The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform
Arne Graue - One of the best experts on this subject based on the ideXlab platform.
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Wettability effects on Water mixing during Waterflood oil recovery
Journal of Petroleum Science and Engineering, 2012Co-Authors: Arne Graue, E. Aspenes, Martin A. Fernø, Roger NeedhamAbstract:We present experimental results of the mixing of injection Water and connate Water during oil production by Waterflooding in two outcrop chalk samples at three different wettabilities. The displacement of connate Water by the injected Water was determined using nuclear tracer imaging (NTI). For all three wettabilities investigated, Strongly Water-wet (Iw=1.00), moderately Water-wet (Iw=0.44) and less Water-wet (Iw=0.28) conditions, the connate Water was fully removed from the core by the injected Water. The connate Water accumulated in front of the injected Water, and constituted a large fraction of the Water that immiscibly displaced the oil from the core plug. The connate Water bank was less pronounced at reduced Water-wet conditions, and the mixing between connate and injected Water was increased at less Water-wet conditions. Connate Water breakthrough was observed at one mobile-oil-pore-volume of Water injected at all three wettabilities. Breakthrough of the injected Water was delayed at Strongly Water-wet conditions compared with less Water-wet conditions, where both Water phases were produced simultaneously. © 2012 Elsevier B.V.
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Wettability Impacts on Oil Displacement in Large Fractured Carbonate Blocks
Energy & Fuels, 2010Co-Authors: Åsmund Haugen, Øyvind Bull, Martin A. Fernø, Arne GraueAbstract:Two-dimensional imaging of Water and oil saturations during Waterfloods in fractured carbonate rock models was obtained using nuclear tracer imaging and magnetic resonance imaging. Large outcrop chalk and limestone blocks were aged in crude oil to obtain wetting conditions from Strongly Water-wet to weakly oil-wet. The change in the oil recovery mechanism as the wettability shifted was investigated with and without the presence of fractures. Visualization of local, in situ fluid saturations during Waterfloods improved the interpretation of the displacement process and oil recovery mechanisms. Experimental results demonstrate how fractures determine the displacement pattern differently depending on the matrix wettability conditions during Waterfloods. At Strongly Water-wet conditions, the fractures had a minor impact on the ultimate recovery but significantly changed the progression of the Water front compared to the unfractured case. At less Water-wet or oil-wet conditions, capillary imbibition of Water f...
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Dynamic laboratory wettability alteration
Energy and Fuels, 2010Co-Authors: M. A. Fern??, M. Torsvik, S. Haugland, Arne GraueAbstract:We present experimental wettability alteration results in originally Strongly Water-wet, outcrop chalk core plugs using a static and two dynamic aging methods. Dynamic aging with continuous crude oil injection during the entire aging process exhibited greater reduction in Water-wetness of the Strongly Water-wet chalk plugs than static aging without flushing. Two dynamic aging procedures were tested to find an optimal flooding rate for the most efficient reduction in Water-wetness: (1) a constant crude oil flooding at 3 cm3/h using variable aging times (48, 96, and 192 h) and (2) a constant aging time (96 h) with variable flooding rates (1, 3, and 5 cm3/h). The aging temperature was kept constant in all tests (90 °C), and the impacts from varying aging times, pore volumes injected, and crude oil injection rate on the wettability alteration process were investigated. Aging was performed on consolidated, porous chalk samples with initial Water present in the pore space. It was shown that static aging, i.e., aging in a stagnant, limited amount of crude oil, and dynamic aging, i.e., with continuous flooding of crude oil, performed equally well in terms of average Amott−Harvey Water indices (Iw 0.6) for short aging times (72 h or less). For longer aging times, the static approach failed to established an Amott−Harvey Water index under Iw = 0.25 and required 3 times as long of an aging time compared to dynamic aging (7 days for dynamic or 24 days for static required to establish Iw 0.25). Amott−Harvey Water indices lower than Iw = 0.25 were established with dynamic aging for shorter aging times (less than 12 days). At a given constant aging time (96 h), it was found that wetting was sensitive to the crude oil injection rate and that there exists an optimal crude oil injection rate with the greatest change in wettability.
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Wettability impacts on oil displacement in large fractured carbonate blocks
Energy and Fuels, 2010Co-Authors: Åsmund Haugen, Øyvind Bull, Martin A. Fernø, Arne GraueAbstract:Two-dimensional imaging of Water and oil saturations during Waterfloods in fractured carbonate rock models was obtained using nuclear tracer imaging and magnetic resonance imaging. Large outcrop chalk and limestone blocks were aged in crude oil to obtain wetting conditions from Strongly Water-wet to weakly oil-wet. The change in the oil recovery mechanism as the wettability shifted was investigated with and without the presence of fractures. Visualization of local, in situ fluid saturations during Waterfloods improved the interpretation of the displacement process and oil recovery mechanisms. Experimental results demonstrate how fractures determine the displacement pattern differently depending on the matrix wettability conditions during Waterfloods. At Strongly Water-wet conditions, the fractures had a minor impact on the ultimate recovery but significantly changed the progression of the Water front compared to the unfractured case. At less Water-wet or oil-wet conditions, capillary imbibition of Water from the fracture to the matrix was reduced and fractures had a major impact on the ultimate recovery and Water breakthrough time.
Åsmund Haugen - One of the best experts on this subject based on the ideXlab platform.
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Wettability Impacts on Oil Displacement in Large Fractured Carbonate Blocks
Energy & Fuels, 2010Co-Authors: Åsmund Haugen, Øyvind Bull, Martin A. Fernø, Arne GraueAbstract:Two-dimensional imaging of Water and oil saturations during Waterfloods in fractured carbonate rock models was obtained using nuclear tracer imaging and magnetic resonance imaging. Large outcrop chalk and limestone blocks were aged in crude oil to obtain wetting conditions from Strongly Water-wet to weakly oil-wet. The change in the oil recovery mechanism as the wettability shifted was investigated with and without the presence of fractures. Visualization of local, in situ fluid saturations during Waterfloods improved the interpretation of the displacement process and oil recovery mechanisms. Experimental results demonstrate how fractures determine the displacement pattern differently depending on the matrix wettability conditions during Waterfloods. At Strongly Water-wet conditions, the fractures had a minor impact on the ultimate recovery but significantly changed the progression of the Water front compared to the unfractured case. At less Water-wet or oil-wet conditions, capillary imbibition of Water f...
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Wettability impacts on oil displacement in large fractured carbonate blocks
Energy and Fuels, 2010Co-Authors: Åsmund Haugen, Øyvind Bull, Martin A. Fernø, Arne GraueAbstract:Two-dimensional imaging of Water and oil saturations during Waterfloods in fractured carbonate rock models was obtained using nuclear tracer imaging and magnetic resonance imaging. Large outcrop chalk and limestone blocks were aged in crude oil to obtain wetting conditions from Strongly Water-wet to weakly oil-wet. The change in the oil recovery mechanism as the wettability shifted was investigated with and without the presence of fractures. Visualization of local, in situ fluid saturations during Waterfloods improved the interpretation of the displacement process and oil recovery mechanisms. Experimental results demonstrate how fractures determine the displacement pattern differently depending on the matrix wettability conditions during Waterfloods. At Strongly Water-wet conditions, the fractures had a minor impact on the ultimate recovery but significantly changed the progression of the Water front compared to the unfractured case. At less Water-wet or oil-wet conditions, capillary imbibition of Water from the fracture to the matrix was reduced and fractures had a major impact on the ultimate recovery and Water breakthrough time.
Yonghao Zhang - One of the best experts on this subject based on the ideXlab platform.
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pore scale study of counter current imbibition in Strongly Water wet fractured porous media using lattice boltzmann method
Physics of Fluids, 2019Co-Authors: Qingqing Gu, Yonghao ZhangAbstract:Oil recovery from naturally fractured reservoirs with low permeability rock remains a challenge. To provide a better understanding of spontaneous imbibition, a key oil recovery mechanism in the fractured reservoir rocks, a pore-scale computational study of the Water imbibition into an artificially generated dual-permeability porous matrix with a fracture attached on top is conducted using a recently improved lattice Boltzmann color-gradient model. Several factors affecting the dynamic countercurrent imbibition processes and the resulting oil recovery have been analyzed, including the Water injection velocity, the geometry configuration of the dual permeability zones, interfacial tension, the viscosity ratio of Water to oil phases, and fracture spacing if there are multiple fractures. Depending on the Water injection velocity and interfacial tension, three different imbibition regimes have been identified: the squeezing regime, the jetting regime, and the dripping regime, each with a distinctively different expelled oil morphology in the fracture. The geometry configuration of the high and low permeability zones affects the amount of oil that can be recovered by the countercurrent imbibition in a fracture-matrix system through transition of the different regimes. In the squeezing regime, which occurs at low Water injection velocity, the build-up squeezing pressure upstream in the fracture enables more Water to imbibe into the permeability zone closer to the fracture inlet thus increasing the oil recovery factor. A larger interfacial tension or a lower Water-to-oil viscosity ratio is favorable for enhancing oil recovery, and new insights into the effect of the viscosity ratio are provided. Introducing an extra parallel fracture can effectively increase the oil recovery factor, and there is an optimal fracture spacing between the two adjacent horizontal fractures to maximize the oil recovery. These findings can aid the optimal design of Water-injecting oil extraction in fractured rocks in reservoirs such as oil shale.
Martin A. Fernø - One of the best experts on this subject based on the ideXlab platform.
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Wettability effects on Water mixing during Waterflood oil recovery
Journal of Petroleum Science and Engineering, 2012Co-Authors: Arne Graue, E. Aspenes, Martin A. Fernø, Roger NeedhamAbstract:We present experimental results of the mixing of injection Water and connate Water during oil production by Waterflooding in two outcrop chalk samples at three different wettabilities. The displacement of connate Water by the injected Water was determined using nuclear tracer imaging (NTI). For all three wettabilities investigated, Strongly Water-wet (Iw=1.00), moderately Water-wet (Iw=0.44) and less Water-wet (Iw=0.28) conditions, the connate Water was fully removed from the core by the injected Water. The connate Water accumulated in front of the injected Water, and constituted a large fraction of the Water that immiscibly displaced the oil from the core plug. The connate Water bank was less pronounced at reduced Water-wet conditions, and the mixing between connate and injected Water was increased at less Water-wet conditions. Connate Water breakthrough was observed at one mobile-oil-pore-volume of Water injected at all three wettabilities. Breakthrough of the injected Water was delayed at Strongly Water-wet conditions compared with less Water-wet conditions, where both Water phases were produced simultaneously. © 2012 Elsevier B.V.
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Wettability Impacts on Oil Displacement in Large Fractured Carbonate Blocks
Energy & Fuels, 2010Co-Authors: Åsmund Haugen, Øyvind Bull, Martin A. Fernø, Arne GraueAbstract:Two-dimensional imaging of Water and oil saturations during Waterfloods in fractured carbonate rock models was obtained using nuclear tracer imaging and magnetic resonance imaging. Large outcrop chalk and limestone blocks were aged in crude oil to obtain wetting conditions from Strongly Water-wet to weakly oil-wet. The change in the oil recovery mechanism as the wettability shifted was investigated with and without the presence of fractures. Visualization of local, in situ fluid saturations during Waterfloods improved the interpretation of the displacement process and oil recovery mechanisms. Experimental results demonstrate how fractures determine the displacement pattern differently depending on the matrix wettability conditions during Waterfloods. At Strongly Water-wet conditions, the fractures had a minor impact on the ultimate recovery but significantly changed the progression of the Water front compared to the unfractured case. At less Water-wet or oil-wet conditions, capillary imbibition of Water f...
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Wettability impacts on oil displacement in large fractured carbonate blocks
Energy and Fuels, 2010Co-Authors: Åsmund Haugen, Øyvind Bull, Martin A. Fernø, Arne GraueAbstract:Two-dimensional imaging of Water and oil saturations during Waterfloods in fractured carbonate rock models was obtained using nuclear tracer imaging and magnetic resonance imaging. Large outcrop chalk and limestone blocks were aged in crude oil to obtain wetting conditions from Strongly Water-wet to weakly oil-wet. The change in the oil recovery mechanism as the wettability shifted was investigated with and without the presence of fractures. Visualization of local, in situ fluid saturations during Waterfloods improved the interpretation of the displacement process and oil recovery mechanisms. Experimental results demonstrate how fractures determine the displacement pattern differently depending on the matrix wettability conditions during Waterfloods. At Strongly Water-wet conditions, the fractures had a minor impact on the ultimate recovery but significantly changed the progression of the Water front compared to the unfractured case. At less Water-wet or oil-wet conditions, capillary imbibition of Water from the fracture to the matrix was reduced and fractures had a major impact on the ultimate recovery and Water breakthrough time.
J H Dane - One of the best experts on this subject based on the ideXlab platform.
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a constitutive model for air napl Water flow in the vadose zone accounting for immobile non occluded residual napl in Strongly Water wet porous media
Journal of Contaminant Hydrology, 2004Co-Authors: Robert J Lenhard, Mart Oostrom, J H DaneAbstract:A hysteretic constitutive model describing relations among relative permeabilities, saturations, and pressures in fluid systems consisting of air, nonaqueous-phase liquid (NAPL), and Water is modified to account for NAPL that is postulated to be immobile in small pores and pore wedges and as films or lenses on Water surfaces. A direct outcome of the model is prediction of the NAPL saturation that remains in the vadose zone after long drainage periods (residual NAPL). Using the modified model, Water and NAPL (free, entrapped by Water, and residual) saturations can be predicted from the capillary pressures and the Water and total-liquid saturation-path histories. Relations between relative permeabilities and saturations are modified to account for the residual NAPL by adjusting the limits of integration in the integral expression used for predicting the NAPL relative permeability. When all of the NAPL is either residual or entrapped (i.e., no free NAPL), then the NAPL relative permeability will be zero. We model residual NAPL using concepts similar to those used to model residual Water. As an initial test of the constitutive model, we compare predictions to published measurements of residual NAPL. Furthermore, we present results using the modified constitutive theory for a scenario involving NAPL imbibition and drainage.
