Micro-scale experimental investigation of the effect of flow rate on trapping in sandstone and carbonate rock samples

التفاصيل البيبلوغرافية
العنوان: Micro-scale experimental investigation of the effect of flow rate on trapping in sandstone and carbonate rock samples
المؤلفون: Mohammad Piri, Mahdi Khishvand, Morteza Akbarabadi
المصدر: Advances in Water Resources. 94:379-399
بيانات النشر: Elsevier BV, 2016.
سنة النشر: 2016
مصطلحات موضوعية: Capillary action, 0208 environmental biotechnology, Mineralogy, 02 engineering and technology, Capillary number, 020801 environmental engineering, Volumetric flow rate, Permeability (earth sciences), Imbibition, Wetting, Porous medium, Porosity, Geology, Water Science and Technology
الوصف: We present the results of a pore-scale experimental study of residual trapping in consolidated sandstone and carbonate rock samples under confining stress. We investigate how the changes in wetting phase flow rate impacts pore-scale distribution of fluids during imbibition in natural, water-wet porous media. We systematically study pore-scale trapping of the nonwetting phase as well as size and distribution of its disconnected globules. Seven sets of drainage-imbibition experiments were performed with brine and oil as the wetting and nonwetting phases, respectively. We utilized a two-phase miniature core-flooding apparatus integrated with an X-ray microtomography system to examine pore-scale fluid distributions in small Bentheimer sandstone (D = 4.9 mm and L = 13 mm) and Gambier limestone (D = 4.4 mm and L = 75 mm) core samples. The results show that with increase in capillary number, the residual oil saturation at the end of the imbibition reduces from 0.46 to 0.20 in Bemtheimer sandstone and from 0.46 to 0.28 in Gambier limestone. We use pore-scale displacement mechanisms, in-situ wettability characteristics, and pore size distribution information to explain the observed capillary desaturation trends. The reduction was believed to be caused by alteration of the order in which pore-scale displacements took place during imbibition. Furthermore, increase in capillary number produced significantly different pore-scale fluid distributions during imbibition. We explored the pore fluid occupancies and studied size and distribution of the trapped oil clusters during different imbibition experiments. The results clearly show that as the capillary number increases, imbibition produces smaller trapped oil globules. In other words, the volume of individual trapped oil globules decreased at higher brine flow rates. Finally, we observed that the pore space in the limestone sample was considerably altered through matrix dissolution at extremely high brine flow rates. This increased the sample porosity from 44% to 62% and permeability from 7.3 D to 80 D. Imbibition in the altered pore space produced lower residual oil saturation (from 0.28 to 0.22) and significantly different distribution of trapped oil globules.
تدمد: 0309-1708
DOI: 10.1016/j.advwatres.2016.05.012
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::183610d8275255e1e2117d1878a9db41
https://doi.org/10.1016/j.advwatres.2016.05.012
Rights: CLOSED
رقم الانضمام: edsair.doi...........183610d8275255e1e2117d1878a9db41
قاعدة البيانات: OpenAIRE
الوصف
تدمد:03091708
DOI:10.1016/j.advwatres.2016.05.012