شبیه سازی سه بعدی جریان نفت درون شکستگی های سنگی دارای سطوح زبر و مقایسه آن با روابط هندسی کلاسیک

نوع مقاله : مقاله پژوهشی

نویسنده

گروه استخراج دانشکده مهندسی معدن، نقت و ژئوفیریک، دانشگاه صنعتی شاهرود

چکیده

بخش عمده جریان هیدروکربن در مخازن شکافدار از طریق (داخل) شکستگی های دارای دیوارهای زبر حادث شده و بنابراین، ارائه مدل های با کارآیی مناسب از رفتار مخازن هیدروکربن، نیازمند فهم عمیق تر از رفتار هیدرولیکی و هیدرومکانیکی شکستگی های سنگی خواهد بود. در این، مقاله رفتار جریان نفت درون شکستگی های سنگی زبر و با هدف بررسی تاثیر زبری و اعتبارسنجی روابط هندسی کلاسیک مطالعه شده است. بدین منظور، جریان نفت در داخل شکستگی های سه بعدی با سطوح زبر با روش عددی حجم محدود شبیه سازی و نتایج حاصل از دیدگاه های مختلفی مورد تحلیل قرار گرفته است. در نهایت، نتایج حاصل از شبیه سازی عددی با روابط هندسی کلاسیک جریان در شکستگی های سنگی و با هدف اعتبارسنجی این روابط مقایسه شده است. نتایج حاصل از این مطالعات نشان می دهد، 1- برای شکستگی های باز، تاثیر زبری سطوح بر روی افت فشار استاتیک بیشتر از چیدمان دهانه مکانیکی است، 2- با افزایش عدد رینولدز، مقدار نفوذپذیری شکستگی ها کاهش می یابد، 3- روابط کلاسیک هندسی دارای خطای نسبی بین 5 تا 35% بوده و هرچه نفوذپذیری شکستگی ها کمتر باشد (فزایش زبری و تغییرات فضایی دهانه) از اعتبار روابط هندسی کلاسیک کاسته می شود.

کلیدواژه‌ها


عنوان مقاله [English]

Tree-dimensional Crude Oil Flow Simulation through Rough-walled Fractures for Evaluating the Classic Geometrical Equations

نویسنده [English]

  • Morteza Javadi
Mining, Petroleum and geophysics Shahrood University of Technology
چکیده [English]

This paper investigates the crude oil flow through open and rough-walled fractures. The aim of this paper is to evaluate the effects of surface roughness and spatial arrangement of aperture segment on fluid flow phenomenon through rough-walled fractures. In addition, the validity of classic geometrical equations of cubic law correction was explored by comparing the output results of numerical simulations (in terms of permeability). To reach this goal, the crude oil flow through three-dimensional rough-walled fractures was numerically simulated by simultaneous solving of Navier-Stokes and mass conservation equations and utilizing FLUENTTM computational software. The numerical crude oil flow simulation was performed for six different three-dimensional geometrical models of fractures whit different roughness and aperture arrangements and constant porosity. The results of fluid flow simulation were analyzed with different points of view and then compared with the classic geometrical equations of cubic law correction. The results of this study show that (i) for the open fractures, the effects of roughness on the pressure lose is higher than spatial arrangement of aperture segment, (ii) due to the nonlinearity of flow, the permeability of fractures decreases by increasing the Reynolds number, and (iii) with the classic geometrical equations of cubic law correction encounter with about 5 to 35% error and the accuracy of these equations will be decrease by decrease the permeability of fractures or increase of roughness and spatial variability of aperture. These findings prove useful in proper understanding of crude oil flow in fractures, or inclusions in computational simulation of large-scale flow in fractured petroleum reservoirs.

کلیدواژه‌ها [English]

  • Crude Oil Flow
  • Flow Simulation
  • Rough-walled Fractures
  • Reynolds Number
  • Permeability
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