Research On The Reservoir Feature And Mian Controlling Factors Research Tight Sand Reservoir Of The Chang8 In HH(HongHe) Oilfield

By the method of the application of sedimentology,petroleum geology,logging and other discipline theory as well as the reservoir group of low permeability tight sandstone reservoir of the Chang8 in HH Oilfield,this paper synthetically discusses characteristics of district Chang 81 segments reservoir and some main controlling factors of sedimentary facies,based on the core observation of geological logging,well logging data,thin section,grain size,mercury injection and scanning electron microscopy analysis on test data.In the region are mainly fine grained,feldspathic lithic sandstone and lithic feldspar sandstone make up the vast majority of types in the region whose porosity and permeability are 3.9%?11%and 0.04×10-3?m2?0.55×10-3?m2,averaged 7.53%porosity,permeability,on average,0.29×10-3?m2,Chang 81 reservoirs include intergranular pore,feldspar dissolved pore and micro fracture pore type,etc.The best Interlayer heterogeneity is 812 small layer and the worst one is Chang 813 small layer,in addition,Chang 811 and Chang 812 long permeability heterogeneity are stronger than Chang 813.As reservoir permeability has positive and negative rhythm characteristics,rhythm and permeability sandstone particle size has a good corresponding relationship.Chang 81 reservoir is a kind of strong heterogeneity reservoir.Low sorting,rounded and compositional maturity is the innate factor of reservoir density,Later compaction,cementation,metasomatism and complicated diagenesis is another cause of the low permeability reservoir's formation.Through sedimentary structure,the comprehensive analysis of log facies,granularity data reveal the research district Chang 8 reservoir of delta front subfacies including the underwater distributary channel,underwater natural levee,crevasse splay,underwater distributary bay and debouch bar microfacies.Chang 81 oil is mainly from the upper section at the bottom of the"shale chang 7 beach"which has sets of hydrocarbon source rock of large thickness,a wide distribution area and high organic matter abundance with the effect of direct cap.Under the small nose structure formation of traps and the conducting of channel micro cracks and pores,the Chang 81 with large reservoir is formed easily.