Presence and Control of Evaporite Top Seals on Occurrence and Distribution of Hydrocarbon Traps: Main Fairway, Central Overthrust Belt, Wyoming and Utah: ABSTRACT
Presence and Control of Evaporite Top Seals on Occurrence and Distribution of Hydrocarbon Traps: Main Fairway, Central Overthrust Belt, Wyoming and Utah: ABSTRACT
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DOI：
10.1306/703c8871-1707-11d7-8645000102c1865d
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发表时间：
1988-02
期刊：
影响因子：
3.5
通讯作者：
J. F. Mcintyre
中科院分区：
文献类型：
--
作者：
J. F. Mcintyre
在中央逆冲断层带航道，已知有18个产油层，其年代从寒武纪到白垩纪不等。四个地层单元——奥陶纪大角组、密西西比纪使命峡谷组、侏罗纪金块组和侏罗纪双溪组——占迄今已发现的估计可采储量14亿桶石油的99%。大量油气聚集的一个关键因素是这些储层上方存在有效的蒸发岩盖层。主要的油气聚集存在于与阿布萨罗卡逆冲断层上盘的古生代或侏罗纪尖灭相关的背斜中，已知的源岩出现在白垩纪下盘地层。需要垂直运移为上覆储层提供油气来源。运移通道是通过这些储层的上盘尖灭处或构造核心的裂缝。上盘储层要么缺乏顶部盖层，要么由于褶皱或断层作用导致顶部盖层被大量裂缝破坏，从而允许垂直运移到更高、密封更有效的储层。在逆冲断层产油航道，使命峡谷组的硬石膏、双溪组的石膏泉段以及侏罗纪普鲁斯盐是三个有效的盖层单元。对逆冲断层带圈闭的分析表明，这些蒸发岩盖层的存在及其韧性性质是在这种高度变形的地形中大量油气聚集的重要控制因素。
In the Central Overthrust belt fairway, there are 18 known productive formations ranging from Cambrian to Cretaceous in age. Four units - the Ordovician Big Horn formation, Mississippian Mission Canyon formation, Jurassic Nugget formation, and Jurassic Twin Creek Formation - account for 99% of a reported 1.4 billion bbl of oil estimated recoverable reserves discovered to date. A critical factor necessary for significant hydrocarbon accumulations is the presence of effective evaporite seals above these reservoirs. Major accumulations exist in anticlines associated with Paleozoic or Jurassic cutoffs in the hanging wall of the Absaroka thrust with recognized source rocks occurring in the Cretaceous footwall section. Vertical migration is required to source the overlying reservoirs. Migration pathways are via hanging wall cutoffs of these reservoirs or through fractures in the cores of the structures. Hanging wall reservoirs either lacking top seals or having top seals disrupted by extensive fracturing due to folding or faulting, permit vertical migration into higher, more effectively sealed reservoirs. In the Overthrust producing fairway, anhydrites of the Mission Canyon formation and Gypsum Spring Member of the Twin Creek formation as well as the Jurassic Preuss salt are the three effective seal units. Analysis of Overthrust belt traps suggestsmore » that the presence and ductile nature of these evaporite seals are important controlling factors for the significant hydrocarbon accumulations in this highly deformed terrain.« less