Study On Waterflood Development-reservoir Characteristics And Waterflooding Pattern Of Chang6Reservoir At Block Wu Liwan

Wu Liwan is located in the middle of northern Shaanxi slope which is in Ordos Basin inChina’s western.The reservoir began to produce since1996,with the inverted nine spot wellpattern, and gradually establish six regions: the North, the Central, the South，fracturing testarea, ZJ53area and/J41area. Due to a variety of factors: reservoir properties, injectionpatterns, mining method and development period, six regions of production situation isdifferent. I he author did a systematical and detailed rcscarch on Chang6reservoir of sixregions at Wu Liwan.Firstly, through the analysis of the static and dynamic data, it summarizes that thereservoir characteristics and the water-lfooding situation of the reservoir change in differentregions at different stages. By comparing the inspection wells and the adjacent developmentwells, it analyzes the parameters: reservoir lithology, physical properties, oil-bearingproperties, clectrical properties whose variation law at waterllooding development proccss.Secondly, it analyses longitudinal and plane of the water-flooded conditions of the reservoir,and summarizes water-Hooded mode of the reservoir, as well as the the watcrflood cfTicicncyof control factors, which consist of waterflood multiples, displacement velocity, wettability,reservoir heterogeneity and permeability. Then it puts forward technology measures toimprove the oil ercovery, and formulates effective development adjustment plan. For the poordevelopment of the regions, it is necessary to improve its water-flooding effect. On the onehand,it is ncccssary lo ameliorate the water absorption condition. On the other hand, for goodwater-Hooding condition changing the chemical profile should be implemented.By deployinginfill wells, to further improve oil recovery, it is guaranteed that the reservoir has highcontinuous development.Through systematic study achieved the following understanding: in the central waterflooding development effect is good, water flooding effect is a bit poor in the south, ZJ41zoneand ZJ53zone. Atfer water-flooding the reservoir characteirstics have changed. On the onehand, clay total begins to reduce, permeability is increasing, the wettability becomeshydrophilic, development effect is better. On the other hand, the water-lfooding led to reservoir heterogeneity enhancing and affect the development elTecl. By unalyzingexpeirmental results, the reasonable water injection ratio, displacement velocity, injectionpressure can increase water flooding efficiency.At the same time, using surfactant can increasethe fluidity of crude oil jm proving water flooding efficiency.