珠江口盆地东部中生界海相油气勘探前景

对南海北部大陆边缘中生代构造演化及周边区域地质研究表明,珠江口盆地东部在中生代时是西藏主特提斯洋(海)的东延部分.从地震反射特征、重力场特征、层速度特征、岩石密度特征、坳陷构造形态特征、连井解释以及区域沉积相的研究,多个方面阐明了在珠江口盆地东部地区广泛存在中生代海相地层.潮汕坳陷、韩江凹陷作为中生代残留坳陷,充填有3套中生代海相地层.潮汕坳陷可以划分为北部斜坡带、北部凹陷带、中央隆起带和南部凹陷带4个构造单元,划分为四种断裂类型.对周边地区露头、井下资料以及本区地质和地球物理方面的研究结果也表明,该区中生界具有较好的生油能力,可能存在3套有效的储盖组合.因而可以预测珠江口盆地中生界海相是一个重要的油气勘探前景区.

OIL AND GAS EXPLORATION PROSPECT OF MESOZOIC IN THE EASTERN PART OF PEARL RIVER MOUTH BASIN

The Mesozoic tectonic revolution of continental margin in the northern area of South China Sea and the regional geology of its ambient region was studied.The result shows that this region is the eastern part of Tibet main Tethys ocean(sea).Analysis on the characters of seismic reflection,gravity filed ,interval velocity,rock's density,tectonic features of depression,well_to_well interpretation and sedimentary facies of surroundings proved that Mesozoic marine strata are widespread in the eastern area of Pearl River Mouth basin.Chaoshan depression and Hanjiang depression are all Mesozoic residual depression where three sets of Mesozoic marine sequences were deposited.Chaoshan depression is composed of four structural units,including northern slope belt,northern depression belt,central massif belt and southern depression belt.The faults of the Mesozoic in Chaoshan depression can be classified into NE trend reverse fault,NE trend normal fault,EW trend normal fault and NW trend strike_slip fault.Associating with the study of outcrops and cores of ambient region,as well as geology and geophysics of this region,it is regarded that the Mesozoic is of good source rocks,and the area may have three sets of efficient reservoir_cover rock systems.The petroleum system of this area shows that Mesozoic of the eastern part of Pearl River Mouth basin may be an important prospect for oil and gas exploration.