پيشبيني نفوذپذيري كلينكنبرگ با استفاده از نفوذپذيري مطلق گاز در سنگهاي كربناته مخازن هيدروكربوري جنوب غرب ايران

Improved LET function and use to modelingrelative permeability curves for one of the Iranian carbonate reservoir rock

ﻧﻔﻮذﭘﺬﻳﺮي ﻳﻜﻲ از ﭘﺎراﻣﺘﺮﻫﺎي اﺳﺎﺳﻲ در ﻣﻄﺎﻟﻌﻪ ﻣﺨﺎزن ﻫﻴﺪروﻛﺮﺑﻮري ﻣﻲﺑﺎﺷﺪ ﻛﻪ اﻧﺪازهﮔﻴﺮي آن ﺑﺎ دﻗﺖ ﺑﺎﻻ از اﻫﻤﻴﺖ ﺑﺴﻴﺎري ﺑﺮﺧﻮردار اﺳﺖ. روشﻫﺎي ﻣﺘﺪاول ﺑﺮاي اﻳﻦ ﻣﻨﻈﻮر اﺳﺘﻔﺎده از دادهﻫﺎي ﭼﺎهآزﻣﺎﻳﻲ و ﻳﺎ اﻧﺪازهﮔﻴﺮي ﻧﻔﻮذﭘﺬﻳﺮي ﻧﻤﻮﻧﻪﻫﺎي ﻣﻐﺰه ﺣﻔﺎريﺷﺪه از ﭼﺎه ﻣﻲﺑﺎﺷﺪ. ﻋﻤﻮﻣﺎ" در آزﻣﺎﻳﺸﮕﺎه ﺑﻪ دﻟﻴﻞ ﻫﺰﻳﻨﻪ ﻛﻢ و ﺳﺮﻋﺖ ﻋﻤﻞ ﺑﺎﻻ، ﻧﻔﻮذﭘﺬﻳﺮي ﻣﻄﻠﻖ ﮔﺎز ﻧﻤﻮﻧﻪﻫﺎي ﭘﻼگ ﻣﻐﺰه اﻧﺪازهﮔﻴﺮي ﻣﻲﺷﻮد. ﻧﻔﻮذﭘﺬﻳﺮي ﮔﺎز در ﻣﺤﻴﻂ ﻣﺘﺨﻠﺨﻞ ﺑﻪ ﻓﺸﺎر ﻣﺘﻮﺳﻂ ﺗﺰرﻳﻖ و ﻧﻮع ﮔﺎز واﺑﺴﺘﻪ اﺳﺖ و ﺑﺎ ﺗﻐﻴﻴﺮ آنﻫﺎ ﻧﺘﺎﻳﺞ ﻣﺘﻔﺎوﺗﻲ ﺑﺪﺳﺖ ﻣﻲآﻳﺪ. ﺑﻨﺎﺑﺮاﻳﻦ اﻧﺪازهﮔﻴﺮي ﻧﻔﻮذﭘﺬﻳﺮي ﺑﺎ اﺷﺒﺎع ﻛﺎﻣﻞ ﻧﻤﻮﻧﻪ از ﻣﺎﻳﻊ و ﻳﺎ ﺗﻌﻴﻴﻦ ﻧﻔﻮذﭘﺬﻳﺮي ﻣﻌﺎدل ﻣﺎﻳﻊ ﺑﻪ ﻃﺮق دﻳﮕﺮ اﻣﺮي ﺿﺮوري ﻣﻲﺑﺎﺷﺪ، ﻛﻪ اﻟﺒﺘﻪ اﻳﻦ روش ﻣﺴﺘﻠﺰم ﺻﺮف ﻫﺰﻳﻨﻪ و زﻣﺎن زﻳﺎد ﻣﻲﺑﺎﺷﺪ. ﻛﻠﻴﻨﻜﻨﺒﺮگ ﺑﺮاي اوﻟﻴﻦ ﺑﺎر ﺑﺎ ﺑﺮرﺳﻲ ﭘﺪﻳﺪه ﻟﻐﺰش ﮔﺎز در ﻣﺤﻴﻂ ﻣﺘﺨﻠﺨﻞ و اﻧﺪازهﮔﻴﺮي ﻧﻔﻮذﭘﺬﻳﺮي ﻣﻄﻠﻖ اﻧﻮاع ﮔﺎزﻫﺎ در ﻓﺸﺎرﻫﺎي ﻣﺨﺘﻠﻒ، راﺑﻄﻪاي ﺑﺮاي ﺗﻌﻴﻴﻦ ﻧﻔﻮذﭘﺬﻳﺮي ﻣﻌﺎدل ﻣﺎﻳﻊ اراﺋﻪ ﻧﻤﻮد. ﻫﺪف از اﻳﻦ ﻣﻄﺎﻟﻌﻪ، اراﺋﻪ رواﺑﻄﻲ ﺗﺠﺮﺑﻲ ﺑﺮاي ﺗﻌﻴﻴﻦ ﻧﻔﻮذﭘﺬﻳﺮي ﺗﺼﺤﻴﺢﺷﺪه ﻛﻠﻴﻨﻜﻨﺒﺮگ (ﻣﻌﺎدل ﻣﺎﻳﻊ) در ﺳﻨﮓﻫﺎي ﻛﺮﺑﻨﺎﺗﻪ ﻛﺸﻮر، ﺑﺎ اﺳﺘﻔﺎده از دادهﻫﺎي اﻧﺪازهﮔﻴﺮي ﻧﻔﻮذﭘﺬﻳﺮي ﻣﻄﻠﻖ ﮔﺎز ﻣﻲﺑﺎﺷﺪ ﻛﻪ ﺗﺎﻛﻨﻮن ﮔﺰارش ﻧﺸﺪه اﺳﺖ. ﺑﺪﻳﻦ ﻣﻨﻈﻮر ﻧﻔﻮذﭘﺬﻳﺮي ﻛﻠﻴﻨﻜﻨﺒﺮگ ﺑﺮ روي 541 ﻧﻤﻮﻧﻪ ﭘﻼگ از ﺳﺎزﻧﺪﻫﺎي ﻣﺨﺘﻠﻒ ﻛﺮﺑﻨﺎﺗﻪ ﺟﻨﻮب ﻏﺮﺑﻲ اﻳﺮان ﺑﺎ داﻣﻨﻪي ﮔﺴﺘﺮده از ﻣﻘﺎدﻳﺮ ﺧﻮاص ﭘﺘﺮوﻓﻴﺰﻳﻜﻲ اﻧﺪازهﮔﻴﺮي ﺷﺪ. رواﺑﻄﻲ ﻧﻤﺎﺋﻲ ﺑﺎ ﻫﻤﺒﺴﺘﮕﻲ ﺑﺎﻻ ﺑﻴﻦ ﻧﻔﻮذﭘﺬﻳﺮي ﻣﻌﺎدل ﻣﺎﻳﻊ و ﻧﻔﻮذﭘﺬﻳﺮي ﻣﻄﻠﻖ ﮔﺎز ﺑﺪﺳﺖ آﻣﺪ. ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﻓﺮاواﻧﻲ و ﻣﺤﺪوده وﺳﻴﻊ ﻧﻤﻮﻧﻪﻫﺎي ﻣﻮرد ﻣﻄﺎﻟﻌﻪ، ﻣﺪلﻫﺎي ﺗﺠﺮﺑﻲ اراﺋﻪ ﺷﺪه در اﻳﻦ ﻣﻘﺎﻟﻪ را ﻣﻲﺗﻮان ﺟﻬﺖ ﭘﻴﺶﺑﻴﻨﻲ و ﺗﻌﻴﻴﻦ ﻧﻔﻮذﭘﺬﻳﺮي ﻣﻌﺎدل ﻣﺎﻳﻊ در ﺳﻨﮓﻫﺎي ﻛﺮﺑﻨﺎﺗﻪ ﺟﻨﻮب ﻏﺮﺑﻲ اﻳﺮان ﻣﻮرد اﺳﺘﻔﺎده ﻗﺮار داد.

Permeability is one of the main parameters in the study of hydrocarbon reservoirs which are needed to be measured correctly. The conventional methods are well testing and direct permeability measurement on the drilled core samples. Absolute air permeability of core plug samples is often measured in the laboratory which is cheap and fast. The absolute air permeability of a rock sample depends on the flowing mean pressure and type of gas and varies with changing them. Hence, measuring liquid permeability of fully saturated core sample or determination of corrected gas permeability which is equivalent to the liquid permeability is essential. This needs to spend enough time and budget. Klinkenberg investigated the effect of gas slippage in porous media and measured absolute permeability of different gases in various mean pressures. He yielded an equation for correcting absolute gas permeability and defining equivalent liquid permeability. The aim of this study was to present some practical relations for determining Klinkenberg corrected gas permeability of carbonate rocks by using their absolute air permeability, which has not been reported yet. For this purpose, Klinkenberg corrected gas permeability of 541 core plugs, with various petrophysical properties from different carbonate formations in the Southwest of Iran was measured. Exponential relations were obtained with very good correlation coefficients. Considering vast petrophysical properties of the studied samples, the yielded equations can be used to predict and determine equivalent liquid permeability of carbonate core samples of Southwest of Iran from their absolute air permeability.