松辽盆地北部深层天然气勘探风险评价

近年来，松辽盆地深层天然气勘探取得重大突破，同时勘探风险评价也受到决策者的高度重视。文章以松辽盆地北部深层为例，从成藏系统的思路出发，对深层潜在的成烃、成藏断陷开展了地质风险综合评价，认为天然气勘探最有利的断陷分别是徐家围子断陷、莺山-双城断陷和古龙-常家围子断陷。在此基础上，对其低风险的徐家围子断陷进行了含油气系统和油气运聚单元划分，计算了各个运聚单元的生气量、排气量和潜在资源量，同时结合地质背景及天然气成藏条件，指出了有利的勘探方向，对降低勘探风险具有理论和实践意义。

EVALUATION OF EXPLORATION RISK OF DEEP GAS IN NORTH SONGLIAO BASIN

In recent years, large breakthroughs have been made in deep gas exploration and evaluation of exploration risk also has drawn much attention of the decision-makers. Taking the deep reservoir in North Songliao Basin as an example, geologic risks of the deep fault depressions with hydrocarbon generating and reservoiring potentials are comprehensively evaluated. Xujiaweizi, Yingshan-Shuangcheng and Gulong-Changjiaweizi fault depressions are believed to be the most favorable. Petroleum systems and hydrocarbon migration and accumulation units are further divided in Xujiaweizi fault depression with low exploration risk. The volumes of gas generated and migrated and the potential gas resources in each migration and accumulation units are estimated. Favorable exploration directions are presented in combination with the geologic settings and gas reservoiring conditions. These results have theoretical and practical significances for lowering exploration risk.