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应用含油气系统理论分析鄂尔多斯盆地古生界天然气成藏规律 ,对揭示该盆地的生烃潜力、主要生排烃期的油气运移方向、天然气的有利聚集地区及其勘探目标 ,都具有重要的现实意义。根据古生界的烃源性质、储层类型及天然气的分布特征 ,将鄂尔多斯盆地古生界含气系统分为下古生界含气系统和上古生界含气系统 ,前者又可分为 3个子系统 ,后者分为 2个子系统。在含气系统的背景中 ,本区天然气藏的分布规律较为清楚 ,控制成藏的地质条件比较明朗。通过对各系统的时空展布特征和静态地质要素与动态地质作用过程的综合分析 ,指出上、下古生界均具有很好的成藏地质背景 ,但对于各含气子系统 ,由于它们处于不同的构造部位 ,所以成藏要素和过程也有较大的差异。分析指出 :下古生界含气系统中的东部含气子系统、上古生界含气系统中的中东部含气子系统成藏条件为最佳 ;下古生界的乌审旗北和吴旗南地区、上古生界中东部的 3个主砂体带 ,特别是最东部的主砂体带 ,应是今后天然气勘探的重点地区。
It is important to reveal the hydrocarbon generation of Palaeozoic in the Ordos Basin based on the petroleum system theory. It is of great importance to reveal the potential of hydrocarbon generation in this basin, the hydrocarbon migration direction in the main hydrocarbon generation and expulsion periods, the favorable accumulation area of natural gas and its exploration targets Realistic meaning. According to the nature of hydrocarbon source in the Paleozoic, the types of reservoirs and the distribution of natural gas, the Paleozoic gas-bearing systems of the Ordos Basin are divided into the Lower Paleozoic gas-bearing systems and the Upper Paleozoic gas-bearing systems. The former can be divided into 3 Sub-system, which is divided into two subsystems. In the background of gas-bearing systems, the distribution of natural gas reservoirs in this area is relatively clear, and the geological conditions controlling gas accumulation are relatively clear. Through the comprehensive analysis of the spatiotemporal distribution characteristics of each system and the static geological elements and dynamic geological processes, it is pointed out that the Upper and Lower Paleozoic have good reservoir-forming geological background, but for each gas-bearing system, Different structural parts, so the accumulation of elements and processes are also quite different. It is pointed out that the gas accumulation in the Middle Paleozoic gas-bearing system is the best in the eastern Paleozoic gas-bearing system and that in the Lower Paleozoic. In the Qiongnan area, the three main sand belts in the middle and upper part of the Upper Paleozoic, especially the easternmost sand belt, should be the key areas for natural gas exploration in the future.