بررسي ساختار منافذ و خصوصيات فرکتال سنگ هاي کربناته ريز دانه‌ي گرو و سرگلو با استفاده از آناليز جذب در فشار پايين نيتروژن
محورهای موضوعی :
سید علی معلمی
1
(پژوهشکده ازدیاد برداشت از مخازن نفت و گاز)
محمدابراهیم شبانی
2
(پژوهشگاه صنعت نفت)
هرمز قلاوند
3
(شرکت ملی نفت ایران)
زیبا زمانی پزوه
4
(پژوهشگاه صنعت نفت)
کلید واژه: خصوصيات ساختاري جذب در فشار پايين نيتروژن حجم منافذ بعد فرکتال شيل گازي گرو و سرگلو,
چکیده مقاله :
در اين مطالعه خصوصيات منافذ نمونه‌هاي سنگ‌هاي کربناته ريزدانه در ايران، برروي 9 نمونه برداشت شده از سازندهاي گرو (5 نمونه) و سرگلو (4 نمونه) با استفاده از روش جذب در فشار پايين نيتروژن مورد ارزيابي قرار گرفت. ميزان کل کربن آلي موجود در نمونه‌هاي سازند گرو مابين wt% 64/0 تا wt% 21/5 (ميانگين wt% 2/3) و براي سازند سرگلو مابين wt% 12/0 تا wt% 94/10 (ميانگين wt% 3/4) متغير مي‌باشد. کاني کربناته بيشترين ميزان کاني (ميانگين wt% 64) موجود در نمونه‌هاي مطالعه شده در هر دو سازند گرو و سرگلو را شامل مي‌شود. بعد از کربنات‌ها، کوارتز (ميانگين wt% 15) و کاني‌هاي رسي(ميانگين wt% 9) قرار مي‌گيرند. حجم منافذ محاسبه شده مابين g100/3cm 6/0 و g100/3cm 5/2 با ميانگين g100/3cm 4/1 متغير است که مشابه تحقيقات انجام شده بروي شيل‌هاي گازي آمريکا مي‌باشد. يک رابطه‌ي خطي ميان ميزان کربن آلي و خصوصيات منافذ براي نمونه‌هاي هر دو سازند گرو و سرگلو مشاهده شد. به دليل تغييرات گسترده‌تر ميزان کل کربن آلي در سازند سرگلو نسبت به سازند گرو، اين رابطه خطي در سازند سرگلو مشهودتر مي‌باشد . بعد فرکتال بدست آمده براي نمونه‌هاي مطالعه شده مابين 45/2 و 81/2 و با ميانگين 64/2 متغير است. مقادير نسبتا بالاي بعد فرکتال بدست آمده نمايانگر ميزان بالاي ناهمواري و پيچيدگي در سطوح منافذ نمونه‌هاي شيلي گرو و سرگلو مي‌باشد. وجود رابطه‌ي مستقيم ميان ميزان ماده آلي و بعد فرکتال را مي‌توان به وجود ريزمنافذ در مواد آلي و در نتيجه ساختار ناهموار و پيچيده منافذ نسبت داد. براساس مشاهدات ميزان ماده آلي به عنوان مهمترين پارامتر کنترل کننده‌ي خصوصيات منافذ در نمونه‌هاي سازند گرو و سرگلو معرفي شد.
The present paper tends to analyze the pore structure of Organic rich carbonaceous rock in 4 samples from Upper Jurassic Sargelu and 5 samples from Lower Cretaceous Garau formation using low pressure nitrogen adsorption. TOC content of Garau samples ranged between 0.64 wt% and 5.21 wt% (mean 3.2 wt%).TOC varied between 0.12 and 10.94 for Sargelu samples. XRD results shows that carbonates are the dominant minerals, followed by quartz and clay minerals. The calculated total pore volume vary between 0.6 cm3/100g to 2.5 cm3/100g with the mean values of 1.4 cm3/100g. A positive linear correlation were found between TOC content of measured samples with pore structure parameters. Due to the larger variation of TOC content this relationship was more obvious for the Sargelu samples. The calculated fractal dimension ranged between 2.45 and 2.81 emphasizing the irregular pore surface of the measured samples. Based on the result of this study organic matter content is recognized as a controlling factor for pore structure and fractal characteristics of the Garau and Sargelu samples.
[1] GASPARIK, M., P. BERTIER, Y. GENSTERBLUM, A. GHANIZADEH, B.M. KROOSS, and R. LITTKE, 2014, Geological controls on the methane storage capacity in organic-rich shales: International Journal of Coal Geology 123, 34-51.
[2] CURTIS, J.B., 2002, Fractured shale-gas systems: AAPG bulletin 86, 1921-38.
[3] JARVIE, D.M., R.J. HILL, T.E. RUBLE, and R.M. POLLASTRO, 2007, Unconventional shale-gas systems: The Mississippian Barnett Shale of north-central Texas as one model for thermogenic shale-gas assessment: AAPG bulletin 91, 475-99.
[4] CLARKSON, C.R., N. SOLANO, R. BUSTIN, A. BUSTIN, G. CHALMERS, L. HE, Y.B. MELNICHENKO, A. RADLIŃSKI, and T.P. BLACH, 2013, Pore structure characterization of North American shale gas reservoirs using USANS/SANS, gas adsorption, and mercury intrusion: Fuel 103, 606-16.
[5] MILLIKEN, K.L., M. RUDNICKI, D.N. AWWILLER, and T. ZHANG, 2013, Organic matter–hosted pore system, Marcellus formation (Devonian), Pennsylvania: AAPG bulletin 97, 177-200.
[6] CLARKSON, C.R., M. FREEMAN, L. HE, M. AGAMALIAN, Y.B. MELNICHENKO, M. MASTALERZ, R. BUSTIN, A. RADLIŃSKI and T.P. BLACH, 2012a, Characterization of tight gas reservoir pore structure using USANS/SANS and gas adsorption analysis: Fuel 95, 371-85.
[7] ROSS, D.J. and R.M. BUSTIN, 2008, Characterizing the shale gas resource potential of Devonian–Mississippian strata in the Western Canada sedimentary basin: Application of an integrated formation evaluation: AAPG bulletin 92, 87-125.
[8] ROSS, D.J. and R.M. BUSTIN, 2009, The importance of shale composition and pore structure upon gas storage potential of shale gas reservoirs: Marine and Petroleum Geology 26, 916-927.
[9] CHALMERS, G.R. and R.M. BUSTIN, 2007, The organic matter distribution and methane capacity of the Lower Cretaceous strata of Northeastern British Columbia, Canada: International Journal of Coal Geology 70, 223-239.
[10] CHALMERS, G.R., R.M. BUSTIN, and I.M. POWER, 2012, Characterization of gas shale pore systems by porosimetry, pycnometry, surface area, and field emission scanning electron microscopy/transmission electron microscopy image analyses: Examples from the Barnett, Woodford, Haynesville, Marcellus, and Doig units: AAPG bulletin 96, 1099-1119.
[11] LOUCKS, R.G., R.M. REED, S.C. RUPPEL, and U. HAMMES, 2012, Spectrum of pore types and networks in mudrocks and a descriptive classification for matrix-related mudrock pores: AAPG bulletin 96, 1071-98.
[12] LOUCKS, R.G., R.M. REED, S.C. RUPPEL, and D.M. JARVIE, 2009, Morphology, genesis, and distribution of nanometer-scale pores in siliceous mudstones of the Mississippian Barnett Shale: Journal of sedimentary research 79, 848-61.
[13] KLAVER J., G. DESBOIS, R. LITTKE, and J.L. URAI, 2015, BIB-SEM characterization of pore space morphology and distribution in postmature to overmature samples from the Haynesville and Bossier Shales. Marine and Petroleum Geology 59, 451-66.
[14] KLAVER J., G. DESBOIS, J.L. URAI, and R. LITTKE, 2012, BIB-SEM study of the pore space morphology in early mature Posidonia Shale from the Hils area, Germany: International Journal of Coal Geology 103, 12-25.
[15] JAMES, G., and J. WYND, 1965, Stratigraphic nomenclature of Iranian oil consortium agreement area: AAPG bulletin 49, 2182-2245.
[16] SETUDEHNIA, A., 1978, The Mesozoic sequence in south-west Iran and adjacent areas: Journal of Petroleum Geology 1, 3-42.
[17] BORDENAVE, M. and R. BURWOOD, 1990, Source rock distribution and maturation in the Zagros orogenic belt: provenance of the Asmari and Bangestan reservoir oil accumulations: Organic Geochemistry 16, 369-387.
[18] LETURMY, P. and C. ROBIN, 2010, Tectonic and stratigraphic evolution of Zagros and Makran during the Mesozoic-Cenozoic: introduction: Geological Society, London, Special Publications 330, 1-4.
[19] BORDENAVE, M. and J. HEGRE, 2005, The influence of tectonics on the entrapment of oil in the Dezful Embayment, Zagros Foldbelt, Iran. Journal of Petroleum Geology 28,339-368.
[20] BRUNAUER, S., P.H. EMMETT, and E. TELLER, Adsorption of gases in multimolecular layers. Journal of the American chemical society 60, 309-319.
[21] BARRETT, E.P., L.G. JOYNER, and P.P. HALENDA, 1951, The determination of pore volume and area distributions in porous substances. I. Computations from nitrogen isotherms: Journal of the American Chemical society 73, 373-380.
[22] DUBININ, M. and V. ASTAKHOV, 1971, Description of adsorption equilibria of vapors on zeolites over wide ranges of temperature and pressure: ACS Publications.
[23] GREGG, S. and K. SING, 1982, Adsorption, Surface Area and Porosity (2nd end.): Academic Press. New York.
[24] LOWELL S., J.E. SHIELDS, M.A. THOMAS, and M. THOMMES, 2012, Characterization of porous solids and powders: surface area, pore size and density. Springer Science & Business Media.
[25] BERTIER P., K. SCHWEINAR, H. STANJEK, A. GHANIZADEH, C.R. CLARKSON, A. BUSCH, N. KAMPMAN, D. PRINZ, A. AMANN-HILDENBRAND, and B.M. KROOSS, 2016, On the use and abuse of N2 physisorption for the characterization of the pore structure of shales. Clay Clay Miner.
[26] KATZ, A.J. and A. THOMPSON, 1985, Fractal sandstone pores: implications for conductivity and pore formation. Physical Review Letters 54, 1325.
[27] ADLER, P.M. and J.F. THOVERT, 1993, Fractal porous media: Transport in Porous Media 13, 41-78.
[28] KLIMENKO, A. Y., D. N. SAULOV, P. MASSAROTTO, and V. RUDOLPH, 2012, Conditional model for sorption in porous media with fractal properties: Transport in Porous Media 92, 745-765.
[29] MAHAMUD, M.M. and M.F. NOVO, 2008, The use of fractal analysis in the textural characterization of coals: Fuel. 87, 222-231.
[30] YAO, Y., D. LIU, D. TANG, S. TANG, and W. HUANG, 2008., Fractal characterization of adsorption-pores of coals from North China: an investigation on CH 4 adsorption capacity of coals: International Journal of Coal Geology 73, 27-42.
[31] ZHANG, L., J. LI., H. TANG, J. GUO, 2014, Fractal pore structure model and multilayer fractal adsorption in shale. Fractals 22, 1440010.
[32] DE BOER, J., D. EVERETT, and F. STONE, 1958, The structure and properties of porous materials: Academic Press, New York.
[33] Bustin R.M., A.M. Bustin., A. Cui, D. Ross and V.M.Pathi, 2008, Impact of shale properties on pore structure and storage characteristics. In: SPE shale gas production conference. Society of Petroleum Engineers.
[34] XIONG, J., X. LIU, and L. LIANG, 2015, Experimental study on the pore structure characteristics of the Upper Ordovician Wufeng Formation shale in the southwest portion of the Sichuan Basin, China. Journal of Natural Gas Science and Engineering 22, 530-539.
[35] Kondla D., H. Sanei, C.R. Clarkson, O.H. Ardakani, X. Wang. and C.Jiang, 2016, Effects of organic and mineral matter on reservoir quality in a Middle Triassic mudstone in the Canadian Arctic: International Journal of Coal Geology 153, 112-26.