http://yetl.yabesh.ir/yetl1/handle/yetl/4303706 Mon, 13 Apr 2026 14:38:06 GMT 2026-04-13T14:38:06Z http://localhost:80/yetl1/bitstream/id/453312/ http://yetl.yabesh.ir/yetl1/handle/yetl/4303706 http://yetl.yabesh.ir/yetl1/handle/yetl/4310461 Study on the Carbonization Behavior of Petroleum-Based Mesophase Prepared by In-Process Hydrogenation Yang, Jingyu; Shi, Huibing; Zhao, Deming; Chen, Minghao; Li, Ming As an excellent precursor of high-modulus carbon materials, petroleum mesophase pitches' spinning performance was limited by its high softening point. Under the premise of ensuring the order degree of mesophase microcrystalline structure, the softening point was reduced by preparing mesophase pitch via in-process hydrogenation using fluid catalytic cracking aromatic-rich oil as raw material and decahydronaphthalene as a hydrogen supplier. The effects of in-process hydrogenation on the properties of mesophase and carbonization behavior during thermal polycondensation were investigated. It was found that the two-stage hydrotreated mesophase pitch produced an optical structure that was 100% generalized, with the highest crystal order of 0.9189, the highest aromaticity Iar of 0.520, and a softening point of 176 °C. The results showed that the addition of decahydronaphthalene promoted the hydrogen transfer reaction of the reaction system, producing light components such as cycloalkyl and saturates. The system mobility was improved, which made the molecular weight of the mesophase pitch concentrated and suitable for the full development of crystals. Wed, 01 Jan 2025 00:00:00 GMT http://yetl.yabesh.ir/yetl1/handle/yetl/4310461 2025-01-01T00:00:00Z http://yetl.yabesh.ir/yetl1/handle/yetl/4310454 Wellhead Corrosion Mechanism and Optimization Under Alternating Injection Condition of Liquid CO2 and Fracturing Fluid Duan, Binghong; Sun, Wei; Wang, Xiaogang; Zhang, Hao; Zhao, Ning With the continuous exploitation of conventional oil and gas resources, their recoverable reserves are decreasing day by day. Unconventional oil and gas resources have attracted much attention, and CO2-enhanced fracturing technology is gradually taking the lead. During the implementation of this technology, the electrochemical corrosion of CO2 on the inner wall of pipelines will have a significant impact on the exploitation efficiency and equipment service life. To elucidate the corrosion mechanism of wellhead components under alternating CO2 and fracturing fluid injection conditions, and to identify the key controlling factors influencing corrosion within actual engineering parameters while investigating their corrosion patterns, this study employs a finite element numerical simulation approach. The research takes into account the structural characteristics and spatial distribution of erosion pits formed in the pipeline following fracturing fluid injection, subsequently conducting a comprehensive analysis of the electrochemical corrosion processes during the CO2 injection phase. The results indicate that injection displacement, pressure, and temperature are the main factors influencing pipeline corrosion, with decreasing degrees of influence. Optimization analysis reveals that the optimal parameter combination is: injection displacement of 3 m3/min, injection pressure of 42 MPa, and injection temperature of −14 °C. Under these conditions, the corrosion on the inner wall of the pipeline is minimized. Specifically, increasing the injection displacement significantly reduces corrosion, increasing the injection pressure makes corrosion more severe while increasing the injection temperature slightly alleviates corrosion. Wed, 01 Jan 2025 00:00:00 GMT http://yetl.yabesh.ir/yetl1/handle/yetl/4310454 2025-01-01T00:00:00Z http://yetl.yabesh.ir/yetl1/handle/yetl/4310444 Experimental Investigation on Fracture Propagation in Heat-Treated Granite Samples During True Triaxial Temporary Plugging and Diversion Fracturing Wang, Qiuyan; Wang, Daobing; Zhu, Haiyan; Wang, Yongliang; Sun, Hai; Yu, Bo Wed, 01 Jan 2025 00:00:00 GMT http://yetl.yabesh.ir/yetl1/handle/yetl/4310444 2025-01-01T00:00:00Z http://yetl.yabesh.ir/yetl1/handle/yetl/4310428 Experimental Study of Sand Wear and Performance Deterioration of Mixed-Type Electrical Submersible Pumps Zhu, Haiwen; Tatu, Tanmay; Baillargeon, David; Song, Paul; Rumbaugh, Michael; Jing, Haorong; Tychus, Adedayo; Adiraju, Sai Praveen; Sun, Qiang; Zhang, Hong-Quan Electrical submersible pumps (ESPs) are widely used in the oil and gas industry to provide external energy to producing wells when the natural drive of the reservoir is insufficient. However, ESPs are susceptible to the repetitive impact wear caused by solid particles, which affect the pump performance and run life. Predicting the degradation in the pump performance is crucial to estimate the workability and overall life of an ESP. Sand erosion testing was carried out at the Tulsa University Artificial Lift Projects (TUALP) on two multistage mixed-flow ESPs. The pumps were tested for 64 h/per pump in intervals of 8, 8, 16, and 32 h. The performance parameters such as head, efficiency, and horsepower were measured before and after each test interval. It was observed that over the 64-h test period, the head of both pumps was reduced by 10–15% and the efficiency decreased by 7–15%. The seal clearances increased by almost 10 times the original value. The degradation of ESP structures is then analyzed in detail. These findings help better understand the wear and process of erosion in ESPs and predict the change in performance over a set period of operation of the ESPs under a sandy flow environment. This study will also provide a reference for the optimal design of ESP. Wed, 01 Jan 2025 00:00:00 GMT http://yetl.yabesh.ir/yetl1/handle/yetl/4310428 2025-01-01T00:00:00Z