Abstract: We carried out a systematic study on the characteristics of conglomerate reservoir and analyzed the main controlling factors related to sedimentation and diagenesis for favorable reservoir development, through core analysis, thin section observation, QEMSEM, XRD, SEM, CL, fluorescence, imaging analysis, in combination with logging and physical property data. The study results show that the framework grain composition, grain size, sorting and conglomerate stone thickness are determined by the provenance and sedimentary environment, that control the strength of calcite cementation and compaction, diagenetic environment, pore fluid properties, and the influence of orthoclase dissolution on reservoir physical properties. Compared with braided channel and distributary inter-channel, conglomerate stones developed in underwater distributary channel microfacies are much thicker with higher rigid particle content, better sorting, more chlorite films, relatively weaker compaction, larger pores, and better connectivity and pore fluid mobility. Therefore, the dissolution products from orthoclase dissolution, such as kaolinite, illite and other clay minerals, are easily carried out and do not precipitated in situ. These dissolution products play an important role in improving physical properties of reservoirs. Besides, reservoirs along the organic matter migration pathway have better physical properties.

Key words: Junggar Basin, Triassic Baikouquan Formation, reservoir characteristics, main controlling factors