摘要
南沙海域西南部具有上始新统-下渐新统、上渐新统-中中新统、上中新统三套油气源岩,其有机质类型属Ⅱ_B-Ⅲ干酪根。根据DavidA. Wood (1988)计算不同地层的TTI值和R_o值,确定了研究区的生油门限深度,万安盆地南部为1700-3500m,曾母盆地西北部为1500-3500m,并分析了有机质成熟度的热演化史。研究区发育有三类储集层:渐新世-晚中新世砂岩、中-晚中新世台地灰岩或礁灰岩和前第三纪裂缝性风化基岩。区域盖层条件良好,并发现有四大类型的圈闭,即背斜、半背斜、断鼻和断块等构造及台地灰岩、礁隆和基岩潜山等地层圈闭类型。作者最后将研究区划分为三个含油气远景区。
The upper Eocene to lower Oligocene, upper Oligocene to middle Miocene and upper Miocene contained Ⅱ_B-Ⅲ type kerogene, may be three suites of oil-& gas-bearing rocks in the southwestem Nansha sea area. Based on the thermo-evolution history of organic material and the calculated TTI and Ro values according to David A. Wood's method (1988), the writers confirm that the oil-generating threshold depth in the southern Wan'an Basin is 1703-3500m, and that of northwestern Zengmu Basin is 1500-3500m. Three kinds of reservoirs, i.e. sandstones of Oligocene-upper Miocene, lime- stone or reef limestones of middle-upper Miocene, weathered basement rocks of pre-Tertiary may be discovered in the region. There good caprocks and excellent traps also develop well, four types of the later are: anticlines, faulted blocks, platform limestones and reef limestone as well as buffed hills. Af- ter comprehensive evaluation, three oil and gas prospectiong provinces in the region are divided by the anthers (Long X.).
出处
《南海地质研究》
1996年第8期75-86,共12页
Gresearch of Eological South China Sea
