts forward different development countermeasures according to specific problems.The remaining oil of the L reservoir is mainly distributed in the main layer of deterioration of the site,the fault shelter,the poor oil layer or the top of the normal gyration thick oil layer.In view of the well pattern is imperfect and partial well pattern can not adapt to the needs of stable production in oil field.The method of oil well diversion and well network adjustment is put forward to solve the problem.In this paper,through the study of a variety of well density calculation methods,and taking into account the factors affecting the well density,including geological factors,development technology factors and economic benefits,we find the advantages and disadvantages of various calculation methods.Combined with the analysis of the characteristics of the L oil reservoir,the technical factors and economic factors were taken into consideration.Finally,the economic net dynamic value method was used to obtain the optimal well pattern density of the L reservoir.The L reservoir is encrypted by combining the calculated well pattern density with the actual well pattern distribution of the reservoir.This method effectively alleviates the problem of unbalanced injection and recovery and imperfect well pattern.In view of the water injection way is single.The method of periodic water injection and stratified water injection is proposed.The main influencing factors of periodic waterflooding were studied.Combined with the geological characteristics of L oil reservoirs,multiple sets of schemes for periodic waterflooding were proposed and numerical simulations were carried out to obtain the optimal waterflood timing,waterflood period and fluctuation range of waterflood for L reservoirs.At the same time,the separated layer method and stratification of separated layer water injection for single wells were studied,numerical simulation was performed and good results were also obtained.This method has effectively alleviated the problems of injecting water into a single layer due to the heterogeneity of the reservoir and unbalanced waterline propulsion.Based on the L reservoir model,according to the above method by different schemes and verified by using the numerical simulation,select the best adjustment programs,and economic evaluation of these methods.The results show that the use of hydrodynamic methods to adjust reservoirs can effectively improve the oil displacement efficiency of oil reservoirs with very high water cuts and have certain economic benefits.