Journal of Energy Science and Technology is an international, peer-reviewed open access journal dedicated to advancing research the field of energy science and technology. The journal provides a rapid publication process to ensure wide dissemination of high-quality articles to scientists, professionals, and interested individuals worldwide. Our goal is to serve as an efficient, reliable, and trusted platform for scholars and readers, publishing cutting-edge research in the field.
Abstract: The drilling fluid in the wellbore would be in a state of continuous circulating flow during the drilling operation, and will undergo the compound heat exchange with the wellbore rock through the convection heat transfer and the heat conduction, causing the mechanical properties of the rock to change with the changing of its own temperature. To study the influence of the temperature changing on the borehole deformation, further enrich the theory of the wellbore stability guarantee and effectively ensure the wellbore stability of the deep coalbed methane (CBM) wells, a high-temperature, high-pressure rock triaxial mechanics testing system was used to test the evolution characteristics of various mechanical properties of deep coal-rock under different experimental temperature conditions (40°C-100°C). The results show that the higher the experimental temperature, the lower the stress value of the deep coal-rock when it fails. In the process of reaching peak strength, the higher the experimental temperature, the higher the proportion of plastic deformation of the deep coal-rock in its entire deformation stage. The compressive strength, elastic modulus, and main crack length of the deep coal-rock will decrease with the experimental temperature. The Poisson's ratio and the central fracture angle will increase with the experimental temperature.Abstract: The drilling fluid in the wellbore would be in a state of continuous circulating flow during the drilling operation, and will undergo the compound heat exchange with the wellbore rock through the convection heat transfer and the heat conduction, causing the mechanical properties of the rock to change with the changing of its own temperature. To stu...Learn More
Abstract: There are precedents for the construction of flooded hydrocarbon reservoir into gas storage abroad, but there is no successful experience of the same type of gas storage in China. This paper takes the reconstruction of gas-cap oil reservoir with strong water flooded layer into gas storage in Block M19 of Liaohe Oilfield as an example to carry out numerical simulation research on drainage and expansion of gas storage, so as to solve how to optimize well pattern design and peak timing under the strong water flooding conditions, and to solve the technical difficulties of efficient drainage and gradually form effective gas storage space. This paper by means of gas reservoir numerical simulation technology, establishes a numerical model of drainage and expansion of gas storage by applying the mechanism model. Through a variety of alternatives, discusses the influence of well pattern, horizontal well location, perforating horizon, Injection timing, injection volume and other factors on water discharge and crude oil recovery. And conduct a simulation study of various factors affecting the movement of gas liquid interface and displacement effect. The simulation results show that the cumulative water production, cumulative oil production and final oil recovery are the largest under the conditions of nine-spot pattern, gas injection at the high point of formation, perforation at the upper level of the horizontal well and perforation at the lower level of the vertical well, and the accumulated oil production rate and accumulated water production rate are positively correlated with the gas injection rate. It shows that under this well pattern, the displacement efficiency is higher, the sweep volume is larger, and it is more conducive to air-driven drainage. Gas injection and drainage for 4 months, gas injection and pressure holding for 3 months, equilibrium period for 1 month, gas production for 4 months, nine-spot well pattern, gas injection at the high point of formation, perforation and drainage at the lower level of the production well, after six cycles of circular injection and production, the drainage effect is the best, which can increase the final oil recovery by 5%.The gas injection rate can be increased to 1.2 times within the permitted operating pressure. The research results will further guide the design of efficient drainage construction method for M19 gas storage, which can not only achieve the purpose of gas storage construction, but also improve crude oil recovery and achieve win-win benefits, and provide reference for the construction of similar gas storage.Abstract: There are precedents for the construction of flooded hydrocarbon reservoir into gas storage abroad, but there is no successful experience of the same type of gas storage in China. This paper takes the reconstruction of gas-cap oil reservoir with strong water flooded layer into gas storage in Block M19 of Liaohe Oilfield as an example to carry out n...Learn More
Abstract: The energy management system is an organic combination of a series of interrelated elements for enterprises to establish and achieve energy policies and objectives. In order to solve the problems of inconsistency of the existing standard system, unclear components and the ambiguity and randomness of a single management method, this paper constructs a three-dimensional structure model of energy management system based on Hall model. from the perspective of energy management, taking the big data formed by the enterprise energy management system as the background, aiming to improve the efficiency and provide reference for the construction of energy management system. By introducing the time dimension to realize the unified expression framework of energy management involved in the energy management standard system and the energy management regulation system, the seven logical steps of the logical dimension of the energy management system are proposed, and the knowledge dimension, which is composed of professional knowledge and skills required to complete the above stages and steps, is added to form a three-dimensional structure space composed of the time dimension, logical dimension and knowledge dimension. Through the example, it is found that the application of Hall's three-dimensional structure model to build an energy management system can greatly improve the efficiency, optimize the existing energy management system and means of the enterprise, and make the establishment of energy management system more systematic, and the energy management system built based on Hall's three-dimensional model can be further promoted and applied.Abstract: The energy management system is an organic combination of a series of interrelated elements for enterprises to establish and achieve energy policies and objectives. In order to solve the problems of inconsistency of the existing standard system, unclear components and the ambiguity and randomness of a single management method, this paper constructs...Learn More
Abstract: At present, most cargo ships still use fossil fuels, causing noise pollution, environmental pollution and carbon emission problems. The gradual emergence of cargo ships powered by electricity and solar energy is one of the ways to solve the problem of pollution and carbon emissions. Very little research has been done on the endurance of solar-powered cargo ships and their economic and environmental benefits. This paper takes a thousand-ton cargo ship as an example to study the longest endurance that can be achieved with existing technology when it is driven by pure solar energy. On the one hand, this study helps to evaluate the feasibility of using pure solar energy to drive cargo ships; on the other hand, it points out the direction for the technological breakthroughs needed in the next step. This paper proposes a calculation formula for the sailing time of a cargo ship driven by pure solar energy, and calculates the sailing time of a cargo ship driven by pure solar energy to be about 4.57 h/day based on the existing average solar energy resources and the latest solar photovoltaic technology. Since pure solar energy cannot guarantee the 24-hour battery life, the dual energy guarantee system of "solar power supply + shore-based charging pile" is further proposed, which is currently a more feasible power scheme for cargo ships. One of the key technological breakthroughs needed to popularize pure solar cargo ships is the further improvement of solar photoelectric conversion efficiency. According to the calculation based on the average element composition of fossil fuels and the chemical reaction equation, it is found that the adoption of this system can bring significant economic and environmental benefits to the cargo ship and shipping industry: an average of 1,000-ton cargo ship can save fuel costs of 26.87 million yuan per year; Reduce carbon dioxide emissions by 10,200 tons/year, sulfur dioxide emissions by 63.75 tons/year, and nitrogen dioxide emissions by 95.62 tons/year. Compared with pure electric cargo ships, using solar power can further save electricity costs of 139,800 yuan/year, reduce carbon dioxide emissions by 327 tons/year, sulfur dioxide by 20 tons/year, and nitrogen dioxide by 10 tons/year. According to the calculation results, the development of solar cargo ships is conducive to economic development and environmental protection, and promotes the development of green water transportation, which is worth promoting.Abstract: At present, most cargo ships still use fossil fuels, causing noise pollution, environmental pollution and carbon emission problems. The gradual emergence of cargo ships powered by electricity and solar energy is one of the ways to solve the problem of pollution and carbon emissions. Very little research has been done on the endurance of solar-power...Learn More
Abstract: With the implementation of the national carbon neutralization and carbon peak strategy, the technology of shipping energy conservation and emission reduction has also been concerned by the public. As there are high-power engines and generator sets in the engine room of the ship, the waste heat temperature of waste gas generated during equipment operation is extremely high, which can be as high as thousands of degrees Celsius. The device first converts waste gas waste heat into mechanical energy through Stirling machine, and then converts it into electrical energy through external generator. The whole working process produces electric energy while reducing the ambient temperature, and improves the utilization efficiency of waste heat. According to the preliminary experiment, about 3.3v electric energy can be generated when the temperature is 433°C. The device has simple structure, no complex mechanical structure, high safety and strong reliability. If multiple equipment can be used in the marine engine room at the same time, it will have a positive help to achieve the goals of carbon neutralization and carbon peak.Abstract: With the implementation of the national carbon neutralization and carbon peak strategy, the technology of shipping energy conservation and emission reduction has also been concerned by the public. As there are high-power engines and generator sets in the engine room of the ship, the waste heat temperature of waste gas generated during equipment ope...Learn More
Abstract: Conventional ac-calorimetry method could accurately measure the in-plane thermal diffusivity of suspended thin films but cannot be applied to small-scale samples due to the large sample size required by this method. This work proposes a novel optical-based ac-calorimetry method that circumvents the limitations of the conventional ac-calorimetry method. This new method uses a modulated continuous-wave laser to heat the sample periodically, and another continuous-wave laser to detect the sample’s temperature response on the surface at different distances from the heating spot via the principle of thermoreflectance. Since this method uses highly focused laser beams with micrometer-scale spot diameters for optical heating and temperature sensing, and this method uses the state-of-the-art thermal model of 3D anisotropic multilayers for signal processing, this method can accurately measure the in-plane thermal conductivity of suspended and supported thin films and bulk materials with sub-millimeter-scale lateral sizes, with a typical measurement uncertainty of less than 5%. This paper describes the details of this technique, including the basic principle, test device, signal acquisition, data processing, and uncertainty analysis. This technique is demonstrated through measurements of a standard sapphire sample, with the phase and amplitude approaches of ac-calorimetry compared. This technique is also compared with some other related optical-based thermal methods for their pros and cons in the end.Abstract: Conventional ac-calorimetry method could accurately measure the in-plane thermal diffusivity of suspended thin films but cannot be applied to small-scale samples due to the large sample size required by this method. This work proposes a novel optical-based ac-calorimetry method that circumvents the limitations of the conventional ac-calorimetry met...Learn More
