The Research On Both Tectonic And Its Dominating Action To Hydrocarbon Of Kongquehe Area In Tarim Basin

This essay makes a study in Kongquehe region, which is located in the southern margin of Tianshan orogenic belt and the northeast of Tarim basin. The evolution in this area is closely related with the evolution in Tianshan orogenic belt, Kuruktag faulted uplift and Altun orogenic belt. Because of its special structural location and the breakthrough of exploration activity in recent years, this area catches great attention of geologists and workers.According to the theoretical foundation of tectonics, high-resolution sequence stratigraphy and petroleum geology;with the combination of field geologic investigation and lab analytical simulation, macroscopic and microscope, and multidisciplinary combination of geology, geophysics and geochemistry;using structural evolution as the main line;based on the modern computer technology and seismic, well and outcrop materials;with the application of basin structural analysis and dynamic analysis methods, the analysis of palaeostructure and palaeogeomorphology, and the new theory and ways of unconformity, hydrocarbon migration and accumulation, this paper makes a comprehensive study on the history of structural evolution and sedimentation-reverse denudation. On the basis of this research, the controlling of the structure and its evolution towards the source rock distribution, reservoir formation, structural trapping distribution and hydrocarbon migration and accumulation has been carried out.From this research, Kongquehe region has experienced eight evolutional phases and a further discussion on foreland basin characteristics in Silurian is made. It is found that the main source rocks are marine argillaceous rock and carbonate rock of passive continental marginal basin in Cambrian early-Ordovician, the nine unconformities are identified, eight structural layers are divided, the Donghe sandstone is considered to be early Carboniferous sedimentation;all these have significant guidance for the adjustment of hydrocarbon exploration strategy. The research of seismic balanced section shows that Kongquehe region has different structural deformation, different sequence deformation and different stacking features in east-west, south-north and vertical direction, among which the tectonic movements in early Hercynian, Indosinian and early Yanshanian have great influence on thestructural deformation.The superimposition characteristic in Kongquehe region is multilayer-storied type, which is as follows: big sag big uplift in lower Paleozoic, gentle sag gentle slope in Carboniferous, and slope in Mesozoic-Cenozoic. Based on the trend exploration method of formation thickness, with the combination of vitrinite reflectance method and acoustic travel time method, the palaeogeomorphology characteristics, tectonic framework, source rock evolution and petroleum migration and accumulation in different periods have been described, the fracturing distribution and formation mechanism have been systematically studied, and the tectonic unit in this region has been redistributed according to Paleozoic and Mesozoic-Cenozoic. From the systematic analysis of fracturing distribution and sequence, there are 5 combination patterns of fracture-fold.According to morphologic characteristics and origin, the trap type can be divided into four categories, which are structural trap, stratigraphic trap, lithologic trap and combination trap and nine sub-categories. Five characteristics of "tectonic controlling" are provided, which are the followings: 1) high-quality source rock of prototype basin in extension period;2) two efficient reservoir forming periods in two key tectonic evolutional periods;3 ) new reservoir forming combination type because of the tapping interface of protype basin;4) multiple reservoir forming models according to the tapping interface of polycyclic basin;5) hydrocarbon distribution is controlled by the tapping of geologic structure and has the characteristics of orderliness and levels.On the basis of the comprehensive research, there are four key exploration fields and four favorable exploration zones in Kongquehe region.