Hydrogen energy is valued for its diverse sources and clean, low-carbon nature and is a promising secondary energy source with wide-ranging applications and a significant role in the global energy transition. Nonetheless, hydrogen’s low energy density makes its large-scale storage and transport challenging. Liquid hydrogen, with its high energy density and easier transport, offers a practical solution. This study examines the global hydrogen liquefaction methods, with a particular emphasis on the liquid nitrogen pre-cooling Claude cycle process. It also examines the factors in the helium refrigeration cycle—such as the helium compressor inlet temperature, outlet pressure, and mass—that affect energy consumption in this process. Using HYSYS software, the hydrogen liquefaction process is simulated, and a complete process system is developed. Based on theoretical principles, this study explores the pre-cooling, refrigeration, and normal-to-secondary hydrogen conversion processes. By calculating and analyzing the process’s energy consumption, an optimized flow scheme for hydrogen liquefaction is proposed to reduce the total power used by energy equipment. The study shows that the hydrogen mass flow rate and key helium cycle parameters—like the compressor inlet temperature, outlet pressure, and flow rate—mainly affect energy consumption. By optimizing these parameters, notable decreases in both the total and specific energy consumption were attained. The total energy consumption dropped by 7.266% from the initial 714.3 kW, and the specific energy consumption was reduced by 11.94% from 11.338 kWh/kg.

Asphaltene deposition remains a critical challenge in water-injected reservoirs, where pressure and compositional variations destabilize the oil phase, triggering precipitation and formation damage. This study explores the application of intermittent waterflooding (IWF) as a practical mitigation strategy, combining alternating injection and well shut-in times to stabilize fluid conditions. A synthetic reservoir model was developed in Eclipse 300 to evaluate how key parameters such as shut-in time, injection rate, and injection timing affect asphaltene behavior under varying operational regimes. Comparative simulations against traditional continuous waterflooding reveal that IWF can significantly suppress near-wellbore deposition, preserve permeability, and improve overall oil recovery. The results show that early injections and optimized cycling schedules maintain reservoir pressure above the bubble point, thereby reducing the extent of destabilization. This study offers a simulation-based framework for IWF design, providing insights into asphaltene control mechanisms and contributing to more efficient reservoir management in fields prone to flow assurance issues.

Hydrogen energy, valued for its diverse sources and clean, low-carbon nature, is a promising secondary energy source with wide-ranging applications and a significant role in the global energy transition. Nonetheless, hydrogen's low energy density makes large-scale storage and transport challenging. Liquid hydrogen, with high energy density and easier transport, offers a practical solution. This study examines global hydrogen liquefaction methods, with particular emphasis on the liquid nitrogen pre-cooling Claude cycle process. It also examines the factors in the helium refrigeration cycle—such as the helium compressor inlet temperature, outlet pressure, and mass—that affect energy consumption in this process. Using HYSYS software, the hydrogen liquefaction process is simulated, and a complete process system is developed. Based on theoretical principles, this study explores the pre-cooling, refrigeration, and normal-to-secondary hydrogen conversion processes. By calculating and analyzing process energy consumption, an optimized flow scheme for hydrogen liquefaction is proposed to reduce the total power used by energy equipment. The study shows hydrogen mass flow rate and key helium cycle parameters—like compressor inlet temperature, outlet pressure, and flow rate—mainly affect energy consumption. By optimizing these parameters, notable decreases in both total and specific energy consumption were attained. The total energy consumption dropped by 7.266% from the initial 714.3 kW, and the specific energy consumption reduced by 11.94% from 11.338 kWh/kg.

During reservoir development, asphaltene precipitation deposition triggers the blockage of seepage channels, significantly reducing the reservoir permeability and seriously affecting the effectiveness of water injection development and the operation efficiency of surface facilities. To alleviate this problem, this study proposes to use intermittent waterflooding (IWF) as an alternative strategy to improve reservoir dynamics by alternating periodic waterflooding and well shut-in operations. A synthetic reservoir model was developed based on the component simulator Eclipse 300, and the influence mechanisms of key parameters such as well shut-in time, injection rate, and injection start-up time were systematically investigated and compared and analyzed with the conventional water injection scheme. Numerical simulation results show that IWF can effectively suppress the amount of asphaltene deposition in the near-well zone. Early injection and higher injection rates can help maintain stable reservoir pressure and oil phase composition, thus limiting asphaltene precipitation. The study shows that optimizing the design of the intermittent water injection cycle helps improve the recovery rate and effectively reduces the risk of asphaltene formation damage, providing a practical water injection management strategy for high-risk reservoirs.

During natural gas production and transportation, multi-stage pressure regulation is often required to meet downstream pressure demands, resulting in substantial waste of residual pressure energy at high-pressure wellheads. This study focuses on high-pressure natural gas at the wellhead of the XC gas well in western Sichuan. Based on thermodynamic and exergy analysis, Aspen HYSYS was employed to simulate residual pressure power generation processes, and a systematic comparison was conducted between single-stage and multi-stage expansion schemes. Under operating conditions of an inlet pressure of 20 MPa, an inlet temperature of 70 °C, and a flow rate of 50 × 10⁴ m³/d, the influence of operating parameters on power generation performance was analyzed. The results indicate that power output increases with increasing natural gas flow rate and inlet temperature but decreases with increasing outlet pressure. Under large pressure differential conditions, single-stage expansion is unable to meet the requirements of high-pressure wellhead residual pressure power generation due to excessive temperature drop and limitations in existing expander performance. On this basis, two-stage, three-stage, and four-stage expansion power generation processes were further developed, and the effects of intermediate pressure selection on power output, heating demand, and pressure energy recovery efficiency were systematically examined. The results show that operating under equal expansion ratio conditions enhances pressure energy utilization. By comprehensively comparing power generation performance, heating power requirements, and economic feasibility, the two-stage expansion scheme was identified as the most favorable option under the investigated operating conditions, providing a practical reference for process design and engineering applications of high-pressure natural gas wellhead residual pressure power generation.

This study investigates the impact of fracture conductivity on hydraulically fractured wells in the Eagle Ford Shale using commercial simulation software. Motivated by recent findings on conductivity degradation and the proven reliability of sensitivity analyses in shale reservoirs, a 17-stage horizontal well was modeled to evaluate productivity optimization. The methodology involved holding fracture fluid volume constant while analyzing conductivity variations across both single-fracture and full-well models. Production simulations were validated against real-time field data. Results indicate that the simulation models accurately represent the reservoir, with single-fracture scenarios yielding similar cumulative production and full-well models showing only minor deviations. Ultimately, the observed differences do not justify a significant deviation from current completion techniques under the modeling assumptions considered, as infinite-acting flow remains the dominant regime due to the reservoir’s low permeability.