琼海凹陷反转构造特征及油气条件分析

珠江口盆地珠Ⅲ拗陷已经发现了大量反转构造油气藏及含油构造，但拗陷北部的琼海凹陷反转构造带研究程度很低.运用生长指数法及位移-距离曲线法分析了琼海凹陷反转构造的反转时期及活动强度.利用沉积分析及定量模拟的手段评价了该区反转构造的烃源岩、储层、盖层条件.结果显示，琼海凹陷构造反转开始于中新世中期；反转构造带发育始新统烃源岩及渐新统-中新统储盖组合；反转时期与文昌组上部烃源岩主排烃期匹配，反转构造带是琼海凹陷有利的勘探方向.

ANALYSIS ON THE INVERSION STRUCTURES AND OIL-GAS CONDITIONS OF THE QIONGHAI SAG

A large number of inversion oil-gas reservoirs and oil-bearing structures have been discovered in Z-3 Depression of Pearl River Mouth Basin, yet the research on the inversion structure belts in Qionghai Sag in the north of the Depression was in low level. The methods of growth index and displacement-distance curve are adopted to analyze the period and intensity of inversion structures. The source rocks, reservoirs and caprock conditions are evaluated through sedimentary analysis and quantitative simulation. The results show that the structural inversion started in the middle Miocene, with the Eocene source rocks and Oligocene-Miocene reservoir-caprock assemblages developed in the inverted structure belts. The inversion period is matched with the main expulsion stage of source rocks in the upper Wenchang Formation, thus it is concluded that the inversion structural belt is a favorable exploration direction for Qionghai Sag.