Volume 1 (2025) 

The characteristics of hydrocarbon source rocks and evaluation of natural hydrogen exploration potential in the deep sag zone of the Jiyang Depression, Bohai Bay Basin

Yongyi Tan, Huilan Tang, Yaowen Ma

Volume 1 (2025), Article ID: eip1v0124a  

Published: 2025-01-24 (Received: 2024-10-26; Revised: 2025-01-10; Accepted: 2025-01-23)

DOI:  https://doi.org/10.5281/zenodo.15567878 

Citation

Tan Y, Tang H, Ma Y. The characteristics of hydrocarbon source rocks and evaluation of natural hydrogen exploration potential in the deep sag zone of the Jiyang Depression, Bohai Bay Basin. Engineering Innovation and Practice, 2025, 1, eip1v0124a.

Abstract

The deep sag zone of the Jiyang Depression, located in the Bohai Bay Basin, is a region with significant oil and gas resource potential, particularly the lower sub-member of the third member of the Shahejie Formation, which is regarded as an enriched layer of high-quality hydrocarbon source rocks. This study focuses on core samples from Well BYP5 to systematically analyze the geological characteristics of the hydrocarbon source rocks and the exploration potential of natural hydrogen in the area. Comprehensive analyses of organic matter content, mineral composition, and thermal evolution characteristics indicate that the hydrocarbon source rocks in the study area have high organic matter abundance, are rich in carbonate minerals, and exhibit high thermal maturity, having undergone significant hydrocarbon generation and expulsion processes. Current measurements of free hydrocarbons and hydrogen index are relatively low, suggesting that the source rocks have reached a highly mature stage of thermal evolution. Core desorption gas analysis reveals a desorption gas content ranging from 0.001 to 0.01 cm³/g, with hydrogen content varying from 1.1% to 19.3% and an average of 7.1%, demonstrating a distinct hydrogen enrichment characteristic. Component analysis of the desorption gas indicates a significant positive correlation between hydrogen and carbon dioxide and a negative correlation with methane. This suggests that hydrogen generation is closely related to organic matter pyrolysis, heterogeneous bond cleavage, and demethylation processes. These findings provide new insights into the exploration of deep and ultra-deep oil and gas resources and offer scientific support for the theoretical study and practical deployment of natural hydrogen exploration. The study aims to deepen understanding of the characteristics of hydrocarbon source rocks and the mechanisms of natural hydrogen formation in the deep sag zone of the Bohai Bay Basin, contributing to the development and utilization of regional oil, gas, and natural hydrogen resources.

Keywords

Jiyang Depression, Bohai Bay Basin, hydrocarbon source rocks, natural hydrogen exploration, thermal evolution

References

[1] Cao X. Occurrence characteristics of the shale oil reservoir in Jiyang Depression, Bohai Bay Basin. Advances in Resources Research, 2022, 2(1), 31-40. 

[2] Ma Y, Qiao Y, Lu P, et al. Reconsideration of shale oil development in Jiyang Depression: Based on hydrocarbon generation, hydrocarbon expulsion, hydrocarbon storage and movable hydrocarbon. Advances in Resources Research, 2023, 3(2), 32-50. 

[3] Wang X. The exploration potential of shale oil reservoirs in Jiyang depression, Bohai Bay Basin: Revaluations based on old oil wells data. Advances in Resources Research, 2021, 1(1), 48-56. 

[4] Wu L, Zhang J. Characteristics of effective source rocks of Paleogene in Jiyang Depression. Geographical Research Bulletin, 2022, 1, 56-62. 

[5] Lu M. Improving the understanding of shale oil in the Jiyang Depression by analyzing the characteristics of shale oil reservoirs. Geographical Research Bulletin, 2023, 2, 120-123. 

[6] Liu X, Zhang J, Guo X, et al. A grading evaluation method of shale oil and gas resources. Resources Data Journal, 2023, 2, 21-34.

[7] Ma X, Li M, Hu K, et al. Origin of abnormally high pressure in the Paleogene in the Jiyang Depression, Bohai Bay Basin and its relationship with continental shale oil enrichment. Experimental Petroleum Geology, 2023, 45(1), 145-156.

[8] Liu X. Geological characteristics and concentrated zones evaluation of tight oil reservoirs: A case study of the sedimentary basins in China. Advances in Resources Research, 2021, 1(1), 33-47.

[9] Zhao P, Wang Q, Li H. Characteristics and distribution of fugitive gas from source rocks in the deep depression zone of Jiyang Depression, Bohai Bay Basin. Petroleum Exploration and Development, 2020, 47(5), 589-596.

[10] Chen P, Zhou T, Gao L. Characteristics of fugitive gas and analysis of hydrocarbon generation process in deep source rocks in Bohai Bay Basin. Petroleum Geology and Recovery, 2019, 26(4), 498-505.

[11] Li Z, Liu B, Gao L. Thermal evolution and fugitive gas generation characteristics of deep source rocks in Bohai Bay Basin. Petroleum Resources and Engineering, 2021, 8(1), 40-47.

[12] Gao L, Liu B, Zhang J. Composition of fugitive gas in gas reservoirs in Bohai Bay Basin and its relationship with hydrocarbon generation and expulsion. Chinese Journal of Geology, 2020, 94(12), 2281-2288.

[13] Zhao P, Wang Q, Li H. Generation mechanism and gas composition characteristics of fugitive gas from source rocks in Bohai Bay Basin. Petroleum Exploration and Development, 2020, 47(6), 663-670.

[14] Gao L, Liu B, Zhang J. Analysis of thermal evolution characteristics and gas composition of deep source rocks in the Bohai Bay Basin. Chinese Journal of Geology, 2020, 94(12), 2281-2288.

[15] Zhang S, He K, Wang X, et al. Deep multi-path compound gas generation model and potential contribution to reservoir formation. Natural Gas Geoscience, 2021, 32(10), 1421-1435.

[16] Zhao X, Zeng S, Meng K, et al. Filling characteristics and accumulation process of deep low-permeability (tight) sandstone gas reservoirs in Banqiao Depression, Huanghua Depression, Bohai Bay Basin. Oil and Gas Geology, 2020, 41(5), 913-927.

[17] Wei Q, Zhu R, Yang Z, et al. Geological characteristics, formation, distribution and resource prospects of natural hydrogen reservoirs. Natural Gas Geoscience, 2023, 35(6), 1113-1122.

[18] Li G, Liu C, Wang F, et al. Geochemical characteristics and hydrocarbon generation models of source rocks in Dongying Formation, Bozhong Depression, Bohai Bay Basin. Chinese Journal of Petroleum, 2022, 43(11), 1568-1584.

[19] Yang X, Liu C, Wang F, et al. Distribution characteristics and origin of overpressure in the Paleogene Dongying Formation in the Southwest Depression of Bozhong Depression, Bohai Bay Basin. Oil and Gas Geology, 2024, 45(1), 96-112.