摘要
南黄海盆地是新生代、中生代、古生代大型叠合盆地,具有良好的油气资源前景.中部隆起是南黄海盆地的二级构造单元,由于缺乏钻探资料,对中部隆起前新生代地层分布和油气资源前景的认识众说纷纭.因此,在中部隆起上实施科学钻探,探查中-古生代地层属性,对研究南黄海区域地质构造特征和油气地质条件意义重大.针对科学钻探目标,采用区域地质背景指导下的地质、地球物理综合研究的方法,拟定了科学钻探井(CSDP-2井)位置;利用叠前时间偏移成像处理剖面,采用地震相、地震速度分析和储层预测技术,进行了钻前层位预测和油气储层分析.该井由青岛海洋地质研究所负责的"大陆架科学钻探"项目实施,全取芯钻探成果表明,中部隆起上赋存了三叠系-奥陶系海相残余地层,发育中等—好级别的、厚度较大的海相中-古生界烃源岩,在三叠系青龙组、二叠系龙潭组和栖霞组、泥盆系和志留系中获得多层不同级别的油气显示.CSDP-2井的钻探发现,结束了关于中部隆起海相地层属性的争论,坚定了南黄海海相油气勘探的信心,为区域地质研究和油气地质条件分析提供了基础数据.
The South Yellow Sea Basin is a multi-cycle superimposed basin composed by themarine Mesozoic-Paleozoic basin and overlaid by the continental Mesozoic-Cenozoic basin on the basis of the Presinian cratonic basement of which marine Mesozoic-Paleozoic layer is considered to have broad oil and gas prospects.The central uplift in the middle of South Yellow Sea Basin is one of the secondary tectonic units in South Yellow Sea Basin,the thickness of the Cenozoic sedimentary layer is no more than 1000 m.As an important part of South Yellow Sea Basin,the central uplift shows a bright prospect of oil and gas within a thick marine sedimentary layer below Cenozoic sediment.The views of pre-Cenozoic strata distribution and its hydrocarbon resources in Central Uplift are controversial due to lacking of drilling data.Therefore,Scientific Drilling in the central uplift to explore the Mesozoic-Paleozoic stratigraphic attributes will be of great significance to study on the characteristics of regional geological structure in the South Yellow Sea and their Petroleum Geology Conditions.In order to clarify the character of the MiddlePaleozoic strata and geological structure and find out the petroleum geological condition,and apply the comprehensive geological and geophysical research method under the guidance of regional geological background,the position of Scientific Drilling Well CSDP-2 is designed.The pre-drilling strata and petroleum reservoir were effectively predicted by using seismic phases and seismic velocity analysis and reservoir prediction methods and techniques in the 2 DPTM(pretime migration)section.The Continental Scientific Drilling Project(CSDP)was organized by Qingdao Institute of Marine Geology(QIMG).The first drilling well(Well CSDP-2)has deployed and finished the core drilling in whole length.The drilling results confirmed the distribution of Mesozoic-Paleozoic marine sedimentary strata in the Central Uplift.The long debate about the properties of marine residual strata in the central uplift will be ended.At the same time,the average-good class and large thickness Mesozoic-Paleozoic marine hydrocarbon source rocks were confirmed and the multilevel-based hydrocarbon shows in Qinglong Formation,Longtan Formation,Qixia Formation and Devonian-Silurian were found during the well drilling.The results indicate a favorable potential of oil and gas exploration in the South Yellow Sea.The confidence in marine hydrocarbon resources exploration will be firmed and the work of marine hydrocarbon resources exploration in the South Yellow Sea,especially in the Central Uplift was promoted greatly.