بررسی نفوذپذیری وابسته به تنش در مخازن شکاف‌دار با استفاده از روش عددی المان مجزاء

نوع مقاله : مقاله پژوهشی

نویسندگان

گروه مکانیک سنگ، دانشکده فنی و مهندسی، دانشگاه تربیت مدرس، تهران، ایران

چکیده

موضوع حساسیت نفوذپذیری نسبت به تنش در مخازن نفتی و گازی یک موضوع بسیار مهم و حیاتی می‌باشد، به‌طوری که تولید از یک مخزن ارتباط تنگاتنگی با ضریب حساسیت تنش آن دارد. در واقع این پدیده بدین صورت است که کاهش فشار مخازن در حالی که تنش روباره دارای مقدار ثابتی است، باعث افزایش تنش موثر و در نتیجه کاهش نفوذپذیری خواهد شد. چنانچه ارتباط دقیق بین کاهش نفوذپذیری با کاهش فشار مخازن به خوبی شناخته شود، می‌توان استخراج هیدروکربور از مخازن را اقتصادی‌تر نمود. در این مقاله با استفاده از روش عددی المان مجزاء یک کد عددی توسط نرم‌افزار UDEC توسعه داده شده است. در کد عددی توسعه داده شده تاثیر ضریب حساسیت بر‌روی پارامترهایی همانند میدان تولید چاه و ضریب پوسته در اطراف یک مخزن با جریان شعاعی بررسی شده است. برای بررسی تاثیر تنش بر‌روی نفوذپذیری شکاف‌های موجود در یک مخزن رابطه بین تنش و نفوذپذیری به‌صورت نمایی فرض شده است. بررسی‌های انجام شده نشان می‌دهد که با افزایش ضریب تراکم‌پذیری شکاف‌ها، ضریب پوسته مخزن دچار افزایش و میزان تولید از چاه دچار کاهش می‌شود. 
 

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

A Numerical Investigation on Stress Dependent Permeability in Jointed Reservoirs

نویسندگان [English]

  • Behnam Ghobadi
  • Hamid Reza Nejati
  • Kamran Goshtasbi
Rock Mechanics Division, School of Engineering, Tarbiat Modares University, Tehran, Iran
چکیده [English]

Stress dependent permeability is a great problem in petroleum engineering and natural fractured reservoirs. Permeability in a fractured porous medium is mainly controlled by the geometry and interaction of the pores and fractures as well as stress state. Interaction between stress and permeability in jointed reservoirs is a crucial factor during different stages of life of  a reservoir such as assessment, productivity and management. Also, reduction in reservoir pressure significantly influence on the reservoir permeability. In this study, it is intended to find the relationship between the stress sensitivity and production rate. For this purpose, distinct element code is used to develop numerical modeling of a reservoir to evaluate the relationship between stress sensitivity and productivity rate. The results of numerical simulations indicated that with increasing the bulk modulus of rock joints, the skin factor increases and consequently the well productivity decreases.
 

کلیدواژه‌ها [English]

  • Stress Dependent Permeability
  • Productivity Rate
  • Skin Factor
  • Distinct Element Method
  • UDEC Software
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