Advances in Offshore Oil and Gas Exploration and Development

Oceans cover nearly 71% of the Earth’s surface, and their underlying sedimentary strata hold vast oil and gas reserves that can alleviate global energy shortages. However, extracting these resources remains highly challenging. On the one hand, the marine environment is complex and harsh, subjecting operations to extreme conditions, such as high pressure, low temperatures, strong ocean currents, and severe corrosion [1,2]. On the other hand, offshore oil and gas development demands highly advanced technological capabilities, facing significant hurdles in high-precision seismic-reflection survey, deep-water drilling, as well as oil and gas transportation [3,4]. Simultaneously, unconventional oil and gas have become increasingly vital to the petroleum industry, necessitating further investigation and research [5,6,7].

Contribution 1 detailed the accumulation mechanisms of uranium (U) and thorium (Th) in the marine sediments of the Doushantuo Formation shales. The results indicated that U accumulation is primarily controlled by the adsorption and complexation of organic matter (OM), while Th enrichment is governed by the adsorption capacity of clay minerals, providing a scientific basis for regional helium exploration.

Contribution 2 discussed the sedimentary distribution, evolutionary patterns, and hydrocarbon control mechanisms of two phases of Lower Cretaceous source rocks in the Northern Persian Gulf. It was found that source rock quality is synergistically regulated by sedimentary facies and terrestrial input, and the depositional sequences align closely with global anoxic events and marine transgressions.

Contribution 3 investigated the development characteristics of natural fractures in the metamorphic basement reservoirs of the Bozhong Depression. These reservoirs underwent multistage structural evolution and predominantly developed tectonic fractures. Natural fractures of various scales promote the development of large-scale effective reservoirs.

Contribution 4 clarified the genesis of pore structure characteristics in the low-permeability sandstone reservoirs of the Eocene Wenchang Formation, Huizhou Sag. By classifying pore-throat types and assessing their impact on physical properties of reservoirs, this study pointed out that the Wenchang Formation exhibits a “high storage but low production”, suggesting that connected intergranular and dissolution pores are the critical determinants of effective permeability.

Contribution 5 focused on the source-to-sink system analysis of the steep-slope zone in the Wushi Sag, Beibuwan Basin. Through a comparison of migratory and progradational fans, the study indicated that migratory fans possess excellent physical properties and oil-bearing capacity, and subsequently established high-quality reservoir prediction models for both fan types.

Contribution 6 appraised the impact of submarine methane-rich fluids on gas hydrate production during depressurization. The research showed that fluid invasion exerts a three-phase effect on gas dynamics, characterized by minimal initial impact, intermediate inhibition, and significant late-stage enhancement and demonstrates a notable “1 + 1 > 2” synergistic effect under low rates of water or methane invasion. These findings provide critical guidance for optimizing hydrate recovery strategies.

Contribution 7 proposed a dual-stage attention-based recurrent neural network prediction model to accurately estimate the remaining useful life of offshore electric submersible pumps (ESPs). This method not only improves prediction accuracy but also mitigates equipment degradation through the optimization of operating parameters, thereby enhancing the reliability and economic efficiency of offshore oil production.

Contribution 8 introduced complex nanofluid dispersions (CNDs) as a fracturing fluid additive to enhance oil recovery in tight offshore reservoirs. By reversing rock wettability and reducing flow resistance, CNDs significantly improved spontaneous imbibition recovery, with field applications confirming its substantial potential for production enhancement.

Contribution 9 presented a conceptual model linking the paleohydrology of a marginal sea lacustrine basin to astronomically forced climate variability. This research emphasized the combined roles of obliquity and eccentricity in regulating the hydroclimate of marginal-marine nearshore environments, which ultimately imprints on the distribution of shale-oil sweet spots.

Contribution 10 clarified the biological assemblage patterns of source rocks in the Basal Silurian Renheqiao Formation of Western Yunnan, China. It was found that organic matter enrichment is controlled by primary producers, whereas the presence of secondary consumers like graptolites is detrimental to accumulation.

Contribution 11 analyzed the strike-slip activity of the Tinjar–West Baram Fault (TWBF) in the southern South China Sea through 2D seismic profile analysis. This research pointed out that the displacement along the TWBF significantly controlled the deep-water sedimentary systems of the Zengmu Basin, which led to a unique “southern oil–northern gas” distribution pattern and diverse trap types.

Contribution 12 investigated the tectonic control on intrabasinal “source-to-sink” systems. It was found that the activity of Fault 3 dominated the paleogeomorphic evolution of the Weixinan Low Uplift and its surrounding areas.

Given the coexistence of potential and challenges, more research should be done to efficiently develop offshore oil and gas. Simultaneously, more attention should be paid to unconventional oil and gas development because conventional oil and gas cannot meet energy consumption requirements associated with the rapid development of the world economy.