مطالعه و ارزیابی عملکرد تزریق متناوب آب و گاز (WAG) در یکی از مخازن نفتی شکاف‌دار غرب ایران

نوع مقاله: مقاله پژوهشی

چکیده

با گسترش و پیشرفت صنعت نفت، تمایل به افزایش تولید از میادین نفتی بیش از پیش مورد توجه و در اولویت قرار گرفت. به همین منظور روش‌های جدید ازدیاد برداشت پیشنهاد و مورد استفاده قرار می‌گیرند. تزریق متناوب آب و گاز نیز از جمله این روش‌ها هستند. در این روش آب و گاز به صورت متناوب و در یک محل به مخزن تزریق می‌شوند. هدف اصلی فرایند تزریق متناوب آب و گاز، افزایش بازدهی تزریق گاز توسط تزریق آب با افزایش سطح تماس سیال تزریقی با مخزن، کنترل نسبت تحرک میان سیال تزریقی و نفت مخزن و ایجاد جبهه حرکت پایدار است. تزریق متناوب آب وگاز به روش‌های امتزاجی، غیرامتزاجی، هیبرید (ترکیبی)، پیوسته و انتخابی پیوسته انجام می‌شود.در این پژوهش، روش‌های مختلف تزریق متناوب آب و گاز در یکی از مخازن شرکت ملی نفت ایران با استفاده از بسته نرم‌افزار تجاری GeoQuest و ماژول ECLIPSE 100 شبیه‌سازی و ضریب بهره‌دهی و تولید تجمعی در پارامترهای مؤثر بر تزریق مانند چرخه (سیکل)، نوع و روش تزریق (غیرامتزاجی، هیبرید (ترکیبی)، و انتخابی پیوسته) مورد بررسی قرار گرفتند. سپس روش‌های تزریق منفرد آب، گاز و تزریق متناوب آب و گاز برای انتخاب روش مناسب تزریق در میدان مورد نظر مقایسه شدند. در نهایت با طراحی سناریوهای مختلف تزریق متناوب آب و گاز و تزریق جداگانه آب و گاز در الگوهای چهار و پنج نقطه‌ای تزریق، ضریب بهره‌دهی، درصد اشباع نفت باقی‌مانده و تولید تجمعی به‌منظور مشخص کردن الگوی بهینه تزریق در روش‌های ذکر شده محاسبه و مورد مقایسه قرار گرفتند. نتایج به‌دست آمده نشان می‌دهد در صورتی که پارامترهای مؤثر بر تزریق متناوب آب و گاز به درستی طراحی و انتخاب شوند، ضریب بهره‌دهی و تولید در این روش به مراتب بیشتر از تزریق جداگانه آب و گاز می‌باشد.

کلیدواژه‌ها


عنوان مقاله [English]

Study and Evaluation of WAG and Comparison with Water and Gas Injection in One of the Fractured Oil Reservoirs in the West of Iran

چکیده [English]

By development and improvement of oil industry, the tendency to increase the production of oil fields has been paid more attention. The growing need to increase the output and ultimate recovery by enhanced oil recovery (EOR) methods has received great significance as far as mature oil fields are concerned. Water Alternating Gas (WAG) injection also is one of these methods. WAG is defined as the injection of both water and gas into the same reservoir. WAG injection is an oil recovery method initially aimed to improve sweep during gas injection mainly by using water to increase the contact surface of injected fluid with the reservoir; it is also to control the mobility of the displacement and create stable mobility front. This including definition covers MWAG (miscible), IWAG (immiscible), HWAG (hybrid), SWAG (simultaneous), SSWAG (selective simultaneous). In this study, the various scenarios of WAG injection have been simulated in one of the reservoirs of National Iranian Oil Company by the GeoQuest commercial software package and ECLIPSE100 module; the efficiency coefficient, total oil production in factors effective on injection such as injection cycle, injection type and injection method (IWAG, HWAG, SWAG and SSWAG) are studied and compared. Then, the scenarios of water, gas, and WAG injection are studied and compared to choose the appropriate method of injection in the interested field. At last, by designing various scenarios of water, gas, and WAG injection in four- and five-spot injection patterns, the efficiency, residual oil saturation, and total oil production are studied and compared in various methods in the above patterns in order to find the optimal and appropriate pattern of injection. The results show that by choosing suitable parameters, the efficiency and production of WAG method will be higher than water and gas injection.

کلیدواژه‌ها [English]

  • Enhanced Oil Recovery (EOR)
  • Simulation
  • Water Alternating Gas (WAG) Injection
  • Efficiency Coefficient
  • Well Pattern
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