Innovative Developments and Future Prospects of Geo-Energy Technology in China

1. Introduction

The development of geological energy in China has a long history. From the utilization of coal in 500 BC to the take-off of the petroleum industry initiated by the Daqing Oilfield in the 20th century and then to the breakthrough development of unconventional energy sources such as shale gas and combustible ice, it demonstrates the iterative upgrading of energy technology. Under the guidance of the “dual carbon” goals, geothermal energy, as an important component of the clean energy system, is embracing unprecedented development opportunities. The paper presents the innovative developments and future prospects of geo-energy technology in China, with key advancements presented in five main areas: geothermal energy extraction, petroleum exploration and production, reservoir characterization and modeling, sequestration of carbon dioxide, and geomechanics for energy and the environment. Through these technological advancements, we can more efficiently develop and comprehensively utilize geothermal resources, thereby providing a scientific basis and innovative models for optimizing the global energy structure, achieving carbon neutrality goals, and promoting the sustainable development of the geological energy industry.

The large-scale development of geothermal energy relies on reservoir modification and the improvement of heat extraction efficiency [1,2,3]. By jointly developing coal and geothermal energy through water-conducting structures and using the rock compression–erosion coupling test system, the influence of hydrothermal flow on the mechanical properties of fractured rocks was revealed. Strategies such as reinforcing fractured rock layers and optimizing well location layouts were proposed, significantly improving the mining efficiency of geothermal wells [4,5]. In terms of reservoir modeling, the fractal seepage model successfully quantified the interaction between pore structure and the coupling of heat, water, and force. Compared with the traditional cubic model, an increase of 0.4% in the fractal dimension can increase the permeability by 11.7% [6]. Furthermore, the application of drilling geometry optimization and ultra-long gravity heat pipe technology has achieved the minimization of heat loss and the maximization of extraction efficiency [7,8]. For the development of hot dry rock, the multi-branch well EGS expands through a complex fracture network, increasing the reservoir permeability and thermal energy extraction efficiency by an order of magnitude, providing a new solution for deep geothermal development [9].

The integration of artificial intelligence (AI) with multidisciplinary technological innovations is propelling oil and gas exploration into a precision-oriented and intelligent new era. Through machine learning algorithms, nuclear magnetic resonance (NMR) analysis, and integration strategies with geological engineering, this synergy has enabled comprehensive breakthroughs across the entire exploration chain—from microscopic pore fluid identification to ultra-deep resource evaluation. Machine learning and computer vision have performed outstandingly in lithology identification, fault detection, and reservoir dynamic optimization, promoting the intelligent transformation of exploration [10]. For shale oil reservoirs, two-dimensional nuclear magnetic resonance technology accurately identified six fluid types, such as free oil and adsorbed oil. Combined with pore size distribution analysis, it was clearly determined that the feldspar shale interlayer was the high-yield target area [11]. Through the “carrier layer exploration” strategy, the Sichuan Basin has broken through the bottleneck of shale gas development with low organic matter abundance and achieved the leap of shale gas from a single layer to multiple layers [12,13]. In terms of the potential assessment of deep liquid oil and gas, comprehensive geochemical analysis has revealed the accumulation conditions of coal-bearing source rocks in the deep Jurassic of the Junggar Basin, providing a basis for ultra-deep exploration [14].

The innovation of reservoir characterization techniques has enhanced the development efficiency of complex reservoirs [15,16]. Local full waveform inversion (FWI) combined with regularization strategies has significantly improved the imaging resolution of karst reservoir fracture structures [17]. Aiming at the salting out problem of deep high-temperature gas reservoirs, a salting out dynamics model was established, providing theoretical support for pore blockage prediction and production system optimization [18]. In the study of fan delta reservoirs, high-resolution sequence stratigraphy and microphase analysis revealed the dominant role of sandy clastic flow and diversion channels. Combined with the fault-source rock coupling model, the distribution law of high-quality reservoirs was clarified [19]. In terms of water flooding development, the proxy model based on the Generative Adversarial Network (cDC-GAN) can quickly predict the fluid distribution and optimize the injection and production schemes, and the computational efficiency is significantly improved compared with traditional simulations [20].

CO₂ storage technology is developing towards high efficiency and safety. The pressure oscillation method combined with nuclear magnetic resonance (NMR) monitoring shortened the hydrate storage cycle by 20% and increased the storage efficiency to 94.2% by breaking the mass transfer barrier [21,22]. Studies on the injection of supercritical CO₂ into coal seams show that the long-term effect can increase the porosity of anthracite by 5.49%, but dynamic disasters caused by the deterioration of coal and rock strength need to be vigilantly monitored [23]. In the assessment of shale sequestration potential, the quantitative relationship between ScCO₂ exposure time and the effective stress coefficient of permeability provides key parameters for the design of sequestration schemes [24]. Furthermore, the establishment of the CO₂ dissolution model in vertical injection wells reduces the leakage risk through droplet dynamics simulation and expands the applicability of saltwater layer storage [25].

The geomechanical challenges in energy and environmental systems encompass a wide spectrum of critical research areas, including but not limited to hydraulic fracturing and rock stability studies. The research on the mechanism of hydraulic fracturing provides a scientific basis for increasing the production of shale reservoirs. Experiments show that fracture propagation preferentially proceeds along mineral boundaries, and the activation of micropores is limited by mineral distribution [26]. In interlaminal shale fracturing, vertical stress difference and interfacial cementation strength are the main controlling factors of fracture penetration ability, and high-viscosity fracturing fluid can enhance the concentration of fracture extension [27]. Pulsed hydraulic fracturing quantified the fatigue damage process of rocks through the strength deterioration model. Low stress is more likely to induce multi-stage fractures than pulsed fracturing [28]. The simulation of multi-cluster fracturing in horizontal wells shows that the pumping rate and the number of perforations are the key parameters for the uniform distribution of proppants. After optimization, the fracture diversion capacity can be increased by more than 30% [29]. The authors in [30] focused on investigating the shear mechanical behavior of anisotropic structural planes. By integrating laboratory tests with three-dimensional discrete element (3DEC) numerical simulations, the study reveals the influence patterns of structural plane dimensions, roughness, and normal stress on shear strength. Ma and colleagues [31] addressed the challenge of acquiring mechanical parameters for surrounding rock in hydropower station surge chambers. It proposed an intelligent inversion method combining particle swarm optimization-support vector machine (PSO-SVM) algorithms, FLAC3D numerical modeling, and orthogonal experimental validation to inversely optimize mechanical parameters and evaluate support schemes.

2. Special Issue Content

Over the past several years, the articles featured in this Special Issue have made notable contributions to China’s energy technology [32]. These studies have driven innovation in China’s geological and energy technologies through multidimensional advancements spanning rock mechanics, geochemistry, and engineering simulations. By addressing critical challenges in oil and gas exploration, coal mine safety, and shale development, they provide scientific and technological support for achieving energy self-sufficiency and advancing the nation’s dual-carbon goals.

In reference [33], shale oil content serves as a critical parameter for reserve assessment and sweet spot optimization. Focusing on sealed coring samples from the Dongying Sag, Bohai Bay Basin, this study compares NMR (nuclear magnetic resonance), Dean–Stark distillation, and rock-eval pyrolysis for oil content quantification. Results demonstrate a hierarchical trend: NMR-derived values > Dean–Stark measurements > rock-eval data. Mechanistic insights reveal that closed pore clusters in low-to-moderate maturity shale impede solvent extraction efficiency during Dean–Stark distillation, and light hydrocarbon loss during sample exposure, crushing, and delayed pyrolysis heating accounts for rock-eval’s underestimation. The non-destructive nature and rapid analysis of NMR position it as the preferred method for engineering-scale shale oil evaluation.

Huang and colleagues [34] constructed an exponential constitutive model for stable rock crack propagation through triaxial compression experiments and crack strain analysis, revealing dynamic relationships between crack geometric parameters (e.g., wing crack length) and loading conditions. They proposed a mechanical model of sliding crack structures within elastic bodies. This research provides a theoretical foundation for evaluating the stability of surrounding rock in deep mines and optimizing shale gas hydraulic fracturing.

The authors in [35] established a dynamic response relationship between the maturity parameters of pyrolytic hydrocarbons and the oil shale pyrolysis process through simulation experiments and geochemical analysis, addressing challenges in core maturity testing for in situ conversion. This work offers a key parameter calibration method for in situ conversion technologies in oil shale-rich regions like the Songliao Basin, facilitating efficient and low-carbon development of oil shale resources and promoting the industrial application of green transformation technologies for unconventional hydrocarbons.

The work in reference [36], through infrared spectroscopy, X-ray diffraction (XRD) analysis, and peak-splitting fitting method, revealed that the aromatic hydrogen rate, aromatic carbon rate, and the aromaticity of outburst coal are significantly higher than those of the primary coal, with a lower degree of aliphatic chain branching.

Liu and colleagues [37] integrated seismic and geological data to construct a high-resolution sequence stratigraphic framework for the Shanxi Formation in the Qinshui Basin, unveiling the dynamic equilibrium mechanism between delta sedimentary evolution and thick coal seam formation. This study can provide a reference for the research on the distribution of thin sand bodies, sedimentary evolution, and peat accumulation regularity in the coal-bearing series under the marine–continental transitional environment.

3. Closing Remarks

This Special Issue highlights cutting-edge advancements in China’s geological energy technologies, showcasing critical innovations that align with the nation’s strategic priorities of clean energy transition, intelligent systems, and operational efficiency. While China has made remarkable progress in this expansive field, the studies presented here aim to enrich scholarly discourse, inspire ongoing research, and accelerate practical applications. Breakthroughs in geothermal energy extraction and CO₂ sequestration technologies are directly advancing the dual-carbon goals (carbon peaking and carbon neutrality), while the integration of AI-driven analytics with high-precision modeling is revolutionizing digital workflows in hydrocarbon exploration and production. Collectively, these efforts position China at the forefront of global energy innovation while addressing pressing ecological and economic challenges.