China National Offshore Oil Corporation (China)

Spatial Redistribution of Gas Hydrates and Its Impact on Pressure-Limited Restart in Deepwater Subsea Flowlines

Hydrates formed during a subsea flowline shutdown can persist as deposits that restrict the subsequent restart. Assessing restartability therefore requires both thermodynamic conditions and the pressure needed to recover flow. This study develops a one-dimensional screening model...

A Review of the Application of Non-Condensable Gases in Heavy Oil: Recovery Methods, Techniques, and Parametrization Employing Experiments, Simulations, and Field Implementations

The use of steam-based thermal recovery techniques in heavy oil exploitation faces critical limitations in deep formations, aquifer-bearing reservoirs, and formations with high clay content. This has motivated increasing research interest in the use of non-condensable gases (NCGs...

Thermodynamic matching mechanism and topological evolution for liquid natural gas integrated liquid air energy storage: A dual-stage refrigeration strategy with pre-cooling

The integration of liquefied natural gas (LNG) cold energy with liquid air energy storage (LAES) is regarded as a promising route for reducing air-liquefaction power consumption and improving large-scale energy-storage performance. In existing studies, performance improvement is...

Evaluation of Residual Strength of Polyester Lines Considering Breakage of Some Strands

To accurately assess damaged polyester lines’ residual strength, this study takes commonly used engineering spiral-strand unjacketed polyester lines as the research object, and first proposes a strand rearrangement-based evaluation method. It accounts for subropes/strands’ load-b...

A Compositional and Genetic Framework for Shale Lithofacies Classification and Reservoir Quality Prediction: Insights From the Wufeng‐Longmaxi Formation, South Sichuan

ABSTRACT Although shales are of fundamental importance in geological research and energy exploration, no consensus has been reached on a unified classification and nomenclature that adequately reflect their multiscale heterogeneity and genetic origins. To address this gap, we pro...

Undrained capacity of shared triple-bucket anchor foundations under combined horizontal and torsional loading

Shared anchors offer a promising solution for reducing mooring system costs in floating offshore wind arrays. However, their capacity may be reduced by varying resultant horizontal and torsional mooring loads under complex environmental loading. Numerical analyses are conducted t...

Wave Resistance of Floating Offshore Wind Turbines Based on a Viscous-Potential Flow Correction Method: Toward Efficient and Sustainable Wet-Towing Operations

Accurate prediction of towing resistance is essential for selecting tug capacity and controlling energy demand during the wet-towing of floating offshore wind turbines (FOWTs). This study established a high-precision CFD numerical wave tank to simulate the towing hydrodynamic per...

Acidification States and Controlling Factors in Subsurface and Bottom Water of the Beibu Gulf, China

Previous studies in the Beibu Gulf have documented the distributions and controlling factors of carbonate system parameters in surface waters; however, their dynamics in subsurface and bottom waters remain poorly constrained. Here, we present the first observations of pH and the...

Effects of Multistage Paleostress Reorientation on the Sealing Capacity of Fault Zones: A Case Study of the Huizhou 19‐6 Area, Pearl River Mouth Basin, Northern South China Sea

ABSTRACT The Paleogene formations in the Huizhou 19‐6 area are dominated by high sand‐content strata. Fault development in this region is controlled by multiple episodes of tectonic activity, forming a structural pattern of ‘initially wrench‐dominated, followed by extensional def...

Enhanced 3D Gravity Inversion Using ResU-Net with Density Logging Constraints: A Dual-Phase Training Approach

Abstract Gravity exploration has become an important geophysical method due to its low cost and high efficiency. With the rise of artificial intelligence, data-driven gravity inversion methods based on deep learning (DL) possess physical property recovery capabilities that conven...

Liquid CO2 Replacement and SequestrationBehavior after Depressurization Production of Methane Hydrates

Abstract Aligned with China’s “dual carbon” strategic objectives, natural gas hydrates─recognized as a crucial source of clean unconventional natural gas─constitute a significant technological avenue for securing national energy stability and meeting carbon reduction targets thro...