摘要：Abundant pyrobitumen related to an abnormal thermal event has been observed in the Ediacaran-lower Cambrian reservoirs of the central Sichuan Basin. Using reflected light microscopy, this study classified reservoir pyrobitumen in the Ediacaran-lower Cambrian into three groups: isotropic, mosaic, and fibrous; the mosaic pyrobitumen was further subdivided into fine-grained, medium-grained, and coarse-grained. Based on organic elemental analysis, carbon isotopic composition, nuclear magnetic resonance, X-ray diffraction, thermogravimetric-mass spectrometry, and fluid inclusion geochemistry, the relationship between the optical texture of pyrobitumen and hydrothermal temperature was determined and the influence of hydrothermal activity on crude oil cracking is discussed. With the exception of the mosaic pyrobitumen (quinoline insoluble matter-enriched tar pad precursor) found in the most porous reservoir zone, the optical texture in the Ediacaranlower Cambrian reservoirs can be used to trace the hydrothermal activity, which occurred at the end of the Permian and may be related to the Emeishan mantle plume. The hydrothermal fluid may have invaded the strata of the second and fourth members of the Dengying Formation and the Longwangmiao Formation, along deep faults in the Gaoshiti area and migrated laterally to the northeast. The intrusion of the hydrothermal fluid directly promoted the cracking of crude oil in the reservoirs, and this behavior advances the previously accepted cracking time by approximately 60 Ma. The study found that hydrothermal activity promoted the cracking of crude oil in the Ediacaran-lower Cambrian reservoirs, which is a significant recognition for understanding the history of hydrocarbon accumulation in the Sichuan Basin.

关键字：Optical texture; Pyrobitumen; Hydrothermal activity; Crude oil cracking; Central Sichuan Basin

ISSN号：0166-5162

卷、期、页：卷: 259

发表日期：2022-07-01

影响因子：6.805700

期刊分区（SCI为中科院分区）：二区

收录情况：SCIE（科学引文索引网络版）,地学领域高质量科技期刊分级目录（国外T1）,EI（工程索引）

发表期刊名称：INTERNATIONAL JOURNAL OF COAL GEOLOGY

参与作者：张本健,马奎,王云龙,杨岱林,耿超,卢嘉勋

通讯作者：朱联强,田兴旺,李强

第一作者：柳广弟,宋泽章,赵文智

论文类型：期刊论文

论文概要：朱联强,柳广弟,宋泽章,张本健,赵文智,田兴旺,马奎,王云龙,杨岱林,李强,耿超,卢嘉勋，Hydrothermal activity in ultra-deep strata and its geological significance for deep earth gas exploration: Implications from pyrobitumen in the Ediacaran-lower Cambrian Strata, Sichuan Basin，INTERNATIONAL JOURNAL OF COAL GEOLOGY，2022，卷: 259

论文题目：Hydrothermal activity in ultra-deep strata and its geological significance for deep earth gas exploration: Implications from pyrobitumen in the Ediacaran-lower Cambrian Strata, Sichuan Basin