『Abstract
This article reviews progress in the understanding of the role
of clay minerals in crude oil formation, migration and accumulation.
Clay minerals are involved in the formation of kerogen, catalytic
cracking of kerogen into petroleum hydrocarbon, the migration
of crude oil, and the continued change to hydrocarbon composition
in underground petroleum reservoirs. In kerogen formation, clay
minerals act as catalysts and sorbents to immobilize organic matter
through ligand exchange, hydrophobic interactions and cation bridges
by the mechanisms of Maillard reactions, polyphenol theory, selective
preservation and sorptive protection. Clay minerals also serve
as catalysts in acid-catalyzed cracking of kerogen into petroleum
hydrocarbon through Lewis and Brφnsted acid sites on the clay
surface. The amount and type of clay mineral affect the composition
of the petroleum. Brφnsted acidity of clay minerals is affected
by the presence and state of interlayer water, and displacement
of this water is a probable driver in crude oil migration from
source rocks. During crude oil migration and accumulation in reservoirs,
the composition of petroleum is continually modified by interaction
with clay minerals. The clays continue to function as sorbents
and catalysts even while they are being transformed by diagenetic
processes. The detail of chemical interactions and reaction mechanisms
between clay minerals and crude oil formation remains to be fully
explained but promises to provide insights with broader application,
including catalytic conversion of biomass as a source of sustainable
energy into the future.
Keywords: Crude oil; Clay minerals; Petroleum; Kerogen; Hydrocarbon;
Catalysis』
Contents
1. Introduction
2. The acidity of clay minerals
3. The role of clay minerals in kerogen formation
3.1. The role of sorption and protection of clay minerals
3.2. The role of clay minerals in degradation-recondensation
of organic matter
3.2.1. Maillard reactions
3.2.2. Polyphenol theory
3.2.3. Clay-humic complexes formation
3.3. The role of clay minerals in selective preservation of organic
matter
4. The catalysis of clay minerals in the conversion of kerogen
into crude oil
4.1. Catalytic hydrocarbon cracking
4.2. Catalytic decarboxylation
5. The expulsion and migration of crude oil from source rocks
6. The role of clay minerals in the reservoirs of crude oil
7. Conclusion
Acknowledgments
References