Research On Dynamic System For Forming Reservoir Of Mesozoic Accumulations In The South Of Ordos Basin

Petroleum system has been the effective assessment method of exploring oil and gas-bearing basins, since Wallace.G.Dow raised it in the early period of 70s. But dynamic system for forming reservoir is a new theory and method, applied to exploring oil and gas, and is based on the further development of petroleum system in the recent years. The thesis was written under the direction of dynamic theory of forming reservoir, follows the rules of comprehensive information, judgment, interpretation and assessment and even makes full use of outcrop geology, data from drilling and logging, data from laboratory analysis and achievements in geophysical exploration. Considering the basic factors of forming reservoir in the south of Ordos Basin as the starting point, the thesis defines that Yanchang Group of Triassic goes into the start of generating oil in the late period of Mid-Jurassic and that the largest oil generation peaks in the middle period of early Cretaceous, after the analogue-history of hydrocarbon generation. Meanwhile it also establishes the relationship between the evolution of oil and gas and the formation of traps, the time of oil exploration. And then it explains that the trend of petroleum in this area has the obvious dual-zone structural characteristic and builds fluid dynamic distribution model with both system of flow by gravity mainly on hydrostatic pressure and system of compaction flow mainly on differential compaction, after the fluid potential whole-zone computation. Finally, it inquires into the law of oil and gas accumulation in this area and points out the advantageous oil and gas-bearing long-range area through distinction of dynamic system for forming reservoir and event analysis.