فهرست مطالب

Petroleum Science and Technology - Volume:9 Issue:4, 2019
  • Volume:9 Issue:4, 2019
  • تاریخ انتشار: 1398/09/29
  • تعداد عناوین: 6
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  • Mehdi Mohammadi * Pages 3-21
    A particular population balance model (PBM) which consists of hydrodynamic and electrostatic parts is developed for electrocoalescence of distributed water droplet in the continuous oil phase. The approach is the modification of a recognized PBM by adding the electrostatic effects on the overall coalescence rate including the number of times (frequency) occurring collision and the efficiency of coalescence. Moreover, the modified model has been being implemented in a CFD-PBM problem for a pilot plant electrocoalescer to predict the profile of water phase and size distribution of droplets. The results recognize the effect of local electric field intensity and local water content on electrocoalescence rate. Furthermore, the results demonstrate that separation for the very small droplets (<4μm) is minor, for the medium sizes (8-32μm) is more considerable, and for larger droplets (>64μm) occurs completely. Ultimately, by making a comparison between the simulation results and the pilot data, the EHD PB model is validated.
    Keywords: Electrocoalescence, w, o Emulsion, Droplet, Electrohydrodynamic (EHD), Population Balance (PB)
  • Wilberforce Aggrey *, Nana Asiedu, Bennet Tackie Otoo, STEPHEN ADJEI, Emmanuel Mensah Bonsu Pages 22-38

    Environmental concerns and cost associated with drilling operations have made us promote the application of biodegradable and renewable drilling fluid additives, particularly at high temperature. In this study, sodium carboxymethyl cellulose (NaCMC) synthesized from cocoa pod husk (cocoa NaCMC) was tested as a filtration agent at high temperature and differential pressure conditions. Moreover, eight mud samples containing various fluid-loss additives were tested. The Filtration test was performed using the permeability plugging tester at 248 °F temperature and 100 psi and 300 psi differential pressures with ceramic discs 10 µm and 90 µm. In addition, the degree filtration agents affect the drilling mud’s rheological parameters were estimated. Also, thermal degradability of the sample was also studied. The results showed that filtration control performance at high temperature and low/high differential pressure was improved by decreasing particle size and increasing concentration. Using the cocoa NaCMC was proved to be a better filtration agent at high-temperature conditions with a high thermal degradability. Finally, the obtained results indicated that the filtration control performance declined in higher permeable formation. Moreover, the drilling fluid’s rheological properties were improved by the cocoa NaCMC, and it was comparable to the industrial PAC.

    Keywords: Cocoa Pod Husk, Cellulose, Sodium Carboxymethyl Cellulose, Filtration Characteristics, Drilling Fluids
  • Yasmin Ali * Pages 39-52
    In this study, biomarker analyses were conducted on four condensate samples recovered from Kafr El Sheikh and Abu Madi Reservoirs in Abu Qir concession, NW offshore Nile Delta. Moreover, according to the obtained results, it was indicated that the condensates are genetically related, and they were derived mainly from clay-rich source rocks of mixed organic sources, with significant input of terrestrial organic sources, deposited in low saline fluvio-deltaic environment. These conclusions are supported by the relative abundance of both C29 and C27 regular steranes, high diasteranes, and Pr /Ph ratios and the lowC29norhopane relative to C30hopane, low isoprenoids/n-alkanes ratios and lack of gammacerane. In addition, biomarker maturity indicators suggested that the condensates were sourced from early mature source rocks. Finally, geochemical and isotopic data from gases indicated that Abu Qir gases are of thermogenic origin generated from source rocks with mixed types II/III kerogens.
    Keywords: Petroleum Geochemistry, Condensate Characterization, Gas Characterization
  • Weiqiang Wang, Jing Cui, Shangshu Wu, Yun Cheng, Guofu Wang, Haijuan Zhang * Pages 53-62
    For removing wax and reducing viscosity of wax, microbial technology can effectively be used, and thereby, by using this technology, the flow properties of crude oil are improved. In this study, optimization of compound bacteria isolated from oil-contaminated soil and its effect on wax content and particle size are investigated. Moreover, experimental results show that the optimized compound bacteria have the highest cell density value under the optimal conditions. After #11 and #12 compound bacteria are added, the wax content reduces from 21.46% to 8.3%, and the wax removal rate becomes 61.32%. In addition, the polarizing microscope analysis demonstrates that the paraffin is degraded with the bacteria, and its wax crystal micro-structure is changed with the bacteria. Moreover, the focused beam reflectance measurement (FBRM) shows that the proportion of particles of large diameter is significantly decreased, and that of small ones is increased. Consequently, the flow properties of waxy crude oil are improved. The viscosity changes at different temperatures after treatment with bacteria. Finally, it is found out that at the temperature which is equal to 40 to 45 ºC, the rate of viscosity reduction is higher than 60%. Therefore, the paraffinic hydrocarbons of crude oil can be degraded with compound bacteria, and their rheological properties are improved.
    Keywords: Waxy Crude Oil, Compound Bacteria, Wax Content, Particle Size, viscosity
  • Sheng Tao Qu, Dong Mei Liu *, Xin Shi, Hai Yan Wang, Xin Wang Pages 63-76

    In this study, the effects of crystallization temperature, crystallization time, and pH value on the textural properties of synthetic ZSM-5 were investigated by the orthogonal test method. Furthermore, the effects of ZSM-5 catalysts synthesized under different preparation conditions on their reactivity during catalytic cracking were evaluated. Moreover, the results have shown that the three factors that affect the ZSM-5 synthesis are in the following order: crystallization temperature > crystallization time > pH value. In addition, the optimal conditions for synthesizing ZSM-5 catalysts were crystallization temperature of 170 °C, crystallization time of 48 h, and pH of 11. Furthermore, under these conditions, the specific surface area, pore-volume, and acidity of the synthetic zeolite were moderate, and the hydrothermal stability was ideal. Finally, when the optimal conditions were applied to the catalytic cleavage of n-hexane, the synthesized zeolite exhibited good activity and stability.

    Keywords: Orthogonal Test, ZSM-5 Zeolite, Preparation Conditions, n-Hexane, Catalytic Cracking
  • Alireza Moazeni, Ehsan Khamehchi * Pages 77-88
    It is essential to obtain valuable information during drilling from the formation that is being drilled for rate optimization. In the drilling operation, the process of lithology and formation determination is extremely obscurant and it seems machine learning, as a novel prediction method that can model complicated situations having a high degree of uncertainty, could be beneficial. In this work, the real-time drilling data was applied to predict the formation type and lithology while drilling that formation using a genetic algorithm and Taguchi design of experiment optimized artificial neural network. Drilling data of twelve wells in one of Iranian gas fields were applied for this work. 47500 sets of data were selected, and after data control, 31200 data sets were selected as valid data and imported to artificial neural networks. For performing this research, by changing the network features and optimizing the structure of the network using the Taguchi method and optimizing the weight and biases of the network using the genetic algorithm, a unique artificial neural network was designed. The results show that the developed hybrid machine learning method can predict formation and lithology with a high degree of accuracy.
    Keywords: Real-Time Drilling Data, Formation Lithology, Virtual Intelligence, Genetic Algorithm, design of experiment