| Yanqi basin, with an area of 13000 squre kilometer, located in the Bayinguoleng Mongolia autonomy state in Xinjiang, is a Mesozoic-Cenozoic superposed basin superimposed in the Southern Tianshan Hercynian erogenic belts. Triassic-Jurassic sedimentary sequence was a reformed basin .which is a set of coal-bearing sequence overlay by Cenozoic red Molasse. From 1993 to 2001, Baolang and Benbutu oil field, with an oil-bearing area of 26.3 squre kilometer and proven reserves of 4172+104t, have been found. Oil production of 23+104t p.a. have been built in the basin. Under the guide of the modern petroleum theory, the dissertation adopts the thoughtfulness of the oil and gas evaluation of the reformed basin, and the methods of multidisciplinary analysis and comprehensive study. Beginning form relation of basin-mountain, the tectonic evolution and the petroleum system and pool-forming process have been studied with the integration of structural physics modeling, balance profile reversion and other new testing technology. The main innovative achievements of the dissertation can be summarized as following:1. On the basis of comprehensive analysis of Yanqi basin relationship to Tianshan orogenic belts, it was suggested that Kuluketage faulted-upheaval was an aulacogen in early Paleozoic, which undergone multiple opening-closing along with Tianshan orogenic belts, and suffered extensively compressing in late Hercyhian cycle and formed a "V-type" thrust-fold belt. Yanqi basin, located in the Northern wing of the "V-type" thrust-fold belt, is related to the reversion of the Kuluketage aulacogen.2. The tectonic framework in the basin presents the lozenge patterns which are consist of the W-E structural belts and NW-SE structural belts. The W-E structural belts are primary, and that the NW-SE structural belts are the transfer belts related to the former. There are five kinds of fault-fold assemblage styles which are respectively thrust-nappe structures, imbricate thrust-propagation folds, face to face thrusts, back to back thrusts and positive flower structures. The tectonic reformation exhibits the characteristics of the basement-involved, multi-phases, inheriting, syn-sedimentation, descending, shifting and transferring. The basement configuration controlled the reformation in the basin. The tectonic framework and border faults of the basin were related to the basement configuration.3. Based on the regional tectonic setting and sedimentary sequence evolution, the structural physics modeling and balance profile reversion are first carried out. Its results approve the Yanqi basin is a Mesozoic-Cenozoic compressive basin(revival foreland basin) in the Tianshan composite orogenic belts. The tectonic evolution in Mesozoic-Cenozoic can be divided into three stages: the weakly compressive stage in the early to middle Jurassic, intensively compressive stage in the late Yanshan cycle, and face to face compressive stage in the Himalaya cycle.4. Combined with the analysis of the hydrocarbon-generation history, hydrocarbon maturity, fluid inclusions, authigenic illites isotopes chronology and trap forming history, it affirms thatJurassic reservoirs formed in three phases: the first in the late Jurassic, which was the primary pool- forming phase, the second in the telophase of Jurassic to Cretaceous, which was the adjusting-destroying phase, the third in Tertiary, which was the secondary phase. The evolution of the Jurassic petroleum system can be divided into three stages: the forming stage in the late Jurassic, the adjusting-destroying stages in Cretaceous, and the activating-reconstructing stage in Tertiary.5. The reservoir types and characteristics are studied. The pool-forming process and model are established. It suggested that the tectonic process is the pivotal and crucial element which controlled the pool-forming, preservation and hydrocarbon distributions, that is the regularity of hydrocarbon distributions. The belting of tectonic reformation determined the difference of the hydrocarbo...
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