Five anomalous structural aspects of rift basins in Thailand and their impact on petroleum systems
Five anomalous structural aspects of rift basins in Thailand and their impact on petroleum systems
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泰国裂谷盆地五个异常构造特征及其对含油气系统的影响
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发表时间：
2015
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影响因子：
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通讯作者：
C. Morley
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文献类型：
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作者：
C. Morley
摘要泰国裂谷盆地的克拉通内、超俯冲带背景使裂谷以几种不同于其他克拉通内裂谷的方式演化。主要区别包括：广泛存在的低角度正断层;盆地反转与裂谷交替;裂谷的历时启动和停止;裂谷后快速沉降;以及广泛的低位移裂谷后断层。这些特征与新生代大陆岩石圈的热、弱、板块边界和应力的快速演化以及俯冲和增生历史有关。低角度正断层通过控制河流-三角洲储层与湖相页岩（源岩和盖层）交指的位置而影响了Alaskit油田。盆地反转与同裂谷段交替，破坏同裂谷结构，并在盆地历史早期停止油气成熟，从而不利于彭世洛盆地南半部的勘探。盆地发展的穿时性导致了泰国湾东部盆地中以天然气为主的大型油气聚集，但对缺乏裂谷后部分的年轻盆地以及裂谷后盆地提供的更多种类的石油系统和圈闭不利。广泛的低位移-长度比裂谷后断层在帕塔尼和北马来盆地形成了重要的油气圈闭。它们代表了一种在后裂谷盆地中不常见的构造样式。
Abstract The intracratonic, supra-subduction zone setting of the Thailand rift basins caused the rifts to evolve in several ways differently from other intracratonic rifts. Key differences include: widespread occurrence of low-angle normal faults; basin inversion alternating with rifting; diachronous initiation and cessation of rifting; rapid post-rift subsidence; and extensive, low-displacement post-rift faults. These characteristics are related to hot, weak continental lithosphere, rapid evolution of the plate boundaries and stresses during the Cenozoic, and the history of subduction and accretion. Low-angle normal faults impacted the Sirikit Field by controlling the location of fluvio-deltaic reservoirs interfingering lacustrine shales (source and seal). Basin inversion alternating with syn-rift section is detrimental to prospectivity of the southern half of the Phitsanulok Basin by destroying syn-rift structure, and halting hydrocarbon maturation early in the basin history. The diachronous timing of basin development resulted in large, gas-dominated hydrocarbon accumulations in the eastern Gulf of Thailand basins, but was detrimental for younger basins that lack the post-rift section, and the greater variety of petroleum systems and traps that post-rift basins offer. The extensive low displacement–length ratio post-rift faults form significant hydrocarbon traps in the Pattani and North Malay basins. They represent a structural style not usually found in post-rift basins.