南黄海中古生界勘探进展及油气潜力

NEW EXPLORATION PROGRESS AND HYDROCARBON POTENTIAL OF THE MESO-PALEOZOIC SYSTEMS IN THE SOUTH YELLOW SEA

2005年南黄海盆地油气勘探由新生界向中古生界转变。综合利用区域地质、地球物理、地球化学和钻井资料,从地层层序、沉积相和沉积体系、残留盆地构造特征以及石油地质条件等几个方面阐述最近几年来南黄海盆地中古生界油气勘探的进展。中古生界残留地层可以分为下构造层(震旦—奥陶系)、中构造层(志留系)和上构造层(泥盆系—三叠系)3套层系。盆地中古生界以海相沉积为主,发育碳酸盐岩台地—斜坡—盆地相沉积体系、碳酸盐岩缓坡—盆地相沉积体系和海陆过渡三角洲沉积体系。中古生界发育下寒武统、上奥陶统—下志留统、上、下二叠统4套区域性烃源岩,其中以二叠系栖霞组、龙潭组和大隆组烃源岩层最为有利。中古生界储层以碳酸盐岩储层为主,其次是碎屑岩储层。综合分析认为,南黄海盆地中古生界油气勘探最有利的区带为中部隆起区。

The main targets of oil and gas exploration in the South Yellow Sea Basin have shifted from the Cenozoic to the Meso-Paleozoic in 2005.In this paper,we presented an integration of data of regional geology,geophysics,geochemistry,and drilling data collected,and a discussion on the new progress of stratigraphic sequences,sedimentary facies,depositional systems,residual basin characteristics and petroleum geological conditions and other aspects of the Mesozoic and the Paleozoic in recent years in the South Yellow Sea Basin.The Meso-Paleozoic residual deposits can be divided into three structural layers：the lower（the Sinian-Ordovician）,the middle（the Silurian）and the upper（the Devonian-Triassic）.Basins in Mesozoic and Paleozoic were marine-oriented and characterized by carbonate platform-slope-basin depositional systems,carbonate ramp-basin depositional system and transitional deltaic systems.The Meso-Paleozoic systems have four sets of source rocks in lower Cambrian,Upper Ordovician-lower Silurian,lower Permian and upper Permian respectively,of which the source rocks in the Qixia Formation,Longtan Formation and Dalong Formation of Permian are the most favorable.The main Mesozoic-Paleozoic reservoirs are carbonate rocks,followed by clastic rocks.Comprehensive analysis reveals that the most favorable exploration area of the Mesozoic and Paleozoic hydrocarbon in the South Yellow Sea Basin is in the Central uplift area.