Origin and reservoir characteristics of Upper Ordovician Trenton–Black River hydrothermal dolomite reservoirs in New York
Origin and reservoir characteristics of Upper Ordovician Trenton–Black River hydrothermal dolomite reservoirs in New York
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DOI：
10.1306/04260605078
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发表时间：
2006-11
期刊：
影响因子：
3.5
通讯作者：
Langhorne B. Smith
中科院分区：
文献类型：
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作者：
Langhorne B. Smith
在过去的十年中，在纽约中南部上奥陶统黑河群横向不连续的泥岩中发现了20多个新的天然气田。这些花岗岩形成于地震数据可探测到的基底扭转断层周围。大多数油田发生在细长的断层边界的构造低点及其周围，这些构造低点被解释为负花状构造。远离这些断层，地层由不透水的石灰岩组成，形成储层的侧向封闭。在大多数情况下，断层在上覆的特伦顿石灰岩和尤蒂卡页岩中消失。大多数孔隙出现在鞍状方解石覆盖的溶洞、角砾岩和裂缝带中。基质孔隙度在本研究描述的黑河岩心中并不常见。基底断裂周围的斑片状分布和地球化学及流体包裹体分析支持鞍状和基质辉长岩与断裂有关的热液成因。这出戏由于其非常规的结构设置（即，结构性低点与高点）。采用适当的构造-地层-成岩一体化模式，在纽约黑河和世界各地的碳酸盐岩中有可能发现更多的热液白云岩天然气藏。
In the past decade, more than 20 new natural gas fields have been discovered in laterally discontinuous dolomites of the Upper Ordovician Black River Group in south-central New York. The dolomites form around basement-rooted wrench faults that are detectable on seismic data. Most fields occur in and around elongate fault-bounded structural lows interpreted to be negative flower structures. Away from these faults, the formation is composed of impermeable limestone and forms the lateral seal for the reservoirs. In most cases, the faults die out within the overlying Trenton Limestone and Utica Shale. Most porosity occurs in saddle dolomite-coated vugs, breccias, and fractured zones. Matrix porosity is uncommon in the Black River cores described for this study. The patchy distribution around basement-rooted faults and geochemical and fluid-inclusion analyses supports a fault-related hydrothermal origin for the saddle and matrix dolomites. This play went for many years without detection because of its unconventional structural setting (i.e., structural lows versus highs). Using the appropriate integrated structural-stratigraphic-diagenetic model, more hydrothermal dolomite natural gas reservoirs are likely to be discovered in the Black River of New York and in carbonates around the world.