Abstract: Bohai Bay Basin is divided into onshore and offshore parts. In onshore gas exploration,only few small gas fields have been found up to now,mainly with associated gas. But in the offshore,gas exploration has taken good effect. Compared with the onshore, offshore Bohai has better geological conditions for forming gas pools,there is much better exploration potential in the offshore. The factors responsible for the gas rich-ness in offshore Bohai are represented as follows:The thicker deposition sediments, it made the main source rock-Eocene Shahejie Formation reach overmature to generate gas;there is huge thickness of Oligocene source rock-Dongying Formation; there are strong Tertiary tectonic movements and high heat-flow in the offshore. In addition,the shallow layer is also a gas exploration area in the offshore.

Key words: offshore Bohai, gas exploration, high mature gas, shallow gas pool

摘要： 渤海湾盆地由陆上和海上两部分组成,至今陆上天然气勘探仅找到以伴生气为主的小气田;海域天然气勘探也取得一定的成效,由于形成条件要优于陆上,勘探前景更为广阔。海域天然气比陆上富集的主要因素表现在:沉积厚度大,使得盆地内主要烃源岩始新世沙河街组达到高成熟生气阶段;存在巨厚的渐新世东营组烃源岩;具有较强的晚期构造运动和较高的热流值,在浅层也有天然气聚集的领域。

关键词: 渤海海域, 天然气勘探, 高成熟气, 浅层气藏