渤海海域盆地石油地质条件与大中型油气田分布特征

Petroleum geologic conditions and distributional features of large-and medium-sized oil and gas fields in Bohai Sea Basin

在回顾渤海海域盆地(渤海湾盆地海域部分)油气勘探历程及相关石油地质理论研究的基础上,总结了渤海海域盆地的新生代构造-沉积演化历程,分析了渤海海域盆地的石油地质条件,着重指出了与相邻陆区的显著差异。首先,渤海海域盆地两期构造旋回相应发育了沙河街组和东营组两套优质烃源岩,其中东营组烃源岩为海域盆地所特有,且晚期快速沉降有助于其成熟,因此,渤海海域盆地具有更为优越的烃源条件;其次,渤海海域盆地新近系广泛发育浅水-极浅水三角洲,是海域特有的一套勘探层系;最后,郯庐断裂带海域部分的长期持续活动最终形成了渤海海域盆地大中型油气田集中分布的油气富集带,是当前渤海油气勘探的重要领域。充分认识渤海海域盆地演化的特殊性及其独特的石油地质条件和油气富集规律,对今后的渤海油气勘探及相关研究具有参考价值。

On the basis of reviewing the petroleum exploration history of the Bohai Sea Basin(the offshore part of the Bohai Bay Basin)and the related petroleum geologic theories,we summarized the Cenozoic tectonic-sedimentary evolution of the Bohai Sea Basin,and analyzed its petroleum geologic conditions,with focus on their significant differences from that of the onshore part of the Bohai Bay Basin.First of all,two sets of high-quality source rocks of the Shahejie Formation and Dongying Formation are developed as the results of two tectonic cycles of the Bohai Sea Basin.The distribution of source rocks of the Dongying Formation is limited to this basin,and the rapid subsidence in late stages contributes to its maturity,both of which manifest the more favorable hydrocarbon source conditions in the Bohai Sea Basin.On the other hand,shallow-extremely shallow-water deltas,a unique series of strata for exploration in the offshore part,are widely developed in the Neogene of the Bohai Sea Basin.In addition,the long-term sustained activities of the Tanlu fault zone in the offshore part eventually resulted in the play fairway with several large-and medium-sized oil and gas fields in the Bohai Sea Basin,which is an important field for oil and gas exploration in the Bohai Sea at present.It’s of referential value for future Bohai Sea exploration and related studies to fully understand the particularity of evolution of the Bohai Sea Basin and its unique petroleum geologic conditions and oil and gas accumulation patterns.