Aiming at the complicated problem of the genesis of high-quality hybrid sedimentary rocks (HSR), the pore-throat systems (PTS), controlling factors and fluid mobility of HSR in the Permian Lucaogou Formation in Jimusar Sag were examined. The results show that the HSR contain 5 types of PTS, intergranular (Type A), mixed intergranular-dissolved-intercrystalline (Type B), dissolved (Type C), mixed dissolved-intercrystalline (Type D) and intercrystalline (Type E) ones. The PTS are controlled by 3 major factors, the component content and arrangement (CCA) of HSR, sedimentary environment and diagenesis. CCA controls the matrix support mode of HSR, and therefore controls the types and changes of PTS. The sedimentary environment mainly controls the macroscopic distribution of PTS, i.e., HSR deposited in the near source and high-energy environment are characterized by high content of coarse-grained component, granular/interbedded-support mode, and development of Type A and Type B PTS. HSR deposited in the medium-energy environment far from source are characterized by dolomitic/mud support mode and Type C and Type D PTS. HSR deposited in low-energy environment far from source have mainly Type E and Type D PTS. Diagenetic processes such as compaction and calcite cementation make the proportions of Type A and Type C PTS decrease further. In the hybrid sedimentary process of sandy-mud, PTS types show a change of “A→B→C→D”, in that of dolomite-sand, PTS types show a change of “A→C→D→E” or “B→D→E”, and in that of dolomite-mud, PTS types show a change of “D→E”, which are affected in details by the contents of coarse-grain component, feldspar and dolomite. The reservoir with Type A pore-throats has the best physical properties and fluid mobility, and the reservoirs with Type D and Type E pore-throats have the poorest. The movable fluid distribution is related to the matrix support mode, and the larger pores in HSR of dolomite/mud support mode have no obvious advantage in fluid mobility. The findings of this study provide a geological basis for evaluating and building reasonable interpretation model of HSR sweet spot.
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