مدل سازی توزیع اندازه ذرات آسفالتین در چاه با استفاده از روش DEM-CFD

نوع مقاله : پژوهشی اصیل

نویسندگان

1 دانشگاه صنعتی امیرکبیر

2 دانشگاه تهران

چکیده
در پژوهش حاضر، تجمع و شکست ذرات آسفالتین با استفاده از کوپل همزمان روش اجزای گسسته و دینامیک سیالات محاسباتی در جریان آرام شبیه سازی شده است. با توجه به ماهیت آسفالتین، یک مدل جدید تجمع جهت مدلسازی فرایند چسبیدن ذرات آسفالتین بر اساس ساختار واقعی کلوخه ها پیشنهاد شده است. برخورد ذرات، راندمان برخورد و شکست کلوخه‌های آسفالتین به صورت دقیق مطالعه شده‌اند. همچنین، رشد ذرات آسفالتین و تغییرات توزیع اندازه ذرات به همراه تغییرات ساختار کلوخه ها بررسی شده است. در طول فرایند توده‌ای شدن ذرات آسفالتین، در بازه زمانی اولیه رشد اندازه ذرات کم است که دلیل آن تجمع ذرات اولیه و شکل گیری کلوخه‌های کوچک می‌باشد. در بازه زمانی میانی به علت برخورد کلوخه‌ها و تشکیل کلوخه‌های بزرگ، رشد اندازه ذرات شدت می‌گیرد و در بازه انتهایی شکست کلوخه‌ها رشد بیشتر آن‌ها را محدود می‌سازد و نهایتا به حالت پایا می‌رسد. توزیع لگاریتمی نرمال بهترین مطابقت را با نتایج توزیع اندازه ذرات نشان می دهد که بر اساس مطالعات قبلی با طبیعت آسفالتین نیز هماهنگی دارد. بر اساس نتایج شبیه سازی، کرنل برخورد و شکست به طور مستقیم محاسبه گردید که با نتایج کرنل برخورد و شکست در مراجع پیشین همخوانی دارد.

کلیدواژه‌ها

موضوعات


عنوان مقاله English

Modeling of asphaltene particle size distribution in well using DEM-CFD

نویسندگان English

hadi bagherzadeh 1
Zahra Mansourpour 2
Bahram Dabir 1
1 Amirkabir University of Technology
2 University of Tehran
چکیده English

In the present study, the agglomeration and fragmentation of asphaltene particles have been simulated in laminar using the simultaneous coupling of Discrete Element method and Computational Fluid Dynamics. A new coalescence model according to the nature of asphaltene has been proposed. Asphaltene flocs have been considered as irregular shape rigid object. Particle collisions and collision efficiency as well as the fragmentation of asphaltene flocs have been studied in details. Furthermore, the asphaltene particles growth and change in particle size distribution along with average fractal dimension changes have been investigated. During the flocculation of the asphaltene particles, the asphaltene particles grow slowly in the initial times. It can be explained by the agglomeration of primary particles and the formation of asphaltene flocs. In the middle time period, due to the collision of the flocs and the formation of large flocs, the growth of the asphaltene particles increase. At the late times, the fragmentations limit the floc growth, and eventually asphaltene particle size approximately reaches a constant value in the steady state. The lognormal distribution provides the best fit for the asphaltene PSDs which, according to previous studies, is also consistent with the nature of asphaltene. The results of proposed collision and fragmentation kernels based on simulation results are agreed well with previous studies.

کلیدواژه‌ها English

Asphaltene Particles
agglomeration
Fragmentation
Discrete Element Method
Computational Fluid Dynamics
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