Research On The Heterogeneity Of The Chang 9 Reservoir In The H224 District Of The JY Oilfield In Orods Basin

Based on well logging data,core data and production date of chang9 reservoir of H224 area in JY oil field,we did some research,such as fine stratigraphic division,sedimentary characteristics,analysis of sedimentary facies or microfacies and physical properties.Then made further of analyzed on micro-and macro-heterogeneity according to these stydies.And studied the influence of heterogeneity on waterflooding combined in production,drew the following conclusions:(1)There are two single layers,chang 91 and chang 92 of H224 area in JY oil field,and 91 can be subdivided into chang 911 and chang 912.The thickness of chang 911 and chang 912 are 23.7m and 22.6m.(2)Sedimentary environment of chang 9 reservoir is mainly delta plain facies,includes four sedimentary microfacies: distributary channel,distributary depressions,crevasses and natural levees.(3)The lithology of the reservoir is mainly arcose.The granularity is almost fine sandstone and medium-fine sandstone.It belongs to low porosity and ultra-low permeability reservoir.And it is primary residual intergranular pore with the kind of middle pore-small middle troats and small pore-small troats.(4)Interlavers are common seen at chang 91 in the study area.There are almost muddy interlavers and calcareous interlavers,mainly is muddy interlavers.There are stable interlayers at chang 911 and chang 912 in study area.Interlayers are mainly gray-black mudstone and silty mudstone,the thickness is generally 2-5m and average is 3.92 m.(5)In plane,it shows a strong plane heterogeneity at chang 91 reservoir,reflected in the differences in reservoir properties,oil saturation,shaliness and effective thickness.(6)Due to the poor porosity and permeability,the water injection pressure gradient is lower than staring pressure gradient and some oil wells get off to the state of low yield.Production performance produce less oil and it have a ineffective water flooding response.(7)The fault has a well barrier property,and the injection production wells on both sides of the fault are mainly water injection.The average liquid production,oil production,water content and injection production ratio of different fault blocks are different.