排烃门限理论在大杨树盆地的应用

排烃门限是油气源岩在沉积埋藏过程中生成的油气满足了源岩自身各种形式的残留需要后开始大量排烃的临界地质条件 .通过源岩生烃量减去残留烃量判别排烃门限 ,进而求得排烃量和油气资源潜量的办法 ,可以规避复杂的排烃机理问题 .大杨树盆地是松辽盆地外围一重要盆地 ,暗色泥岩生烃条件理想 ,有机质已经成熟 ,但资源前景一直不明朗 .利用排烃门限理论对盆地油气资源前景进行研究表明 ,源岩已经进入排油气门限并开始大量排烃 ,天然气勘探前景好于液态石油的勘探前景 .盆地可聚资源量达 (1834.4 774～ 12 134.16 35 )× 10 4 t ,显示了良好的勘探前景

Application of hydrocarbon expulsion threshold theory to Dayangshu Basin

The threshold of hydrocarbon expulsion is the critical geological condition when hydrocarbon amount generated from the source rock is enough to meet hydrocarbon retention in the source rock itself and begin to be largely expelled. We can identify the threshold by the amount of hydrocarbon generation substracting the amount of retention, and then obtain the amounts of hydrocarbon expulsion and potential resource, which can avoid studying the complicated mechanism of hydrocarbon expulsion. Dayangshu Basin is one peripheral basin of Songliao Basin, whose oil and gas potentials are still not clear. The oil and gas potentials in Dayangshu Basin are predicted by the method, and it is shown that the ripe mudstone in the basin is developed and has the ideal conditions of hydrocarbon generation. The source rock enters the threshold of hydrocarbon expulsion and begins to largely expel oil and gas. A good exploration prospects is shown in Dayangshu Basin, and the amount of its accumulative resources can reach to 1 834.477 4×10~4～12 134.163 5×10~4 t.