Dolomitization history and porosity evolution of a giant, deeply buried Ediacaran gas field (Sichuan Basin, China)
Dolomitization history and porosity evolution of a giant, deeply buried Ediacaran gas field (Sichuan Basin, China)
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深埋埃迪卡拉系巨型气田的白云石化历史和孔隙度演化（中国四川盆地）
DOI：
10.1016/j.precamres.2020.105595
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发表时间：
2020-03
影响因子：
3.8
通讯作者：
Immenhauser Adrian
中科院分区：
文献类型：
--
作者：
Hu Yongjie;Cai Chunfang;Pederson Chelsea L.;Liu Dawei;Jiang Lei;He Xunyun;Shi Shuyuan;Immenhauser Adrian
深埋（> 7 km）的埃迪卡拉纪（震旦纪）灯影组（约。中国四川盆地前寒武纪白云岩气藏（551.1-541 Ma）是世界上最大的前寒武纪白云岩气藏。然而，由于对灯影组复杂的岩化历史和孔隙演化的认识有限，灯影组天然气勘探受到阻碍。进行了新的岩石学、地球化学和岩石物理学分析，并在此进行了讨论，以更好地了解地层的复杂性。微生物岩，白云颗粒岩，结晶白云岩岩性从平台边缘具有较高的原生孔隙度相对于白云泥岩和较常见的微生物岩岩性从低能量的平台内部。空间上可变的原生孔隙随后被大气溶解和风化作用叠加，常常诱发次生孔隙。各种形式的硅化作用（萨布哈、回流和埋藏硅化作用以及胶结作用）增加了这些岩石对化学和物理压实作用以及孔隙破坏的抵抗力。在深埋藏区域，中至粗晶白云岩胶结物和鞍状白云岩分别在120-160 ℃和160-220 ℃的流体温度下沉淀。深埋溶解的意义进行了严格的讨论和限制：（i）晚成岩矿物的腐蚀，（ii）孔隙横切（或周围形成）缝合线，（iii）固体沥青的出现在次生孔隙的中心。晚深埋藏阶段发育有孔洞、晶间和晶内孔隙，孔隙类型约为1000 ~ 1000 m。整个灯影储层孔隙度的20%。在此埋藏阶段引起腐蚀的机制包括热液脉冲和热化学硫酸盐还原。与中生代的许多碳酸盐岩储层类似，本研究记录了由于其特定的碳酸盐岩性质和成岩作用，与平台内部相比，平台边缘具有更好的孔隙度和更高的天然气产量。这里显示的数据记录了复杂的多相石化历史和深埋前寒武系白云岩储层的高天然气生产潜力。
The deeply buried (> 7 km) upper Ediacaran (Sinian) Dengying Formation (ca. 551.1-541 Ma) in the Sichuan Basin, China, is the largest Precambrian dolostone gas reservoir worldwide. Gas exploration from the Dengying Formation, however, is hampered by a limited understanding of its complex dolomitization history and porosity evolution. New petrological, geochemical and petrophysical analyses were performed and are discussed here to develop a better understanding of the formation's complexities. Microbialite, dolo-grainstone, and crystalline dolostone lithologies from the platform margin have high primary porosities relative to dolo-mudstone and less common microbialite lithologies from the low-energy platform interior. Spatially-variable primary porosity was subsequently overprinted by meteoric dissolution and dolomitization, often inducing secondary porosity. The various forms of dolomitization (sabkha, reflux, and burial dolomitization, and cementation) increased the resistivity of these rocks to chemical and physical compaction and porosity destruction. In the deep burial domain, medium- to coarse-crystalline dolomite cements and saddle dolomite precipitated at fluid temperatures of 120-160 degrees C and 160-220 degrees C, respectively. The significance of deep burial dissolution is critically discussed and constrained by: (i) corrosion of late diagenetic minerals, (ii) pores cross-cutting (or forming around) stylolites, and (iii) the occurrence of solid bitumen in the center of secondary pores. Vuggy, inter- and intracrystalline pores developed during a late and deep burial stage, and comprise ca. 20% of the overall Dengying reservoir porosity. Mechanisms which induced corrosion at this burial stage include hydrothermal pulses and thermochemical sulfate reduction. Similar to many carbonate reservoirs in the Phanerozoic, this study documents that the platform margin has better porosities and higher gas production compared to the platform interior due to its specific carbonate rock properties and diagenesis. Data shown here document the complex multiphase dolomitization history and high potential for gas production from deeply buried Precambrian dolostone reservoirs.
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影响因子：
5.8
作者：
H. Qing;E. Mountjoy
通讯作者：
H. Qing;E. Mountjoy
DOI：
10.1007/978-3-319-78527-1
发表时间：
1973
期刊：
Stable Isotope Geochemistry
影响因子：
--
作者：
J. Hoefs
通讯作者：
J. Hoefs
影响因子：
3.5
作者：
A. Saller;D. A. Pollitt;J. Dickson
通讯作者：
A. Saller;D. A. Pollitt;J. Dickson
DOI：
10.1016/c2010-0-65780-4
发表时间：
2013-10
期刊：
--
影响因子：
--
作者：
C. Moore;W. J. Wade
通讯作者：
C. Moore;W. J. Wade
影响因子：
3.5
作者：
Grotzinger, John;Al-Rawahi, Zuwaina
通讯作者：
Al-Rawahi, Zuwaina