Exploration Targets Research Articles

Source Rock Characteristics and Petroleum‐Geological Significance of Paleogene Niubao Formation in the Nima Basin, Central Tibet, China

ABSTRACTNima Basin, as a typical Tethys area, is a Cenozoic oil‐bearing basin in the middle of Qinghai‐Tibet Plateau, which is expected to become an important target for petroleum exploration. The main controlling factors and models of organic matter enrichment are not yet clear. To identify the organic geochemical characteristics of high‐quality source rocks and the main controlling factors of their formation, this study analyzes the paleoclimate and paleo‐salinity indexes based on the analysis of the major and trace elements through systematic sampling of the muddy sediments of Niubao Formation in Well Shuangdi 1, Cebuco Depression. The results show that the organic matter of the E1‐2n source rocks in Nima Basin is differentially enriched, which shows that the organic matter of the middle E1‐2n source rocks is more enriched than that of the upper E1‐2n source rocks. Hydrocarbon source rocks of the middle E1‐2n are mainly of type I organic matter, while those of the upper E1‐2n are mainly of type Ⅱ1 organic matter, both of which are in the mature stage. Organic matter enrichment is primarily governed by a combination of climate and redox conditions, with humid climate and reducing environments emerging as the dominant factors, whereas salinity exerts a lesser influence. On the one hand, this study can supplement the accumulation mechanism of organic matter in the Tethys domain in Asia; on the other hand, it will fill the gap in the geological research of Nima Basin, contributing to the prediction and exploration of oil and gas resources in the Nima Basin.

Mapping the developmental trajectory of human astrocytes reveals divergence in glioblastoma.

Glioblastoma (GBM) is defined by heterogeneous and resilient cell populations that closely reflect neurodevelopmental cell types. Although it is clear that GBM echoes early and immature cell states, identifying the specific developmental programmes disrupted in these tumours has been hindered by a lack of high-resolution trajectories of glial and neuronal lineages. Here we delineate the course of human astrocyte maturation to uncover discrete developmental stages and attributes mirrored by GBM. We generated a transcriptomic and epigenomic map of human astrocyte maturation using cortical organoids maintained in culture for nearly 2 years. Through this approach, we chronicled a multiphase developmental process. Our time course of human astrocyte maturation includes a molecularly distinct intermediate period that serves as a lineage commitment checkpoint upstream of mature quiescence. This intermediate stage acts as a site of developmental deviation separating IDH-wild-type neoplastic astrocyte-lineage cells from quiescent astrocyte populations. Interestingly, IDH1-mutant tumour astrocyte-lineage cells are the exception to this developmental perturbation, where immature properties are suppressed as a result of D-2-hydroxyglutarate oncometabolite exposure. We propose that this defiance is a consequence of IDH1-mutant-associated epigenetic dysregulation, and we identified biased DNA hydroxymethylation (5hmC) in maturation genes as a possible mechanism. Together, this study illustrates a distinct cellular state aberration in GBM astrocyte-lineage cells and presents developmental targets for experimental and therapeutic exploration.

Causal Association Between Cerebrospinal Fluid Metabolites and Parkinson's Disease: A Two-Sample Bidirectional Mendelian Randomization Study.

Observational studies suggest CSF metabolites may be linked to Parkinson's disease (PD) onset, but causality is uncertain. This study uses a two-sample bidirectional Mendelian randomization approach to investigate the causal relationship between CSF metabolites and PD. Data on 338 CSF metabolites and PD-related traits were obtained from genome-wide association studies (GWAS). Causal relationships between CSF metabolites and PD were assessed using inverse variance-weighted (IVW), MR-Egger regression, weighted median method, simple mode, and weighted mode. Sensitivity analyses for heterogeneity and pleiotropy were conducted to explore the robustness of the results. Our analysis identified an association between nine CSF metabolites and PD. Notably, significant increases in the risk of PD were observed for Ribitol (IVW, OR: 1.45; 95% CI: 1.09-1.91; P=9.04×E-03), Lysine (IVW, OR: 1.54; 95% CI: 1.09-2.17; P=1.24×E-02), and O-sulfo-l-tyrosine (IVW, OR: 1.38; 95% CI: 1.06-1.79; P=1.60×E-02). Additionally, we found that elevated levels of oxidized cysteinyl-glycine and 1,5-anhydroglucitol were associated with a decreased risk of PD. Furthermore, PD was associated with alterations in 12 CSF metabolites, including significant increases in Acetoacetate (IVW, OR: 1.15; 95% CI: 1.02-1.30; P=1.79×E-02), S-methylcysteine (IVW, OR: 1.14; 95% CI: 1.02-1.29; P=2.62×E-02), and N-acetyl-3-methylhistidine (IVW, OR: 1.12; 95% CI: 1.01-1.23; P=2.22×E-02). The identified CSF metabolites may serve as potential CSF metabolic biomarkers for screening and preventing PD in clinical practice and could also be considered as candidate molecules for future mechanistic exploration and drug target selection.

Geochemical footprints of peraluminous rare-metal granites and pegmatites in the northern French Massif Central and implications for exploration targeting

Geochemical footprints of peraluminous rare-metal granites and pegmatites in the northern French Massif Central and implications for exploration targeting

Harnessing the Deep: Development of an Innovative Underwater Power Generation System for Sustainable Energy Harvesting

Abstract: The proposed project would be an innovative underwater bio-mimetic robot that is supposed to be able to move with autonomous navigation and work freely in deep-sea areas. It will be the new target for exploration and rescue missions. The new robot, in this context, will take the best qualities of the marine organism represented by an octopus or a manta ray for the current underwater robotic system, giving it very adaptable, efficient, and quiet movement. It will come out with a flexible articulated body structure that, being composed of shape-memory alloys and advanced polymer-based materials, will slide through the complex aquatic terrain. Advanced AI-based situational awareness of the robot will allow it to recognize and interact with objects and environments using sensor fusion techniques such as sonar, lidar, and bio-acoustic echolocation. Its lifespan and resistance to damage will be increased by using self-healing material technologies. The tether-free cutting-edge communication mechanism will be based on underwater wireless optical communication (UWOC) and will ensure robust data transmission in the deep-sea context. This innovation will fill the long-sought gap in underwater exploration and search-and-rescue operations in hazardous or inaccessible areas, such as deep oceanic trenches and under-ice regions. It is to be designed to function independently for long periods using power-efficient modular battery packs inductively charged by marine renewable energy sources. It involves principles of robotics, biomimicry, AI, and material science. It promises an advancement in deep-sea technology never achieved before.

GEOSEISMIC CHARACTERISTICS, HYDROCARBON POTENTIAL AND RESOURCES OF THE NORTH KARA SEDIMENTARY BASIN

This study presents a geological model of the North Kara sedimentary basin, which was developed based on the integrated interpretation of seismic and geological data on islands and Siberian continental margin, and provides seismostratigraphic and structural-tectonic characterization of the basin. The results of the study indicate that the sedimentary cover of much of the basin is composed of Paleozoic sediments of Cambrian to Permian age, reaching 13–14 km in thickness in depression zones. The thickness of Mesozoic sediments over much of the basin is < 1 km; in the northwest, where the North Kara basin borders the Barents Sea basin, the thickness of Mesozoic sediments increases to 5–6 km, and the sedimentary cover comprises Paleozoic, Triassic, Jurassic and Cretaceous geoseismic sequences. In terms of its hydrocarbon potential, the North Kara sedimentary basin is regarded as part of the potential oil and gas-bearing area of the same name, having a good hydrocarbon potential based on seismic stratigraphic and structural-tectonic considerations. A number of large depressions and uplifts recognized in the structural geometries of different stratigraphic levels can be associated with petroleum generation and accumulation zones; a number of anticlinal, structural-tectonic, structural-stratigraphic traps that are distinguished in different sedimentary complexes ranging in age from Cambrian to Jurassic can be considered as promising exploration targets. The proposed quantitative assessment shows that the most probable initial in-place hydrocarbon resources of the North Kara sedimentary basin are equal to about 10.7 billion tons of hydrocarbon equivalent.

Delineating Structural Features Related to Hydrothermal Alterations for Possible Mineralization in Share Area, Kwara State Nigeria Using Aeromagnetic Data

Mineral deposits of significant economic value are abundant in the subsurface of Nigeria, presenting a promising alternative to the nations over dependence on petroleum revenues. This study interprets aeromagnetic data from Share, Kwara State, Nigeria, to delineate subsurface structural features associated with hydrothermal zones, which are key indicators for potential mineralization. The methodologies applied upward continuation, analytic signal, tilt derivative, and first vertical derivative (FVD). These offer insights into subsurface geology that can be broadly applied in geophysical exploration and mineral resource management. The results reveal structural trends predominantly in the NE–SW direction, with some NW–SE alignments, indicative of hydrothermal alterations linked to mineral deposits. The analytical signal map identified amplitude values ranging from 0.004 nT/m to 0.073 nT/m, with low and intermediate magnetic intensities linked to sediment-filled basement rocks and possible limestone and sandstone formations. High-gradient anomalies, 1.280 nT/m to 1.374 nT/m, were attributed to geological contacts, fractures, dykes, and hydrothermal vents. Depth estimates from the source parameter imaging map revealed hydrothermal and structural zones at depths ranging from 287.9 m to 1360.7 m, with deeper sources >1202.1 m indicating tectonic activity and mineralization potential. The FVD and Tilt Derivative maps further highlighted faulted zones, shear structures, and intrusive bodies with intensities between 0.031 nT/m and 0.041 nT/m, suggesting active tectonics. High magnetic anomalies in the central, northeastern, and southeastern regions were identified as prime targets for exploration, indicating magnetite-rich bodies, igneous intrusions, and hydrothermal zones. Integrated exploration strategies combining geophysical, geochemical, and structural data are recommended to refine anomaly delineation, prioritize field validation, and enhance mineralization discovery. These findings establish the Share area as a promising site for regional mineral exploration, supporting Nigeria’s diversification efforts toward sustainable resource development.

Application of the Hydrocarbon Generation Potential Method in Resource Potential Evaluation: A Case Study of the Qiongzhusi Formation in the Sichuan Basin, China

Global recoverable shale gas reserves are estimated to be 214.5 × 1012 m3. Estimation methods for shale gas resources, such as volumetric, analog, and genetic approaches, have been widely used in previous studies. However, these approaches have notable limitations, including the substantial effect of rock heterogeneity, difficulties in determining the similarity of analog accumulations, and unsuitability for evaluating high-mature–overmature source rocks. In the Qiongzhusi Formation (Є1q) of the Sichuan Basin, China, extensive development of high-mature–overmature shales has led to significant advancements in conventional and unconventional shale gas exploration. This progress highlights the need for the development of an integrated evaluation system for conventional and unconventional resources. Hence, this study uses the whole petroleum system theory and an improved hydrocarbon generation potential method to analyze the distribution patterns of hydrocarbon generation, retention, and expulsion during various stages of oil and gas accumulation in the Є1q. In addition, it assesses the resource potential of conventional and shale oil and gas. Hydrocarbon generation and expulsion centers are favorable exploration targets for conventional oil and gas, primarily located in the central and northern regions of the Mianyang—Changning rift trough, with an estimated resource potential of 6560 × 1012 m3. Hydrocarbon retention centers represent promising targets for shale oil and gas exploration, concentrated in the central Mianyang—Changning rift trough, with a resource potential of 287 × 1012 m3. This study provides strategic guidance for future oil and gas exploration in the Є1q and offers a methodological reference for integrated resource assessments of conventional and unconventional oil and gas systems of high-mature–overmature source rocks in similar basins worldwide.

Enhancing Equanimity with Non-Invasive Brain Stimulation: A Novel Framework for Mindfulness Interventions.

Mindfulness has gained widespread recognition for its benefits to mental health, cognitive performance, and wellbeing. However, the multifaceted nature of mindfulness, encompassing elements like attentional focus, emotional regulation, and present-moment awareness, complicates its definition and measurement. A key component that may underlie its broad benefits is equanimity - the ability to maintain an open and non-reactive attitude toward all sensory experiences. Empirical research suggests that mindfulness works through a combination of top-down attentional control and bottom-up sensory and emotional processes, and that equanimity's role in regulating those bottom-up processes drives the psychological and physiological benefits, making it a promising target for both theoretical and practical exploration. Given these findings, the development of interventions that specifically augment equanimity could improve the impact of mindfulness practices. Research into non-invasive brain stimulation (NIBS) suggests that it is a potential tool for altering neural circuits involved in mindfulness. However, most NIBS studies to date have focused on improving cognitive control systems, leaving equanimity relatively unexplored. Preliminary findings from focused ultrasound interventions targeting the posterior cingulate cortex (PCC) suggest that NIBS can directly facilitate equanimity by inhibiting self-referential processing in the default mode network (DMN) to promote a more present-centered state of awareness. Future research should prioritize the integration of NIBS with well-defined mindfulness training protocols, focusing on equanimity as a core target. This approach could provide a novel framework for advancing both contemplative neuroscience and clinical applications, offering new insights into the mechanisms of mindfulness and refining NIBS methodologies to support individualized, precision wellness interventions.

Provenance characteristics from the Mesozoic to the Cenozoic era and their implications for basin-mountain system evolution in the southwestern Junggar Basin: Insights from field outcrop observations in the Tostai area

The Mesozoic-Cenozoic formations in the southwestern Junggar Basin are a key target for oil and gas exploration. However, complex provenance conditions hinder a comprehensive understanding of sedimentary reservoirs. Based on the petrology and elemental geochemistry analysis of field outcrops in the Tostai area, research is conducted on the tectonic background, sediment transport distances, compositions of parent rocks, and evolutionary characteristics of provenance conditions in the provenance areas. It is generally believed that there have been three notable shifts in basin-mountain relationships during this period. Initially, from the Triassic to the Jurassic, the Northern Tianshan magmatic rock area predominated as the primary provenance, with decreasing basin-mountain proximity and predominantly magmatic rock sediment composition indicating near provenance. Subsequently, heightened Cretaceous tectonic activity in the Tianshan Mountains leads to significant uplift of metamorphic rock regions in the Middle Tianshan Mountains, gradually becoming the provenance for the study area. This increased distance between the provenance and sedimentary areas is marked by a substantial presence of metamorphic rocks in sediments, indicating a far provenance. Finally, the Cenozoic Himalayan movement resulted in the vigorous uplift of the magmatic rock area in the northern Tianshan Mountains, re-establishing it as the primary provenance. This minimized the basin-mountain distance, leading to the deposition of the near-provenance transported alluvial fans, braided rivers, and predominantly magmatic rock sediments.

Robotic Badges for Girl Scouts

This three-day computer science (CS) robotics coding exploration targets three Girl Scouts (n.d.) Brownie (2nd/3rd grades) badges. For each badge, a 60-minute session follows the 5E instructional model, which incorporates various robots to provide learners with diverse coding experiences. Throughout the coding exploration, learners engaged with real-life robot applications and used different robots to complete coding challenges. This learning exploration concluded by having learners complete at least one robot coding challenge per session, tailored to their capability, and utilize their expressive language skills to describe and explain their designed artifacts, algorithms, and block-based codes. This coding exploration can be extended to support broader elementary-level CS instruction.

Innovative airborne geophysical strategies to assist the exploration of critical metal systems

Critical metals are essential in sustaining the high technology and the green energy transition of modern societies. The future discovery of new critical metal deposits will likely be made at increasing depths and under thick cover sequences. The key roles of the four airborne geophysical exploration methods, gravity, magnetometry, electromagnetism and gamma-ray spectrometry, are reviewed in this article. The measured data from airborne magnetic, gravity and electromagnetic surveys can be inverted to reveal the distribution of underlying mineral prospects in terms of magnetic susceptibility, density and electrical resistivity/conductivity beneath the surface.The interpretation of geophysical data is important in relating geophysical responses to the lithology and geophysical anomalies to potential exploration targets that are concealed under cover. Gamma-ray spectrometry can identify near-surface hydrothermal alteration zones and uranium systems. Structural complexity maps can provide additional key parameters for the exploration targeting of structurally controlled critical metal systems. We briefly discuss the application of airborne geophysical methods to efficiently guide the exploration of concealed critical metal deposits. A robust understanding of the geological setting of the respective mineral prospect is the most relevant factor in choosing the most efficient geophysical exploration strategy. Geophysical tools will likely play an increasingly important role in guiding the future discovery of concealed critical mineral systems.

Segmented evolution and exploration targets of the Cambrian platform margin in the Manxi area, Tarim Basin

Segmented evolution and exploration targets of the Cambrian platform margin in the Manxi area, Tarim Basin

Contribution of Induced Polarization to the Identification of Mineralization in the Agnibilékrou Department (Eastern Côte d’Ivoire)

The chargeability maps of the Siakakro, N’Guessankro, and Mossikro sites (Agnibilékrou Department, in the east of Côte d’Ivoire) are established from induced polarization (IP) measurements. These maps reveal both polarizable and weakly polarizable structures, with anomalies primarily oriented NE-SW. These orientations, influenced by geological faults, facilitate the migration of hydrothermal fluids and the potential formation of mineral deposits. The zones with high chargeability are mainly located in the center and east of the sites, suggesting the presence of sulfides and representing promising targets for mining exploration. The weakly polarizable areas are associated with sandy-clay formations and non-conductive materials, limiting their mining potential. However, their proximity to faults, especially at N’Guessankro, justifies further investigations to identify potential hidden mineralization. In summary, the zones with high chargeability, particularly at Siakakro, should be prioritized for exploratory drilling. Further exploration, particularly around geological contact zones, is necessary to assess the economic potential of these anomalies.

Delineation of mineralization-related geologic structures and lithological units using airborne magnetic and radiometric data

The Ilesha and Ado-Ekiti areas are characterized by extensive mineral potentials, including both metallic and non-metallic resources. To detect the probable zones of mineralization, airborne magnetic and radiometric data were applied to map lineaments and lithological components. o generate comprehensive structural maps, the Centre for Exploration Targeting (CET) grid analysis tool was applied to total magnetic intensity data upward continued to 100 m, First Vertical Derivative (FVD), Second Vertical Derivative (SVD), Analytic Signal (ASIG), Tilt Angle Derivative (TAD), and Total Horizontal Derivative (THD) grids. The structural maps strongly correlated with each other were observed to be characterized by polyphase deformations, and oriented in the NE–SW, N–S, and E–W directions. The dominant NE–SW trend is related to the Ifewara-Zungeru zone caused by the Pan-African Orogeny and other tectonic events. Distinct lithological areas were mapped using radiometric anomalies. A major lineament that falls within the potassium-rich and magnetically concentrated zone indicated possible igneous related gold site. In general, the lineaments that have been detected are probable hosts for metallogenic minerals. Furthermore, the depth estimate involving the Source Parameter Imaging (SPI) and Standard Euler Deconvolution (SED) detected thin sedimentation (≤ 482 m).

A Fuzzy Gold Mineral Prediction Model Integrating with Knowledge-Driven and Data-Driven: A Case Study of the Hatu Region in Xinjiang, China

As mineral resources become increasingly scarce, the search for potential ore deposits presents a significant challenge in geological exploration. Subjective factors often constrain traditional knowledge-driven approaches, while purely data-driven methods may overlook the geological significance of data relationships, potentially compromising the accuracy and reliability of predictions. To address these issues, this study proposes a novel mineral prediction model that integrates fuzzy comprehensive evaluation with both knowledge-driven and data-driven approaches (FCEKDD), resulting in an optimized comprehensive mineral prediction model based on multi-source geoscience data. This model establishes comprehensive exploration indicators based on expert knowledge and quantitatively assesses these indicators through fuzzy evaluation methods to evaluate mineralization potential, thereby delineating exploration targets within the study area. Ultimately, a three-layer predictive framework is constructed using the C-A fractal method. Experimental results indicate that 57.1% of known mineral points are within the primary prediction zone, thus demonstrating the model’s high predictive accuracy. Comparisons with a random forest model reveal that the FCEKDD model has advantages in addressing geoscience data uncertainty and interpreting geological phenomena. This research validates the reliability and applicability of the proposed model in mineral exploration mapping, providing an effective solution for future mineral resource exploration.

Processing Strategy for Deep Imaging Beneath Complex Shallow Structures Under Shallow Water: a Case Study in the Enping Sag

Abstract As offshore exploration targets deeper parts of shallow-water areas in the eastern South China Sea, an increasing number of hydrocarbon discoveries have been made in recent years, and the difficulty of such exploration has increased. One such challenge lies in mid-depth imaging beneath complex shallow geological structures. When a seismic wave penetrates through groups of densely distributed fractures and/or volcanic rocks, only a fraction of the energy reaches the target depth. As the ray path becomes complex, the middle to deep imaging quality becomes significantly poorer. In this study we applied three techniques: 3D joint source and receiver deghosting and zero-phasing, dynamic resolution time-lag full waveform inversion (DR-TLFWI), and least square Q-compensated Kirchhoff pre-stack depth migration (LSQPSDM), to improve the related seismic data and ultimately improve the imaging quality beneath complex shallow geological structures in the shallow-water environment of the eastern South China Sea, providing better subsurface understanding for the exploration of this area.

Stabilization of a Hydride Superionic Conducting Phase Via Cation Substitution in Ba-Li Based Oxyhydride

Hydride ions (H–) are attractive charge carriers with basic characteristics suitable for fast ion conduction, including monovalence, moderate ionic size, and large polarizability. The strong reducing property based on the standard redox potential (Eº(H–/H2) = –2.3 V vs. SHE) can lead to high energy density in batteries and high efficiency in energy/material conversion devices. For H– conductors, mixed-anion compounds such as oxyhydrides are currently the primary targets of materials exploration. This is because, compared to simple metal hydrides, the coexistence of multiple anions facilitates the control of parameters essential for developing H– conductors, such as the H– concentration and configuration.Recently, we reported H– conducting Ba-Li oxyhydrides (BLHO) with the K2NiF4-type structure [1]. BLHO has a stable composition of the highly vacant Ba1.75LiH2.7O0.9 under ambient pressure and forms the superlattice structure at low temperature due to the three types of long-range ordering, namely Heq/VH, Hap/Oap, and Ba/VBa (Heq, Oap, and V M represent hydrogen at equatorial anion sites, oxygen at apical anion sites, and a vacancy at M sites, respectively). These long-range orderings are successively disordered upon heating; Ba/VBa and Heq/VH at 300 ºC; Hap/Oap at 350 ºC (each phase is called b-, γ-, d-BLHO from the lower temperature side). The H– conductivity enhances after the β-γ transition to the so-called superionic conduction state, which exhibits conductivity over 10–2 S·cm–1 nearly independent of the temperature. The introduction of structural randomness into BLHO via elemental substitutions should stabilize the γ- and δ-phases at lower temperatures. In this study, we synthesized solid solutions of BLHO in which Li and Ba were partially substituted by cations with different sizes and valences, respectively, and investigated the impact of the elemental substitution on the phase transition behavior and H– conductivities [2 - 4].[1] F. Takeiri, G. Kobayashi et al., Nat. Mater., 21, 325–330 (2022)[2] K. Okamoto, G. Kobayashi et al., J. Mater. Chem. A, 10, 23023-23027 (2022).[3] K. Okamoto, G. Kobayashi et al., Adv. Sci., 10, 2203541 (2023).[4] H. Yaguchi, G. Kobayashi et al., (in preparation). Figure 1

Organic petrology and geochemistry of the late Neogene Shizigou Formation in the Qaidam Basin, China: Characteristics of a prospective microbial gas source rock

The discovery of natural gas trapped in the late Neogene Shizigou Formation in the Yikeyawuru anticline indicates the potential for additional microbial gas reservoirs outside of the primary exploration targets for microbial gas in the younger, i.e., the Pleistocene sediments of the Qaidam Basin. In this study, a detailed investigation is presented on the bulk geochemistry and organic petrography of the potential microbial source rocks as well as on molecular organic geochemistry of the solvent extracts obtained from the late Neogene Shizigou Formation of the Yiliping Depression. The objectives are to elucidate i) the depositional environment, ii) biological sources of organic matter (OM), and iii) biodegradation levels in these microbial gas source rocks.The samples from the well situated at the center of the Yiliping Depression (the H 1 well) exhibit minor variations in total organic carbon (TOC) and total sulfur contents, whereas the samples from the well located at the margin of the depression (the Y 3 well) show large variations in these values. All these samples are presently thermally immature. The kerogen of the TOC-rich Y 3 well samples is mainly composed of mixed types II–III kerogen and characterized by a complex maceral composition (i.e., a mixture of large fragments of huminite, semifusinite, fusinite, resinite/fluorinite, lamalginite, and liptodetrinite). In contrast, samples from the H 1 well contain typically type III kerogen with a less complex maceral composition consisting of huminite, lamalginite, and liptodetrinite. The molecular data illustrates that the OM is predominantly derived from bacterial and algal biomass as well as aquatic higher plants (primarily in the Y 3 well samples), while angiosperms are the primary source of the subordinate terrestrial OM in the samples. The marginal area is characterized by salinity levels akin to normal marine conditions with bottom-water paleoredox conditions ranging from dyoxic (samples with high TOC content) to oxic, whereas the central area developed a mesosaline environment with oxic bottom-water conditions prevailing. In contrast to the primary microbial gas producing layer, the Pleistocene Qigequan Formation, the late Neogene Shizigou Formation exhibits a higher contribution of emergent macrophytes but a reduced abundance of lower aquatic organisms in the OM as well as a higher salinity level in the water column. Despite the late Neogene Shizigou Formation demonstrating a lower potential for hydrocarbon generation and a lower degree of biodegradation of OM than the Qigequan Formation, it still shows generally favorable geological and geochemical conditions that are conducive to the development of microbial gas reservoirs, which is underscored by the biodegradation levels between 3 and 4 for the studied samples.

An Intelligent Kick Detection Model for Large-Hole Ultra-Deep Wells in the Sichuan Basin

The Sichuan Basin has abundant deep and ultra-deep natural gas resources, making it a primary target for exploration and the development of China’s oil and gas industry. However, during the drilling of ultra-deep wells in the Sichuan Basin, complex geological conditions frequently lead to gas kicks, posing significant challenges to well control and safety. Compared to traditional kick detection methods, artificial intelligence technology can improve the accuracy and timeliness of kick detection. However, there are limited real-world kick data available from drilling operations, and the datasets are extremely imbalanced, making it difficult to train intelligent models with sufficient accuracy and generalization capabilities. To address this issue, this paper proposes a kick data augmentation method based on a time-series generative adversarial network (TimeGAN). This method generates synthetic kick samples from real datasets and then employs a long short-term memory (LSTM) neural network to extract multivariate time-series features of surface drilling parameters. A multilayer perceptron (MLP) network is used for data classification tasks, constructing an intelligent kick detection model. Using real drilling data from ultra-deep wells in the SY block of the Sichuan Basin, the effects of k-fold cross-validation, data dimensionality, various imbalanced data handling techniques, and the sample imbalance ratio on the model’s kick detection performance are analyzed. Ablation experiments are also conducted to assess the contribution of each module in identifying kick. The results show that TimeGAN outperforms other imbalanced data handling techniques. The accuracy, recall, precision, and F1-score of the kick identification model are highest when the sample imbalance ratio is at 1 but decrease as the imbalance ratio increases. This indicates that maintaining a balance between positive and negative samples is essential for training a reliable intelligent kick detection model. The trained model is applied during the drilling of seven ultra-deep wells in Sichuan, demonstrating its effectiveness and accuracy in real-world kick detection.