دولومیتی شدن فراگیر و تأثیر آن بر کیفیت مخزنی سازند جهرم در شمال و شمال غرب بندرعباس

نوع مقاله: مقاله پژوهشی

نویسندگان

1 گروه زمین‌شناسی، دانشکده علوم، دانشگاه زنجان، ایران

2 پژوهشکده ازدیاد و برداشت از مخازن نفت و گاز، تهران، ایران

3 گروه زمین‌شناسی، دانشکده علوم، دانشگاه فردوسی مشهد، ایران

چکیده

در این تحقیق، به منظور بررسی خصوصیات انواع مختلف دولومیت‌ها و تأثیر آنها در کیفیت مخزنی سازند جهرم، از دو برش تحت‌الارضی در میدان‌های گازی سرخون (چاه 14) و نمک غربی (چاه 1)، به همراه دو رخنمون سطحی (تاقدیس‌های فینو و خوش) استفاده شده است. بخش‌های قاعده‌ای سازند جهرم در اکثر برش‌های منطقه بندرعباس توسط سیالات دولومیت‌ساز شدیداً تحت تأثیر قرار گرفته است. بر اساس شواهد پتروگرافی و استفاده از میکروسکوپ‌های پلاریزان، کاتدولومینسانس و الکترونی، چهار نوع دولومیت، در سازند جهرم تشخیص داده شده است. مطالعات صورت گرفته، بیان می‌کند که سازند جهرم در برش‌هایی می‌تواند به عنوان یک سنگ مخزن مناسب در نظر گرفته شود که در قاعده این سازند فرآیند دولومیتی شدن به میزان گسترده اتفاق افتاده باشد، و به دنبال تأثیر فرآیند دولومیتی شدن، به میزان قابل توجهی تخلخل قالبی حاصل از انحلال فرامینیفرهای بنتیک ایجاد گردد.
 

کلیدواژه‌ها


عنوان مقاله [English]

Pervasive Dolomitization and its Effects on Reservoir Quality of the Jahrum Formation in the North and Northwestern Bandar-Abbas

نویسندگان [English]

  • Afshin Zohdi 1
  • Seyed Ali Moallemi 2
  • Reza Moussavi Harami 3
  • Asadollah Mahboubi 3
1 Department of Geology, Faculty of Sciences, University of Zanjan, Iran
2 IOR/EOR Institute for Oil and Gas Reservoirs, Tehran, Iran
3 Department of Geology, Faculty of Sciences, Ferdowsi University of Mashhad, Iran
چکیده [English]

In this paper, we aim to recognize the different types of Jahrum dolomite and also to discuss the effects of dolomitization on the reservoir quality of the Jahrum formation in Bandar-Abbas region. For these purposes, we used a combination of two subsurface well sections at the Sarkhun-14 and West-Namak-01 gas-fields along with two outcrops (Finu and Khush anticlines). The lower stratigraphic intervals of the Jahrum formation were strongly altered by dolomitizing fluids. Based on petrographic observation by using polarized light, cathodoluminescence, and scanning electron microscopes, four different types of dolomite were distinguished. These data indicated that, when pervasive dolomitization occurred at the lower stratigraphic interval of Jahrum formation, this could be considered as suitable reservoir rocks and the effects of Mg-fluids on previous carbonate rocks formed abundant biomouldic porosity as a result of the dissolution of large benthic foraminifera.
 

کلیدواژه‌ها [English]

  • Dolomitization
  • Reservoir Quality
  • Jahrum Formation
  • Bandar-Abbas
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