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ORIGINAL RESEARCH article

Front. Earth Sci.

Sec. Sedimentology, Stratigraphy and Diagenesis

This article is part of the Research TopicAdvances in Sequence Stratigraphy Interpretation and Their ImplicationsView all 8 articles

Favorable Conditions for Deep Dissolution Reservoirs in Warm Basins with Stable Source-to-Sink Systems: Example from the Eastern Pearl River Mouth Basin

Provisionally accepted
Xiaoping  LiXiaoping Li*Xiaoyan  LiXiaoyan LiQibiao  ZangQibiao ZangJinliang  LiuJinliang LiuYushu  XiangYushu XiangWenfang  TaoWenfang TaoGuofu  CaiGuofu CaiFengjuan  ZhouFengjuan Zhou
  • China National Offshore Oil Corporation - Shenzhen, Shenzhen, China

The final, formatted version of the article will be published soon.

Exploration results demonstrate the development of high-quality reservoirs with superior physical properties (porosity up to 22%, permeability up to 4 D) in the deep Paleogene strata of the eastern Pearl River Mouth Basin, despite burial depths greater than 3,500 m and formation temperatures exceeding 120 ° C. Their formation is closely linked to dissolution by fluids. By integrating petrographic, geochemical, and basin analysis methods, this study identifies three principal types of dissolution fluids in the study area: meteoric water, organic acids, and hydrothermal fluids. Accordingly, three categories of dissolution reservoirs are delineated. The favorable geological conditions for each reservoir type are elucidated as follows: (1) Meteoric water dissolution reservoirs require prolonged shallow burial due to early tectonic uplift, early active faults serving as infiltration pathways, and sealing preservation provided by overlying thick mudstones. (2) Organic acid dissolution reservoirs are governed by a strong supply of organic acid sourced from hydrocarbon-rich sags, effective transport through late-stage active faults, and a close source-reservoir configuration. (3) Hydrothermal dissolution reservoirs are primarily associated with deep-seated faults (especially for NNW-trending concealed faults) penetrating the Moho, which act as conduits for hydrothermal fluid migration. This study clarifies that, within the context of a stable source-to-sink system and a warm basin setting, the differential distribution of deep high-quality reservoirs is predominantly controlled by the types of dissolution fluids and their specific geological conditions. Three conditions are the favorable geological conditions for their formation: 1. A stable source-sink system provides the material basis and dissolution channels for reservoirs;2.Multi-source fluids are driving forces for the formation of reservoir improvement;3.Tectonic activities provide channels and open environments for dissolution. These findings contribute to a deeper understanding of the genesis of deep reservoir and provide guidance for exploration in analogous basins.

Keywords: Deep strata, Dissolution reservoir, Favorable geological conditions, Hydrothermal fluid, Meteoric water, organic acid, Paleogene, Pearl River Mouth Basin

Received: 22 Nov 2025; Accepted: 29 Jan 2026.

Copyright: © 2026 Li, Li, Zang, Liu, Xiang, Tao, Cai and Zhou. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Xiaoping Li

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