ارزیابی غیرمتعارف سازند کژدمی در دو میدان شمال غرب خلیج فارس

نوع مقاله : مقاله پژوهشی

نویسندگان

1 گروه زمین‌شناسی کاربردی، دانشکده علوم زمین، دانشگاه صنعتی شاهرود، شاهرود، ایران

2 گروه معدن، نفت و ژئوفیزیک و نفت، دانشکده علوم زمین، دانشگاه صنعتی شاهرود، شاهرود، ایران

چکیده

در این مطالعه، به منظور ارزیابی پتانسیل غیرمتعارف سنگ منشأ کژدمی در میادینA  و C در شمال غرب خلیج فارس، از نتایج آنالیز راک-اول به­همراه ضریب انعکاس ویترینایت و محاسبات مرتبط با ارزیابی شیل­های گازی استفاده شده است. در این تحقیق ضمن بررسی بلوغ، نوع گاز تولیدی از سنگ منشأ براساس نمودار TR-RO و استفاده از دیاگرام عنکبوتی به مقایسه پارامترهای مختلف بلوغ و ارزیابی اولیه اقتصادی مخازن غیرمتعارف سازند مذکور پرداخته شده است. سازند کژدمی در میدان A تولید گاز کمی دارد و در میدان C بین پنجره نفتی و گازی قرار دارد. نتایج حاصل از نمودار TR-RO، نشان­دهنده آنست­ که نمونه­های مورد مطالعه در میادین A و C در مرحله تولید گاز در اواخر دیاژنز و اوایل پنجره بلوغ قرار گرفته­اند. با توجه به دیاگرام عنکبوتی و ضخامت زیاد سازند کژدمی در میدان C، انتظار تولید گاز بیشتری در اعماق زیادتر، از این سازند می­رود.

کلیدواژه‌ها


عنوان مقاله [English]

An unconventional evaluation of the Kazhdumi Formation in two northwest fields of the Persian Gulf

نویسندگان [English]

  • zahra rostami 1
  • Seyed Reza Ghavvami riyabi 2
  • Farajolah Fardoust 1
1 Department of Applied Geology, Faculty of Earth Sciences, Shahrood university of technoogy, Shahrood, Iran
2 Department of Mining, Petroleum and Geophysics and Petroleum, Faculty of Earth Sciences, Shahrood university of technoogy, Shahrood, Iran
چکیده [English]

Extended abstract
Introduction
The Persian Gulf, as the richest hydrocarbon pool in the world, plays a very important role in the world's energy equations. Approximately two-thirds of proven oil reserves and one third of global natural gas reserves are available to the Persian Gulf States. Iran's water borders in the Persian Gulf hold a significant portion, 16 oil fields developed in Jurassic, Cretaceous and Tertiary carbonate reservoirs.
Materials and methods:
 In this study, Rock-eval analysis was used and a series of calculations were performed for evaluating unconventional Kazhdumi source rocks in the A and C fields in the north west of Persian Gulf. According to the research and exploitation of hydrocarbon reservoirs in the world, today these reserves are divided into two main groups of conventional reservoirs and unconventional reservoirs. Conventional tanks are located in the form of oil traps, source rocks, reservoir rocks and rock covers. However, in unconventional reservoirs, with the presence of special petrological features, the possibility of direct exploitation of the source rock is provided. It is also possible that part of an oil system will be operated as a conventional reservoir and another part as an unconventional reservoir. In unconventional reservoirs, with mature source rocks converting organic matter to hydrocarbons, if permeability is created, we will be able to extract hydrocarbons. This is done at the shale gases, that are currently being used around the world.
Gas shales are a diverse group of rocks in which methane is trapped. Then methane is extracted from gaseous shale by distillation or hydraulic fracturing. Today, oil and gas shales are a good alternative to conventional hydrocarbon resources due to depletion of conventional ones.
Results and discussion
 Gas shales have a high content of organic matter. If organic matter enters the gas window maturely and the dry gas production stage is ongoing, then on-site gas generation takes place in them. This is considered as shale gas (unconventional tanks). For this purpose, by drawing geochemical logs of parameters S1, S2, S1 + S2 and TOC (Table 1), field data A and C were examined. There is evidence of good to very good hydrocarbon generation power at the source rock. Then, by examining the characteristics of Barnett shale (as a producer and important shale in the United States) the set of geochemical parameters of the Kazhdumi Formation for A and C fields have been compared with the minimum threshold values in Barnett's shale.
Conclusions
Kazhdumi Formation has a small amount of gas production in field A, and is located in the C field between oil and gas windows. The evaluation of the vitrinite reflection coefficient, the maturity of the samples and the probability of the gas shale potential are investigated. The results of the TR-RO graph have represented the biogenic source of gas production in A and C fields. In deeper depth, there is a higher production of gas for this formation in the A and C fields.

کلیدواژه‌ها [English]

  • Rock-Eval analysis
  • TR-RO diagram
  • Spider Diagram
  • Gas shale
  • Unconventional Reservoir
-بوردانوف، ام.ال. و آگغه، جی.آ.، 1390. سیستم­های نفتی ایران و توزیع امروزی میدان­های نفت و گاز در کمربند چین­خوردگی زاگرس و مناطق دریایی مجاور: ترجمه کسایی نجفی، م.، پژوهشگاه صنعت نفت، تهران، 68 ص.
-ربانی، ا.، 1392. زمین­شناسی و ژئوشیمی نفت خلیج فارس، چاپ اول، انتشارات دانشگاه تفرش، 576 ص.
-رضایی م.ر.، 1387. زمین­شناسی نفت، چاپ سوم، انتشارات فرهیختگان علوی، تهران، 472 ص.
-قوامی ریابی، س.ر.، رستگار کلاته، ا. و توانگر، م.، 1394. ارزیابی توان هیدروکربورزایی سازندهای گرو- سرگلو ناحیه لرستان به عنوان شیل گازی: دومین کنگره بین­المللی زمین­شناسی کاربردی، دانشگاه آزاد اسلامی مشهد.
-کمالی، م. و قربانی، ب.، 1385. ژئوشیمی آلی از فیتوپلانکتون­ها تا تولید نفت، چاپ اول، انتشارات آرین زمین، تهران، 318 ص.
 
 
 
-Alsharhan, A.S. and Kenedall, C.G.S.C., 1991. Cretaceouschronostratigraphy, unconformities and eustaticsealevel changes in the sediments of abuDahbi, United Arab Emirates: Cretac, Res: v. 12, p. 379-401.
-Baer, M.T., 2013. Circumstances influencing the development and end-use of natural gas from shale formation in the United States: Office of policy and international affairs U.S. department of energy, p. 1-29.
-Bordenave, M.L., 2002. The middle Cretaceous and early Miocenepetroleum system in the Zagros domain of Iran and it prospect evaluation: In: Journal of AAPG Annual meeting Houston, American association of petroleum geologists, p. 1-9.
-Bordenave, M.L. and Burwood, R., 1990. Source rock distribution and maturation in the Zagros organic belt, provenance of the Asmari and Sarvak reservoir oil accumulation: Journal of Organig geochemistry, v. 16. p. 369-387.
-Curtis, J.B., 2009. Fractured shale gas system: Journal of the American association of petroleum geologists, v. 86(11), p. 1921-1938.
-Edwards, PB. and Streitberg, E., 2013. Have we deciphered the Canning Discovery of the Ungani oil field, in the sedimentary of Basins of western Australia edited by M. Keep, and S.J. Moss: Journalof Petroleum exploration society of Australia, Western Australian basin symposium, p. 13.
-Espitalie, J. and Bordenave, M.L., 1993. Rock-eval pyrolysis: Journal of applied petroleum geochemistry, v. 2, 12, p. 14-24.
-Ghazban, F., 2009. Petroleum geology of the persian gulf: Tehran university press, Tehran, 707 p.
-Jarvie, D.M., Hill, R.J., Ruble, T.E. and Pollastro, R.M., 2001. Unconventional shale-gas system: The Mississippian Barnet Shale of north-central Texas as one model forthermogenic shale-gas assessment: Journal of Americn Associate Petroleum Geol Bulletin, v. 91, p. 475-499.
-Jarvie, D.M., Hill, R.J., Ruble, T.E. and Pollastro, R.M., 2007. Unconventional shale-gas system: The Mississippian Barnet Shale of north-central Texas as one model for thermogenic shale-gas assessment: Journal of AAPG bulletin, v. 91, 4, p. 475-499.
-Jarvie, D.M., 2008. Unconventional shale resource plays: shale-gas and shale-oil opportunities: in Fort Worth business press meeting, energy institute, texaschristian university, p. 1-38.
-Konyuhov, A.L. and Maleki, B., 2006. The Persian Gulf basin: geological history, sedimentary formations, and petroleum potential: Journal of lithology & Mineral Resource, v. 41, p. 344-361.
-Peters, K.E. and Fowler, M.G., 2002. Applications of petroleum geochemistry to exploration and reservoir management: Journal of Organic geochemistry, v. 33, 1, p. 5-36.
-Rabbani, A.R., 2007. Petroleum geochemistry, offshore SE Iran: Journal of Geochemistry International, v. 45(11), p. 1164-1172.
-Rabbani, A.R., Kotarba, M.J., Baniasad, A.R., Hosseiny, E. and Weiclaw, D., 2014. Geochemical characteristics and genetic types of the crude oils from the Iranian sector of the persian gulf: Journal of Organic Geochemistry, v. 70, p. 29-43.
-Holditch, S. A., 2001. The increasing rol of unconventional reserves in the future of the Oil &Gas business: Schlumberger Presentation, v. 55(11), p. 34-79.
-Sweeny, J. and Burnham, A.K., 1990. Evalution of a simple model of vitrinite reflectance base on chemical kinetics: Journal of AAPG Bull, v. 74, p. 1559-1570.
-Talukdar, S.C., 2002. Application of geochemistry for shale gas assessment: weatherford baseline resolution, p. 1-6.