A data augmentation method for lacustrine shale lithofacies classification based on a conditional diffusion probabilistic model: A case study from the Dongying Depression, Bohai Bay Basin, China
Available online 7 February 2026
Accurate identification of lithofacies is critical for shale hydrocarbon exploration and development. Although machine learning (ML) is one of the most effective approaches for predicting shale lithofacies,...
Digital twin driven ram BOP shear capability analysis
Available online 6 February 2026
As a critical component of the oil drilling control system, blowout preventers (BOPs) shear failure accidents can occur in case of blowout incidents. Existing methods based on simulation and empirical...
Techno-economic co-optimization of CO2 enhanced oil recovery strategies in a tight oil reservoir using coupled improved evolutionary algorithm and machine learning framework
Available online 6 February 2026
Massive carbon dioxide (CO2) emissions drive climate change. Injecting CO2 into unconventional reservoirs achieves both enhanced oil recovery (EOR) and geological sequestration. However, simultaneously...
Hydraulic-mechanical analysis of induced stress change in unconventional reservoirs using a novel fundamental solution of poromechanics in a half space
Available online 6 February 2026
The production of fractured unconventional reservoirs induces stress changes, which will affect the production performance of neighboring wells. To quantify such effects, the analytical solution is...
Full waveform inversion via BEEMD-based gradient decomposition
Available online 6 February 2026
Full waveform inversion (FWI) gradient inherently contains both tomographic and migration components, which are responsible for updating large-scale background velocity and small-scale structural details,...
Gas-solid two-phase flow erosion of needle throttle valve in shale gas field based on CFD-DEM model
Available online 5 February 2026
Needle throttle valve (NTV) is a key equipment to ensure the safe production of shale gas fields, but it is often seriously eroded by the solid particles in the produced gas. At this work, the CFD-DEM...
Stress characteristics and sealing mechanism of steel-titanium heterogeneous drill pipe joints
Available online 5 February 2026
Titanium alloy drill pipes exhibit promising potential for ultra-deep well drilling due to their high specific strength and superior corrosion resistance. However, the engagement surfaces of the pin...
Numerical investigation of the effect of reactive transport in rock matrix on fracture fluid flow and heat transfer behavior in enhanced geothermal systems
Available online 3 February 2026
Quantitatively understanding reactive transport in matrix-fracture systems and the corresponding effect on reservoir fluid flow and heat transfer behavior is essential for the prediction of long-term...
Research on the intelligent characterization of interwell section architecture based on Bayesian expert systems
Available online 3 February 2026
The characterization of interwell section architecture is critical for revealing reservoir lateral heterogeneity and connectivity. This process integrates well and seismic data with geological knowledge...
Development of mahua oil (Madhuca indica) methyl ester based drilling mud as a sustainable alternative to oil based mud for unconventional reservoirs
January 2026
The exploration of untapped unconventional reservoirs has increased to fulfill the growing global demand for energy. Traditionally, oil-based mud (OBM) is preferred for drilling such formations; however,...
Simulation analysis of hydraulic fracture initiation and propagation mechanisms under mixed-mode and reservoir fracturing
January 2026
With the increasing demand for the development of unconventional oil and gas resources, hydraulic fracturing has become a key technology for enhancing reservoir permeability. However, achieving controlled...
Biomimetic inspired superhydrophobic nanofluids: Enhancing wellbore stability and reservoir protection in shale drilling
January 2026
Shale oil and gas, as typical unconventional resources, have gradually altered the global energy supply and demand landscape, attracting significant attention over recent decades. However, challenges...
Performance of steam injection process in layered heavy oil reservoirs: An experimental and numerical investigation
January 2026
Layered heavy oil reservoirs are widely distributed hydrocarbon resources and play a crucial role in fulfilling the global increasing demand for energy. Due to the existence of interlayer heterogeneity,...
Improved probabilistic seismic AVO inversion constrained by instantaneous phase using quadratic PP-reflectivity approximation and IA2RMS-Gibbs algorithm
January 2026
Seismic amplitude variation with offset (AVO) inversion is a cornerstone of oil and gas reservoir prediction, enabling the estimation of subsurface elastic parameters and characterization of stratigraphic...
Impacts of Himalayan tectonism on Eocene gas shale and its pore structure within the Lesser Himalayas, Nepal: Insights for shale gas accumulation and preservation
January 2026
This study investigates the complex relationship between organic matter (OM), tectonic deformation, and pore structure development in Eocene Bhainskati shale within the Lesser Himalayan foreland basin,...
Unveiling the role of residual structure in hydrate secondary formation through molecular dynamics simulations
January 2026
The rapid secondary formation of gas hydrate is a potential cause of flowline blockage in deepwater oil and gas production systems, posing serious flow assurance challenges. However, its microscopic...
CFD study on gas-solid hydrodynamics during the scale-up of high-density circulating fluidized bed
January 2026
High-density circulating fluidized bed (HDCFB) offers high gas-solid contact efficiency and shows great application prospects in the petrochemical industry. It is important to study the scale-up of...
Insight into porosity of shale oil reservoirs: Comparison of helium, low-temperature nitrogen adsorption−desorption, and nuclear magnetic resonance methods
January 2026
Porosity is a fundamental parameter in characterizing the pore structure of shale oil reservoirs, as it directly affects the accuracy of shale oil reserve estimations. Despite the availability of various...
Characterization of multiple fractured layers using a rock-physics-based shear wave splitting analysis: Application to four-component VSP
January 2026
Shear wave splitting (SWS) analysis has been widely employed for fracture characterization in both global seismology and seismic exploration. Two key SWS attributes—fast shear wave polarization and...
Differential hydrocarbon enrichment in Ordovician strata controlled by intra-cratonic ultra-deep strike-slip fault movements, eastern Shunbei area, Tarim Basin, China: Constraints from in-situ calcite U-Pb dating and fluid inclusions
January 2026
Intracratonic strike-slip faults in central-western China's Tarim Basin serve as critical conduits for hydrocarbon migration and accumulation. This study integrates geochemical characterization, in-situ...
Interfacial plugging of shale microfractures using functionalized graphene oxide with high dispersion stability under harsh conditions
January 2026
Shale gas development often suffers from wellbore instability due to microfractures in the formation, posing serious challenges to drilling safety and efficiency. This study presents a functionalized...
New injection method using composite gel system and gel breaker to improve sweep efficiency and mitigate formation damage
January 2026
Polymer gels can cause damage to lowly to moderately permeable formations during both oilfield applications and laboratory evaluations of conformance treatment. To enhance reservoir sweep efficiency...
Production performance of a post-fracturing elastoplastic model for deep shale gas reservoirs
January 2026
Deep shale gas reservoirs are characterized by high temperature, high pressure, and ultra-low permeability, making them highly susceptible to plastic deformation during hydraulic fracturing. In such...
A novel semi-analytical model for pressure transient analysis of fault-controlled fractured-caved gas reservoirs and field applications
January 2026
Fractured-caved gas reservoirs are widely distributed and hold substantial reserves in northwestern China, showing considerable development potential. However, their strong heterogeneity and significant...
Organic and inorganic pore networks in medium- to low-maturity shale: Insights from SEM analysis of Shahejie Formation in the Dongying Sag
January 2026
The spatial distribution and structural characteristics of organic and inorganic pore networks are crucial for evaluating the storage capacity of medium- to low-maturity shale reservoirs. Based on scanning...