气源断裂与盖层时空匹配关系及对天然气成藏的控制作用——以徐家围子断陷为例

Time and space matching relation between gas source faults and cap rocks and its controlling action on gas accumulation:An example from Xujiaweizi Depression

在气源断裂与盖层发育、断裂活动期及封气能力形成期分析的基础上,对徐家围子断陷气源断裂与盖层时空匹配关系及对天然气成藏的控制作用进行了研究,认为徐家围子断陷气源断裂与登二段泥岩盖层空间匹配关系相对较好,与营一段顶部火山岩盖层空间匹配关系相对较差;气源断裂与登二段泥岩盖层及营一段顶部火山岩盖层时间匹配关系较好。气源断裂与盖层时空匹配关系对营城组天然气成藏的控制作用主要表现为天然气聚集层位和聚集部位受气源断裂与盖层空间匹配关系的影响;天然气聚集程度受气源断裂与盖层时间匹配关系的影响。

Based on the study of development of gas source faults and cap rocks, active state of fault and formation period of sealing ability, time and space matching relation between gas source faults and cap rocks and its controlling action on gas accumulation in Xujiaweizi Depression were studied. The result shows that the space matching relation between gas source faults and mudstone cap rocks of Kit]2 is good, but the space matching relation between gas source faults and volcanic cap rocks on the top of KlyC1 is bad. The time matching relations of gas source faults with mudstone cap rocks of Kid2 and volcanic cap rocks on the top of Klyc1 is good. The space matching relation between gas source faults and cap rocks influences the gas accumulation layer and location, while the time matching relation between gas source faults and cap rocks influences the gas accumulation degree.