扬子陆块东南缘海相油气勘探前景

扬子陆块东南缘震旦纪—中三叠世海相地层发育在华南板块早、晚两期陆内裂谷盆地演化的巨型旋回中。该区层序地层发育了13个超层序和94个层序,其中第3个超层序(下寒武统)和第12、13超层序(二叠系)的海侵层序组是该区主要的烃源岩层位。烃源岩发育的有利相带为台盆相或受局限的台地相、外陆棚相、深水盆地相。已在江苏句容、江西萍乡—乐平、广西十万大山等地发现多处油气显示。经对油气资源的初步评价,扬子陆块东南缘海相地层的油气远景资源量超过20×10~8t 油当量。认为上古生界石炭系一二叠系海相—海陆交互相地层是该区的主要勘探目的层系,面积达40×10~4 km~2的扬子东南裂谷盆地带(江苏句容常州—江西乐平萍乡—广西十万大山海相地层分布带)是中国南方较有前景的海相油气勘探领域之一。建议加强该带海相石油及其伴生气、裂解气、海陆交互相煤系及其煤成气、煤层气的联合勘探研究工作。

Petroleum Exploration Prospect in the Marine Strata Region of Southeastern Margin of Yangzi Landmass

The Sinian—Middle Triassic marine strata in the southeast- ern margin region of the Yangzi landmass were developed with- in two megcycles evolved in the intracontinental rift basins of South China plate.The recent sequence stratigraphy research indicates that there are 13 super-sequences and 94 sequences developed in this studied region,in which the Low Cambrian TST of Super-sequence 3 and the Permian Super-sequences 12 and 13 are the best regional source rocks.The sedimentary fa- cies belts where source rock are well developed are the plat- form basin,restricted platform,outer shelf and deep basin fa- cies.In this region,some oil and gas showings have been dis- covered in Jurong Basin,Pingxiang-Leping Basin and Shiwan- dashan Basin.The resource evaluation has proved that there is over 2.0×10~9t of oil equivalent in this prospective marine strata region with an area of 400×10~3 km~2.It is suggested that more attention and research should be paid to the Permian and Carboniferous strata for petroleum exploration.