Energy storage is essential for solar energy utilization, and thermocline storage tanks are commonly used. To improve temperature stratification and storage efficiency, we investigated the effect of different water distributor configurations on tank stratification. We numerically analyzed the heat storage processes in hot water tanks with three water distribution configurations: star, antenna, and octagonal. Temperature stratification was evaluated based on thermocline thickness and storage efficiency. Thermal storage efficiency improves by 0.45% when the outlet direction of the water distributor matches the fluid’s motion direction during natural stratification. The energy storage process is categorized into three stages based on efficiency changes, with different factors affecting efficiency at each stage. In the initial stage, antenna-type and octagonal water distribution improve temperature uniformity along the axial section, reduce thermocline thickness, and enhance stratification. Final efficiency during this stage is primarily influenced by energy loss resulting from the mixing of hot and cold water. In the development stage, energy storage efficiency decreases mainly because the lower boundary of the thermocline reaches the exit, causing partial discharge of hot water. Among the three configurations, the octagonal water distribution exhibits the lowest energy loss, 6.4% lower than that of the star-type distribution.

Integration of source, grid, load, and storage is an important measure for energy transformation. However, at present, the oilfield industry lacks mature models and related technologies. Therefore, an oilfield intelligent energy system integrating source, power grid, load, and storage is proposed in this paper. In view of the poor oilfield data quality, abnormal/missing data diagnosis and repair methods are proposed to improve the information accuracy of the intelligent cloud management center. The improved photovoltaic prediction method of conditional generation countermeasure network (CGAN), PV-VSG control of additional control, and flexible load control are put forward to upgrade the intelligent deployment system. The system design and key technologies can provide reference for the construction of new power systems and energy Internet in the future oilfield industry.

While the size of the four-bar linkage is the basis of kinematic performance analysis in a beam pumping unit, there is still a lack of effective and direct measurement of it. Since the motor input power and the polished rod position are commonly used production data, a size identification algorithm of the four-bar linkage based on the motor input power and the polished rod position is proposed in this paper. Firstly, the kinematic model of a beam pumping unit, the speed model of a motor, the initial value, and the state space model are established. Secondly, a Cubature Kalman filter with nonlinear constraints is designed and the size identification algorithm is worked out. Lastly, the model and the size identification algorithm are validated based on the simulated and measured data, and the characteristics of identification with different measurement covariance are studied. The results demonstrate that both the model and the algorithm are feasible. The maximum relative error between the identified and the real size increases from 0.23% to 9.37% when the covariance increases from 10⁻⁶ to 10⁻¹. With the measured covariance of the polished rod velocity, the maximum relative error is 7.09%. A comparison of several current identification methods demonstrates that the proposed algorithm is more accurate.

Calibrating traditional inventory-based emission estimates with top-down point source inversion results is of significant importance. To address the challenges posed by satellite remote sensing in accurately assessing methane point source emissions and the inefficiency of ground-based mobile measurement due to the lack of prior information, this paper proposes a novel space-ground integration system of methane emission monitoring and quantification. The system utilizes a classic matched filter (CMF) algorithm to retrieve greenhouse gas concentration increments from multi-temporal hyperspectral images, thereby identifying continuous point sources, which subsequently guides the development of ground-based emission data collection plans. The EMISSION-PARTITION model is applied to quantify point source emission intensities. In April 2024, our team conducted an experiment based on this system in a petrochemical industrial park in Dongying, China. Satellite observations identified key continuous point sources with an uncertainty of 8.08%. The point source emission intensities quantified from mobile measurement ranged from a minimum of 139.36 kg/hto a maximum of 107.42 kg/h, with uncertainties controlled within 19.1%. This experiment provides valuable insights for similar greenhouse gas emission monitoring and quantification tasks.

During heavy oil development, the gathering and transportation of low-temperature wellhead-produced fluids are often accompanied by high viscosity, pipe-wall deposition, and high flow resistance, threatening the continuous and stable operation of gathering systems. Existing studies on wellhead heating mainly focus on overall steady-state heating performance, while variable-flow heat transfer and start–stop control in local heating systems remain insufficiently explored. This study aims to evaluate the steady-state heating capacity, transient thermal response, and start–stop control performance of a localized electric heating section under variable-flow conditions. A 3D fluid–solid-coupled heat-transfer model of the heating element, pipe wall, and internal fluid was developed using COMSOL Multiphysics. The steady-state temperature field, transient heating and cooling behavior, and start–stop control characteristics were analyzed under different flow rates. The results show that, at a heating power of 15 kW and a flow rate of 20 m³/d, the maximum outer-wall temperature reached 564 K, and the average outlet fluid temperature reached 308.83 K, indicating effective heating performance. As the flow rate increased from 10 m³/d to 30 m³/d, the maximum pipe-wall temperature and fluid temperature rise both decreased, whereas the average fluid-side heat-transfer coefficient increased from approximately 700 W/(m²·K) to 1800 W/(m²·K), demonstrating enhanced convective heat transfer. Under a dual-threshold control strategy of 463.15–483.15 K, the system maintained the target temperature near 473.15 K under all tested conditions, while the load factor increased from 37.83% to 86.15%. These findings provide theoretical references and engineering support for optimizing power configuration and improving temperature control strategies in local heating systems for wellhead-produced fluids.